Occlusion 26 / orthodontic courses by Indian dental academy

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CONTENTSCONTENTS1)1) IntroductionIntroduction2)2) DefinitionDefinition3)3) Review of LiteratureReview of Literature4)4) Concepts of Occlusion Concepts of Occlusion 5)5) Development of OcclusionDevelopment of Occlusion

(a)(a) Mouth of NeonateMouth of Neonate-- Gum Pad StageGum Pad Stage-- Precociously erupted primary teethPrecociously erupted primary teeth

(b)(b) Deciduous DentitionDeciduous Dentition-- Eruption age and sequence of deciduous dentitionEruption age and sequence of deciduous dentition-- Characteristics of Primary DentitionCharacteristics of Primary Dentition-- SpacingSpacing-- Normal Overbite & Deep BiteNormal Overbite & Deep Bite-- Inter Incisal AngleInter Incisal Angle-- Occlusal RelationsOcclusal Relations

(c)(c) Mixed Dentition PeriodMixed Dentition Period-- First Transitional PeriodFirst Transitional Period-- Inter Trasitional PeriodInter Trasitional Period-- Second Transitional Period. Second Transitional Period.

(d)(d) Self Correcting Dental AnomaliesSelf Correcting Dental Anomalieswww.indiandentalacademy.comwww.indiandentalacademy.com

6) Permanent Dentition6) Permanent Dentition (a)(a) Alignment and Occlusion of DentitionAlignment and Occlusion of Dentition

-- Dental Arch FormDental Arch Form(b)(b) Intra Arch AlginmentIntra Arch Alginment

-- Curvatures of Occlusal PlaneCurvatures of Occlusal Plane(c)(c) Inter Arch AlignmentInter Arch Alignment

-- Arch LengthArch Length-- Arch WidthArch Width-- Bucco-occlusal contact relationshipBucco-occlusal contact relationship-- Mesio Occlusal Contact Relationship (in posteriors)Mesio Occlusal Contact Relationship (in posteriors)

Class-IClass-I Class-IIClass-II Class-IIIClass-III-- Common Occlusal Relationship of Anterior TeethCommon Occlusal Relationship of Anterior Teeth

(d)(d) Andrew’s Six Keys to OcclusionAndrew’s Six Keys to Occlusion(e)(e) Various Mandibular Movements & Occlusal Contacts during these Various Mandibular Movements & Occlusal Contacts during these movements.movements.

7)7) Types of OcclusionTypes of Occlusion8) Bio-Mechanics of Occlusion8) Bio-Mechanics of Occlusion9)9) Applied AspectsApplied Aspects10) Occlusion in Prosthodontics10) Occlusion in Prosthodontics11) Conclusions11) Conclusions12) References.12) References.


Occlusion --> Ob + ClaudreOcclusion --> Ob + Claudre " To Close Up"" To Close Up"

The term "occlusion' used in dentistry means The term "occlusion' used in dentistry means contact relationship of teeth in contact relationship of teeth in function or parafunction. or parafunction.

However, term refers not only to contact of arches at an However, term refers not only to contact of arches at an occlusal interface but also to all those factors concerned occlusal interface but also to all those factors concerned with development and stability of masticatory system and with development and stability of masticatory system and with use of teeth in oral motor behaviour. The primary with use of teeth in oral motor behaviour. The primary components of human dental occlusion are : components of human dental occlusion are :

(a)(a) The dentitionThe dentition (b)(b) Neuro Muscular SystemNeuro Muscular System (c)(c) Cranio facial structures. Cranio facial structures. The development and maturation of these The development and maturation of these

components are inter-related, so that growth, components are inter-related, so that growth, adaptations and change actively participate in adaptations and change actively participate in development of adult occlusion. development of adult occlusion.

INTRODUCTION


DEFINITIONDEFINITION According to GPT/8According to GPT/8 : : Occlusion may be defined as : Occlusion may be defined as : -- act or process of closure or being closed or shut off. act or process of closure or being closed or shut off. -- static relationship between incisal and masticatory surfaces of static relationship between incisal and masticatory surfaces of maxillary or mandibular teeth / tooth analoguesmaxillary or mandibular teeth / tooth analogues. . In latin Occ = Up In latin Occ = Up Clusion Clusion -- ClosingClosing

JABLONSKI (1982)JABLONSKI (1982) It is relationship between all components of masticatory system in normal It is relationship between all components of masticatory system in normal

function, parafunction and dysfunction including morphology, and functional function, parafunction and dysfunction including morphology, and functional features of contacting surfaces of opposing teeth and restorations, occlusal features of contacting surfaces of opposing teeth and restorations, occlusal trauma, neuromuscular physiology, psychophysiological state and the trauma, neuromuscular physiology, psychophysiological state and the diagnosis, prevention and treatment of functional disordersdiagnosis, prevention and treatment of functional disorders. .

DYNAMIC OCCLUSION (Davies and Gray)DYNAMIC OCCLUSION (Davies and Gray)Refers to the occlusal contacts that are made whilst mandible is moving Refers to the occlusal contacts that are made whilst mandible is moving relative to the maxilla, the mandible being guided by muscles of mastication relative to the maxilla, the mandible being guided by muscles of mastication and anterior and posterior guidance mechanism of mandible, Anterior and anterior and posterior guidance mechanism of mandible, Anterior guidance of teeth which may touch during eccentric movement of mandible, guidance of teeth which may touch during eccentric movement of mandible, posterior guidance, TMJposterior guidance, TMJ. .


As defined byAs defined by Dorland's Medical DictionaryDorland's Medical Dictionary Occlusion is Act of closure or state of being closed. Occlusion is Act of closure or state of being closed. According to "WHEELERSAccording to "WHEELERS occlusion refers not only to contact of occlusion refers not only to contact of

arches at an occlusal interface but also to all those factors arches at an occlusal interface but also to all those factors concerned with development and stability of masticatory system and concerned with development and stability of masticatory system and with use of teeth in oral motor behaviour. with use of teeth in oral motor behaviour.

According to BisharaAccording to Bishara, Occlusion is way maxillary and mandibular , Occlusion is way maxillary and mandibular teeth articulates. teeth articulates.

Ash and RamfjordAsh and Ramfjord defines occlusion as contact relationship of defines occlusion as contact relationship of teeth in function and parafunction. teeth in function and parafunction.

In reality, Dental Occlusion is much more complex relationship In reality, Dental Occlusion is much more complex relationship because it involves study of : because it involves study of :

TeethTeeth :: MorphologyMorphology :: angulationangulation Muscles of MasticationMuscles of Mastication Skeletal StructuresSkeletal Structures TMJTMJ Functional Jaw Movements. Functional Jaw Movements.


Peter E. DawsonPeter E. Dawson in an article quoted a classification in an article quoted a classification system for a occlusions that relate maximal system for a occlusions that relate maximal intercuspation to the position and condition of intercuspation to the position and condition of temporomandibular joints. temporomandibular joints.

A recently introduced term ‘adaptive centric posture’ is A recently introduced term ‘adaptive centric posture’ is used in this classification to distinguish deform TMJs that used in this classification to distinguish deform TMJs that have remodeled or adapted to a conformation that can have remodeled or adapted to a conformation that can comfortably accept maximal loadingcomfortably accept maximal loading..

Review of Literature


Classification of OcclusionClassification of Occlusion:: Type I Type I Maximal intercuspation occurs in harmony Maximal intercuspation occurs in harmony with the verifiable centric with the verifiable centric

relationrelation Type I (A)Type I (A) Maximal intercuspation occurs in harmony Maximal intercuspation occurs in harmony with adaptive centric with adaptive centric

posture.posture. Type IIType II Condyles must displace from verified centric relation for maximal Condyles must displace from verified centric relation for maximal

intercuspation to occur.intercuspation to occur. Type II (A)Type II (A) Condyles must displace from adaptive centric posture for Condyles must displace from adaptive centric posture for

maximal intercuspation to occur maximal intercuspation to occur Type IIIType III Centric relation or adaptive centric posture can not be verified. The Centric relation or adaptive centric posture can not be verified. The

TMJs accepts loading without causing discomfort, so the relationship of TMJs accepts loading without causing discomfort, so the relationship of maximal intercuspation to correct condyle position can not be immediately maximal intercuspation to correct condyle position can not be immediately determined.The condition is diagnosed as transitory and treatable to determined.The condition is diagnosed as transitory and treatable to achieve centric relation or adaptive centric postureachieve centric relation or adaptive centric posture

Type IVType IV occlusal relationship is in a stage of progressive disorder because occlusal relationship is in a stage of progressive disorder because of pathologically unstable and actively progressive deformity of TMJs. of pathologically unstable and actively progressive deformity of TMJs.

Type IVType IV occlusion may be described specifically as (1) progressive open occlusion may be described specifically as (1) progressive open

occlusion (2) Progressive asymmetry (3) progressive mandibular retrusionocclusion (2) Progressive asymmetry (3) progressive mandibular retrusion..


CONCEPTS OF OCCLUSIONCONCEPTS OF OCCLUSION GNATHOLOGICAL APPROACH GNATHOLOGICAL APPROACH PHILOSOPHY OF ARNE G. LAURITZENPHILOSOPHY OF ARNE G. LAURITZEN NILES GUICHET AND GNATHOLOGYNILES GUICHET AND GNATHOLOGY VISION OF TRANSOGRAPHIC CONCEPTVISION OF TRANSOGRAPHIC CONCEPT FREEDOM IN CENTRIC CONCEPTFREEDOM IN CENTRIC CONCEPT OCCLUSAL CONCEPTS OF SCHUYLEROCCLUSAL CONCEPTS OF SCHUYLER BEYRON’S OCCLUSAL CONCEPTS BEYRON’S OCCLUSAL CONCEPTS THE PANKEY – MANN PHILOSOPHYTHE PANKEY – MANN PHILOSOPHY DAWSON’S CONCEPT OF COMPLETE DENTISTRY DAWSON’S CONCEPT OF COMPLETE DENTISTRY GERBER’S CONDYLAR DISPLACEMENT THEORYGERBER’S CONDYLAR DISPLACEMENT THEORY


DEVELOPMENT OF OCCLUSIONDEVELOPMENT OF OCCLUSION

MOUTH OF NEONATEMOUTH OF NEONATE(1)(1) Gum Pads : Gum Pads :

Alveolar processes at birth are called Gum Pads Alveolar processes at birth are called Gum Pads -- There are horse shoe shapedThere are horse shoe shaped-- Consist of 2 parts : labiobuccal and lingual. Consist of 2 parts : labiobuccal and lingual. -- The 2 portions of gum pads are separated from arch other The 2 portions of gum pads are separated from arch other by groove called by groove called Dental GrooveDental Groove. The gum pads are divided into 10 . The gum pads are divided into 10 segments by certain grooves called segments by certain grooves called Transverse GroovesTransverse Grooves. Each of . Each of these segments consist of one developing deciduous tooth sac. these segments consist of one developing deciduous tooth sac.

Gingival GrooveGingival Groove Separates gum pad from palate and floor of mouth. Separates gum pad from palate and floor of mouth. Transverse groove between canine of first deciduous molar segment Transverse groove between canine of first deciduous molar segment

is called lateral sulcus. The lateral sulcii are useful in judging inter-is called lateral sulcus. The lateral sulcii are useful in judging inter-arch relationship in early stage. The lateral sulcus of mandibular arch relationship in early stage. The lateral sulcus of mandibular arch is normally more distal to that of maxillary arch.arch is normally more distal to that of maxillary arch.


Upper and lower gum pads are almost similar to each other. Upper Upper and lower gum pads are almost similar to each other. Upper gum pad is both wide as well as longer than mandibular gum pad. gum pad is both wide as well as longer than mandibular gum pad. Thus when upper and lower pads are approximated there is complete Thus when upper and lower pads are approximated there is complete overjet all around. Contact occurs between upper and lower gum overjet all around. Contact occurs between upper and lower gum pads in first molar region and space exists between them in anterior pads in first molar region and space exists between them in anterior region. This region. This infantile open biteinfantile open bite is considered normal & helps in is considered normal & helps in sucklingsuckling


DECIDUOUS DENTITIONDECIDUOUS DENTITIONAny considerations of development of occlusion should begin with Any considerations of development of occlusion should begin with occlusion of Deciduous teeth. occlusion of Deciduous teeth.

(a)(a) Eruption Age and Sequence of Deciduous Dentition : Eruption Age and Sequence of Deciduous Dentition : Mandibular central Incisors are 1st teeth to erupt by 6-7 months of ageMandibular central Incisors are 1st teeth to erupt by 6-7 months of ageVariation of 3 months from mean age has been accepted as normalVariation of 3 months from mean age has been accepted as normalSequence of eruption is : A - B - D - C - E. Sequence of eruption is : A - B - D - C - E. (b)(b)Characteristics of Primary DentitionCharacteristics of Primary Dentition(1)(1) SpacingSpacing (i)(i) Physiologic SpacingPhysiologic Spacing

-- Normal spaces between deciduous teethNormal spaces between deciduous teeth -- Help to accommodate larger permanent successors Help to accommodate larger permanent successors -- Baume in 1950 termed it as : Baume in 1950 termed it as :

Closed arch dentition Closed arch dentition Spaced arch dentition Spaced arch dentition


(ii)(ii) Primate Space (Anthropoid / Simian Primate Space (Anthropoid / Simian Space)Space)The spacing found mesial to maxillary The spacing found mesial to maxillary cuspids and distal to mandibular cuspids and distal to mandibular cuspids are termed as Primate spaces. cuspids are termed as Primate spaces.

(iii)(iii)Delabarre in 1918 was the first to Delabarre in 1918 was the first to describe inter proximal spacing in describe inter proximal spacing in primary dentition. primary dentition.

(2)(2) Normal Overbite and DeepbiteNormal Overbite and DeepbiteNormal overbite is usually present inNormal overbite is usually present inchildren. children. In some cases, deep bite is present duringIn some cases, deep bite is present duringinitial stages of development. initial stages of development. Later deepbite is reduced due to :Later deepbite is reduced due to :-- Eruption of deciduous molars. Eruption of deciduous molars. -- Attrition of IncisorsAttrition of Incisors-- Forward movement of mandible due to Forward movement of mandible due to

growth. growth.


(3)(3) Overbite and OverjetOverbite and OverjetDuring Primary dentitionDuring Primary dentition-- Overbite decreases by slight amount. Overbite decreases by slight amount. -- Overjet reduced to zero. Overjet reduced to zero. From the early mixed dentition to completion of permanent occlusion. From the early mixed dentition to completion of permanent occlusion. average overbite increases slightly and then decreases. average overbite increases slightly and then decreases. (4)(4) Inter Incisal AngleInter Incisal Angle : : It is angle formed between the intersection of long axis of upper It is angle formed between the intersection of long axis of upper

incisors and lower incisors. incisors and lower incisors. In Primary dentition, as incisor are more upright, there is an increase in In Primary dentition, as incisor are more upright, there is an increase in

Inter incisal angle. Inter incisal angle. (5)(5) Occlusal RelationsOcclusal Relations

Baumes ClassificationBaumes Classification(a)(a) Flush terminal plane - 76%Flush terminal plane - 76%(b)(b) Mesial Step Terminal Plane - 14%Mesial Step Terminal Plane - 14%(c)(c) Distal Step Terminal Plane - 10%Distal Step Terminal Plane - 10%


Flush terminal Flush terminal

Distal step Distal step

Mesial stepMesial step


Mixed Dentition PeriodMixed Dentition Period-- Begins at approximately 6 years of age. Begins at approximately 6 years of age. -- Classified into 3 phases : Classified into 3 phases : (a)(a) First Transitional Period :First Transitional Period :Characterized by : Characterized by : (i)(i) Emergence of 1st permanent molars.Emergence of 1st permanent molars. • Mandibular 1st molar - 1st permanent tooth to erupt at 6 Mandibular 1st molar - 1st permanent tooth to erupt at 6

years of age. years of age. • Location and relationship depends uponLocation and relationship depends upon distal surface relationship upper and lowerdistal surface relationship upper and lower

2nd deciduous molars2nd deciduous molars. .


BAUMES CLASSIFICATIONBAUMES CLASSIFICATIONFlush Terminal PlaneFlush Terminal Plane : : • 76 76 %Distal surface of upper and lower 2nd deciduous molars are in %Distal surface of upper and lower 2nd deciduous molars are in

one vertical plane. Thus erupting 1st permanent molars may be in one vertical plane. Thus erupting 1st permanent molars may be in a flush or end on relationship. This is normal feature of deciduous a flush or end on relationship. This is normal feature of deciduous dentition. For transition of such an end on molar relation to class - I dentition. For transition of such an end on molar relation to class - I molar relation, the lower molar has to move forward by about 3-molar relation, the lower molar has to move forward by about 3-5mm relative to upper molar. This occurs by utilization of 5mm relative to upper molar. This occurs by utilization of Physiologic spaces and leaving space in lower arch and by Physiologic spaces and leaving space in lower arch and by differential forward growth of mandible. differential forward growth of mandible.

• Shift of lower molar from flush terminal plane to class - I Shift of lower molar from flush terminal plane to class - I relation can occur in 2 ways : (i) Early (ii) Late Shiftrelation can occur in 2 ways : (i) Early (ii) Late Shift

Early shift occurs during early mixed dentition period. Eruptive Early shift occurs during early mixed dentition period. Eruptive force of 1st permanent molar is sufficient to push deciduous first force of 1st permanent molar is sufficient to push deciduous first and 2nd molars forward in arch to close primate space and and 2nd molars forward in arch to close primate space and thereby establish class I molar relationship. thereby establish class I molar relationship.

Many children lack primate space and thus erupting permanent Many children lack primate space and thus erupting permanent molars are unable to move forward to establish Class I molars are unable to move forward to establish Class I relationship. In these cases, to when deciduous 2nd molar relationship. In these cases, to when deciduous 2nd molar exfoliate the permanent first molar drift mesially utilization exfoliate the permanent first molar drift mesially utilization leeway space. This occur in late mixed dentition period and is leeway space. This occur in late mixed dentition period and is thus called late shiftthus called late shift. .


Mesial Step Terminal PlaneMesial Step Terminal Plane (14%) :(14%) : In this type of relationship distal surface of lower 2nd deciduous In this type of relationship distal surface of lower 2nd deciduous

molar is more mesial than that of upper. This permanent molars molar is more mesial than that of upper. This permanent molars erupt directly in erupt directly in

Angles Class - I occlusion. This type of mesial step terminal Angles Class - I occlusion. This type of mesial step terminal plane most commonly occur due to early forward growth of plane most commonly occur due to early forward growth of mandible. If differential growth of mandible in forward direction mandible. If differential growth of mandible in forward direction persists, it can lead to Angles Class-III malocclusion persists, it can lead to Angles Class-III malocclusion

Distal Step Terminal Plane (10%)Distal Step Terminal Plane (10%) This is characterized by distal surface of lower This is characterized by distal surface of lower 2nd deciduous surface of lower 2nd deciduous 2nd deciduous surface of lower 2nd deciduous molar being more distal to that of upper. Thus molar being more distal to that of upper. Thus erupting molars may be in Angle's class II erupting molars may be in Angle's class II malocclusion. malocclusion.


(ii) (ii) Exchange of Incisors Exchange of Incisors -- Permanent Incisors are larger in size than primary. Permanent Incisors are larger in size than primary. -- Warren MayneWarren Mayne gave gave Incisal liabilityIncisal liability in 1969. in 1969.

This is difference between amount of space needed for This is difference between amount of space needed for accommodation of incisors and amount of space accommodation of incisors and amount of space available for this : available for this :

-- In maxilla - 7mm. In maxilla - 7mm. In mandible - 5mm. In mandible - 5mm.

-- Incisor liability is overcome by following factors. Incisor liability is overcome by following factors. Utilization of Inter dental spaces seen in primary Utilization of Inter dental spaces seen in primary

dentition. dentition. Increase in Inter canine width. Increase in Inter canine width. Change in Incisor Inclination. Change in Incisor Inclination. Incisor Position. Incisor Position.


b)b) Inter Transitional PeriodInter Transitional PeriodThis phase during mixed dentition period is relatively This phase during mixed dentition period is relatively static and no change occurs. static and no change occurs.

(c)(c)Second Transitional PeriodSecond Transitional Period-- Characterized by replacement of deciduous molars and Characterized by replacement of deciduous molars and

canines by permanent premolars and canine canines by permanent premolars and canine respectively respectively

-- Leeway Space of Nance - The combined mesiodistal Leeway Space of Nance - The combined mesiodistal width of permanent canines and premolars is usually width of permanent canines and premolars is usually less that that of deciduous canines and molars. less that that of deciduous canines and molars. In MaxillaIn Maxilla -- 1.8mm1.8mmIn Mandible -In Mandible - 3.4mm. 3.4mm. This excess space available after exchange of This excess space available after exchange of deciduous molars and canines is utilized for mesial drifts deciduous molars and canines is utilized for mesial drifts of mandibular molars to establish class I molar relation. of mandibular molars to establish class I molar relation.


SELF CORRECTING DENTAL ANOMALIESSELF CORRECTING DENTAL ANOMALIES These anomalies occur in certain period of development and get corrected These anomalies occur in certain period of development and get corrected

by themselves as development progresses. These are also called by themselves as development progresses. These are also called Transient or self correcting malocclusionTransient or self correcting malocclusion

I.I. During Gum Pad StageDuring Gum Pad Stage-- Increased overjet all aroundIncreased overjet all around-- Reterognathic relation of lower gum pad. Reterognathic relation of lower gum pad. -- Anterior open bite. Anterior open bite. -- Infantile swallow. Infantile swallow. II.II. During DeciduousDuring Deciduous-- SpacingSpacing

-- Physiologic spacesPhysiologic spaces-- Primate spacesPrimate spaces

-- Anterior deep biteAnterior deep bite-- Molar Relationship. Molar Relationship. III.III. During Mixed DentitionDuring Mixed Dentition-- End on molar relationship. End on molar relationship. -- Incisal LiabilityIncisal Liability


Ugly - Duckling Stage -Ugly - Duckling Stage - Also known as "Broad Bent Phenomenon". Also known as "Broad Bent Phenomenon". Seen at around 10 - 13 years of age. Seen at around 10 - 13 years of age. In this there is unesthetic metamorphosis leading to Esthetic Results. In this there is unesthetic metamorphosis leading to Esthetic Results. This is particular situation seen during eruption of permanent canines. As This is particular situation seen during eruption of permanent canines. As developing permanent canines erupt, they displace roots of lateral incisor developing permanent canines erupt, they displace roots of lateral incisor mesially. This result in transmitting of force on to roots of central incisors mesially. This result in transmitting of force on to roots of central incisors which gets displaced mesially. A resultant divergence of crowns of 2 central which gets displaced mesially. A resultant divergence of crowns of 2 central incisors cause midline spacing. The condition usually corrects by itself incisors cause midline spacing. The condition usually corrects by itself when canines erupt and pressure is transferred from roots to coronal area of when canines erupt and pressure is transferred from roots to coronal area of incisors. incisors.


PERMANENT DENTITIONPERMANENT DENTITION Permanent dentition forms within jaws soon after birth, Permanent dentition forms within jaws soon after birth,

except for cusps of 1st permanent molars which form except for cusps of 1st permanent molars which form before birth. Permanent incisors develop lingual or before birth. Permanent incisors develop lingual or palatal to deciduous incisors and move labially as they palatal to deciduous incisors and move labially as they erupt. Premolars develop below diverging roots of erupt. Premolars develop below diverging roots of deciduous molars. Eruption sequence of permanent deciduous molars. Eruption sequence of permanent dentition may exhibit variation. Frequently seen dentition may exhibit variation. Frequently seen sequence in maxillary arch are : sequence in maxillary arch are :

6 - 1 - 2 - 4 - 3 - 5 - 7. or6 - 1 - 2 - 4 - 3 - 5 - 7. or 6 - 1 - 2 - 3 - 4 - 5 - 7. 6 - 1 - 2 - 3 - 4 - 5 - 7.

In mandibular arch In mandibular arch 6 - 1 -2 - 3 - 4 - 5 - 76 - 1 -2 - 3 - 4 - 5 - 7oror6 – 1- 2 - 4 - 3 - 5 - 7.6 – 1- 2 - 4 - 3 - 5 - 7.


Alignment and Occlusion of Dentition :Alignment and Occlusion of Dentition : Dental Arch FormDental Arch Form• The teeth are positioned on maxilla and mandible in such a The teeth are positioned on maxilla and mandible in such a

way as to produce curved arch when seen from occlusal surface. way as to produce curved arch when seen from occlusal surface. The arch form is in large part determined by shape of underlying The arch form is in large part determined by shape of underlying basal bone. basal bone.

• On basis of qualitative observations, antheropologists have On basis of qualitative observations, antheropologists have described general shape of palatal arch as being paraploid, U-described general shape of palatal arch as being paraploid, U-shaped, ellipsoid, round and horse shoe shape shaped, ellipsoid, round and horse shoe shape

• Discrepancies in arch between the maxillary and mandibular Discrepancies in arch between the maxillary and mandibular arches generally result in poor occlusal relationships. arches generally result in poor occlusal relationships.

INTRA ARCH ALIGNMENTINTRA ARCH ALIGNMENT Intra arch tooth alignment refers to relationship of teeth to each other Intra arch tooth alignment refers to relationship of teeth to each other

within dental arch. within dental arch. The occlusal planes of dental arches are curved in manner that The occlusal planes of dental arches are curved in manner that

permits maximum use of tooth contact during function as flat permits maximum use of tooth contact during function as flat occlusal plane will not permit simultaneous functional contact in occlusal plane will not permit simultaneous functional contact in more than one area of dental arch. more than one area of dental arch.


The occlusal surfaces of teeth are made up of numerous cusps, The occlusal surfaces of teeth are made up of numerous cusps, grooves and sulci. During function these occlusal elements permit grooves and sulci. During function these occlusal elements permit effective breaking up of food and mixing with saliva to form bolus effective breaking up of food and mixing with saliva to form bolus that is easily swallowed. that is easily swallowed.

The area of tooth between, buccal and lingual cusp tips of The area of tooth between, buccal and lingual cusp tips of posterior teeth is called posterior teeth is called occlusal tableocclusal table . The major forces of . The major forces of mastication are applied on this area. The occlusal table represents mastication are applied on this area. The occlusal table represents approximately 50% - 60% of total buccolingual dimension of approximately 50% - 60% of total buccolingual dimension of posterior tooth and is postitioned over long axis of root structure. It posterior tooth and is postitioned over long axis of root structure. It is called is called inner aspectinner aspect of tooth because it falls between cusps tips. of tooth because it falls between cusps tips. Likewise, occlusal area outside cusp tips is called Likewise, occlusal area outside cusp tips is called outer aspectouter aspect. . The inner and outer aspects of tooth are made up of inclines that The inner and outer aspects of tooth are made up of inclines that extend from cusp tips to either the central fossa. extend from cusp tips to either the central fossa.

Contour on lingual and labial surfaces of teeth. Thus these Contour on lingual and labial surfaces of teeth. Thus these inclines are called inner and outer inclines. inclines are called inner and outer inclines.


CURVATURES OF OCCLUSAL PLANECURVATURES OF OCCLUSAL PLANE Curve of SpeeCurve of Spee

When examining the arches from lateral view, mesiodistal axial relationship When examining the arches from lateral view, mesiodistal axial relationship can be seen. If lines are extended through long axis of roots occlusally can be seen. If lines are extended through long axis of roots occlusally through crowns, angulation of teeth with respect of alveolar bone can be through crowns, angulation of teeth with respect of alveolar bone can be observed. In mandibular arch both anterior and posterior teeth are mesially observed. In mandibular arch both anterior and posterior teeth are mesially inclined. The second and third molars are more inclined premolars. In inclined. The second and third molars are more inclined premolars. In maxillary arch a different pattern of inclination erupts. The anterior teeth are maxillary arch a different pattern of inclination erupts. The anterior teeth are generally mesially inclined, with most posterior molars being distally inclined. generally mesially inclined, with most posterior molars being distally inclined. If from lateral view an imaginary line is draw through buccal cusp tips of If from lateral view an imaginary line is draw through buccal cusp tips of posterior teeth. Curved line following plane of occlusion will be established posterior teeth. Curved line following plane of occlusion will be established that is convex in maxillary arch and concave in mandibular arch. The convex that is convex in maxillary arch and concave in mandibular arch. The convex and concave lines match perfectly when dental arches are placed into and concave lines match perfectly when dental arches are placed into occlusion. This curvature of dental arches was first described by Von Spee & occlusion. This curvature of dental arches was first described by Von Spee & is therefore referred to as Curve of Speeis therefore referred to as Curve of Spee


Curve of Wilson :Curve of Wilson :When observing dental arches from frontal view, buccolingual axial When observing dental arches from frontal view, buccolingual axial relationship can be seen. Generally posterior teeth in maxillary arch relationship can be seen. Generally posterior teeth in maxillary arch have slight buccal inclination. In mandibular arch posterior teeth have slight buccal inclination. In mandibular arch posterior teeth have have

slightly lingual inclination. If a line is drawn through buccal and slightly lingual inclination. If a line is drawn through buccal and lingual cusp tips of both right and left posterior teeth, curved plane of lingual cusp tips of both right and left posterior teeth, curved plane of occlusion will be observed. The curvature is convex in maxillary arch occlusion will be observed. The curvature is convex in maxillary arch and concave in mandibular arch. Again, if arches are brought into and concave in mandibular arch. Again, if arches are brought into occlusion, tooth curvatures will match perfectly. This curvature in occlusion, tooth curvatures will match perfectly. This curvature in occlusal plane observed from frontal view is called occlusal plane observed from frontal view is called CURVE OF CURVE OF WILSONWILSON


Curve of MonsoonCurve of MonsoonBonwill, one of first to describe dental arches, noted that an Bonwill, one of first to describe dental arches, noted that an equilateral triangle existed between centres of condyles and equilateral triangle existed between centres of condyles and mesial contact areas of mandibular central incisors. He mesial contact areas of mandibular central incisors. He depicted this as having 4-inch sides. In other words, the depicted this as having 4-inch sides. In other words, the distance from mesial contact area of mandibular central distance from mesial contact area of mandibular central incisor to centre of either condyle was 4 inches and incisor to centre of either condyle was 4 inches and distance between centres of condyles was 4 inch. In 1932, distance between centres of condyles was 4 inch. In 1932, Monson, used Bonwill's triangle and proposed a theory that Monson, used Bonwill's triangle and proposed a theory that sphere erusted with radius of 4 inches, with centre that was sphere erusted with radius of 4 inches, with centre that was an equal distance from occlusal surfaces of posterior teeth an equal distance from occlusal surfaces of posterior teeth and from centres of condyles. The curve formed was and from centres of condyles. The curve formed was known as known as CURVE OF MONSONCURVE OF MONSON


INTER ARCH TOOTH ALIGNMENTINTER ARCH TOOTH ALIGNMENTRefers to relationship of teeth in one arch to those in other. When two Refers to relationship of teeth in one arch to those in other. When two arches come in contact, as in mandibular closure,occlusal relationship of arches come in contact, as in mandibular closure,occlusal relationship of teeth is established. teeth is established.

Arch LengthArch Length : :The distance of line that begins at distal surface of third molar The distance of line that begins at distal surface of third molar extends mesially through all proximal contact areas around entire arch and extends mesially through all proximal contact areas around entire arch and end at distal surface of opposite third molar.end at distal surface of opposite third molar.For maxillary arch length is 128mm. For mandibular arch arch length is For maxillary arch length is 128mm. For mandibular arch arch length is 126mm. 126mm.

Arch WidthArch Width : is distance across the arch. The width of mandibular arch is : is distance across the arch. The width of mandibular arch is slightly less than maxillary arch., thus when the arches occlude, each slightly less than maxillary arch., thus when the arches occlude, each maxillary tooth is more facially positioned than occluding mandibular tooth. maxillary tooth is more facially positioned than occluding mandibular tooth.

Because maxillary teeth are more facially positioned, normal occlusal Because maxillary teeth are more facially positioned, normal occlusal relation is :relation is :

Buccal cusps of posterior mandibular teeth occlude along central fossa area Buccal cusps of posterior mandibular teeth occlude along central fossa area of maxillary teeth. of maxillary teeth.

Lingual cusps of posterior maxillary teeth occlude along central fossa of Lingual cusps of posterior maxillary teeth occlude along central fossa of mandibular teeth. mandibular teeth.


CENTRIC / SUPPORTING AND NON CENTRIC / CENTRIC / SUPPORTING AND NON CENTRIC / GUIDING CUSPSGUIDING CUSPS..

Buccal cusp of mandibular posterior teeth and lingual cusp of maxillary Buccal cusp of mandibular posterior teeth and lingual cusp of maxillary posterior teeth occlude with posterior teeth occlude with opposing central fossaopposing central fossa. These cusps are . These cusps are called called CENTRIC OR SUPPORTING CUSPSCENTRIC OR SUPPORTING CUSPS

These cusps are mainly important for keeping distance between maxilla These cusps are mainly important for keeping distance between maxilla and mandible. This distance supports the vertical facial height and is and mandible. This distance supports the vertical facial height and is called called VERTICAL DIMENSION OF OCCLUSIONVERTICAL DIMENSION OF OCCLUSION. .

Buccal cusps of maxillary posterior teeth and lingual cusp of mandibular Buccal cusps of maxillary posterior teeth and lingual cusp of mandibular posterior teeth area called posterior teeth area called GUIDING OR NON CENTRIC CUSP /GUIDING OR NON CENTRIC CUSP / SHEARING CUSPSHEARING CUSP

The major role of non-centric cusp is to minimize tissue impingment and The major role of non-centric cusp is to minimize tissue impingment and maintain bolus of food on occlusal table for mastication. They also give maintain bolus of food on occlusal table for mastication. They also give stability to mandible so that when teeth are in full occlusion tight definite stability to mandible so that when teeth are in full occlusion tight definite occlusal relationship results. This relationship of teeth in their maximum occlusal relationship results. This relationship of teeth in their maximum intercuspation is called intercuspation is called Maximum Inter Cuspal PositionMaximum Inter Cuspal Position. .


BUCCOLINGUAL OCCLUSAL - CONTACT RELATIONSHIPBUCCOLINGUAL OCCLUSAL - CONTACT RELATIONSHIP If imaginary line is extended through all buccal cusp tips of mandibular If imaginary line is extended through all buccal cusp tips of mandibular

posterior teeth, bucco occlusal line is established. In normal arch this line posterior teeth, bucco occlusal line is established. In normal arch this line flows smoothly and continuously, revealing general arch form. It also flows smoothly and continuously, revealing general arch form. It also represents demarcation between inner and outer aspects of buccal cusps. represents demarcation between inner and outer aspects of buccal cusps.

If imaginary line is extended through lingual cusps of maxillary If imaginary line is extended through lingual cusps of maxillary posterior teeth, linguo occlusal line is observed. This line reveals general posterior teeth, linguo occlusal line is observed. This line reveals general arch form and represents demarcation between outer and inner aspects of arch form and represents demarcation between outer and inner aspects of centric cusps. centric cusps.

If third imaginary line is extended through central develop mental grooves If third imaginary line is extended through central develop mental grooves of maxillary and mandibular posterior teeth, the CF line is established.of maxillary and mandibular posterior teeth, the CF line is established.


Once CF is established important relationship of proximal contain areas is Once CF is established important relationship of proximal contain areas is noted. These areas are generally located slightly buccal to CF line which noted. These areas are generally located slightly buccal to CF line which allows greater lingual embrasure area and smalled buccal embrasure allows greater lingual embrasure area and smalled buccal embrasure area. During function, larger lingual embrasure area will act as major area. During function, larger lingual embrasure area will act as major spillway for food bang masticated when teeth as brought in contact, spillway for food bang masticated when teeth as brought in contact, majority of food is shunted to tongue, which is more efficient in returning majority of food is shunted to tongue, which is more efficient in returning food to occlusal table the is buccinator and perioral musculature. food to occlusal table the is buccinator and perioral musculature.

To visualize buccolingual relationship of posterior teeth in occlusion To visualize buccolingual relationship of posterior teeth in occlusion appropriate imaginary lines must be matched. The BO line of mandibular appropriate imaginary lines must be matched. The BO line of mandibular occludes with CF line of maxillary teeth. Simultaneously the CO maxillary occludes with CF line of maxillary teeth. Simultaneously the CO maxillary teeth occludes with CF line of mandibular teeth.teeth occludes with CF line of mandibular teeth.


MESIODISTAL OCCLUSAL - CONTACT RELATIONSHIPMESIODISTAL OCCLUSAL - CONTACT RELATIONSHIPOcclusal contacts occur when centric cusp contact opposing C.F. Viewed from Occlusal contacts occur when centric cusp contact opposing C.F. Viewed from facial, these cusps typically contact in one of 2 areas. facial, these cusps typically contact in one of 2 areas.

CF areasCF areas Marginal ridge and embrasure areas. Marginal ridge and embrasure areas.

Contacts between cusp tips and CF area have been involved to grinding of Contacts between cusp tips and CF area have been involved to grinding of pestle in mortar. When 2 unlike curved surfaces meet, only certain portions pestle in mortar. When 2 unlike curved surfaces meet, only certain portions come into contact at given time, leaving other areas free of contact to act as come into contact at given time, leaving other areas free of contact to act as spillways for substance being crushed. When mandible shifts during spillways for substance being crushed. When mandible shifts during mastication, different areas contact, creating different spillways. This shifting mastication, different areas contact, creating different spillways. This shifting increases efficiency of mastication. The second type of occlusal contact is increases efficiency of mastication. The second type of occlusal contact is between cusp types and marginal ridges. Marginal ridges are slightly raised between cusp types and marginal ridges. Marginal ridges are slightly raised convex areas at mesial & distal borders of occlusal surfaces that joins with inter convex areas at mesial & distal borders of occlusal surfaces that joins with inter proximal surface of teeth. The most elevated portion of marginal ridge is only proximal surface of teeth. The most elevated portion of marginal ridge is only slightly convex. Therefore his type of contact is best depicted by cusp tip slightly convex. Therefore his type of contact is best depicted by cusp tip contacting flat surface. In this relationship the cusp tip can penetrate through contacting flat surface. In this relationship the cusp tip can penetrate through food easily and spillways are provided in all directions. When mandible moves food easily and spillways are provided in all directions. When mandible moves laterally, actual contacts areas shifts, increase efficiency of cheweing stroke. laterally, actual contacts areas shifts, increase efficiency of cheweing stroke. Exact cusp tip is not solely responsible for occlusal contact. Circular area Exact cusp tip is not solely responsible for occlusal contact. Circular area around true cusp tip with radius about 0.5mm provides contact area with around true cusp tip with radius about 0.5mm provides contact area with opposing tooth surface. opposing tooth surface.


OCCLUSAL RELATIONSHIPS OFOCCLUSAL RELATIONSHIPS OFPOSTERIOR TEETHPOSTERIOR TEETH

Class-IClass-I(i)(i) Mesiobuccal cusp of mandibular first molar Mesiobuccal cusp of mandibular first molar

occludes in embrasure area between maxillary occludes in embrasure area between maxillary 2nd premolar and 1st molar. 2nd premolar and 1st molar.

(ii)(ii) Mesiobuccal cusp of maxillary first molar is Mesiobuccal cusp of maxillary first molar is aligned directly over buccal groove of aligned directly over buccal groove of mandibular 1st molar. mandibular 1st molar.

(iii)(iii) Mesiolingual cusp of maxillary first molar is Mesiolingual cusp of maxillary first molar is situated in CF area of mandibular 1st molar. situated in CF area of mandibular 1st molar. In this relationship each mandibular tooth In this relationship each mandibular tooth occludes to its counterpart and adjacent occludes to its counterpart and adjacent mesial tooth. mesial tooth.

Contacts between molar occur on both cusp Contacts between molar occur on both cusp tips and fossae and on cusp tips and marginal tips and fossae and on cusp tips and marginal ridges. ridges.

Two variation in occlusal contact patterns can Two variation in occlusal contact patterns can result with respect to marginal ridge areas. In result with respect to marginal ridge areas. In some instances cusps contacts the embrasure some instances cusps contacts the embrasure area directly, resulting in 2 contacts on area of area directly, resulting in 2 contacts on area of cusp tips. In other instance, cusp tip is cusp tips. In other instance, cusp tip is positioned so that it contacts only one positioned so that it contacts only one marginal ridge, resulting in only one contact on marginal ridge, resulting in only one contact on cusp tip.cusp tip.


Class IIClass IIIn some patient maxillary arch is In some patient maxillary arch is large or advanced anteriorly or large or advanced anteriorly or mandibular arch is small or mandibular arch is small or positioned posteriorly. These positioned posteriorly. These conditions will result in conditions will result in mandibular 1st molar being mandibular 1st molar being positioned distal to class I molar positioned distal to class I molar relationship. Described as Class relationship. Described as Class II molar relationship. II molar relationship.

(i)(i) Mesiobuccal cusp of mandibular Mesiobuccal cusp of mandibular 1st molar occludes in CF area of 1st molar occludes in CF area of maxillary 1st molar. maxillary 1st molar.

(ii) Mesiobuccal cusp of mandibular (ii) Mesiobuccal cusp of mandibular first molar is aligned with buccal first molar is aligned with buccal groace of maxillary 1st molar. groace of maxillary 1st molar.

(Iii) Distolingual cusp of maxillary (Iii) Distolingual cusp of maxillary first molar occludes in CF area first molar occludes in CF area of mandibular 1st molar.of mandibular 1st molar.


Class-IIIClass-III Due to predominant growth of Due to predominant growth of

mandible. In this relationship, mandible. In this relationship, growth positions mandibular molar growth positions mandibular molar mesial to maxillary molars. mesial to maxillary molars.

(i)(i) Distobuccal cusp of mandibular 1st Distobuccal cusp of mandibular 1st molar is situated in embrasure molar is situated in embrasure between maxillary 2nd premolar and between maxillary 2nd premolar and 1st molar . 1st molar .

(ii)(ii) Mesiobuccal cusp of maxillary 1st Mesiobuccal cusp of maxillary 1st molar is situated over embrasure molar is situated over embrasure between mandibular 1st and 2nd between mandibular 1st and 2nd molar. molar.

(iii) Mesolingual cusp of maxillary 1st (iii) Mesolingual cusp of maxillary 1st molar is situated in mesial pit of molar is situated in mesial pit of mandibular 2nd molarmandibular 2nd molar


OCCLUSAL RELATIONSHIP OF ANTERIOR TEETHOCCLUSAL RELATIONSHIP OF ANTERIOR TEETH Maxillary anterior teeth are normally positioned labial to mandibular anteriorMaxillary anterior teeth are normally positioned labial to mandibular anterior teeth. teeth. Both maxillary and mandibular anteriors are inclined to the labial, ranging Both maxillary and mandibular anteriors are inclined to the labial, ranging 12-28º from vertical reference line. 12-28º from vertical reference line. Incisal edges of mandibular incisors contacting lingual surfaces of maxillary Incisal edges of mandibular incisors contacting lingual surfaces of maxillary

incisors. These contacts commonly occur in lingual fossae of maxillary incisors. These contacts commonly occur in lingual fossae of maxillary incisors approximately 4mm gingival to incisal edges. incisors approximately 4mm gingival to incisal edges.

Purpose of anterior teeth is to guide mandible during various lateral Purpose of anterior teeth is to guide mandible during various lateral movements. The anterior tooth contacts that provide guidance of mandible movements. The anterior tooth contacts that provide guidance of mandible are called are called Anterior GuidanceAnterior Guidance,, Characteristics of anterior guidance are Characteristics of anterior guidance are dictated by exact position and relationship of anterior teeth, which can be dictated by exact position and relationship of anterior teeth, which can be examined both horizontally and vertically. examined both horizontally and vertically.

Horizontal distance by which maxillary anteriors overlap mandibular Horizontal distance by which maxillary anteriors overlap mandibular anteriors is called anteriors is called Horizontal over lap - OverjetHorizontal over lap - Overjet. It is the distance between . It is the distance between labial nasal edge of maxillary incisor and labial surface of mandibular incisor labial nasal edge of maxillary incisor and labial surface of mandibular incisor in ICP. in ICP.

Vertical overlap is distance between incisal edges of opposing anterior teeth Vertical overlap is distance between incisal edges of opposing anterior teeth which is approximately 3 - 5mm. which is approximately 3 - 5mm.

Important function of anterior teeth is that of performing initial acts of Important function of anterior teeth is that of performing initial acts of mastication. Anterior teeth function to incise food when introduced in oral mastication. Anterior teeth function to incise food when introduced in oral cavity. cavity.

Anterior teeth also plays significant role in speech, lip support and Anterior teeth also plays significant role in speech, lip support and aesthetics. aesthetics.



ANDREW’S SIX KEYS TO NORMAL OCCLUSIONANDREW’S SIX KEYS TO NORMAL OCCLUSIONAndrew’s during 1970s put forward six keys to normal occlusion.Andrew’s during 1970s put forward six keys to normal occlusion.The six key are considered under the following headings:The six key are considered under the following headings:MOLAR INTERARCH RELATIONSHIP.MOLAR INTERARCH RELATIONSHIP. The Mesio buccal cusp of upper first molar should occlude in the groove The Mesio buccal cusp of upper first molar should occlude in the groove

between mesial and medial buccal cusp of lower first molar. The mesio between mesial and medial buccal cusp of lower first molar. The mesio lingual cusp of upper first molar should occlude in the central fossa of lingual cusp of upper first molar should occlude in the central fossa of lower first molar. The crown of upper first molar must be angulated so lower first molar. The crown of upper first molar must be angulated so that distal marginal ridge occludes with the mesial marginal ridge of that distal marginal ridge occludes with the mesial marginal ridge of second molarsecond molar

MESIO DISTAL CROWNMESIO DISTAL CROWN ANGULATIONANGULATION The Second Key makes use of a line that passes along the long axis of The Second Key makes use of a line that passes along the long axis of

crown through the most prominent part in the center of labial or buccal crown through the most prominent part in the center of labial or buccal surface. This line is called long axis of clinical crown.surface. This line is called long axis of clinical crown.

For occlusion to be considered normal, gingival part of long axis of crown For occlusion to be considered normal, gingival part of long axis of crown must be distal to the occlusal part of the line. Different teeth exhibit must be distal to the occlusal part of the line. Different teeth exhibit different crown angulation.different crown angulation.


LABIO LINGUAL CROWN INCLINATION LABIO LINGUAL CROWN INCLINATION The crown inclination is determined from mesial or distal view. If the gingival The crown inclination is determined from mesial or distal view. If the gingival

area of crown is more lingualy placed than the occlusal area, it is referred to area of crown is more lingualy placed than the occlusal area, it is referred to as positive crown inclinication. In case the gingival area of crown is more as positive crown inclinication. In case the gingival area of crown is more labially or buccally placed than the occlusal area it is referred to as negative labially or buccally placed than the occlusal area it is referred to as negative crown inclinicationcrown inclinication

The Maxillary incisors exhibit a positive crown inclination while mandibular The Maxillary incisors exhibit a positive crown inclination while mandibular incisors show negative crown inclination. The maxillary and mandibular incisors show negative crown inclination. The maxillary and mandibular posteriors have negative crown inclination.posteriors have negative crown inclination.

ABSENCE OF ROTATION.ABSENCE OF ROTATION.Normal occlusion is characterized by absence of rotation.Normal occlusion is characterized by absence of rotation.Rotated posteriors occupy more space in a dental arch. While rotated incisors Rotated posteriors occupy more space in a dental arch. While rotated incisors

occupy less space in dental arch.occupy less space in dental arch.TIGHT CONTACTSTIGHT CONTACTS For normal occlusion there should be tight contact between adjacent teeth.For normal occlusion there should be tight contact between adjacent teeth.CURVE OF SPEECURVE OF SPEENormal occlusal plane according to Andrew’s should be flat with curve of spee Normal occlusal plane according to Andrew’s should be flat with curve of spee

not exceeding 1.5 mm.not exceeding 1.5 mm.



VARIOUS MANDIBULAR MOVEMENTS AND VARIOUS MANDIBULAR MOVEMENTS AND OCCLUSAL CONTACTS DURING THESE OCCLUSAL CONTACTS DURING THESE MOVEMENTSMOVEMENTS

To this point only static relationships of posterior To this point only static relationships of posterior and anterior teeth have been discussed. Masticatory and anterior teeth have been discussed. Masticatory system is extremely dynamic. TMJ and associated system is extremely dynamic. TMJ and associated musculature permit mandible to move in all 3 planes i.e. musculature permit mandible to move in all 3 planes i.e. sagittal, horizontal, frontal. Along with these movements sagittal, horizontal, frontal. Along with these movements come potential tooth contacts. The term come potential tooth contacts. The term EccentricEccentric have have been used to describe any movement of mandible from been used to describe any movement of mandible from ICP that result in tooth contact. Three basic eccentric ICP that result in tooth contact. Three basic eccentric movements are : movements are :

(i)(i) ProtrusiveProtrusive (ii)(ii) LaterotrusiveLaterotrusive (iii)(iii) RetrusiveRetrusive


(i)(i) Protrusive Mandibular Protrusive Mandibular MovementMovement : This movement : This movement occurs when mandible moves occurs when mandible moves forward from ICP. Any area of forward from ICP. Any area of tooth that contacts opposing tooth tooth that contacts opposing tooth during protrusive movement is during protrusive movement is considered to be protrusive considered to be protrusive contact. In normal occlusal contact. In normal occlusal relationship the predominant relationship the predominant protrusive contacts occur on protrusive contacts occur on anterior teeth, between incisal and anterior teeth, between incisal and labial edges of mandibular incisors labial edges of mandibular incisors and against lingual fossa areas and against lingual fossa areas and incisal edges of maxillary and incisal edges of maxillary incisors. On posterior teeth incisors. On posterior teeth protrusive movement causes protrusive movement causes mandibular centric cusps to pass mandibular centric cusps to pass anteriorly across occlusal surfaces anteriorly across occlusal surfaces of maxillary teeth. Protrusive of maxillary teeth. Protrusive posterior contacts occur between posterior contacts occur between distal inclines of maxillary lingual distal inclines of maxillary lingual cusps and mesial induces of cusps and mesial induces of opposing fossae and marginal opposing fossae and marginal ridges. Posterior protrusive ridges. Posterior protrusive contacts can also occur between contacts can also occur between mesial inclines of mandibular mesial inclines of mandibular buccal cusps and distal inclines of buccal cusps and distal inclines of opposing fossae and marginal opposing fossae and marginal ridgesridges


(ii)(ii) Laterotrusive Mandibular MovementLaterotrusive Mandibular Movement During lateral mandibular movement; right and left During lateral mandibular movement; right and left

mandibular posterior teeth move across their opposing teeth in mandibular posterior teeth move across their opposing teeth in different directions. If for example, mandible moves laterally to left, different directions. If for example, mandible moves laterally to left, left mandibular posterior teeth will move laterally across their left mandibular posterior teeth will move laterally across their opposing teeth. However, right mandibular posteriors will move opposing teeth. However, right mandibular posteriors will move medially across their opposing teeth. medially across their opposing teeth.

Posterior teeth on left side during left lateral movement Posterior teeth on left side during left lateral movement reveals that contacts can occur on 2 incline areas. One contact reveals that contacts can occur on 2 incline areas. One contact between inner inclines of maxillary buccal cusps and outer inclines between inner inclines of maxillary buccal cusps and outer inclines of mandibular buccal cusps. Other contact is between outer inclines of mandibular buccal cusps. Other contact is between outer inclines of maxillary lingual cusps & inner inclines of mandibular linqual of maxillary lingual cusps & inner inclines of mandibular linqual cups. Both these contacts are called LATEROTRUSIVE cups. Both these contacts are called LATEROTRUSIVE

The term lingual to lingual Laterotrusive & buccal to buccal The term lingual to lingual Laterotrusive & buccal to buccal laterotrusive issued to differentiate those occuring between laterotrusive issued to differentiate those occuring between opposing lingual cusp from those occurring between buccal cusps. opposing lingual cusp from those occurring between buccal cusps.


Working ContactWorking Contact :- Is :- Is commonly used for both these commonly used for both these laterotrusive contacts laterotrusive contacts

During same lateral During same lateral movement, right mandibular movement, right mandibular posterior teeth are passing in posterior teeth are passing in medial direction across their medial direction across their opposing teeth. The potential opposing teeth. The potential sites for occlusal contacts are sites for occlusal contacts are between inner inclines of between inner inclines of mandibular buccal cusps. These mandibular buccal cusps. These are called are called Mediotrusive Mediotrusive contacts. During left lateral contacts. During left lateral movement most function occur movement most function occur on left side, therefore right side on left side, therefore right side has been desiqnated as non-has been desiqnated as non-working side . Thus these working side . Thus these mediotrusive contacts are also mediotrusive contacts are also called called Nonworking contacts or Nonworking contacts or Balancing contacts.Balancing contacts.


(viii)(viii) Retrusive Mandibular Retrusive Mandibular Movement.Movement.:- Occurs when :- Occurs when mandible moves posteriorly mandible moves posteriorly from 1CP.These movements from 1CP.These movements are restricted by ligamentous are restricted by ligamentous structures. During retrusive structures. During retrusive movement mandibular buccal movement mandibular buccal cusps move distally across cusps move distally across occlusal surface of their occlusal surface of their opposing maxillary teeth. opposing maxillary teeth. Areas of potential contact Areas of potential contact occurs between distal inclines occurs between distal inclines of mandibular buccal cusps & of mandibular buccal cusps & mesial inclines of opposing mesial inclines of opposing fossae & marginal ridges. In fossae & marginal ridges. In maxillary arch retrusive maxillary arch retrusive contacts occurs between contacts occurs between mesial inclines of opposing mesial inclines of opposing CF's & marginal ridges.CF's & marginal ridges.


TYPES OF OCCLUSIONTYPES OF OCCLUSION Normal OcclusionNormal Occlusion: : Within frameworks of function occlusion (the correlation Within frameworks of function occlusion (the correlation

between occlusion of teeth and movement of mandible) any mouth that has between occlusion of teeth and movement of mandible) any mouth that has exhibited its ability to survive is considered normal. It is : exhibited its ability to survive is considered normal. It is :

Physiological Physiological AdaptiveAdaptive Physiological OcclusionPhysiological Occlusion:: is state of equilibrium in which there is no is state of equilibrium in which there is no

pathology or other dysfunction of any component of somatognathic system pathology or other dysfunction of any component of somatognathic system occurring as result of occlusal activity, regardless of arrangement of teeth. occurring as result of occlusal activity, regardless of arrangement of teeth.

Pathological OcclusionPathological Occlusion: : It occurs when anything related to occlusal activity It occurs when anything related to occlusal activity causes injury or impaired function somatognathic system. causes injury or impaired function somatognathic system.

Adaptive OcclusionAdaptive Occlusion: : It is between physiologic and pathologic occlusion. It is between physiologic and pathologic occlusion. Structurally there is potential dysfunction, but it has not occurred to any great Structurally there is potential dysfunction, but it has not occurred to any great extent, e.g. persons having facets of wear has adaptive and require periodic extent, e.g. persons having facets of wear has adaptive and require periodic examination but not treatment. examination but not treatment.

Ideal Occlusion:Ideal Occlusion: A so called ideal occlusion can also be called, physiologic, A so called ideal occlusion can also be called, physiologic, functional or normal. When local occlusion exists. Somatognathic system functional or normal. When local occlusion exists. Somatognathic system usually functions in good health. In an ideal occlusion lateral forces are usually functions in good health. In an ideal occlusion lateral forces are eliminated or minimized and occlusal forces are directed along long tooth and eliminated or minimized and occlusal forces are directed along long tooth and distributed equally on as many teeth as possible. Stamp cusps occlude against distributed equally on as many teeth as possible. Stamp cusps occlude against marginal ridges or into opposing occlusal fossa rather than interproximal marginal ridges or into opposing occlusal fossa rather than interproximal embrasure. Usually there is full component of teeth in both arches. Each embrasure. Usually there is full component of teeth in both arches. Each posterior tooth should have at least one antagonist to occlude & work against. posterior tooth should have at least one antagonist to occlude & work against.


The most ideal occlusion is mutually Protected The most ideal occlusion is mutually Protected occlusion in which posterior teeth protect anterior occlusion in which posterior teeth protect anterior teeth during centric closure & anterior teeth protect teeth during centric closure & anterior teeth protect posterior teeth in any movement or position away from posterior teeth in any movement or position away from centric contact position. centric contact position.

Disclusion: Disclusion: During protrusive sliding movements of During protrusive sliding movements of mandible the incisors and canines act together in mandible the incisors and canines act together in coupling effect as anteriors discludes in group coupling effect as anteriors discludes in group function. In lateral excursions of mandible cuspids on function. In lateral excursions of mandible cuspids on working side act as discluders. Some times central working side act as discluders. Some times central and lateral incisors also help cuspids which is not and lateral incisors also help cuspids which is not always present but acceptable. always present but acceptable.

When determinants of occlusion and tooth When determinants of occlusion and tooth arrangements are compatible, an occlusion can be arrangements are compatible, an occlusion can be considered stable. Stuart refers to tooth arrangement considered stable. Stuart refers to tooth arrangement as an as an ORGANIZED OR ORGANICORGANIZED OR ORGANIC OCCLUSION OCCLUSION . . www.indiandentalacademy.comwww.indiandentalacademy.com

THERAPEUTIC OCCLUSIONTHERAPEUTIC OCCLUSIONIt is one in which arrangement of teeth and their opposing occlusal surfaces It is one in which arrangement of teeth and their opposing occlusal surfaces satisfies function and esthetic requirements while distributing the forces of satisfies function and esthetic requirements while distributing the forces of occlusion over as many teeth during functions of mandible. occlusion over as many teeth during functions of mandible. Three most popular concepts of therapeutic occlusion are: Three most popular concepts of therapeutic occlusion are:

(a)(a) Fully balanced occlusion. Fully balanced occlusion. (b)(b) Unilateral balanced occlusionUnilateral balanced occlusion(c)(c) Cusp-fossa occlusionCusp-fossa occlusion(a)(a) Fully Balanced Occlusion : Fully Balanced Occlusion : It originated in denture construction, where it was It originated in denture construction, where it was

felt that there should be bilateral equal contact of anterior and posterior teeth felt that there should be bilateral equal contact of anterior and posterior teeth during CR as well as during protrusive and lateral excursive movement of during CR as well as during protrusive and lateral excursive movement of mandible. The concept was advanced by Gpsi, McCollum. Gerber et al. It mandible. The concept was advanced by Gpsi, McCollum. Gerber et al. It works for removable dentures but in natural dentition it doesn't offer 'position' for works for removable dentures but in natural dentition it doesn't offer 'position' for teeth or mandible that are god holding positions during centric closure. teeth or mandible that are god holding positions during centric closure.

(b)(b) Unilateral Balanced OcclusionUnilateral Balanced Occlusion : Advanced by Schuyler, Pankey, Mann & : Advanced by Schuyler, Pankey, Mann & Ramfjord. It allows for contact of all teeth during centric position. With some Ramfjord. It allows for contact of all teeth during centric position. With some freedom of movement anteroposteriorly. The centric slide of about 0.2 - 1mm at freedom of movement anteroposteriorly. The centric slide of about 0.2 - 1mm at same vertical dimension is known as long centric. During lateral movement, same vertical dimension is known as long centric. During lateral movement, disclusion occurs against canines and buccal cusps of maxillary and mandibular disclusion occurs against canines and buccal cusps of maxillary and mandibular premolars and molars of working side. This is referred to as premolars and molars of working side. This is referred to as Group FunctionGroup Function. . There are no tooth contacts on non working during lateral excursive movement. There are no tooth contacts on non working during lateral excursive movement. Group function or posterior teeth with equally distributed occlusal forces on each Group function or posterior teeth with equally distributed occlusal forces on each involved tooth is very difficult to achieve but even if done, patient often develops involved tooth is very difficult to achieve but even if done, patient often develops occlusal awareness that leads to bruxism and occlusal disharmony. occlusal awareness that leads to bruxism and occlusal disharmony.


(c)(c) Cusp- Fossa occlusion Cusp- Fossa occlusion :- Concept is based on gnathological :- Concept is based on gnathological principles of jaw function as well as physiological principles of principles of jaw function as well as physiological principles of somatognathic system.somatognathic system.

During closure of posterior teeth into the intercuspation During closure of posterior teeth into the intercuspation position, all stamp cusps occlude simultaneously into their opposing position, all stamp cusps occlude simultaneously into their opposing occlusion fossa. It is a distal limit occlusion in that the condyles & occlusion fossa. It is a distal limit occlusion in that the condyles & consequently cusp of mandibular teeth are functioning in their most consequently cusp of mandibular teeth are functioning in their most distal positions.distal positions.

At same time that stamp cusps make final contact in cusp At same time that stamp cusps make final contact in cusp fossa occlusion, condyles are positioned in their most retruded or fossa occlusion, condyles are positioned in their most retruded or unstrained position in their respective fossae. Since CO & CR tooth unstrained position in their respective fossae. Since CO & CR tooth contacts are coincident there is not centric interference to cause contacts are coincident there is not centric interference to cause occlusal slide & deviation of mandible. Patient close to CR occlusion occlusal slide & deviation of mandible. Patient close to CR occlusion where no single tooth carries more or less than its share of occlusal where no single tooth carries more or less than its share of occlusal load. Occlusal forces are at an equilibrium throughout the mouth. load. Occlusal forces are at an equilibrium throughout the mouth. During centric contact of posterior teeth in cusp-fossa occlusion During centric contact of posterior teeth in cusp-fossa occlusion anterior teeth do not touch having ideal space of .01mm betweem anterior teeth do not touch having ideal space of .01mm betweem maxiallary & mandibular incisors & canines at CO. In this occlusion maxiallary & mandibular incisors & canines at CO. In this occlusion centric closure is positive closing position in which all posterior teeth centric closure is positive closing position in which all posterior teeth contact simultanceously. The reciprocating contacts positioned as contact simultanceously. The reciprocating contacts positioned as they are around fossa prevent tipping or rotation or teeth when they are around fossa prevent tipping or rotation or teeth when occlusal forces are applied. occlusal forces are applied.


Mutually protected occlusionMutually protected occlusion :- :- When condyler & incisal guidance act together to disclude the When condyler & incisal guidance act together to disclude the

posterior teeth. It is referred to as mutually protected occlusion. A posterior teeth. It is referred to as mutually protected occlusion. A cusp-fossa arrangement is functional occlusion. It is an artificial cusp-fossa arrangement is functional occlusion. It is an artificial occlusion in which attention is directed specially to performance as occlusion in which attention is directed specially to performance as differently from structure & appearance. eg. in cusp-fossa occlusal differently from structure & appearance. eg. in cusp-fossa occlusal scheme a tooth is not always restored to its textbook image. It may scheme a tooth is not always restored to its textbook image. It may have slightly altered shape to allow proper position of cusp- ridges & have slightly altered shape to allow proper position of cusp- ridges & groves in function.groves in function.

Anterior teeth protect the posterior & posterior teeth protect anterior Anterior teeth protect the posterior & posterior teeth protect anterior during denture closure. Cusp-fossa occlusion can therefore be during denture closure. Cusp-fossa occlusion can therefore be defined as mutually protected occlusion. defined as mutually protected occlusion.

During working side movement cannot act as discluders of posterior During working side movement cannot act as discluders of posterior teeth hence called canine protected occlusion, canine rise, canine teeth hence called canine protected occlusion, canine rise, canine disclusion & canine left.disclusion & canine left.

This scheme is designed to eliminate lateral forces on posterior This scheme is designed to eliminate lateral forces on posterior teeth. Because anterior teeth are lightly in contact in CO, posterior teeth. Because anterior teeth are lightly in contact in CO, posterior teeth support forces in CO protecting, periodontally vunerable teeth support forces in CO protecting, periodontally vunerable anterior teeth from heavy clenching & chewing forces. Canine is anterior teeth from heavy clenching & chewing forces. Canine is structurally, neurologically & positionally well suited to support structurally, neurologically & positionally well suited to support lateral forces in exclusion. So this type of occlusion also called lateral forces in exclusion. So this type of occlusion also called Canine Guided Occusion.Canine Guided Occusion.


BIO-MECHANICS OF OCCLUSION:BIO-MECHANICS OF OCCLUSION:Dental factors of occlusion.Dental factors of occlusion. If dentition is functioning in health and form of dentition is esthetic, If dentition is functioning in health and form of dentition is esthetic,

restoration of individual teeth requires duplication of existing occlusal restoration of individual teeth requires duplication of existing occlusal form. form.

Unless there is evidence of dysfunction such as occlusal trauma, Unless there is evidence of dysfunction such as occlusal trauma, excessive tooth wear, clearly unacceptable occlusal plane excessive tooth wear, clearly unacceptable occlusal plane orientation or joint and muscle dysfunctioning occlusion should be orientation or joint and muscle dysfunctioning occlusion should be considered normal restorations should be patterned to follow considered normal restorations should be patterned to follow morphology of adjacent and opposing teeth. Anatomic factors morphology of adjacent and opposing teeth. Anatomic factors important in the development occlusal patterns for restored tooth important in the development occlusal patterns for restored tooth include the following :include the following :

Cusp HeightCusp Height Cusp angleCusp angle Marginal ridge heightMarginal ridge height Contact area positionContact area position Contact area heightContact area height Fossa size Fossa size Triangular and oblique ridge height.Triangular and oblique ridge height. Triangular and oblique ridge directionsTriangular and oblique ridge directions Groove depth and widthGroove depth and width Groove directionGroove direction Faciolingual dimension of occlusal tableFaciolingual dimension of occlusal table


Changes that should be particularly avoided include irregular adjacent Changes that should be particularly avoided include irregular adjacent marginal ridge heights, changes in size and location of proximal marginal ridge heights, changes in size and location of proximal contact area, widening or narrowing the buccolingual width of occlusal contact area, widening or narrowing the buccolingual width of occlusal table, increase or decrese of cusp angulation, groove depth or table, increase or decrese of cusp angulation, groove depth or angulation and location of occlusal contact areas. Common problems angulation and location of occlusal contact areas. Common problems observed from such changes include the following observed from such changes include the following

Wedging of food interproximally during mastication that is often Wedging of food interproximally during mastication that is often associated with irregular marginal ridge heights and missing contact associated with irregular marginal ridge heights and missing contact areasareas

Deflection of mandible from intercuspal position that is often Deflection of mandible from intercuspal position that is often associated with abnormally steep cusp heights or pre-mature occlusal associated with abnormally steep cusp heights or pre-mature occlusal contacts.contacts.

Working cusp interferences that are often associated with abnormally Working cusp interferences that are often associated with abnormally steep cusp heights or improperly angled triangular or oblique ridges steep cusp heights or improperly angled triangular or oblique ridges and grooves.and grooves.

Balancing cusp interferences associated with abnormally steep cusp Balancing cusp interferences associated with abnormally steep cusp heightsheights

Supra eruption and shifts in tooth position that must result from lack of Supra eruption and shifts in tooth position that must result from lack of occlusal and proximal contacts.occlusal and proximal contacts.


APPLIED ASPECTSAPPLIED ASPECTS The concepts of occlusion are established & recognized as guidline by all The concepts of occlusion are established & recognized as guidline by all

departments of dentistry. The need to maintain this relation is of almost departments of dentistry. The need to maintain this relation is of almost importance. The salient features are :-importance. The salient features are :-

1.1. In small children with decidous dentition of nursing bottle caries or rampant In small children with decidous dentition of nursing bottle caries or rampant caries is present then teeth get decalcified at very rapid rate & if unrestored caries is present then teeth get decalcified at very rapid rate & if unrestored for some time the other teeth migrate mesally the contact relation as well as for some time the other teeth migrate mesally the contact relation as well as integrity & occlusion of arch is lost.integrity & occlusion of arch is lost.

2.2. In children if we see that by age of 5-6 years the physiologic space have not In children if we see that by age of 5-6 years the physiologic space have not yet develop that it is indicative of developing malocclusion.yet develop that it is indicative of developing malocclusion.

3.3. In cases of restoration of teeth using amalgam / composite /GIC/ Zinc In cases of restoration of teeth using amalgam / composite /GIC/ Zinc phosphate etc. we should take care to check for high points, because these phosphate etc. we should take care to check for high points, because these can lead to deviations in occlusion & discomfort to patient.can lead to deviations in occlusion & discomfort to patient.

4.4. Extraction of deciduous teeth unless & until its the last or only alternative, Extraction of deciduous teeth unless & until its the last or only alternative, should not be done. This may lead to malocclusion because these decidous should not be done. This may lead to malocclusion because these decidous teeth act as guide for permanent teeth.teeth act as guide for permanent teeth.

5.5. If in mixed dentition period we see developing situation of crowding for If in mixed dentition period we see developing situation of crowding for permanent teeth then serial extraction should be considered.permanent teeth then serial extraction should be considered.

6.6. When giving patient fixed or removable prosthesis complete / partial than When giving patient fixed or removable prosthesis complete / partial than the points occlusion should be kept in mind & implemented during the points occlusion should be kept in mind & implemented during construction phase patient needing CD must not be given non-anatomic construction phase patient needing CD must not be given non-anatomic teeth or set up should not monoplane, just for ease of clinician. teeth or set up should not monoplane, just for ease of clinician. Multiple extractions without replacement should not be done as it may Multiple extractions without replacement should not be done as it may cause changes in vertical dimension of occlusion & may also lead to cause changes in vertical dimension of occlusion & may also lead to mutilated or collapsed occlusion.mutilated or collapsed occlusion.


OCCLUSION IN PROSTHODONTICS:OCCLUSION IN PROSTHODONTICS:Occlusion may be discussed from two view pointsOcclusion may be discussed from two view pointsStatic RelationsStatic RelationsDynamic RelationsDynamic Relations

STATIC CONCEPT:STATIC CONCEPT:Static relations in occlusion are those which occur in Static relations in occlusion are those which occur in many possible contacts of teeth without interposition of many possible contacts of teeth without interposition of food.Static Relations in occlusion includefood.Static Relations in occlusion include

Centric occlusionCentric occlusionProtrusive OcclusionProtrusive OcclusionRight & left lateral occlusionRight & left lateral occlusion Intermediate occlusionIntermediate occlusion


DYNAMIC CONCEPTDYNAMIC CONCEPT::It is primarily concerned with opening & closing It is primarily concerned with opening & closing movements involved in mastication while static concept movements involved in mastication while static concept is concerned primarily with tooth contacts made at is concerned primarily with tooth contacts made at various positions. In this concept, jaw movements & various positions. In this concept, jaw movements & tooth contacts that are made as teeth of one jaw guide tooth contacts that are made as teeth of one jaw guide over teeth of opposing jaw are not functional movements over teeth of opposing jaw are not functional movements or contacts. This phase of occlusion is admitted to be or contacts. This phase of occlusion is admitted to be controlled by TMJ, muscles & ligaments & teeth. controlled by TMJ, muscles & ligaments & teeth. Functional movements are the movements of lower teeth Functional movements are the movements of lower teeth as they approach upper teeth in chewing cycle.The as they approach upper teeth in chewing cycle.The direction of closure is influenced bydirection of closure is influenced by

TMJTMJOcclusal form of teethOcclusal form of teethOcclusal planeOcclusal planeMusculature (contraction & relaxation times of muscle)Musculature (contraction & relaxation times of muscle)Resistance of food & relative tolerance of supporting Resistance of food & relative tolerance of supporting

tissues.tissues. www.indiandentalacademy.comwww.indiandentalacademy.com

TYPES OF COMPLETE DENTURE OCCLUSION:TYPES OF COMPLETE DENTURE OCCLUSION:Balanced OcclusionBalanced OcclusionMonoplane OcclusionMonoplane OcclusionLingualized OcclusionLingualized OcclusionI)I) BALANCED OCLUSION:BALANCED OCLUSION: DEFINITION:DEFINITION: Simultaneous contacting of maxillary & mandibular Simultaneous contacting of maxillary & mandibular

teeth on right & left and in posterior & anterior occlusal areas in teeth on right & left and in posterior & anterior occlusal areas in centric & accentric positions, developed to lessen or limit tipping or centric & accentric positions, developed to lessen or limit tipping or rotating of denture bases in relation to supporting structures.rotating of denture bases in relation to supporting structures.

CHARACTERISTICS REQUIREMENTS OF BALANCEDCHARACTERISTICS REQUIREMENTS OF BALANCED OCCLUSION:OCCLUSION:

All teeth of working side should glide evenly against opposing teeth.All teeth of working side should glide evenly against opposing teeth. No single tooth should produce any interference or disocclusion of other No single tooth should produce any interference or disocclusion of other

teeth.teeth. There should be contacts in balancing side, but they should not interfere There should be contacts in balancing side, but they should not interfere

with smooth gliding movements of working side.with smooth gliding movements of working side. There should be simultaneous contact during protrusion.There should be simultaneous contact during protrusion.


IMPORTANCE OF BALANCED OCCLUSION:IMPORTANCE OF BALANCED OCCLUSION: Balanced occlusion is one of most important factors that affect Balanced occlusion is one of most important factors that affect

denture stability. Absence of occlusal balance will result in leverage denture stability. Absence of occlusal balance will result in leverage of denture during mandibular movement.of denture during mandibular movement.

Sheppard stated that, “ENTER BOLUS, EXIT BALANCE” according Sheppard stated that, “ENTER BOLUS, EXIT BALANCE” according to this statement, balancing contact is absent when food enters oral to this statement, balancing contact is absent when food enters oral cavity. This makes us think that balanced occlusion has no function cavity. This makes us think that balanced occlusion has no function during mastication or as its role essential in complete denture.during mastication or as its role essential in complete denture.

Brewer reported importance of balanced occlusion. He reported Brewer reported importance of balanced occlusion. He reported that on an average normal individual makes masticatory tooth that on an average normal individual makes masticatory tooth contact only for 10 mnts in one full day as compared to 4 hours of contact only for 10 mnts in one full day as compared to 4 hours of total tooth contact during other functions. So for these hours of total tooth contact during other functions. So for these hours of tooth contact, balanced occlusion is important to maintain stability of tooth contact, balanced occlusion is important to maintain stability of denture. Hence, balanced occlusion is more critical during denture. Hence, balanced occlusion is more critical during parafunctional movementsparafunctional movements..


GENERAL CONSIDERATIONS FOR BALANCEDGENERAL CONSIDERATIONS FOR BALANCEDOCCLUSION:OCCLUSION:Ideal balanced occlusion can be achieved in cases with wide & large ridges Ideal balanced occlusion can be achieved in cases with wide & large ridges

& in complete dentures, with teeth arranged dose to ridge.& in complete dentures, with teeth arranged dose to ridge.Complete dentures that have teeth arranged away from the ridge & those Complete dentures that have teeth arranged away from the ridge & those

that rest on wide ridges provide ideal balanced occlusion.that rest on wide ridges provide ideal balanced occlusion.Ideal balance can be achieved by arranging the teeth slightly on lingual Ideal balance can be achieved by arranging the teeth slightly on lingual

side of crest of ridge. Arranging the teeth buccally will lead to poor side of crest of ridge. Arranging the teeth buccally will lead to poor balanced occlusion. If the teeth are set outside ridge the denture may balanced occlusion. If the teeth are set outside ridge the denture may elevate on one side during tooth contact stability of denture against elevate on one side during tooth contact stability of denture against these lever forces is called as LEVER BALANCE .Lever balance is these lever forces is called as LEVER BALANCE .Lever balance is different from balanced occlusion. It can be safely quoted that lever different from balanced occlusion. It can be safely quoted that lever balance is also necessary for balanced occlusion.balance is also necessary for balanced occlusion.

Complete denture should be designed in such a way that the forces of Complete denture should be designed in such a way that the forces of occlusion are centered anteroposteriorly in the denture.occlusion are centered anteroposteriorly in the denture.

TYPES OF BALANCED OCCLUSION: Unilateral balanced occlusion Bilateral balanced Protrusive balanced occlusion Lateral balanced occlusion


i)i) UNILATERAL BALANCED OCCLUSION:UNILATERAL BALANCED OCCLUSION:This is type of occlusion seen on occlusal surface of teeth on one side when This is type of occlusion seen on occlusal surface of teeth on one side when they occlude simultaneously with smooth, uninterrupted glide. This not followed they occlude simultaneously with smooth, uninterrupted glide. This not followed during complete denture construction. It is more pertained to fixed partial during complete denture construction. It is more pertained to fixed partial denturesdentures..

ii)ii) BILATERAL BALANCED OCCLUSIONBILATERAL BALANCED OCCLUSION::This is type of occlusion that is seen when simultaneous contact occurs on both This is type of occlusion that is seen when simultaneous contact occurs on both sides in centric & eccentric positions bilateral balanced occlusion helps to sides in centric & eccentric positions bilateral balanced occlusion helps to distribute the occlusal load evenly across the arch & therefore helps to improve distribute the occlusal load evenly across the arch & therefore helps to improve stability of denture during centric eccentric or parafunctional movements.stability of denture during centric eccentric or parafunctional movements.For minimal occlusal balance, there should be at least 3 points of contact on For minimal occlusal balance, there should be at least 3 points of contact on occlusal plane. More the number of contacts, better the balance Bilateral occlusal plane. More the number of contacts, better the balance Bilateral balanced occlusion can be protrusive or lateral balancebalanced occlusion can be protrusive or lateral balance..

iii)iii) PROTRUSIVE BALANCED OCCLUSION:PROTRUSIVE BALANCED OCCLUSION:This type of balanced occlusion is present when mandible in forward direction & This type of balanced occlusion is present when mandible in forward direction & occlusal contacts are smooth & simultaneous anteriorly & posteriorly. There occlusal contacts are smooth & simultaneous anteriorly & posteriorly. There should be at least three points of contact in occlusal plane. Two of these should should be at least three points of contact in occlusal plane. Two of these should be located posteriorly & one should be located in anterior region. This is absent be located posteriorly & one should be located in anterior region. This is absent in natural dentition.in natural dentition.

FACTORS THAT GOVERN PROTRUSIVE BALANCE:FACTORS THAT GOVERN PROTRUSIVE BALANCE: Inclination of condylar path: This inclination recorded on patient represents the Inclination of condylar path: This inclination recorded on patient represents the

path travelled by condyle in protrusion which is modified by combined action of path travelled by condyle in protrusion which is modified by combined action of all tissue in temperomandibular joint & ridges covered by recording bases.all tissue in temperomandibular joint & ridges covered by recording bases.

Angle of incisal guidance closes for patient.Angle of incisal guidance closes for patient. Angle of plane occlusionAngle of plane occlusion Compensating curves chosen for orientation with condylar path Compensating curves chosen for orientation with condylar path Cuspal height & inclination of posterior teeth.Cuspal height & inclination of posterior teeth.


iv)iv) LATERAL BALANCED LATERAL BALANCED OCCLUSION:OCCLUSION:

In lateral balance, there will In lateral balance, there will be a minimal simultaneous three be a minimal simultaneous three point contact present during lateral point contact present during lateral movement of mandible.movement of mandible.

Lateral balanced occlusion is Lateral balanced occlusion is absent in normal dentition, when a absent in normal dentition, when a dentulous person with canine guided dentulous person with canine guided of all occlusion moves his mandible of all occlusion moves his mandible to right, there will be canine guided to right, there will be canine guided disocclusion of all these teeth. Even disocclusion of all these teeth. Even canine of opposite side will not have canine of opposite side will not have contact.contact.

If this relationship is followed If this relationship is followed during teeth arrangement then during teeth arrangement then denture will lose its stability due to denture will lose its stability due to lever action. To prevent this teeth lever action. To prevent this teeth should be arranged such that there should be arranged such that there is simultaneous teeth contact in is simultaneous teeth contact in balancing & working sides.balancing & working sides.


FACTORS THAT GOVERN LATERAL BALANCE:FACTORS THAT GOVERN LATERAL BALANCE: Angle of inclination of condylar path on balancing side. Angle of inclination of condylar path on balancing side. Angle of indication of plane of occlusion on balancing side and working Angle of indication of plane of occlusion on balancing side and working

side. side. Compensating curve on balancing side and working side. Compensating curve on balancing side and working side. Buccal cusp heights or indication of teeth on balancing side. Buccal cusp heights or indication of teeth on balancing side. Lingual cusp heights or indication on working side. Lingual cusp heights or indication on working side. Bennett side shift on working side. Bennett side shift on working side. Steep cusps, produce more displacement of denture base that shallower Steep cusps, produce more displacement of denture base that shallower

or cuspless forms. Forces of occlusion acting on complete denture should or cuspless forms. Forces of occlusion acting on complete denture should be balanced from right to left and anterior to posterior direction.be balanced from right to left and anterior to posterior direction.

An increase in any of above forces will affect balanced occlusion leading An increase in any of above forces will affect balanced occlusion leading to compromised stability of denture. to compromised stability of denture.

If vertical overlap of anterior teeth is increased for aesthetic and phonetic If vertical overlap of anterior teeth is increased for aesthetic and phonetic reasons, then the horizontal overlap should adjusted to reduce the incisal reasons, then the horizontal overlap should adjusted to reduce the incisal guidance angle. guidance angle.

This adjustment provides space for free movement of ant-teeth. Without This adjustment provides space for free movement of ant-teeth. Without this adjustment there will be increased anterior interference leading to this adjustment there will be increased anterior interference leading to initial instability of denture base during protrusion. In long run, this may initial instability of denture base during protrusion. In long run, this may lead to resorption of residual alveolar ridge in anterior region. lead to resorption of residual alveolar ridge in anterior region.



FACTOR INFUENCING BALANCEDFACTOR INFUENCING BALANCEDOCCLUSIONOCCLUSION Five basis factors that determine the balance of an occlusionFive basis factors that determine the balance of an occlusionare : are :

Inclination of condylar path or condylar guidance Inclination of condylar path or condylar guidance Incisal guidanceIncisal guidanceOrientation of plane of occlusion or occlusal planeOrientation of plane of occlusion or occlusal planeCuspal Angulation Cuspal Angulation Compensating CurveCompensating Curve


(i) (i) Inclination of Condylar Path :Inclination of Condylar Path : It is also called first factor of occlusion. This is only factor, which can It is also called first factor of occlusion. This is only factor, which can

be recorded from patient. It is registered using protrusive be recorded from patient. It is registered using protrusive registration (i.e. patient is asked to protrude with occlusal rims. Inter-registration (i.e. patient is asked to protrude with occlusal rims. Inter-occlusal record material is Injected between occlusal rims in this occlusal record material is Injected between occlusal rims in this position. The occlusal rims with inter occlusal record are transferred position. The occlusal rims with inter occlusal record are transferred to articular. Since the occlusal rims are in protrusive relation, upper to articular. Since the occlusal rims are in protrusive relation, upper member of articulator is moved back to accommodate them. The member of articulator is moved back to accommodate them. The interocclusal record is carefully removed and upper member is interocclusal record is carefully removed and upper member is allowed to slide forward to its original position. The condylar allowed to slide forward to its original position. The condylar guidance should be adjusted till upper member slides freely into guidance should be adjusted till upper member slides freely into position. It is transferred to articulator as condylar guidance. position. It is transferred to articulator as condylar guidance.

Increase in condylar guidance will increase jar separation Increase in condylar guidance will increase jar separation during protrusion. This factor of balanced occlusion can't be during protrusion. This factor of balanced occlusion can't be modified. All other four factors of occlusion should be modified to modified. All other four factors of occlusion should be modified to compensate effects of this factor. In patients with steep condylar compensate effects of this factor. In patients with steep condylar guidance, incisal guidance should be decreased to reduce amount guidance, incisal guidance should be decreased to reduce amount of jaw separation produced during protrusion and vice-versa. But it of jaw separation produced during protrusion and vice-versa. But it should be remembered that incisal guidance can't be made steep should be remembered that incisal guidance can't be made steep because it has its own effectsbecause it has its own effects


(ii)(ii) Incisal Guidance :Incisal Guidance : This is defined as "The influence of contacting surfaces of mandibular and This is defined as "The influence of contacting surfaces of mandibular and

maxillary anterior teeth on mandibular movements". maxillary anterior teeth on mandibular movements". It is called 2nd factor of occlusion. It is determined by dentist and It is called 2nd factor of occlusion. It is determined by dentist and

customized for patient during anterior try in. It acts as controlling path for customized for patient during anterior try in. It acts as controlling path for movement of casts in an articulator. It should be set depending upon the movement of casts in an articulator. It should be set depending upon the desired overjet and overbite planned for the patient. If overjet is increased, desired overjet and overbite planned for the patient. If overjet is increased, the inclination of incisal guidance is decreased. If overbite is increased, then the inclination of incisal guidance is decreased. If overbite is increased, then incisal inclination increases. The incisal guidance has more influence on incisal inclination increases. The incisal guidance has more influence on posterior teeth than the condylar guidance. This is because the action of posterior teeth than the condylar guidance. This is because the action of incisal inclination is closer to teeth than action of condylar guidance. During incisal inclination is closer to teeth than action of condylar guidance. During protrusive movements, incisal edge of mandibular anterior teeth move in protrusive movements, incisal edge of mandibular anterior teeth move in downward and forward path corresponding to palatal surfaces of upper downward and forward path corresponding to palatal surfaces of upper incisors. This is known as protrusive incisal path or incisal guidance. The incisors. This is known as protrusive incisal path or incisal guidance. The angle formed by this protrusive path to horizontal plane is called as angle formed by this protrusive path to horizontal plane is called as Protrusive Incisal path inclination or incisal guide angle. Protrusive Incisal path inclination or incisal guide angle.

Influences of shape of posterior teeth. If incisal guidance is steep, Influences of shape of posterior teeth. If incisal guidance is steep, steep cusps or steep occlusal plane or steep compensatory curve is needed steep cusps or steep occlusal plane or steep compensatory curve is needed to produce balanced occlusion. In comple denture, the incisal guide angle to produce balanced occlusion. In comple denture, the incisal guide angle should be as flat as possible. Hence, while arranging anterior teeth, for should be as flat as possible. Hence, while arranging anterior teeth, for aesthetics, a suitable vertical overlap and horizontal overlap should be aesthetics, a suitable vertical overlap and horizontal overlap should be chosen to achieve balanced occlusion. Also, incisal guidance can't be chosen to achieve balanced occlusion. Also, incisal guidance can't be altered beyond limits. The location and angulation of incisors are governed altered beyond limits. The location and angulation of incisors are governed by various factors like aesthetics, function and phonetics etc. by various factors like aesthetics, function and phonetics etc.


(iii)(iii) Plane of Occlusion or occlusal planePlane of Occlusion or occlusal plane : : It is defined as an imaginary surface which is related anatomically to cranium It is defined as an imaginary surface which is related anatomically to cranium

and which theoretically touches incisal edges of incisors and tips of occluding and which theoretically touches incisal edges of incisors and tips of occluding surface of posterior teeth. It is not plane in true sense of word but represents surface of posterior teeth. It is not plane in true sense of word but represents mean curvature of surface. mean curvature of surface.

It is established interiorly by height of lower canine, which nearly coincides It is established interiorly by height of lower canine, which nearly coincides with commissar of mouth and posteriorly by height of retromolar pad. It is with commissar of mouth and posteriorly by height of retromolar pad. It is usually parallel to traqus line or camper's line. It can be slightly altered and its usually parallel to traqus line or camper's line. It can be slightly altered and its role is not as important as other factors. Tilting the plane of occlusion beyond role is not as important as other factors. Tilting the plane of occlusion beyond 10° is not advisable.10° is not advisable.

(iv)(iv) Compensating Curve :Compensating Curve : It is defined as "the anteroposterior and lateral curvature in alignment of It is defined as "the anteroposterior and lateral curvature in alignment of

posterior and lateral curvature in alignment of occluding surfaces and incisal posterior and lateral curvature in alignment of occluding surfaces and incisal edges of artificial teeth which are used to develop balanced occlusion." edges of artificial teeth which are used to develop balanced occlusion."

It is important factor for establishing balanced occlusion. It is It is important factor for establishing balanced occlusion. It is determine by inclination of posterior teeth and their vertical relationship to determine by inclination of posterior teeth and their vertical relationship to occlusal plane. The posterior teeth should be arranged such that their occlusal plane. The posterior teeth should be arranged such that their occlusal surfaces from a curve. This curve should be in harmony with occlusal surfaces from a curve. This curve should be in harmony with movements of mandible guided posteriorly by condylar path. movements of mandible guided posteriorly by condylar path.

A steep condylar path requires sleep compensatory curve to A steep condylar path requires sleep compensatory curve to produce balanced occlusion. If shallow compensating curve is given for same produce balanced occlusion. If shallow compensating curve is given for same situation, there will be loss of balancing molar contacts during protrusion.situation, there will be loss of balancing molar contacts during protrusion.

There are 2 types of compensating curves namely : There are 2 types of compensating curves namely : Anteroposterior curvesAnteroposterior curves Lateral CurvesLateral Curves www.indiandentalacademy.comwww.indiandentalacademy.com

ANTEROPOSTERIOR COMPENSATING CURVESANTEROPOSTERIOR COMPENSATING CURVES : : These are These are compensatory curves running in anteroposterior direction. They compensatory curves running in anteroposterior direction. They compensate for curve of spee seen in natural dentition. compensate for curve of spee seen in natural dentition. Compensating Curve for Curve of Spee :Compensating Curve for Curve of Spee : Defined as Anatomic Curvature Defined as Anatomic Curvature

of occlusal alignment of teeth beginning at tip of lower canine and following of occlusal alignment of teeth beginning at tip of lower canine and following buccal cusps of lower canine and following buccal cusps of natural premolars buccal cusps of lower canine and following buccal cusps of natural premolars and molars,continuing to anterior border of ramus as described by Grafton. It and molars,continuing to anterior border of ramus as described by Grafton. It is an imaginanory curve joining buccal cusps of mandibular posterior teeth is an imaginanory curve joining buccal cusps of mandibular posterior teeth starting from canine passing through head of condyle. It is seen in natural starting from canine passing through head of condyle. It is seen in natural dentition and should be reproduced in a C.D. The significance of this curve is dentition and should be reproduced in a C.D. The significance of this curve is that, when patient moves his mandible forward, posterior teeth set on this that, when patient moves his mandible forward, posterior teeth set on this curve will continue to remain in contact. If teeth are not arranged according to curve will continue to remain in contact. If teeth are not arranged according to this curve, there will be dis-occlusion during protrusion of mandible this curve, there will be dis-occlusion during protrusion of mandible (Christensens Phenonenon). (Christensens Phenonenon).

LATERAL COMPENSATING CURVES :LATERAL COMPENSATING CURVES : These curves run transversely These curves run transversely from one side of arch to other the following curves fall in this category. from one side of arch to other the following curves fall in this category. Compensating Curve for Monson Curve :Compensating Curve for Monson Curve : Monson’s curve is defined as Monson’s curve is defined as

'The curve of occlusion in which each cusp and incisal edge touches or 'The curve of occlusion in which each cusp and incisal edge touches or conforms to segment of a sphere of 8 inches in daimeter with its centre in conforms to segment of a sphere of 8 inches in daimeter with its centre in region of Glabella." region of Glabella."

This curve runs across palatal and buccal cusps of maxillary molars. This curve runs across palatal and buccal cusps of maxillary molars. During lateral movements of mandibular lingual cusps on working side During lateral movements of mandibular lingual cusps on working side should slide along inner inclines of maxillary buccal cusp. In balances should slide along inner inclines of maxillary buccal cusp. In balances side the mandibular buccal cusps should contact inner inclines of side the mandibular buccal cusps should contact inner inclines of maxillary palatal cusp. This relationship forms a balance. Only if teeth maxillary palatal cusp. This relationship forms a balance. Only if teeth are set following the monsoons curve there will be lateral balance of are set following the monsoons curve there will be lateral balance of occlusion. occlusion.


Compensating Curve for Anti-Monson or Wilsons Curve :Compensating Curve for Anti-Monson or Wilsons Curve : Wilsons curve is defined as " A curve of occlusion which is convex Wilsons curve is defined as " A curve of occlusion which is convex upwards". upwards".

This curve run and opposite to direction of monsoons curve this This curve run and opposite to direction of monsoons curve this curve is followed when 1st premolars are arranged. The premolars curve is followed when 1st premolars are arranged. The premolars are arranged according to this curve so that they do not produce are arranged according to this curve so that they do not produce any interferance to lateral movements. any interferance to lateral movements.

Reverse CurveReverse Curve : "A curve of occlusion which is transverse cross : "A curve of occlusion which is transverse cross section conforms to line which is convex upward." It was originally section conforms to line which is convex upward." It was originally developed to improve stability of denture. It is explained in relation developed to improve stability of denture. It is explained in relation of mandibular posterior teeth. The reverse curve was modified by of mandibular posterior teeth. The reverse curve was modified by Max Pleasure to for pleasure curve. Max Pleasure to for pleasure curve.

Pleasure Curve Pleasure Curve : "A curve of occlusion which is transverse cross-: "A curve of occlusion which is transverse cross-section conforms to line which is convex upward except for last section conforms to line which is convex upward except for last molars. molars.

It was proposed by Max Pleasure. He proposed this curve to It was proposed by Max Pleasure. He proposed this curve to balances occlusion and increase stability of denture. Here the first balances occlusion and increase stability of denture. Here the first molar is horizontal and 2nd premolar is bucally tilted. The 2nd molar molar is horizontal and 2nd premolar is bucally tilted. The 2nd molar independently follows the anteroposterior compensating curved and independently follows the anteroposterior compensating curved and lingually tilted. This curve runs from palatal cusp of 1st premolar to lingually tilted. This curve runs from palatal cusp of 1st premolar to distobuccal cusp of 2nd molar. The 2nd molar gives occlusal distobuccal cusp of 2nd molar. The 2nd molar gives occlusal balance and 2nd premolar gives lever balance. balance and 2nd premolar gives lever balance.


(V)(V) CUSPAL ANGULATION :CUSPAL ANGULATION :

Cusp angle is defined as " The angle made by average slope Cusp angle is defined as " The angle made by average slope of cusp with cusp plane measured mesiodstally or of cusp with cusp plane measured mesiodstally or buccolingually." buccolingually."

Cusps on teeth or inclination of cuspless teeth are important Cusps on teeth or inclination of cuspless teeth are important factors that modify effect of plane of occlusion of factors that modify effect of plane of occlusion of compensating curves. The mesiodistal cusps lock occlusion compensating curves. The mesiodistal cusps lock occlusion such that repositioning of teeth doesnot occur due to settling such that repositioning of teeth doesnot occur due to settling of base. of base.

In order to prevent locking occlusion, mesiodistal cusps are In order to prevent locking occlusion, mesiodistal cusps are reduced during occlusal reshaping. In absence of mesiodistal reduced during occlusal reshaping. In absence of mesiodistal cusps, buccolingual cusps are considered factor for balanced cusps, buccolingual cusps are considered factor for balanced occlusion. In cases with shallow overbite, cuspal angle should occlusion. In cases with shallow overbite, cuspal angle should be reduced to balance incisal guidance. This is done because be reduced to balance incisal guidance. This is done because jaw separation will be less in cases with overbite. Teeth with jaw separation will be less in cases with overbite. Teeth with sleep cusp will produce occlusal interference in these cases. sleep cusp will produce occlusal interference in these cases.

In case with deep bite, jaw separation is more during In case with deep bite, jaw separation is more during protrusion teeth with high cuspal inclines are reguided in protrusion teeth with high cuspal inclines are reguided in these cases to produce posterior contact during protrusion. these cases to produce posterior contact during protrusion.


MONOPLANE OR NON-BALANCED OCCLUSIONMONOPLANE OR NON-BALANCED OCCLUSIONIt is an arrangement of teeth with form or purpose. It includes theIt is an arrangement of teeth with form or purpose. It includes thefollowing concepts of occlusion:following concepts of occlusion: Spherical theory Spherical theory Organic occlusionOrganic occlusion Occlusal balancing ramps for protrusive balance Occlusal balancing ramps for protrusive balance TransographicsTransographicsGeneral ConsiderationsGeneral ConsiderationsThe following point have to be considered while using a non-balancedThe following point have to be considered while using a non-balancedocclusion for a denture:occlusion for a denture: Opposing artificial teeth should not contact when the jaws are in Opposing artificial teeth should not contact when the jaws are in

eccentric relation, because it may give destabilizing forces to the eccentric relation, because it may give destabilizing forces to the basal seat area. The architecture of the basal seat does not allow basal seat area. The architecture of the basal seat does not allow tooth contact when the mandibule is in eccentric position.tooth contact when the mandibule is in eccentric position.

Tooth contact should occur only when the mandible is in centric Tooth contact should occur only when the mandible is in centric relation to the maxilla.relation to the maxilla.

The patient should be encouraged to repeat the mandibular The patient should be encouraged to repeat the mandibular movements till there is no discomfort in the centric relation.movements till there is no discomfort in the centric relation.


LINGUALIZED OCCLUSION:LINGUALIZED OCCLUSION: Lingualized occlusion, one of the more popular occlusal schemes was Lingualized occlusion, one of the more popular occlusal schemes was

introduced by Alfred Gysi in 1927. The basic concepts of lingualized introduced by Alfred Gysi in 1927. The basic concepts of lingualized occlusion were suggested by Payne. It was Earl pound who first used the occlusion were suggested by Payne. It was Earl pound who first used the term “lingualized occlusion”.term “lingualized occlusion”.

This occlusal scheme was introduced as an attempt to maintain the This occlusal scheme was introduced as an attempt to maintain the esthetics and food penetration advantages of the anatomic form while esthetics and food penetration advantages of the anatomic form while maintaining the mechanical freedon of the non-anatomic forms.maintaining the mechanical freedon of the non-anatomic forms.IndicationsIndications

In a situation where the patient places a high priority on aesthetics but the In a situation where the patient places a high priority on aesthetics but the oral condition requires the use of non-anatomic teeth, e.g. severe alveolar oral condition requires the use of non-anatomic teeth, e.g. severe alveolar ridge resorption, Class II ridge relationship.ridge resorption, Class II ridge relationship.

When a complete denture opposes a removable partial denture.When a complete denture opposes a removable partial denture. Parafunctional habits.Parafunctional habits. AdvantagesAdvantagesPaynePayne stated the advantages as: stated the advantages as: Can be adapted to different types of ridgesCan be adapted to different types of ridges A solid maximum intercuspationA solid maximum intercuspation Absence of deflective occlusal contact in lateral excursionsAbsence of deflective occlusal contact in lateral excursions Esthetic arrangement of teethEsthetic arrangement of teeth Balanced articulation can be achieved.Balanced articulation can be achieved.


Types of Tooth Forms usedTypes of Tooth Forms used Semianatomic teethSemianatomic teeth Non-anatomic teethNon-anatomic teeth Myerson lingualized integration tooth molds.Myerson lingualized integration tooth molds.Principles of Lingualized OcclusionPrinciples of Lingualized Occlusion Anatomic teeth are used for the maxillary denture. Teeth with Anatomic teeth are used for the maxillary denture. Teeth with

prominent lingual cusps are helpful.prominent lingual cusps are helpful. The buccal cusps are raised above the occlusal plane. They have The buccal cusps are raised above the occlusal plane. They have

no functional role. They improve esthetics and help prevent cheek no functional role. They improve esthetics and help prevent cheek biting.biting.

Non-anatomic or semi-anatomic teeth are used for the mandibular Non-anatomic or semi-anatomic teeth are used for the mandibular denture. A narrow occlusal table is preferred where severe residual denture. A narrow occlusal table is preferred where severe residual ridge resorption has occurred.ridge resorption has occurred.

Modification of the mandibular posterior teeth is accomplished using Modification of the mandibular posterior teeth is accomplished using selective grinding.selective grinding.

When the patient moves into a working relationship, the lingual cusp When the patient moves into a working relationship, the lingual cusp of the maxillary teeth functions against the mandibular teeth (hence of the maxillary teeth functions against the mandibular teeth (hence the term lingualized occlusion.)the term lingualized occlusion.)


CONCLUSION :CONCLUSION :

To understand occlusion in broadest sense, it is necessary to consider, in To understand occlusion in broadest sense, it is necessary to consider, in addition to TMJ articulation, muscles and teeth, some of neurobehavioral addition to TMJ articulation, muscles and teeth, some of neurobehavioral mechanism that gives meaning to presence and function of masticatory mechanism that gives meaning to presence and function of masticatory system. Although many of neural interactive mechanisms between system. Although many of neural interactive mechanisms between occlusion & thoughts, sensibleness and emotions are complex and often occlusion & thoughts, sensibleness and emotions are complex and often intermediate, it is possible to suggest strategies that could account for intermediate, it is possible to suggest strategies that could account for variety of responses that occur in function and parafunction. variety of responses that occur in function and parafunction.

The obvious strategy to compensate for wear of proximal contact areas is The obvious strategy to compensate for wear of proximal contact areas is mesial migration of teeth, and strategy to compensate of for wear of mesial migration of teeth, and strategy to compensate of for wear of occlusal surfaces is explain of teeth. The strategy for regulating the occlusal surfaces is explain of teeth. The strategy for regulating the contraction of jaw elevators to achieve normal resting position of mandible contraction of jaw elevators to achieve normal resting position of mandible with a small interocclusal space is postural refresh. The overall strategy for with a small interocclusal space is postural refresh. The overall strategy for motivation to have access to muscle of mastication might be to provide motivation to have access to muscle of mastication might be to provide 'drive' for ingestive processes, specially during early stages of devlopment 'drive' for ingestive processes, specially during early stages of devlopment of masticatory system and maturation of nervous system. Swallowing in of masticatory system and maturation of nervous system. Swallowing in fetal life, suckling in newborn and chewing in young infant. fetal life, suckling in newborn and chewing in young infant.

Functional disturbances of masticatory system may involve psycho Functional disturbances of masticatory system may involve psycho physiological mechanisms that are related to tech and their functions. physiological mechanisms that are related to tech and their functions. Therefore occlusal interferences to function or parafunction may then Therefore occlusal interferences to function or parafunction may then involve more than simply contact relations of teeth they may involve psycho involve more than simply contact relations of teeth they may involve psycho physiological mechanisms of human behaviorphysiological mechanisms of human behavior as well. as well.


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