Classification of Malocclusion Jai.pptsaurabh / orthodontic courses by Indian dental academy

Seminar on Classification of malocclusion

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INDIAN DENTAL ACADEMY

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Index• Introduction• What is a classification system• Definition of classification• Purpose of classification• When to classify• Characteristic of normal occlusion• Keys of normal occlusion• Definition of malocclusion• Types of malocclusion• Various classification of malocclusion• Summery• Bibliography


Introduction

• It has been said that the introduction of Angle classification of malocclusion was the principal step in turning disorganized clinical concept into the disciplined science of orthodontics.

• Many new and simplified system for classifying malocclusion have been introduces, and each soon has many modification.


What is a classification system

• Whenever we examine a patient we subconsciously classify him or her in many different ways.

• Like a 8 year boy not having permanent central incisors. But in this one sentence we have classified him in 3 standard : age sex and time of eruption.

• But this doesn’t tell us about treatment plan or prognosis.


What is a classification system

• So a classification system is a grouping of clinical cases of similar apperance for ease in handling and discussion, it is not a system of diagnosis, method for determining prognosis, or way of defining treatment


DEFINITION OF CLASSIFICATION

STRANG – Classification is a process to analyze cases of malocclusion for the purpose of segregating them into a small number of groups, which are characterized by certain specific and fundamental variations from the normal occlusion of teeth. These variations, in turn, become influential and deciding factor in determining the correct plan of treatment.


Purpose of classification

• Than one must ask why to classify?• Several reason for doing this are:• 1) historically: certain type are always been

grouped together, thus the literature may confined, ex: treatment of Angle class 2 div 1. so if we go through an article we should have a clear concept how does Angle class 2 div 1 appear, however all cases of Angle class 2 div 1 are not alike, there etiology nor there prognosis nor the treatment plan are same .



• 2)Ease of reference: so the listener have rough idea of problem simply by one label like Angle class 2 div 1. Later fine necessary detail can be given, so with his previous experience he can tell problem encountered in treatment, although have no knowledge of etiology, prognosis, or best treatment plan. Thus aid in comparison.



• 3) self communicating reason: like if we are saying severe Angle class 2 div 1, we are

a) identifying problem of which we must be worry.

b) recalling past difficulties with similar cases

c) alerting ourselves to possible strategies and appliance that may be necessary in treatment.



• So we can say that classification is done for• 1) traditional reasons• 2) ease of reference• 3) for purpose of comparison • 4) for ease of self communication


PURPOSE OF CLASSIFICATION

(AJODO 1992 SEPT.; STRANG)

1. Grouping various malocclusions.2. Diagnosis .3. Treatment planning. 4. Comparision. 5. Visualizing and understanding the

problem associated with that malocclusion.

6. Communication.www.indiandentalacademy.com

When to classify

• One of the most common mistake is that of trying to label each case immediately.

• The classification is not diagnosis.• It is better first to describe that what is wrong

in complete and precise manner. And if at the end of examination, it fall into a certain group, it should be then named.


Characteristic of normal occlusion

• The famous anatomist John Hunter described what orthodontists call a ideal occlusion today as early as in 18th century.

• Carabelli in mid 19th was the first to describe abnormal relationship of upper and lower dental arches in a systematic way.

• The term “edge to edge” and “overbite” are derived from carabelli system


Characteristic of normal occlusion

• Historically dental arches described in simple geometric terms such as ellipse, parabola, or modified spheres, etc.

• Ideal arrangement of teeth in geometrically described by Angle as an “ line of occlusion”.

• It is best described by as a catenary curve- curved fromed when a chain or rope is hang from both ends.


LINE OF OCCLUSION


Line of occlusion

• Is a smooth (catenary) curve passing through the central fossa of each upper molar and across the cingulum of upper canine and incisor teeth. The same line runs along the buccal cusps and incisal edges of the lower teeth, thus specifying the occlusion as well as interarch relationship.


Line of occlusion

• Spatial position of each teeth within the arches can be described in relation to the line of occlusion.

• Angle termed the movement necessary to bring a tooth into the line of occlusion as first, second, third order, according to type of movement required.


Line of occlusion

1) first order band: in- out movement. 2) second order band: tip or angulations

movement.

3) third order band: torque or inclination movement.


Old Glory

• Angle also describe the normal occlusion in term of “old glory”.

• “It represent all the teeth in normal occlusion, it will be seen that each dental arch describe a graceful curve, and that all the teeth in these arches are so arranged as to be in harmony with their fallow in same arch, as well as those in opposing arch, each tooth help to maintain every other tooth in these harmonious relationship for the cusps interlock and each incline plane serves to prevent each tooth from sliding out of position.”


• Ideal occlusion : The maximum intercuspal contact

(centric occlusion) and the unstrained retruded position of the mandible (centric relation) should approximately coincide. There should be a maximum of 2mm. difference between the two.


Keys of normal occlusion

• Andrew describe 6 significant characteristic observed in a study of 120 cases of non orthodontic normal occlusions. The cases were collected over a period of 4 years from 1960 to 1964. Criteria for selection were:-

• Casts were of the people who never had orthodontic treatment.

• Teeth were straight and pleasing in appearance



• The casts occluded into a position that looked generally correct.

• The patient would not benefit from orthodontic treatment.



• According to Andrew’s:• 1)molar relationship: the mesiobuccal cusp of upper

first molar occludes with the groove between the mesiobuccal and middle buccal cusp of lower first molar.

The mesio-lingual cusp of upper first molar should occlude into central fossa of lower first molar.

The crown of upper first molar should be angulated so that the distal marginal ridge occludes with the mesial marginal ridge of lower second molar.



• 2) crown angulation: all tooth crown are angulated mesially (mesiodistal tip)

• 3) crown inclination: refer to labiolingual or buccolingual inclination of crown of teeth.

a) maxillary Incisors are inclined towards the buccal or labial surface.(positive crown inclination)

b) Upper posterior teeth are inclined lingually, similarly from the canine to premolar. Upper molar are slightly more incline. (negative crown inclination).



c) lower posterior teeth are inclined lingually, progressively more from canine to molars. (negative crown inclination)

d) lower incisor are slightly lingually incline.(negative crown inclination)

4) rotation: are not present 5) Spaces: are not present between teeth 6) Occlusal plane: plane is either flat or slightly

curved.( curve of spee)



• 7)Tooth size: both arches should have balance tooth size, if not there would be spacing in one arch and crowding in opposing arch.

• Evaluation of tooth size discrepancy can be done by Bolton’s analysis;-

The anterior ratio:- (Σ width of six lower anterior teeth/Σ width of six upper anterior teeth × 100),


Keys of normal occlusion• And overall ratio (Σ width of lower 12 teeth/Σ width of

upper 12 teeth × 100).• Normal values= for anterior ratio=77.2 for overall ratio=91.3• The most common anterior tooth size discrepancy consist

of small lateral incisor in upper arch and/ or large lateral incisor in lower arch.

• In buccal segment small upper second premolar is most common discrepancy.


DEFINITION OF MALOCCLUSION

ANGLE - Malocclusion is defined as any deviation from the ideal occlusion.

STRANG – Malocclusion is any perversion of normal occlusion of teeth.

T.C WHITE – A condition where there is a departure from the normal relation of teeth to other teeth in the same arch and to teeth in the opposing arch.


TYPES OF MALOCCLUSION

It can be divided into :

1. Intra-arch malocclusion

2. Inter-arch malocclusion

3. skeletal malocclusion


INTRA-ARCH MALOCCLUSIONIt includes:-variations in individual tooth position; and malocclusion affecting a group of teeth. These are :• Distal inclination or distal tipping .• Mesial inclination or mesial tipping. • Lingual inclination or lingual tipping. • Buccal inclination or buccal tipping. • Mesial displacement.• Distal displacement.• Rotation. • Distolingual or mesiobuccal rotation.• Mesiolingual or distobuccal rotation.• Transposition. www.indiandentalacademy.com



INTER-ARCH MALOCCLUSION

• Sagittal plane malocclusion . Prenormal occlusion . Postnormal occlusion .• Vertical plane malocclusion .

Open bite, Deep bite• Transverse plane malocclusion. buccal or lingual cross bite


SKELETAL MALOCCLUSION

• Sagittal plane prognathism retrognathism• Transverse plane narrowing of arch widening of arch• Vertical plane increase or decrease facial height


Various Types of classifications systems

• Angle’s classification• Dewey’s modification• Lischer’s modification• Angle’s classification revisited• Modified Angle’s classification• Simon’s classification• Bennett’s classification• Ballard classification• Ackermann- Profit classification• British standard classification for incisors• WHO classification• Classification for Deciduous tooth.• Canine classification• Pseudo- class 1 malocclusion• Peck and Peck classificationwww.indiandentalacademy.com

Angle’s classificationEdward Hartley Angle -In 1899SALIENT FEATURES

• Based on molar relation.• Based on the mesio-distal relation of teeth.• Only maxillary first molar is the key to occlusion .

Angle classified malocclusion into 3 main classes designated by roman numerical class I, class II & class III .


Angle’s classification

• Clinician now use angle system in different way than it was originally presented, now it has shifted from the molar to skeletal relation.

• Because class 2 molar relationship may result in several different ways, each require a different strategy in treatment, but skeletal class 2 is not misunderstood, since it dominates the occlusion and its treatment.



• Angle originally presented his classification on the theory that the maxillary first permanent molar invariably in a correct position.

• But later this hypothesis was discarded in cephalometric studies.

• In this usually clinician miss the malfunction of muscles and problem in growth etc.

• And even first molar relationship change during various stages of development of dentition.



• Despite of its criticism, it is still the most traditional, most practical, and hence the most popular classification at present.



• Normal Occlusion: the mesio-buccal

cusp of the upper first molar occludes in the buccal groove of the lower first molar.

If this molar relationship existed and the teeth were arranged on a smoothly curving line of occlusion, then normal occlusion would result.


Angle’s classificationClass I

Mesio-buccal cusp of maxillary first molar falls on to the mesio-buccal groove of mandibular first permanent molar .



• Patient may exhibit dental irregularities like: crowding spacing rotation missing tooth, etc.• Patient may exhibit bimaxillary protrusion bimaxillary retrusion


BIMAXILLARY DENTAL PROTRUSION


MAXILLARY-MANDIBULAR DENTAL RETRUSION


Class II Disto- buccal cusp of maxillary first

molar falls on the mesiobuccal groove of mandibular first permanent molar.

It is divided into: Class II Div 1: Upper incisors are

proclined. Class II Div 2: Upper laterals overlap

centrals and the centrals are retroclined.


Characteristic features ofClass II div 1

• Upper lip is hypotonic and fail to form lip seal• Lower lip cushions the palatal aspect of upper

lip• Tongue occupy lower posture • Unrestrained buccinator activity result is

narrowing of upper arch at premolar and canine region resulting in “v”shape arch

• Hyper-active mentalis activity that accentuates narrowing of arch.


Class II div 2

• Variation;- Lingually inclined central and lateral incisor

with canine labially tipped.• Give arch a “squarish “ appearance.• Have normal perioral muscle activity.• May have abnormal path of closure due to

tipped incisor


Class II subdivision

• When one side of arch have class I relation and other have class II, refer as subdivision

• Ex. class II,div 1, subdivision class II,div 2, subdivision

• In this patient can exhibit abnormalities like:-


MANDIBULAR RETRUSION


MAXILLARY PROGNATHIC JAW


MAXILLARY PROGNATHISM & MANDIBULAR RETROGNATHISM


Class III Mesio- buccal cusp of maxillary first

permanent molar occludes in the interdental space between mandibular first and second molars.


Types of class III• True:- skeletal due to: excessively large mandible forwardly place mandible smaller than normal maxilla retropositioned maxilla combination of above


Types of class III• Pseudo : forward movement of mandible

during closure. Due to: 1) occlusal abnormalities 2)premature loss of deciduous teeth, so child tend

to move mandible forward to make contact. 3)enlarge adenoid, so child move tongue forward

to prevent contact of tongue to adenoid, that’s bring the mandible forward.(also know as adenoid faceses)

• Subdivision: if class I on one side and class III on other.


MANDIBULAR PROGRANATHIC JAW


MANDIBULAR DENTAL PROTRUSION


SALIENT FEATURESLower incisor tends to be lingually inclined. The patient can present with: • Normal Overjet. • An edge to edge incisor relation. • Anterior cross bite. The space available for tongue

is usually more. Thus, tongue occupies lower position, resulting in a narrow arch.



• Special points:-Usually molar position are not fully class I , II or III, but rather in an intermediate relationship.

• So molar relationship between class I and class II are called “ end-to-end malocclusion (notation E)”.

• And those between class I and class III are called “super I malocclusion( notation S1).



• This help clinician to better describe the occlusion.

• They also reveals bilateral asymmetries, severity of malocclusion, for example;

a mild class 2 occlusion(End to end)can be differentiated from class2 ( fully developed).


Drawbacks of Angle’s classificationAJODO(1992); PROFFIT; GRABER;

INTERNET

1. Considers malocclusion only in antero-posterior relations .

2. If molars are absent – cannot classify.3. Does not describe skeletal relationship.4. Maxillary and mandibular molars are not fixed

points in the skull anatomy – key ridge. Key ridge “is out line that represent zygomatic process of maxilla, it’s a dense thickening of bone, it extent upward to join dorsal limit of orbit and run parallel to lateral border of orbit.”

5. Cannot be applied to deciduous dentition.www.indiandentalacademy.com

Angle’s classification6. Severity of malocclusion cannot be described.

7. Does not consider vertical/ transverse relation.

8. Individual tooth malrelation is not considered.

9. Does not differentiate skeletal/ dental mal-relation.

10. Didn’t explain about Soft tissues. Saddle angle. Gonial angle/cranial base rotation. TMJ associated problems.


Dewey’s modification (1935)

• Given by Martin Dewey, initially Angle’s protégé but later his rival.

• He modified Angle’s class I and III classifications.

Modification of class Iclass I molar relation with :Type 1; crowding of anterior teeth.Type 2; proclined upper incisors.Type 3; anterior cross bite .Type 4; posterior cross bite. Type 5; mesial migration of molars due to early

loss of teeth mesial to them.www.indiandentalacademy.com

• Modification of class III

class III molar

relation with Type 1 –edge to edge

incisor relationship.Type 2 –mandibular

incisor crowdingType 3 –incisors in

cross-bite.


MODIFIED ANGLE’S CLASSIFICATIONA Premolar Derived Classification

• Class I: The most anterior upper premolar fits exactly into the embrasure created by the distal contact of the most anterior lower premolar.


• Class II : when one upper second premolar correctly opposes two lower premolars.

• Class III: when two upper premolars oppose one lower premolar.


ANGLE’S CLASSIFICATION REVISITED: A MODIFIED ANGLE CLASSIFICATION

• HISTORY:

Original classification by Angle had Class II as a full premolar-width distoclusion

Class III as a full premolar-width mesioclusion.Assuming an average premolar width of 7.5 mm, then Class I

ranged from 7 mm.mesioclusion to 7 mm. distoclusion, for a total range of Class I of 14 mm as given in 1900. This range was far too broad, and hence in 1907, Angle revised his definition, making Class II more than half of a cusp distoclusion and Class III more than half of a cusp mesioclusion. Angle's modification reduced the range from 14 mm. to a 7 mm. range.


GOAL OF REDIFINING ANGLE’S CLASSIFICATION

• Since many orthodontists consider class I as goal of successful treatment, therefore, it was necessary to redefine class I malocclusion.

• However, the large 7mm. range of class I has been discarded in this modified version and all the teeth visible from buccal view must occlude with two antagonist teeth as Angle demanded for ideal occlusion in old glory.


Lischer’s ModificationUsed different terminologies for the same

molar relationships, described by Angle.Nuetro - occlusion ; synonymous to Angle’s

class I malocclusion.Disto - occlusion ;synonymous to Angle’s

class II malocclusion.Mesio - occlusion ; synonymous to Angle’s

class III malocclusion.


Lischer’s ModificationHe described individual tooth malpositions : position– version.• Lingo version/ labioversion.• Mesioversion/distoversion .• Infraversion/supraversion.• Torsiversion or rotation .• Perversion or impaction.• Transversion or transposition.


Lischer’s modofication

• His nomenclature describe individual tooth malpossition.

• It simply done by adding suffix “version” to a word to indicate the direction from normal position.

• Axiversion= the wrong axial inclination.• The terms combined when a tooth assume a

malpossition involving more than one direction than normal. Ex: mesiolabioversion.


Bennett’s classification, 1912 Classified based on the etiology.It is always more useful, important , and practical to

classify according to their origin.• Some problem site of origin are1) Osseous:- include problem in abnormal growth size,

shape, timing or proportion of any bone in craniofacial region.

2) Muscular:-include all problem in malfunction of dentofacial musculature. Like abnormal persistent contraction of mandibular muscles can result in retarded mandibular growth.


Bennett’s classification• Another example is thumb sucking:- this itself a

complicated neuromuscular reflex involving many muscles, temporomandibular articulation, throat, tongue, and arms. Continue sucking may narrow the maxillary dental arch. This in turn give rise to mandibular retraction because narrowing of maxillary arch result in tooth interference, so mandible shift posteriorly by muscles to a position of better occlusion.


Bennett’s classification• 3) Dental:- involve the teeth and their

supporting structure. The malpossition of teeth on bone is different from growth of bone or muscular contraction.

This is usually the easiest to treat and retain but care must be taken to determine whether it is secondary to abnormal osseous growth or malfunction of muscle.


Bennett’s classification This defect may involve :- malpossition of teeth Abnormal number of teeth Abnormal size of teeth Abnormal conformation or texture of

teeth etc.• Based on these Bennett classify malocclusion

in 3 groups.www.indiandentalacademy.com

Bennett’s classification Class 1:- Abnormal position of one or

more teeth due to local causes. Class 2:- Abnormal formation of a part or

whole of either arch due developmental defects of bone.

Class 3:- Abnormal relationship between upper and lower arches due to abnormal formation of either arch.


Ballard’s classification (1964)• He gives a skeletal classification of

malocclusion • They are malocclusions caused due to

abnormality in maxilla and mandible .

• The defects can be in Size. position . relationship between the jaw.


Ballard’s classification It is divided the malocclusion

into Skeletal class I, II, III

• Skeletal class I- The upward projection of axis of lower incisors would pass through the crowns of upper incisors.

• Both bases are normal.


Ballard’s classification• Skeletal class II- The lower apical base

is relatively too far back. The lower incisor axis would pass palatal to the upper incisor crown.

• Skeletal class III- The lower apical base is placed relatively too for forward, the projection of lower incisor axis would pass labial to upper incisor crown .


Assumptions made in classification

• Inclinations of incisors within each arch are normal.

• If this is not so, then dental correction of incisor inclinations are made such that the lower central will make an angle of about 90 to the mandibular plane and to upper centrals at an angle of 110 to Frankfort Horizontal plane.


Simon’s classification 1930

--He put forward “craniometric classification”--It is based on specific recording of vertical

orientation of jaw to cranium by what Simon called “Gnathostatic” cast. In this top of maxillary study model was parallel with F-H plan.

--This permit more precious appraisal of jaw relationship.

--After introduction of cephalometric radiography Simon’s concept incorporated in routine diagnosis although gnathostatic casts are abandoned.

- www.indiandentalacademy.com

Simon’s classification• Simon gives classification based on

position of teeth to these three different planes:

1. Frankfort horizontal plane.

2. Orbital plane .

3. Mid-Sagittal plane .


Simon’s classification1) Frankfort horizontal plane ; explains the

vertical relationship of teeth to the plane.• Attraction – close to the plane .• Abstraction –away from the plane. 2) Orbital plane ; perpendicular plane

dropped at right angle to F-H plane from the lower most border of the bony orbit. Show antero-posterior relationship.

• protraction; teeth are placed forward.• Retraction ;teeth are placed behind.


Simon’s classification Law of cuspids: Normally the orbital plane

passes through the distal 1/3rd cuspid region but its not always necessary for the plane to coincide with the distal 1/3rd of cuspid – hence , is not reliable.

3)Mid Sagittal plane ; shows Transverse relationship.

• Contraction; teeth are placed closer to the plane.

• Distraction; away from the plane .www.indiandentalacademy.com


Simon’s classification

• Among these terms only three terms are in common use: protraction, retraction, contraction.

• Ex: Angle class 2 can be due to maxillary protraction or mandibular retraction, or both.

• The principal contribution of Simon’s system is its emphasis on the orientation of dental arches to facial skeletal. In addition it separate carefully problem in malpossition of teeth from osseous dysplasia.


Simon’s classification• This system is more precious than angle

system, and in three dimension. • But it is cumbersome, confusing at times ex:

attraction is intrusion of maxillary teeth or extrusion of mandibular teeth.

• So little use in practice• However it had a great impact on orthodontic

thinking and even have altered the fashion in which the Angle system was used.


British standard 4492, (1983)

classified incisor relationship into:

• Class 1 incisor relationship.• Class 2 incisor relationship.• Class 3 incisor relationship.

• Class 1:- The incisal edges of lowers occlude or lieimmediately below the plateau of upper

centrals.www.indiandentalacademy.com

• Class 2: The lower incisal edges lie posterior to the cingulum plateau of upper incisors .

Division 1: upper incisors are proclined and have increased Overjet.

Division 2: upper incisors are retroclined .

• Class 3 : lower incisal edges lie anterior to the cingulum, plateau of upper incisors and Overjet is reduced/ reversed.


British standard classification


W.H.O Classification (Geneva 1995)

• Classified malocclusion in 6 groups which are again divide in subgroups.

• K07.0 - Major anomalies of the jaw size. Excludes; Acromegaly (E22.0). Hemifacial atrophy or hypertrophy. (Q64.40),(Q64.41) Robin’s syndrome .Unilateral condylar hyperplasia. (k10.81)Unilateral condylar hypoplasia.(k10.82)

• K07.00 – Maxillary macrogonathism(maxillary hyperplasia)



• K07.01 – Mandibular macrogonathism(mandibular hyperplasia).

• K07.02 – macrogonathism, both jaws.

• K07.03 – maxillary microgonathism(maxillary hypoplasia).

• K07.04 – mandibular microgonathism(mandibular hypoplasia).



• K07.05 – microgonathism, both jaws.

• K07.08 – other specified jaw size anomalies.

• K07.09 – anomalies of jaw size , unspecified.



K07.1 – anomalies of jaw -cranial base relationships

• K07.10 – Asymmetries Excludes –

Hemifacial atrophy (Q64.40) . Hemifacial hypertrophy (Q67.41) . Unilateral condylar hyperplasia(k10.81) Unilateral condylar hypoplasia(k10.82)

• K07.11– mandibular prognathism.• KO7.12– Maxillary prognathism .



• K07.13—Mandibular retrognathism.

• K07.14– Maxillary retrognathism .

• K07.18– Other specified anomalies of jaw- cranial base relationship.

• K07.19– Anomaly of jaw -cranial base relationship, unspecified .



K07.2– Anomalies of dental arch relationship.

• K07.20– Disto-occlusion .

• K07.21—Mesio-occlusion.

• KO7.22– Excessive Overjet (horizontal overbite).

• K07.23—Excessive over bite (vertical overbite). www.indiandentalacademy.com


• K07.24—Open bite.

• K07.25—Cross bite.

• K07.26– Midline deviation.

• K07.27—Posterior lingual occlusion of mandibular teeth.

• K07.28– Other specified anomalies of dental arch relationship.

• K07.29– Anomaly of dental arch relationship, unspecified.



K07.3– Anomalies of tooth position.

• K07.30– Crowding.

• K07.31– Displacement.

• K07.32– Rotation.

• K07.33– Spacing (Diastema).www.indiandentalacademy.com


• K07.34– Transposition.

• K07.35– Embedded or impacted teeth in abnormal position.Excludes– Embedded or impacted teeth in normal position.

• K07.38– Other specified anomalies of tooth position.

• K07.39– Anomaly of tooth position, unspecified.



K07.4 – Malocclusion, unspecified.

K07.5 – Dentofacial functional abnormalities,

excluding bruxism (teeth grinding).

◦ KO7.5O - Abnormal jaw closure.

◦ KO7.51 – Malocclusion due to abnormal swallowing.



◦ KO7.54 – malocclusion due to mouth breathing .

◦ KO7.55 - malocclusion due to tongue ,lip or finger habits.

◦ KO7.58 - other specified dentofacial functional abnormalities.

◦ KO7 .59 - dentofacial functional abnormality , unspecified .


Ackermann – Profitt Classification (1960)

J.L. Ackermann and W.R. Proffit

develop a diagrammatic classification, based on Venn symbolic diagram to assist in describing more fully the severity of malocclusion.

Venn proposed his diagram as a visual demonstration of interaction among part of a complex structure.


• They identifies 5 major characteristic of malocclusion.

A) Group1:-Intra-arch alignment since the alignment and symmetry are common

to all dentition, this represented as the outer or universal group.

The possibilities are ideal, crowded, spacing and mutilated teeth.

Individual tooth irregularities are described.B) Group2:- profile The profile is affected by many malocclusion so it

become second major set. This may be anteriorly or posteriorly divergent

with lips being concave, straight or convex.www.indiandentalacademy.com

• C) Group3:-Transverse skeletal and dental relationships are evaluated .

Buccal and palatal cross bites (unilateral or bilateral) or whether skeletal or dental cross bites.

• D)Group4:- Involves assessment of the sagittal relationship

• It is classified as Angle’s malocclusion. Differentiation is made between skeletal and dental malocclusions.

• E) Group5:-Malocclusion in vertical plane - Anterior or posterior open bite. Anterior deep bite or posterior collapsed bite. www.indiandentalacademy.com



• This approach overcome four major weakness of Angle’s system:

• 1) incorporate an evalution of crowding and asymmetry within dental arches and inclusion of evaluation of incisor protrusion.

• 2) recognizes the relationship between protrusion and crowding.

• 3)include the transverse and vertical as well as antero-posterior plans of space



• 4) incorporate information about skeletal jaw proportion at appropriate point, that is, in the description of relationships in each of the planes of space.

• Patients with combination of problem in more than one plane of space had more severe malocclusion than patient having malocclusion in one plane only.


• These overlapping of groups is seen in the center of venn daigram( group 6 to 9). These are more sever problem, with characteristic from contiguous and enveloping group. Group 9 would be the most severe, with involvement of all groups (alignment, profile, transverse, antero-posterior and vertical problems).

• This classification system is readily accepted for computer processing and would require only a numerical scale in programming for automated data retrival.

• This system help the orthodontist to organize a list of problems for a patient and, in turn give the patient a better understanding of length and difficulty of the proposed treatment.


Classification For Deciduous Dentition

• Since Angle’s and many other system of classification are based on permanent molar relationship , so for purpose of decidious dentition we require a different classification.

• This classification is based on terminal planes.• Terminal planes:- they are the distal surface of

both upper and lower decidious second molar.• Based on there relationship we can classify the

decidious dentition.



• They are classified in three basic groups:-• 1) Distal step:- here the distal surface of lower second deciduous molar

is more distal to distal surface of upper deciduous second molar. This usually allow the permanent molar to erupt in class 2

relationship.• 2) Flush terminal planes:- here distal surface of both upper are lower

deciduous molar are in one line only. This is normal for deciduous dentition.

This usually allow the permanent molar to erupt in End- End relationship but slowly can convert to class 1 molar relationship.



• 3) Mesial step:- here the distal surface of lower primary second molar is more mesial to the distal surface of upper primary second molar.

This usually result in class 3 relationship of permanent dentition.

• Forward movement of permanent molar occur by occupying the “primate space” in early mesial shift, or by occupying “leeway space” in late mesial shift, and due to forward growth of mandible.

• The amount of leeway space is total 1.8mm in maxilla and 3.4mm in mandible.




Canine classification

• According to position of canine we can also classify the malocclusion.

• It is classify in 3 groups:-• Class 1:- distal slope of lower canine occlude with

mesial slop of upper canine.• Class 2:- mesial slop of lower canine occlude with

distal slop of upper canine.• Class 3:- lower canine is too far mesially than the

upper canine.


Canine classification

• For stable occlusion class 1 canine relationship is recommended.

• This classification is also helpful to classify malocclusion in patient who have missing first molars.


Pseudo Class 1 MalocclusionA newly define type of malocclusion

• According to Jan De Baets, and Martin Chiarini, certain types of malocclusion develop spontaneously from a crowded anterior segment through the interaction of specific environmental factors.

• Pseudo- class 1 is clearly distinguishable from Angle’s class 1 by mesial rotation of the upper first molar and crowding of lower incisor.


Pseudo Class 1 Malocclusion


Pseudo Class 1 Malocclusion

• P-C1 is in reality, is a mild dental class 2 malocclusion, but due to some changes it appear class 1.

• Most mature P-C1 malocclusion also have overerupted lower second molars and anterior deep bite.

• So P-C1 have following features:-1.Mesial rotation of upper first molars2.Crowding of lower incisors3.Lack of space for lower canine to erupt.


Development of P-C1

• Step 1:- because of lower incisor crowding and lack of space available for erupting lower canine, these teeth erupt more mesially than normal. The lower premolar than erupt mesially as well. Further the distal migration of lower canine is blocked by it’s class 1 relationship with it’s antagonist.


Development of P-C1


Development of P-C1

• Step 2:- despite the available Leeway space, the second premolar also erupt in Class 1 relationship i.e.- more mesial than normal.


Development of P-C1

• Step 3:- the erupting lower second molars rapidly close the leeway space, without spontaneous decrease in incisor crowding, while the mesially rotated upper first molar rotate further into the space left by deciduous molar.

• Because of delayed eruption of upper second molar and mesial rotation of upper first molar, lower second molar over-erupt, and permanently lock the occlusion.


Development of P-C1


Development of P-C1

• Step 4:- now the occlusal force acting on erupting teeth in a cusp-to-cusp relationship will deliver mesially directed force vector to lower arch, causing mesial drift and settling of lower teeth into stable occlusal contact of P-C1.

• Lower crowding may increase, upper incisor overerupt until they find an occlusal contact with lower incisor.


Development of P-C1

• The lower lip pushes the overerupted incisor back, and thus overjet remain within normal limits.

• As a result, the dentition appear to be a Class 1 occlusion with lower incisor crowding, but in reality, it is a mild dental Class 2.


Classification of Maxillary tooth transpositions

• Given by Sheldon Peck and Leena Peck, known as Peck and Peck classification.

• They collected published cases of transposition involving maxillary teeth worldwide, and with a sample of 201 cases , they find five common types of maxillary tooth transposition:-


Peck And Peck Classification

1. Canine- first premolar(Mx.C.P1) 143 cases2. Canine- lateral incisor(Mx.C.l2) 40 cases3. Canine to first molar site(Mx.C to M1) 8 cases4. Lateral incisor to central incisor(Mx.I2.I1) 6

cases5. Canine to central incisor(Mx.C.I1) 4 cases.





• Definition of transposition:- is the positional interchange of two adjacent teeth, especially their roots, or the developmental or eruption of a tooth in a position occupied normally by another tooth.

• So we can say clearly the most frequently reported type is Mx.C.P1 comprising 71% next is Mx.C.I2 comprising 20% , and other three types are comparatively rare.


Pseudo-transposition

• These are cases that mimic transposition but actually are not.

• One type of this is a form of hyperdontia best called supernumerary distal maxillary premolar. In this a premolar like supernumerary tooth erupt between maxillary first and second molar.


Pseudo-transposition

• One publish case reported transposition of maxillary second premolar with first molar. But actually it was a case supernumerary distal maxillary premolar coupled with an absent or previously extracted second premolar.

• So this system help to clarify scientific understanding of these rare and severe positional variations. So clinical management of these problems improved with this new awareness.


Summery

• Angle’s classification still serves a very useful purpose in describing the antero-posterior relationship of maxillary and mandibular molars which usually reflect the jaw relationship. Modified by our broad knowledge of growth and development and role played by function, the Angle’s classification is an important tool of diagnosis for a dentist. Together with the terms on the previous pages describing individual tooth positions it is possible to scientifically categorize malocclusion and communicate this information accurately to others.


Summery

• The angle’s classification is most useful and effective mechanism when application is restricted to tooth and dental arch relationship.

• The classification of Simon is most precise description of dento-facial abnormalities.

• The Ackermann and Profit classification include all 3 planes –vertical ,sagittal, transverse, and also tell us about the severity of malocclusion.


Summery

• Because no unit of face and cranium are immune to disturbance and the stability of all related structure, the solution for perfect classification may lie in first discovering the fundamental proportional relationship to a constant structure and than relate it with other structure.


BIBLIOGRAPHY

1. AJO-DO, Volume 1992 Sep (277 - 284): VIEW POINT – Katz.2. T.C WHITE, J.H GARDINER,B.C LEIGHTON Orthodontic for dental

students,3rd Ed., MacMillan; page no.(58-80).(253-254)3. T.M GRABER, Orthodontic principal and practice, 3rd Ed., page no.

(226-252).4. WILLIAM R.PROFIT, Contemporary orthodontics, 3rd Ed., (2-10,

185-191).5. SAMIR E.BISHARA, Text book of orthodontics ,page no (84-93).6. Dr. BHALAJHI SUNDARESA IYYER, orthodontic art and science,3rd

Ed.,page no(63-80)7. ICD-DA World health organization Geneva 1995, page no(69-71)


BIBLIOGRAPHY

8. John C Bennet, Richard P mcLanughlin,Orthodontic management of the dentition with the preadjusted appliance,pgge no.(202-203)

9. Graber, Vanaredal, Vig, orthodontic current principles and techniques.

10. McLaughlin, Bennett, Trevisi, Systemized Orthodontic Treatment Mechanics, page no.(285)

11. Alexander Jacobson, Radiographic Cephalometry, page no.(59-60)


BIBLIOGRAPHY

13. Shobha Tandon, text book of pedodontics, page no(112-113)

14. T.M. Graber, Orthodontic principles and practice. page no(183, 250-252)

15. Angle’s orthodontics, jan 1942 vol 12 page no(40-48)

16. JCO 1995 Feb, page no.(73-88)17. AJODO 1995 May, page no. ( 505-517)


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