Arajhkbi.ppt

Types of Types of malocclusionmalocclusion

Made by Cristian Made by Cristian Corceac & Andrian Corceac & Andrian

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Various systems of Various systems of classification:classification:

Angle system and it’s modificationsAngle system and it’s modifications Simons systemSimons system Etiological classificationEtiological classification Baume classification of primary Baume classification of primary

teethteeth Ackermann classificationAckermann classification Ballards classificationBallards classification WHO classificationWHO classification

Angle’s classification of Angle’s classification of malocclusion:malocclusion:

Was considered the father of modern Was considered the father of modern orthodonticsorthodontics

Based on the mesio-distal relation of Based on the mesio-distal relation of the teeth, dental arches and jawsthe teeth, dental arches and jaws

Maxillary 1 permanent molar- key to Maxillary 1 permanent molar- key to occlusion.occlusion.

Class I malocclusion:Class I malocclusion:

Class I molar relationship:Class I molar relationship:

-mesiobuccal cusp of the maxillary -mesiobuccal cusp of the maxillary first molar occludes in the buccal first molar occludes in the buccal groove of the mandibular 1 groove of the mandibular 1 permanent molar.permanent molar.

Angle’s class II Angle’s class II malocclusion:malocclusion:

Class II molar relationship- disto-Class II molar relationship- disto-buccal cusp of the upper first buccal cusp of the upper first permanent molar occludes in the permanent molar occludes in the buccal groove of the lower 1 molar.buccal groove of the lower 1 molar.

It is sub classified into:It is sub classified into:

-class II division 1-class II division 1

-class II division 2-class II division 2

Class II div 1:Class II div 1:

Proclined upper incisorsProclined upper incisors Presence of abnormal muscle Presence of abnormal muscle

activity- characteristic featureactivity- characteristic feature Altered tongue position- accentuatesAltered tongue position- accentuates Narrowing of upper archNarrowing of upper arch

Class II div 2:Class II div 2:

Lingually inclined upper central Lingually inclined upper central incisorsincisors

Labially tipped lateral incisors Labially tipped lateral incisors overlapping the centralsoverlapping the centrals

Normal perioral muscle activityNormal perioral muscle activity Abnormal backward path of closureAbnormal backward path of closure

This study was designed to analyze This study was designed to analyze the effect of class II malocclusion the effect of class II malocclusion as a factor in the development of as a factor in the development of

obstructive sleep apnea syndrome.obstructive sleep apnea syndrome.

Class III malocclusion:Class III malocclusion:

Class III molar relationship:Class III molar relationship:

-Mesiobuccal cusp of maxillary first -Mesiobuccal cusp of maxillary first molar occludes in the interdental molar occludes in the interdental space between the distal cusp of space between the distal cusp of mandibular first molar and second mandibular first molar and second molar.molar.

-Classified into:-Classified into:

a.a. True class IIITrue class III

b.b. Pseudoclass IIIPseudoclass III

Features of class III Features of class III malocclusionmalocclusion

A concave facial profile;A concave facial profile; A retrusive nasomaxillar area;A retrusive nasomaxillar area; Prominent lower third of the face;Prominent lower third of the face; Narrow upper arch;Narrow upper arch; Reduced or reversed overjet.Reduced or reversed overjet.

Cause Aetiology

Skeletal pattrn(Class III)- Long mandible;- Forward placement of glenoid fossa positioning the mandible more anteriorly;-Short and/or retrognathic maxilla;-Short anterior cranial base

Anterior mandibular displacement on closure

- Premature contact

Retained primary upper incisors These may deflect the eruption path of their successors palatally into crossbite

Restrained of maxillary growth- Found in repaired cleft lip & palate & attributed to the effect of postsurgical scar tissue

True class IIITrue class III

Lower incisors lingually inclinedLower incisors lingually inclined Lower tongue posture- narrow upper Lower tongue posture- narrow upper

arch.arch.

Pseudo class IIIPseudo class III Caused by forward movement of the Caused by forward movement of the

mandible- postural or habitual class mandible- postural or habitual class IIIIII

Causes of pseudo class III: occlusal Causes of pseudo class III: occlusal prematurity loss of deciduous molars prematurity loss of deciduous molars large adenoids.large adenoids.

The benefits attributed to the treatment of pseudo-Class III malocclusion The benefits attributed to the treatment of pseudo-Class III malocclusion in the mixed dentition are:in the mixed dentition are:

preventing unfavourable growth of skeletal components (in fact, early preventing unfavourable growth of skeletal components (in fact, early treatment of anterior crossbite can help to minimize adaptations that are treatment of anterior crossbite can help to minimize adaptations that are often seen in severe late adolescent malocclusion);2often seen in severe late adolescent malocclusion);2

preventing functional posterior crossbite and habits, such as bruxism preventing functional posterior crossbite and habits, such as bruxism that can develop from anterior or posterior interferences;11that can develop from anterior or posterior interferences;11

gaining space for eruption of canines (lack of space could be caused gaining space for eruption of canines (lack of space could be caused by retro-inclination of upper incisors frequently found in pseudo or Class by retro-inclination of upper incisors frequently found in pseudo or Class III malocclusion);3III malocclusion);3

avoiding the risk of periodontal problems to mandibular incisors avoiding the risk of periodontal problems to mandibular incisors caused by the traumatic occlusion due to the crossbite.caused by the traumatic occlusion due to the crossbite.

Short comings of Angle’s Short comings of Angle’s classification:classification:

Does not consider malocclusion in vertical and Does not consider malocclusion in vertical and transverse plane.transverse plane.

Cannot be applied if first permanent molars are Cannot be applied if first permanent molars are missing.missing.

Cannot be used in deciduous dentition.Cannot be used in deciduous dentition. Does not indicate the etiology of malocclusion.Does not indicate the etiology of malocclusion. No skeletal relationship is considered.No skeletal relationship is considered. Malfunctions of muscles and bones are Malfunctions of muscles and bones are

overlooked.overlooked. Does not indicate the complexity of the problem.Does not indicate the complexity of the problem. First permanent molar not a fixed pointFirst permanent molar not a fixed point

Treatment:Treatment:

FrankelFrankel KiraxKirax McNamaraMcNamara Twin blocksTwin blocks Herbst Herbst Distal Jet Distal Jet BionatorBionator

FrankelFrankel

Hyrax:Hyrax:

TwinBlockTwinBlock::

HerbstHerbst::

Distal Jet:Distal Jet:

BionatorBionator::

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