DEPARTMENT OF ORTHODONTICS

COLLEGE OF DENTAL SCIENCES, DAVANGERE

PRESENTED BY

HOW ZHUO YUANKIKLAWALA DIVYESH VIJAYKUMAR

STAFF’S SIGNATURE

Classification of Malocclusion

Occlusion Occlusion can be defined very simplyOcclusion can be defined very simply : it means the contacts between teeth. : it means the contacts between teeth. Angle defined occlusion as the normal relation of the occlusal inclined planes of Angle defined occlusion as the normal relation of the occlusal inclined planes of

the teeth when the jaws are closed.the teeth when the jaws are closed. It is a complex phenomenon involving teeth, periodontal ligament, jaws, TMJ, It is a complex phenomenon involving teeth, periodontal ligament, jaws, TMJ,

muscles & nervous system.muscles & nervous system.

Malocclusion A A malocclusionmalocclusion refers to the misalignment of teeth and/or incorrect relation refers to the misalignment of teeth and/or incorrect relation

between the teeth of the two dental arches (maxilla and mandible).between the teeth of the two dental arches (maxilla and mandible).

Classification of MalocclusionClassification involves the grouping of numerous malocclusion together into simpler or Classification involves the grouping of numerous malocclusion together into simpler or smaller groups.smaller groups.

Advantages of Classification It helps in diagnosis & planning treatment for the patient.It helps in diagnosis & planning treatment for the patient. Helps in visualizing & understanding the problems associated with that Helps in visualizing & understanding the problems associated with that

malocclusionmalocclusion Helps in communicating the problemHelps in communicating the problem Comparison of various malocclusion is made easy by classification.Comparison of various malocclusion is made easy by classification.

Intra – arch Malocclusion Intra – arch Malocclusion that include variations in individual tooth positions & Intra – arch Malocclusion that include variations in individual tooth positions &

malocclusion affecting a group of teeth within an arch.malocclusion affecting a group of teeth within an arch. The individual teeth malposition can be abnormal inclination (or tipping) of the The individual teeth malposition can be abnormal inclination (or tipping) of the

teeth or abnormal displacements.teeth or abnormal displacements.

Some commonly seen individual teeth malpositions are:

o Distal inclination

o Mesial inclination

o Lingual inclination:

o Buccal inclination:

o Mesial/ Distal displacement :

o Lingual/Buccal displacement :

o Infra/Supra–occlusion :

o Rotations :

o Transposition

Inter – arch Malocclusion Inter – arch Malocclusion that comprise of malrelation of dental arches to one Inter – arch Malocclusion that comprise of malrelation of dental arches to one

another upon skeletal bony bases which may themselves be normally related. another upon skeletal bony bases which may themselves be normally related. And can occur in theAnd can occur in the

oo Sagittal plane Sagittal plane oo Vertical plane Vertical plane oo Transverse plane.Transverse plane.

oo Sagittal planeSagittal plane : Upper & Lower arches are abnormally related to each other in : Upper & Lower arches are abnormally related to each other in Sagittal plane.Sagittal plane.

oo Pre – normal occlusionPre – normal occlusion : condition where the lower arch is more forwardly placed : condition where the lower arch is more forwardly placed when the pt bites in centric occlusion.when the pt bites in centric occlusion.

oo Post – normal occlusionPost – normal occlusion : condition where the lower arch is more distally placed : condition where the lower arch is more distally placed when the pt bites in centric occlusion.when the pt bites in centric occlusion.

oo Vertical planeVertical plane : Malocclusion which include deep bite & open bite where an : Malocclusion which include deep bite & open bite where an abnormal vertical relation exists btw the teeth of the upper & lower teeth. abnormal vertical relation exists btw the teeth of the upper & lower teeth.

oo Deep bite/increased over biteDeep bite/increased over bite :There is excessive vertical overlap btw upper and :There is excessive vertical overlap btw upper and lower anteriors.lower anteriors.

oo Open biteOpen bite : There is no vertical overlap btw upper & lower teeth. Thus a space : There is no vertical overlap btw upper & lower teeth. Thus a space may exist btw the upper & lower teeth.may exist btw the upper & lower teeth.

Skeletal Malocclusion Malocclusion caused due to abnormalities in the maxilla & mandible. Malocclusion caused due to abnormalities in the maxilla & mandible. Defects can be size, position or relationship btw the jaws.Defects can be size, position or relationship btw the jaws. And can occur in the three planes….And can occur in the three planes….

oo Sagittal plane Sagittal plane oo Vertical planeVertical planeoo Transverse plane.Transverse plane.

Sagittal plane : RetrognathismRetrognathism refers to backward movement of the jaw. refers to backward movement of the jaw.

PrognathismPrognathism refers to the forward movement of the jaw. refers to the forward movement of the jaw.

Transverse plane: Usually a result of narrowing or widening of the jaws. Transverse malocclusion usually Usually a result of narrowing or widening of the jaws. Transverse malocclusion usually referred as Crossbite.referred as Crossbite.

Vertical planeIn vertical plane abnormal variations in the vertical measurements of the jaws can affectIn vertical plane abnormal variations in the vertical measurements of the jaws can affect the lower facial height.the lower facial height.

Angle’s System of Malocclusion Edward AngleEdward Angle “father of modern orthodontics” , was the first to classify “father of modern orthodontics” , was the first to classify

malocclusion in the year malocclusion in the year 18991899. . It was based on the mesio – distal relation of the teeth, dental arches & the jaws.It was based on the mesio – distal relation of the teeth, dental arches & the jaws. The The maxillary 1maxillary 1stst molar is the key of occlusion. molar is the key of occlusion. He classified malocclusion into tree main classes I , II and IIIHe classified malocclusion into tree main classes I , II and III..

Angle’s class I The mesio-buccal cusp of the upper first molar should rest on the buccal groove The mesio-buccal cusp of the upper first molar should rest on the buccal groove

of the mandibular first molar. of the mandibular first molar. But the other teeth have problems like spacing, crowding, over or under eruption, But the other teeth have problems like spacing, crowding, over or under eruption,

rotations, etc. rotations, etc.

Angle’s class II The disto - buccal cusp of the upper first molar should rest on the buccal groove The disto - buccal cusp of the upper first molar should rest on the buccal groove

of the mandibular first molar. of the mandibular first molar. Mesio - buccal cusp rests in between the first mandibular molars and second Mesio - buccal cusp rests in between the first mandibular molars and second

premolars.premolars.

Angle’s class II, division 1

The molar relationships are like that of Class II and the anterior teeth are The molar relationships are like that of Class II and the anterior teeth are protruded. protruded.

Characteristic feature is the presence of abnormal muscle activity.Characteristic feature is the presence of abnormal muscle activity. Narrowing of the upper arch at the premolar & canine region Narrowing of the upper arch at the premolar & canine region V–shaped upper V–shaped upper

arch.arch.

Angle’s class II, division 2 The molar relationships are like that of Class II, but the central are lingually

inclined & the lateral teeth are seen overlapping the centrals. Variations of this form are lingually inclined central & lateral incisors with the

canines labially tipped. Lingually inclined upper central gives the arch a squarish appearance.

Angle’s class II, Subdivision

When a Class II molar relation exists on one side and a Class I relation on the When a Class II molar relation exists on one side and a Class I relation on the other, it is referred to as Class II, subdivision.other, it is referred to as Class II, subdivision.

Based on whether it is a division 1 or division 2 it can be called Based on whether it is a division 1 or division 2 it can be called oo Class II, division 1, subdivision, orClass II, division 1, subdivision, oroo Class II division 2, subdivision.Class II division 2, subdivision.

This malocclusion exhibits a Class III molar relation with the mesio – buccal This malocclusion exhibits a Class III molar relation with the mesio – buccal cusp of the maxillary 1cusp of the maxillary 1stst permanent molar occluding in the interdental space btw permanent molar occluding in the interdental space btw the mandibular 1the mandibular 1stst & 2 & 2ndnd molars. molars.

Angle’s Class III This malocclusion exhibits a Class III molar relation with the mesio – buccal

cusp of the maxillary 1st permanent molar occluding in the interdental space btw the mandibular 1st & 2nd molars.

And this can be classified into: And this can be classified into: o True Class III andTrue Class III and

o Pseudo Class IIIPseudo Class III

True Class III

This malocclusion of Genetic origin that can occur due to the following causes:This malocclusion of Genetic origin that can occur due to the following causes:oo Excessively large mandibleExcessively large mandibleoo Forwardly placed mandibleForwardly placed mandibleoo Smaller than normal maxillaSmaller than normal maxillaoo Retropositioned maxillaRetropositioned maxillaoo Combination of the above causes.Combination of the above causes.

The lower incisors tend to be lingually inclined.The lower incisors tend to be lingually inclined. Patient can present with normal overjet, an edge to edge incisor relation or Patient can present with normal overjet, an edge to edge incisor relation or

anterior crossbite. anterior crossbite. The space available for the tongue in usually more The space available for the tongue in usually more Narrow upper arch Narrow upper arch

Pseudo Class III (Postural Class III/ Habitual)

This type of malocclusion is produced by forward movement of the mandible This type of malocclusion is produced by forward movement of the mandible during jaw closure.during jaw closure.

Causes:Causes:oo Presence of occlusal prematurities may deflect the mandible forward.Presence of occlusal prematurities may deflect the mandible forward.oo In case of premature loss of deciduous posteriors, the child tends to move In case of premature loss of deciduous posteriors, the child tends to move

the mandible forward for proper contact in the anterior. the mandible forward for proper contact in the anterior. oo A child with enlarged adenoids tends to move the mandible forward in an A child with enlarged adenoids tends to move the mandible forward in an

attempt to prevent the tongue from contacting the adenoids.attempt to prevent the tongue from contacting the adenoids.

Drawbacks of Angle’s Classification Malocclusion considered only in antero-posterior plane. He did not consider Malocclusion considered only in antero-posterior plane. He did not consider

malocclusion in the transverse and vertical planes.malocclusion in the transverse and vertical planes. Angle considered the molars are fixed points in the skull. But this is not found to Angle considered the molars are fixed points in the skull. But this is not found to

be so.be so. The classification cannot be applied if the 1The classification cannot be applied if the 1stst molar is extracted or missing. molar is extracted or missing. The classification cannot be applied to deciduous dentition .The classification cannot be applied to deciduous dentition . does not differentiate btw skeletal and dental malocclusion.does not differentiate btw skeletal and dental malocclusion. does not highlight the etio of malocclusion.does not highlight the etio of malocclusion. Individual tooth malocclusion has not been considered by Angle.Individual tooth malocclusion has not been considered by Angle.

Dewey’s modification of Angle’s Malocclusion Dewey divided Angle’s Class I into five typesDewey divided Angle’s Class I into five types And Class III into three types. And Class III into three types.

Class I modification of DeweyType 1Type 1:Class I malocclusion with crowded ant. Teeth.:Class I malocclusion with crowded ant. Teeth.Type 2Type 2:Class I malocclusion with protrusive maxillary incisors.:Class I malocclusion with protrusive maxillary incisors.Type 3Type 3:Class I malocclusion with ant. Crossbite.:Class I malocclusion with ant. Crossbite.Type 4Type 4:Class I malocclusion with post. Crossbite.:Class I malocclusion with post. Crossbite.Type 5Type 5:the permanent molar is drifted mesially due to early extraction of 2:the permanent molar is drifted mesially due to early extraction of 2ndnd deciduous deciduous

molar or 2molar or 2ndnd premolar. premolar.

Class III modification of DeweyType 1Type 1: Pt. shows edge to edge bite, suggestive of forwardly moved mandibular dental : Pt. shows edge to edge bite, suggestive of forwardly moved mandibular dental

arch.arch.Type 2Type 2: Mandibular incisors are crowded & are in lingual relation to the maxillary : Mandibular incisors are crowded & are in lingual relation to the maxillary

incisors.incisors.Type 3Type 3:Maxillary incisors are crowded & are in crossbite in relation to the mandibular :Maxillary incisors are crowded & are in crossbite in relation to the mandibular

ant.ant.

Lischer’s Modifications of Angle’s ClassificationLischer substituted the term Class I, II and III given by Angle with the terms of neutrocclusion, distocclusion and mesiocclusion. In addition to these, he added a few more terms, which designated certain other malocclusions.

Neutrocclusion: Synonymous with Angle’s Class I malocclusion Distocclusion: Synonymous with Angle’s Class II malocclusion Mesiocclusion: Synonymous with Angle’s Class III malocclusion Buccocclusion: Buccal placement of a totth or a group of teeth Linguocclusion: Lingual placement of a tooth or a group of teeth Supraocclusion: When a tooth or group of teeth have erupted beyond normal

level Infraocclusion: When a tooth or group of teeth have not erupted to normal level Mesioversion: Mesial to the normal position Distoversion: Distal to the normal position Transversion: Transposition of two teeth Axiversion: Abnormal axial inclination of a tooth Torsiversion: Rotation of a tooth around its long axis

Simon’s Classification Malocclusion can occur in antero-posterior, tranverse and in the vertical planes.

Simon had put forward a craniometric classification of malocclusion that related the dental arches in all these 3 planes.

Simon’s system of classification made use of 3 anthropometric planes i.e., the Frankfort horizontal plane, the orbital plane and the mid-sagittal plane.

The classification of malocclusion was based on abnormal deviations of the dental arches from their normal position in relation to these 3 planes.

Frankfort Horizontal Plane This is a plane that connects the upper margin of the external auditory meatus to

the infraorbital margin. This plane is used to classify malocclusion ins a vertical plane. Two terms are

used to describe any abnormal relation of the teeth to this plane. When the dental arch / part of it is closer than normal to the Frankfort plane, it is

called attraction. When the dental arch or part of it is farther away from the Frankfort horizontal

plane, it is called abstraction.

Orbital Plane This plane is perpendicular to the Frankfort horizontal plane, dropped down from

the bony orbital margin directly under the pupil of the eye. According to Simon, this plane should pass through the distal 3rd of the upper

canine. This is called Simon’s Law of Canine. This plane is used to describe malocclusion in a sagittal or antero-posterior

direction. When the dental arch / part of it is farther from the orbital plane, it is called

protraction. When the arch or part of it is closer or more posteriorly placed in relation to this

plane, it is called retraction.

Mid-sagittal Plane The midsagittal plane is used to describe malocclusion in the transverse direction. When a part of whole of the arch is away from the mid-sagittal plane it is called

distraction. When the arch or part of it is closer to the mid-sagittal plane it is called

contraction.

Bennet’s ClassificationNorman Bennet classified malocclusion based on its etiology

Class I – Abnormal position of one or more teeth due to local causes

Class II – Abnormal formation of a part of or whole of either arch due to developmental defects of bone

Class III – Abnormal relationship between upper and lower arches, and between either arch an dfacial contour and correlated abnormal formation of either arch.

Ackerman-Profitt System of ClassificationAckerman and Profitt in 1960 proposed a diagrammatic classification of malocclusion to overcome the limitations of the Angel’s classification. Salient features of the classification include:

Transverse as well as vertical discrepancies can be considered in addition to anteroposterior malrelations

Crowding and arch asymmetry can be evaluated Incisor protrusion is taken into account.

This system of classification is based on the Venn symbolic diagram that identifies fibe major characteristics to be considered and described in the classification.

Step 1 (Alignment)The first step involves assessment of the alignment and asymmetry of the dental arch. It is classified as ideal / crowded / spaced.

Step 2 (Profile)It involves the consideration of the profile. The profile is described as convex / straight / concave. The facial divergence is also considered i.e., anterior or posterior divergence.

Step 3 (Type)The transverse skeletal and dental relationship is evaluated. Buccal and palatal crossbites if any are noted. The crossbite is further subclassified as unilateral or bilateral. In addition, differentiation is made between skeletal and dental crossbite.

Step 4 (Class)This involves the assessment of the sagittal relationship. It is classified as Angle’s Class I / Class II / Class III malocclusion. Differentiation is made between skeletal an dental malocclusion.

Step 5 (Bite depth)Malocclusions in the vertical plane are noted. They are described as anterior or posterior open bit, anterior deep bite or posterior collapsed bite. A mention is made whether the malocclusion is skeletal or dental.