10 Classification of malocclusion

10

Classification of malocclusion

Table 10.1 The Angle classification of malocclusion.

Classification Notes
Class I The buccal groove of the mandibular first permanent molar should occlude with the mesio-buccal cusp of the maxillary first molar. This is considered to be the normal relationship.
Class II The buccal groove of the mandibular first permanent molar occludes posterior to the mesio-buccal cusp of the maxillary first molar. The degree of discepancy is described as a fraction of the mesio-distal width of a premolar unit.
Division 1 The maxillary central incisors are proclined or normally inclined and the overjet is increased.
Division 2 The maxillary central incisors are retroclined.
Class III The buccal groove of the mandibular first permanent molar occludes anterior to the mesio-buccal cusp of the maxillary first molar.

Table 10.2 The British Standards Institute’s classification of incisor relationship.

Incisor classification Definition
Class I The lower incisor edges occlude on or lie below the cingulum plateau of the upper incisiors.
Class II, division 1 The lower incisor edges occlude behind the cingulum plateau of the upper incisors and the upper incisors are normally inclined or proclined.
Class II, division 2 The lower incisor edges occlude behind the cingulum plateau of the upper incisors and the upper incisors are retroclined.
Class III The lower incisor edges occlude anterior to the cingulum plateau of the upper incisors.

Figure 10.1 Andrews Class I molar relationship (i) results in better buccal intercuspation (note the maxillary premolar occlusion) than an Angle Class I relationship (ii) where the first molar is slightly further anteriorly positioned.

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Jan 1, 2015 | Posted by in Orthodontics | Comments Off on 10 Classification of malocclusion
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