Malocclusion

MALOCCLUSION

Proposed by Edward H. Angle in 1890, the Angle Classifications are based on the relationship of the buccal groove of the mandibular first permanent molar and the mesiobuccal cusp of the maxillary first permanent molar. This classification is considered to be one of the most commonly used as its easy to use.

According to Edward H. Angle, the normal occlusion exists when the mesiobuccal cusp of the upper first molar occludes with the buccal groove of the lower first molar.

Any diversion from this alignment falls under the three classifications of malocclusion, and these categories are as follows:

Class I malocclusion: A normal molar relationship is present, but there is crowding, misalignment of the teeth, rotations, cross-bites, and other alignment irregularities.

Class II malocclusion: The mesiobuccal cusp of the maxillary first molar occludes anterior to the buccal groove of the mandibular first molar. Class II is categorized into two further parts:

  • Class II, Division 1: The anterior maxillary teeth are tilted forward or proclined, presenting a large overjet.
  • Class II, Division 2: The anterior maxillary teeth are retroclined, creating a deep overbite.

The classical features of Angle's Class II div 2 group of malocclusion are as follows:

  1. Orthognathic maxilla and a mild retrognathic mandible.
  2. Marked horizontal growth pattern with forwardly rotated mandibular base.
  3. Skeletal deep bite.
  4. Retroclined upper incisors with near-normal lower anterior teeth.
Angle's Class II Malocclusion

Class III malocclusion: The mesiobuccal cusp of the upper first molar falls posterior to the buccal groove of the lower first molar.





Ref: 
  1. https://yorkmillsortho.ca/angles-classifications-of-malocclusion/
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