Lab 2.1 Classification of Malocclusion Flashcards
When the teeth in the mandibular arch come into contact with those in the maxillary arch in any functional relation, are said to be in __________?
Occlusion
A condition in which there is a deflection from the normal relation of the teeth to other teeth in the same arch and/or to teeth in the opposing arch.
Malocclusion
Classifications of malocclusion can be divided into two types, which are?
a) Quantitative and Qualitative
b) Intra-arch and Inter-arch
This classification is based on the relationship of the mesiobuccal cusp of the maxillary first molar and the buccal groove of the mandibular first molar
Angle’s classification of malocclusion
The mesiobuccal cusp of the upper first permanent molar occludes with the mesiobuccal groove of the lower first molar, but line of occlusion is incorrect because of malposed teeth, rotations or other discrepancies.
Class I malocclusion
The mesiobuccal cusp of the lower first permanent molar occludes distal to the class I position.
Class II malocclusion
- Condition when class II molar relationship is present with proclined upper central incisors.
- There is an increase in overjet.
Class II Div 1
- Condition when class II molar relationship is present with retroclined upper central incisors, upper lateral incisors may be proclined or normally inclined.
- Overjet is usually minimal or may be increased.
Class II Div 2
Condition when the class II molar relationship exists on only one side with normal molar relationship on the other side.
Class II Subdivision
The mesiobuccal cusp of the lower first molar occludes mesial to the class I position.
Class III malocclusion
Due to occlusal prematurity, when the mandible moves from rest position to occlusion, it slides forward.
Pseudo Class III malocclusion
It’s also known as postural class III.
Pseudo Class III malocclusion
Condition in which class III molar relationship is present only on one side with normal relation on the other side.
Class III Sub-division
What are the 2 modifications of Angle’s Classifications?
- Lischer’s modification
- Dewey’s modification
He introduced following names to the Angle’s classification:
* Neutrocclusion
* Distocclusion
* Mesiocclusion
Benno Lischer
Neutrocclusion
Class I
Distocclusion
Class II
Mesiocclusion
Class III
He divided Angle’s class I & III into further types.
Martin Dewey
Identify the Class and Type:
- Crowded maxillary anterior teeth. Canines may be abnormally positioned.
Class I Type 1
Identify the Class and Type:
- Proclined or labioversion of maxillary incisors.
Class I Type 2
Identify the Class and Type:
- Anterior cross bite present.
Class I Type 3
Identify the Class and Type:
- Posterior cross bite present.
Class I Type 4
Identify the Class and Type:
- Mesioversion of molars.
Class I Type 5
Identify the Class and Type:
- Well aligned teeth & dental arches. Edge-edge relationship.
Class III Type 1
Identify the Class and Type:
- Crowded mandibular incisors.
Class III Type 2