46. Class II malocclusion. Clinical manifestation and diagnosis Flashcards
(16 cards)
Class II malocclusion clinical manifestation and diagnosis
What is Class II malocclusion?
Distal position of mandibular teeth compared to maxillary teeth
The buccal groove of the mandibular first molar is distal to the mesiobuccal cusp of the maxillary first molar.
Class II malocclusion clinical manifestation and diagnosis
What are the two divisions of Class II malocclusion?
Class II malocclusion can be divided into:
* Class II division 1
* Class II division 2
Class II malocclusion clinical manifestation and diagnosis
What characterizes Class II division 1?
Proclined maxillary anterior teeth
This results in an increased overjet.
Class II malocclusion clinical manifestation and diagnosis
What characterizes Class II division 2?
Proclination of maxillary lateral incisors and retroclination of maxillary central incisors.
Class II malocclusion clinical manifestation and diagnosis
Aetiological factors of Class II malocclusion
- Convex profile
- Dolicochephalic shape of the head
- Shallow/deep mentolabial fold
- Hyperactive M. mentalis
- Hypoactive upper lip
- Lip trap
Class II malocclusion clinical manifestation and diagnosis
Extraoral features of Class II division 1
- Convex profile
- Dolicochephalic shape of the head
- Shallow/deep mentolabial fold
- Hyperactive M. mentalis
- Hypoactive upper lip
- Lip trap
Class II malocclusion clinical manifestation and diagnosis
Extraoral features of Class II division 2
- Straight or convex profile
- Mesocephalic or dolicocephalic shape of the head
- Normal mentolabial fold
- No hyperactive M. mentalis
- (No) hypoactive upper lip
Class II malocclusion clinical manifestation and diagnosis
Intraoral features of Class II division 1
- Class II molar relation
- Proclined maxillary anterior teeth
- Flaring and spaced dentition
- V-shaped palatal arch
- Deep palate
- Excessive curve of Spee
- Increased overbite
- Short hypotonic upper lip
- Constricted, narrow upper arch
Class II malocclusion clinical manifestation and diagnosis
What could cause a constricted, narrow upper arch in Class II division 1?
- Abnormal activity of the M. buccinators=>
- Constricted, narrow upper arch.
Class II malocclusion clinical manifestation and diagnosis
Intraoral features of Class II division 2
- Excessive lingual inclination of the maxillary central incisors
- Overlapped by maxillary lateral incisors
- U-shaped palatal arch
- Deep overbite and minimal overjet
- Incisal edges of lower incisors may contact soft tissues of the palate with extreme overbite
- Mandibular labial gingiva may get traumatised by lingually inclined maxillary incisors in absence of overjet
Class II malocclusion clinical manifestation and diagnosis
What does a convex facial profile indicate?
Class II jaw relationship
A convex profile occurs when the maxilla is projected too forward or the mandible is too backward.
Class II malocclusion clinical manifestation and diagnosis
What does a concave facial profile indicate?
Class III relationship
A concave profile occurs when the maxilla is positioned backward or the mandible protrudes forward.
Class II malocclusion clinical manifestation and diagnosis
What is the Eschler-Bittner test used for?
To analyze functional changes in Class II malocclusion
The test assesses the relationship of the mandible to achieve a Class I molar relationship.
Class II malocclusion clinical manifestation and diagnosis
If facial profile improves during Eschler-Bittner test, what does it indicate?
- The maxilla is in correct position and normal development
It suggests that the mandible is retruded.
Class II malocclusion clinical manifestation and diagnosis
If the facial profile worsens during the Eschler-Bittner test, what does it indicate?
The maxilla is protruded and has excessive growth
This suggests that the maxilla’s position is not ideal.
Class II malocclusion clinical manifestation and diagnosis
If profile initially improves during the Eschler-Bittner test but then worsens
Both maxilla and mandible have sagittal discrepancies
This indicates complex malocclusion issues.
