From: Three-dimensional functional unit analysis of hemifacial microsomia mandible—a preliminary report
Type | Features |
---|---|
I | All the elements of the mandible exist |
Various degree of hypoplasia of mandible | |
Decrease of cartilage and articular cavity size of the temporomandibular joint | |
Normal hinge movement with mouth opening limitation | |
All masseteric muscles are in low volume but in normal range | |
IIA | Abnormal shape of articular structure |
The head of the condyle is cone shape and anterior than normal position | |
The coronoid process and gonial angle are normal | |
Temporomandibular joint is able to move in hinge axis but translation is impossible | |
All masseteric muscles exist but are in hypotrophy | |
II B | No articulation exists between the condyle and temporal bone |
Various sizes of coronoid process | |
Possible abnormal position of the condyle | |
Various defects of pterygoid and masseter muscles | |
No adhesion of lateral pterygoid muscles to the mandible | |
III | Deficiency of the mandibular ramus |
Significant hypotrophy of masseteric muscles | |
No adhesion of lateral pterygoid and temporalis muscles to the mandible |