GenetIic and Environmental Influence
Genetic Influence certainly plays a role in dentofacial deformities. Patterns of inheritance, such as a familial tendency toward a prognathic or deficient mandible, are often seen in a patient with a dentofacial deformity.
However, the multifactorial nature of facial development precludes the prediction of an inherited pattern of a particular facial abnormality.
bony apposition include superior surface ‘of alveolar process and posterior and superior surfaces of
mandibular ramus, B, Forward and downward growth of nasal complex and maxilla in “expanding V:’
Resorption of bone at superior surface of palate occurs simultaneously with apposition at inferior surfaces
of palate and alveolar processes, In addition, growth in posterior area of maxilla results in downward
and forward expansion of maxilla. (From Enlow DH: Handbook of tilcial growth, Philadelphia,
1975, WB Saunders
growth center or limitation in function and the resulting soft tissue influence on developing
bone are responsible for resulting mandibular deficiency. A, Abnormal appearance of facial
skeleton with severe, mandibular deficiency. B, Severe class II malocclusion resulting from skeletal
abnormality.
an inuucdiatc result of trJUIIlJ. further effects on the development of fJcial bones may occur, which is most evident when ankvlosis of the mandibular condyle occurs as a result of trauma. In the CJ~e of temporomandibular
joint (I’~l.I) ankylosis ill a grO\\’illg child, alteration of growth may result from dcstructioi of the area of growth ill the T;”!J cartilage. as well as from limitntion in function. which decreases till’ influence of soft tissues on
developing hone (Fig. 25-2),
