The most obvious clinical feature of mandibular deficiency is the retruded position of the chin as viewed. from the profile aspect. Other facial features often associated with mandibular deficiency may include an excess labiomental fold with a procumbent appearance of the lower lip, abnormal posture of the upper lip, and poor throat form. Intraorally, mandibular deficiency is associated with class· II molar and cuspid relationships and an increased overjet in the incisor area.
portion of mandible is osteotomized, moved forward, and stabilized (Fig. 25-19, A, C, and D). In addition to anterior or posterior repositioning of the chin, vertical reduction or augmentation and correction of asymmetries
can also be accomplished with inferior border osteotomies. Alloplastic materials can occasionally be used to augment chin projection; the material is onlayed in areas of bone deficiencies (Fig. 25-19, B).