Combined orthodontic-surgical correction of moderate mandibular deficiency.

Carefully planned, coordinated, and executed orthodontic and surgical treatment is a viable alternative to traditional orthodontic treatment of patients with moderate mandibular deficiency. Recognition of their clinical manifestations is essential to distinguish between relative and absolute mandibular deficiency. If after clinical analysis of the Class II patient, esthetic priorities are established to maintain a balanced relationship between the upper lip and nose and not reduce the prominence of the upper lip, mandibular deficiency must be treated by surgical advancement of the mandible, superior repositioning of the maxilla, and consequent autorotational movement of the mandible forward and upward, or a combination of these procedures. The common denominator of successful therapy of absolute mandibular deficiency involves surgery to advance the mandible; relative mandibular deficiency, on the other hand, is treated by maxillary surgery to reposition the maxilla superiorly to allow forward and upward movement of the retropositioned mandible (autorotation). In actual clinical practice many patients manifest a combination of absolute and relative mandibular deficiency and are treated by maxillary and mandibular surgery. Lateral maxillary osteotomies, in concert with rapid maxillary expansion and genioplasty to alter the dimensions of the chin, are essential adjunctive surgical procedures to achieve three-dimensional esthetic and occlusal balance.