The mandibular deficiency syndrome is a constellation of abnormalities, including a spectrum of skeletal, neuromuscular, occlusal, and esthetic conditions. The extremes of this syndrome exhibit different skeletal and esthetic morphology and growth patterns. Different orthodontic and surgical approaches must be considered for optimal functional and esthetic correction in the three different facial types. Differentiation between cases with low, medium, and high mandibular plane angles and knowledge of the growth tendencies will permit different surgical and orthodontic considerations for each of the three basic morphologic types. Predictable functional and esthetic results can then be expected.