Deliberate surgical control of mandibular growth. I. A biomechanical theory.

Basic descriptive principles governing mandibular growth have been discussed. These principles were applied to evaluate growth changes after mandibular advancement surgery in 15 patients with idiopathic mandibular retrognathism. Subsequent mandibular growth proceeded in a downward and backward direction in all cases. This pattern of growth is not seen normally in patients with a low or median mandibular plane angle type of facial morphology. Since the functional biomechanical vector of force in the condylar-ascending mandibular ramus complex was changed surgically, it is postulated that this affected the subsequent pattern of mandibular relocation. A hypothesis for the specific manner in which surgical alteration of the basic biomechanics of mandibular function can deliberately affect subsequent mandibular growth direction is presented. Case reports are used to illustrate these effects. Further animal and clinical studies are currently underway to better elucidate the hypothesis put forth herein.