Le Fort III advancement with gradual distraction using internal devices.

The purpose of this report is to demonstrate a practical clinical method for advancement of the midface using a combination of Le Fort III osteotomy and gradual distraction. Use of internal, submergible distraction devices and modification of the Ilizarov distraction protocol are presented. Case reports show the effect of departing from the Ilizarov protocol by eliminating the latency period, initiating distraction intraoperatively, and rapidly distracting the segments postoperatively. A method of controlling fragment distraction rate by regulating pressures within the osteotomy site is described. The design and surgical application of internal distraction devices are shown. Nine patients with midface hypoplasia related to craniofacial anomalies underwent Le Fort III osteotomies assisted by gradual distraction. Ages ranged from 4 to 13 years. Custom internal distraction devices were employed to meet the unique requirements of each patient. Activation of the distraction device was accomplished by a percutaneous pin that remained in place for 3 to 5 days. The rate of transport was determined by regulating the forces within the distraction site. The internal devices remained in place for 6 months for fixation of the transported fragment. Midface advancement, measured as the anterior displacement of the infraorbital rim, ranged from 16 to 30 mm, with a mean of 20 mm. The typical force required to produce incremental movement of the Le Fort III osteotomy was found to be between 7 and 9 kg as transport exceeded 10 mm. Four patients with obstructive sleep apnea prior to surgery had resolution of the disorder. All the midface advancements remained clinically stable. Establishment of osseous continuity was verified by surgical examination in the four patients in whom the distraction devices have been removed. Combining intraoperative advancement of the Le Fort III osteotomy with gradual distraction consistently resulted in larger movements than could be achieved with conventional osteotomies and rigid fixation alone. The pediatric craniofacial skeleton responds differently to distraction than does the orthopedic skeleton. Eliminating the latency period, establishing a substantial bone gap intraoperatively, and rapidly distracting the fragment postoperatively did not adversely affect the osseous union in these patients. The internal, submergible feature of the device design offers advantages in patient acceptance, fixation stability, and wound management. This method of Le Fort III midface advancement has been shown to be clinically practical and effective.