Le Fort III distraction: controlling position and path of the osteotomized midface segment on a rigid platform.

ABSTRACT

BACKGROUND: Precise control of the position of the midface through distraction with the rigid external distraction (RED) device has been a challenge. The present RED device with wire attachments to the intraoral dental splint and to the skeletal bone plates allows for flexibility in the vertical plane of the osteotomized Le Fort III segment. This tends to rotate the midface in a counterclockwise direction with inferior movement of the posterior nasal spine. OBJECTIVES: To report the development of a rigid distraction splint attachment to the RED device that permits precise control of the position of the midface during the latency period and through the activation and consolidation phases. METHODS: This paper describes the appliance design and the clinical application of a new device in controlling the position of the midface during distraction. Placement of the device and application of the desired force vectors are discussed. Patients treated by this modified device are illustrated to document the planned midface position after Le Fort III midface advancement. RESULTS: Examination of predistraction and postdistraction cephalograms of 2 patients treated with the new device showed advancement with minimum inferior displacement of the midface during all phases of the distraction process. CONCLUSIONS: The new device prevents undesired inferior movement of the posterior midface immediately after osteotomy and helps to stabilize the midface during the latency period. The device enables directional control of the distraction vectors, resulting in more predictable midface position at the end of treatment.