9.7\ LeFort III Osteotomy

9.7.1\ Discussion

The LeFort III procedure is indicated for correcting midface hypoplasia involving the nasal and zygomatic complex and orbits, such as with Crouzon, Apert, and Pfeiffer syndromes. Indeed, LeFort III advancement can augment the orbital volume and surface area with correction of the ocular bulb proptosis in addition to correcting malocclusion. While variations exist, the LeFort III procedure essentially involves performing osteotomies through the frontozygomatic suture, floor of the orbit, and the nasion and separating the vomer and ethmoid from the cranial base in the midline and the pterygomaxillary junction. Mobilization of the midface is an extensive procedure, with a high risk of blood loss. In order to minimize morbidity, gradual advancement via distraction osteogenesis can be performed (Fig. 9.15). Once again, high-resolution craniofacial CT with 3D reconstructions can be used to assess the degree of anatomic changes after surgical treatment and evaluate certain complications. In addition to some of the complications that may be encountered with LeFort I osteotomy and distraction,

complications­ particular to LeFort III procedures include cerebrospinal fluid rhinorrhea, meningitis, and ocular and cerebral injury.

Fig. 9.15  LeFort III osteotomy with distraction osteogenesis. Postoperative 3D CT image shows bilateral transorbital and zygomatic osteotomies with distraction devices in position

9.8\ Fixation of Mandible

Fractures

9.8.1\ Discussion

A variety of techniques can be used to treat mandible fractures, including maxillomandibular fixation (Figs. 9.16 and 9.17), open reduction and internal fixation using plates and screws with or without maxillomandibular fixation (Fig. 9.18), and external fixation device application (Fig. 9.19). Maxillomandibular fixation consists of applying circumdental wires, securing Erich arch

a

b

bars or their derivatives to the mandible and maxilla, confirming appropriate reduction, and applying fixation wires.

Complications that may result from mandible fracture fixation include malunion/nonunion, hardware failure, and osteomyelitis. Imaging plays a role in evaluating these complications and planning a secondary operation. The panorex and 3D CT images are particularly useful for providing a complete view of the hardware and fractures. Most of the hardware fixation components are metallic, although sometimes stiff rubber bands are used to secure the maxilla to the mandible