Zygomatic Fractures

Without treatment in a timely Zygomatic Fractures manner, many individuals will develop future problems, the severity and consequences of which can be much greater than if the injury had been immediately repaired. However, modern craniofacial surgical techniques can now offer hope for patients with pre-existing post-traumatic facial deformities despite considerable delays between injury, diagnosis, Front and lateral three dimensional CT Scans demonstrate and treatment. These innovative displaced fractures of all zygomatic buttresses. techniques establish a higher standard of care for the management of facial injuries. The following sections describe the different areas and types of facial fractures:

ZYGOMATIC FRACTURES The zygomatic bone occupies a prominent and important posi- tion in the facial skeleton. It plays a key role in determining facial width as well as acting as a major Patient with a left displaced An open reduction with rigid buttress of the midface. Its anteri- zygomatic fracture. miniplate fixation was performed or projection forms the malar emi- with postoperative result shown. nence and is often referred to as the malar bone. The zygoma has several important articulations in the midface. The zygoma forms a significant portion of the floor and object, or secondary to motor vehicle accidents. Moderate lateral wall of the orbit. In addi- force may result in minimally or nondisplaced fractures at tion, the zygoma meets the lateral the suture lines. More severe blows frequently result in skull to form the zygomatic arch. inferior, medial, and posterior displacement of the zygoma. Comminuted fractures of the body with separation at the The zygoma is the main but- suture lines are most often the result of high-velocity motor tress between the maxilla and the vehicle accidents. In general, displaced fractures will skull; but in spite of its sturdiness, involve the inferior orbital rim and orbital floor, the zygo- its prominent location makes it maticofrontal suture, the zygomaticomaxillary buttress, prone to fracture. The mechanism and the zygomatic arch. Occasionally, however, a direct of injury usually involves a blow blow to the arch will result in an isolated depressed fracture to the side of the face from a fist, of the arch only.

©1997 Erlanger Health System Tennessee Craniofacial Center 1(800) 418-3223 Radiographic evaluation of the fracture MAXILLARY FRACTURES is mandatory and may include both plain films and a computed tomographic (CT) The maxilla forms the largest component of scan. The CT scan has now essentially the middle third of the facial skeleton. The maxil- replaced plain films as the Ògold standardÓ la is a key bone in the midface that is closely asso- in both evaluation and treatment planning. ciated with adjacent bones providing structural If physical findings and plain films are not support between the cranial base and the occlusal suggestive of a zygomatic fracture, the eval- plane. Fractures of the maxilla occur less fre- uation may end here. However, if they do quently than those of the mandible or nose due to suggest fracture, a coronal and axial CT the strong structural support of this bone. The scan should be obtained. The CT scan will midface consists of alternating thick and thin sec- accurately reveal the extent of orbital tions of bone that are capable of resisting signifi- involvement, as well as degree of displace- cant force. This structurally strong bone provides ment of the fractures. This study is vital for protection for the globes and brain, projection of planning the operative approach. the midface, and support for occlusion. Reestablishing continuity of these buttresses is the Historically, closed reduction was the foundation on which maxillary fracture treatment method of choice for nearly all zygomatic is based. fractures. Multiple methods were employed, but most involved simply exert- Renee LeFort (1901) provided the earliest clas- ing pressure underneath the malar emi- sification system of maxillary fractures. His nence and popping the fragments back into model described Ògreat lines of weakness in the alignment. Not only were these results fre- faceÓ using low-velocity impact forces directed quently unsatisfactory, but they were against cadaver skulls. A discussion of fractures of fraught with complications including per- the maxilla would not be complete without a sistent diplopia, orbital dystopia, malunion, description of LeFortÕs work. and significant residual deformity. In our The Lefort I fracture, or transverse fracture, own experience, closed reductions yield extends through the base of the maxillary sinuses unpredictable results with significant above the teeth apices essentially separating the chance of relapse. We feel that plate and alveolar processes, palate, and pterygoid process- screw fixation is now the standard of care. es from the facial structures above. This trans- The treatment of zygomatic fractures has verse fracture across the entire lower maxilla dramatically progressed over the past sev- separates the alveolus as a mobile unit from the eral decades from an entirely closed rest of the midface. Fracture dislocations of seg- approach to the more aggressive open ments of the alveolus may be associated with this reduction and rigid miniplate fixation of fracture. With high-energy injuries, the palate today. If a zygomatic fracture is displaced, may be split in the midline in addition to the we do an open reduction and rigid stabi- LeFort I fracture. lization with mini-and microplates. The A pyramidal fracture of the maxilla is synony- floor of the orbit is routinely explored and mous with a LeFort II fracture. This fracture pat- reconstructed, if needed, to restore orbital tern begins laterally, similar to a LeFort I, but volume. The complications of an inade- medially diverges in a superior direction to quately or unreduced zygomatic fracture include part of the medial orbit as well as the are very difficult to correct secondarily and nose. The fracture extending across the nose may usually avoidable. We feel that early diag- be variable, involving only the nasal cartilage or nosis combined with this aggressive surgi- as extensive as to separate the nasofrontal suture. cal treatment yields the best results.