Laboratory Studies
If alcohol or illicit drug use is suspected, obtain and document serum levels.
As with most surgical patients, appropriate preoperative laboratory tests (eg, complete blood cell count, metabolic panels, activated partial thromboplastin time) and an international normalized ratio are necessary in those with zygomatic arch fracture. Obtain a pregnancy test when clinically warranted.
Imaging Studies
A chest radiograph may be necessary before proceeding with the repair.
Roentgenograms can be used but are limited by the lack of ability to detect differences in tissue density of less than 10%, making evaluation of soft tissue difficult at best. Standard facial series are the norm and are obtained with varying angulation of the x-ray beam vector. The Caldwell projection allows for visualization of the orbital floor and zygomatic process above the dense petrous pyramids. A submental vertex view affords excellent detail of the zygomatic arches. Anterior-posterior and Waters views reveal much less about the zygomaticomaxillary complex (ZMC) than other planes and are of limited value.
Computed tomography (CT) scans have supplanted radiographs in the evaluation of midfacial trauma and are the current modality of choice. [3] A gray-scale image is created based on various soft tissue linear coefficients that are assigned a particular shade of gray. Direct axial, coronal, or sagittal images can be obtained with proper positioning of the patient. CT scanning without contrast provides views of high-density bone.
Obtain both axial and direct coronal, 1.5- to 2-mm cuts to properly evaluate the orbit. If the patient cannot be manipulated into proper position for direct coronal images, coronal views also may be obtained indirectly by a reformat of thin axial windows. Coronal orbital views provide bone and soft tissue windows, allowing for detailed images of the lateral orbital wall, ZMC, and adjacent soft tissue and bone structures.
Magnetic resonance imaging (MRI) uses a magnetic field and the activity of hydrogen atoms within this field to produce magnificently detailed images of the orbit. MRI enables multiplanar imaging and is excellent for evaluating soft tissue masses and optic nerve pathology. [4] However, although MRI provides exquisite detail of the orbital region, CT scanning remains the imaging modality of choice for evaluation of orbital trauma because of its ability to discern detail of bony structures. Of note, intraocular ferromagnetic foreign bodies can add additional insult to the eye and surrounding structures secondary to the magnetic field of MRI.
Other Tests
An electrocardiogram also may be necessary before proceeding with the repair.
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Gillies approach to reduction of a zygomatic arch fracture.
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Anatomic depiction of the masseter muscle as it relates to the zygomaticomaxillary complex and mandible.
