Signs and symptoms - Loss of cheek projection with increased width of the face - Loss of sensation in the cheek and upper lip due to infraorbital nerve injury - Facial bruising - Periorbital ecchymosis - Soft tissue gas, swelling, trismus, altered mastication, diplopia, and ophthalmoplegia as indirect features of the injury

Cause - Usually caused by a direct blow to the malar eminence of the cheek during assault - Zygomatic arch fractures at its weakest point, 1.5cm behind the zygomaticotemporal suture - Zygomas have attachments to the cranium and maxilla, forming the zygomaticomaxillary complex - Zygomaticomaxillary and zygomaticotemporal sutures are present in the upper and transverse maxillary bone - Zygomaticomaxillary and frontozygomatic sutures are present in the lateral and vertical maxillary bone

Treatment - Non-displaced or minimally displaced fractures can be treated conservatively - Open reduction and internal fixation is reserved for severely angulated or comminuted fractures - Fixation aims to restore the normal appearance of the face - Attention is given to the position of the malar eminence and reduction of orbital volume - Failure to correct the fracture can result in rotational deformity and increased volume of the orbit

Prognosis - Prognosis of tripod fractures is generally good - Persistent post-surgical facial asymmetry may occur in some cases - Further treatment may be required to address facial asymmetry

References - Fraioli, RE; Branstetter BF, 4th; Deleyiannis, FW (February 2008). Facial fractures: beyond Le Fort. - Winegar, BA; Murillo, H; Tantiwongkosi, B (2013). Spectrum of critical imaging findings in complex facial skeletal trauma. - Buchanan, EP; Hopper, RA; Suver, DW; Hayes, AG; Gruss, JS; Birgfeld, CB (December 2012). Zygomaticomaxillary complex fractures and their association with naso-orbito-ethmoid fractures: a 5-year review. - Swanson, E; Vercler, C; Yaremchuk, MJ; Gordon, CR (May 2012). Modified Gillies approach for zygomatic arch fracture reduction in the setting of bicoronal exposure. - Linnau, KF; Stanley RB, Jr; Hallam, DK; Gross, JA; Mann, FA (October 2003). Imaging of high-energy midfacial trauma: what the surgeon needs to know.