A new proposal of classification of zygomatic arch fractures

Among facial fractures, zygomatic arch fractures occur rather frequently. Facial fractures have recently been classified in fine detail according to computed tomographic findings. Nevertheless, there exists no classification of the zygomatic arch fracture, which has a physiognomically important place, to provide guidance for treatment. We aimed to make a detailed classification of zygomatic fractures in various shapes, which does not exist in the literature, and to form an algorithm for treatment.

A total of 451 patients with zygomatic arch fractures treated in our clinic from 1987 through 2004 were assessed retrospectively from the treatment viewpoint together with radiological and clinical findings.

At the end of this assessment, arch fractures were divided into 2 groups: 1) isolated fractures in which the zygomatic arch alone broke, and 2) combined fractures in which the zygomatic arch broke together with the other facial bones. Isolated fractures were also divided into 2 subgroups as A) 2 fractures in the arch, and B) more than 2. Isolated arch fractures with more than 2 fracture lines were also classified as V-shaped fractures where fragments are partially reduced and those where fragments are displaced. As for combined fractures, they were subgrouped as A) single fracture in the arch, and B) plural. Plural fractures were further classified within their own group, also according to whether fragments were displaced or not.

In the 2 fractures and V-shaped fracture subgroups of isolated fractures, preservation of fragments in reduced position was satisfactory during the closed reduction and afterwards. As for those with more than 2 fractures of isolated arch fractures, they required open reduction and internal rigid fixation. The same treatment was used in combined zygomatic arch fractures where there were more than one displaced fractures. In addition to classification, we formed an algorithm to guide us in treatment based on our series.