Enophthalmos and Orbital Volume Changes in Zygomaticomaxillary Complex Fractures: Is There a Correlation Between Them?

Purpose: The orbital cavity can be affected in zygomaticomaxillary complex (ZMC) fractures. The aim of this study was to assess the relation between orbital volume changes and enophthalmos in patients with ZMC fractures. Materials and Methods: A descriptive study of consecutive adult patients with recent isolated unilateral ZMC fractures who were otherwise healthy was performed from 2016 through 2017. Multislice computed tomographic (CT) scans were taken of all patients and enophthalmos was measured clinically using a Hertel exophthalmometer. In the axial plane, enophthalmos was measured on CT scan using Mimics software. Three-dimensional reconstruction and volume measurement of the orbital cavity also were performed using Mimics software. The correlation between clinical and radiographic amounts of enophthalmos was measured by Pearson correlation coefficient analysis. The association among radio-graphic enophthalmos, clinical enophthalmos, and volume changes of the orbital cavity was assessed by linear regression. The P value was set at .01. Results: Ninety-six patients (77 men, 19 women; mean age, 28.48 +/- 8.29 yr) were assessed. Mean volumes of control and fractured bony orbits measured on CT scan were 29.02 +/- 1.71 and 32.05 +/- 2.22 cm(3), respectively (P < .001). There was a strong positive correlation between clinically and radiographically measured amounts of enophthalmos (correlation coefficient = 0.97; P < .001). Based on the linear regression model, for each 1-cm(3) orbital volume change, clinical and radiographic enophthalmos amounts changed by 0.68 and 0.71 mm, respectively (P < .0001). Conclusion: ZMC fractures commonly increase orbital volume and the degree of change is strongly correlated with enophthalmos. (C) 2018 American Association of Oral and Maxillofacial Surgeons