Computer-assisted Volume Measurement in the Surgical Correction of Orbitozygomatic Injuries

Objective:To calibrate the orbital volume variations of orbitozygomatic fracture patients in order to get the critical value for prospective evaluate the incidence of postoperative enophthalmos. Methods: 20 patients with the orbitozygomatic fractures were scanned by Multiply Spiral CT preoperatively and postoperatively. Orbital volume was measured by the Simplant analytic software and compared statistically. Results: Preoperatively, orbital volume enlarged in all patients, with a range of 0.07～7.50 cm3 compared with the opposite intact orbit, with a mean of 3.51 cm3±3.05. But this decreased to 0.93 cm3±1.00 following operation. Significant differences in orbital volumes existed before and after operation (P0.01). 12 patients showed clinical enophthalmos after operation. Their preoperative orbital volume was 4.60 cm3±1.27. Conclusions:The measurement of orbital volume can help operator to make operation plan and restore original orbital volume.