A computer-based method for calculation of orbital floor fractures from coronal computed tomography scans

Purpose: A computer program recently developed for the calculation of the o rbital floor and fracture areas from coronal computed tomography (CI) scans was used in a study to evaluate the accuracy and ability of this new metho d. Material and Methods: The size of orbital floors and fabricated fractures i n 14 dried, anatomic specimens were measured in coronal CT scans by 3 indep endent observers. Based on this data set, the orbital floor and fracture re gions were calculated with the newly developed computer program. These calc ulated regions were then compared with a direct measurement of the specimen s that had been obtained by digital photography. The accuracy of the comput er-based calculations was assessed using Lin's concordance correlation coef ficient. Results: The size of the orbital floor (mean +/- SD) was found to be 5.21 /- 0.39 cm(2) by direct measurement of the specimens and 5.30 +/- 0.52 cm(2 ) by calculation with the computer program. The region of the fracture (mea n +/- SD) was 1.05 +/- 0.64 cm(2) by direct measurement and 1.01 +/- 0.62 c m(2) by computer calculation. The between-method mean difference (direct me asurement minus computer based calculation) was -0.09 cm(2) (or 1.7% of mea n orbital floor region) for orbital floor region and 0.04 cm(2) (or 3.8% of mean fracture region) for fracture region. Conclusions: This accurate and time-saving method is practicable for determ ining the size and location of orbital floor fractures. This calculation pr ogram can be advantageously applied in the clinical management of blowout f ractures of the orbit. (C) 2001 American Association of Oral and Maxillofac ial Surgeons.