3-D analysis of dislocation in zygoma fractures

Abstract

Objective: When fractured, zygomas rotate and dislocate. The present study quantitatively elucidates the pattern of the rotation.

Methods: 50 patients with tri-pod-type zygoma fractures were involved in this study. After defining a 3-dimensional coordinate system--consisting of the M-L axis (the axis directed from the medial to lateral side of the skull), I-S axis (directed from the inferior to superior side), and P-A axis (directed from the posterior to anterior side), the degree with which the fractured zygomas rotated around each of these axes was measured using 3-dimensional graphic software. Thereafter, the tendency of the rotation was compared between the three rotational axes.

Results: Rotation around the I-S axis was the most frequent with a 96% incidence, followed by a substantial margin by rotation around the M-L axis with a 26% incidence; rotation around the P-A axis was rare, with an incidence of 10%. Furthermore, the degree of P-A axis rotation was minor compared to I-S and M-L axis rotations.

Conclusion: The main factor of zygoma dislocation in zygoma fracture is rotation around the I-S axis. This finding is helpful for effective performance to reposition fractured zygomas.

Keywords: Analysis; Diagnosis; Evaluation; Fracture; Reposition; Zygoma.