Zygomatic air cell defect (ZACD). Prevalence and characteristics in a dental clinic outpatient population.

OBJECTIVES

To determine the prevalence and characteristics of zygomatic air cell defect (ZACD) among a general dental clinic population.

METHODS

The panoramic radiographs of 2734 dental clinic outpatients were examined for the presence of ZACD. ZACD was defined as a nonexpansile, nondestructive cyst-like radiolucency in the zygomatic process of the temporal bone which appears similar to the mastoid air cells and which does not extend further anteriorly than the zygomaticotemporal suture.

RESULTS

ZACD was found in 40 patients (1.5%) with a mean age of 49.6 (s.d. 18.0) years. Twenty cases (50%) each occurred in males and females. Meta-analysis of three large case series comprising 4579 patients revealed a total of 76 cases of ZACD (1.7% prevalence) occurring over an age range of 15-83 years. Thirty-four (44.7%) occurred in males while 42 (55.3%) occurred in females. Bilateral ZACD were found in 17 patients (22.4%).

CONCLUSIONS

ZACD is not a rare anatomical variant, and clinicians planning eminectomy or other surgical procedures involving the zygomatic arch are advised to obtain appropriate presurgical imaging studies to avoid the need for creative intra-operative reconstruction.