Prevalence of zygomatic air cell defects in a North American population.

Zygomatic air cell defects (ZACDs) are asymptomatic defects present in the zygomatic process and articular eminence of the temporal bone. This defect is considered a normal anatomical variant and can be detected on routine panoramic images. The objective of this study was to determine the prevalence, dominant type, and location of ZACDs in a North American population. A total of 1724 panoramic images of adult patients were analyzed by a third-year dental student in conjunction with an oral and maxillofacial radiologist. Patient demographics (age and sex) as well as ZACD location (unilateral right/left or bilateral) and appearance (unilocular or multilocular) were evaluated. Statistical analyses included the Clopper-Pearson method to calculate the 95% CI, Student t test for independent samples, and Fisher exact test. The prevalence of ZACDs in this study population was 2.1%. A total of 24 women (2.3%) and 12 men (1.7%) were affected, with no statistically significant difference between the sexes. The mean (SD) age of patients presenting with a ZACD was 56.6 (17.7) years, while that of patients without a ZACD was 53.0 (16.3) years, with no statistically significant difference between groups. Among the 36 patients with ZACDs, 28 (1.6%) had unilateral and 8 (0.5%) had bilateral lesions. One patient with bilateral ZACDs had a unilocular lesion on the right side and a multilocular lesion on the left, so there were a total of 31 unilocular lesions (1.8%) and 6 multilocular lesions (0.3%). The results of this study indicate that the prevalence of ZACDs in the study population was 2.1%, without any statistically significant differences based on the sex or age of the patient or laterality or appearance of the lesions.