Assessment of mastoid emissary foramen morphology: a multidetector computed tomography study

Objectives: This study aimed to assess the occurrence and morphological features of the mastoid emissary foramen (MEF) using multidetector computed tomography (MDCT) images. The analysis highlights the clinical significance of these structures and their implications for surgical procedures. Methods: A total of 357 patients were evaluated using MDCT in bone window mode with a high-resolution technique (1 mm). The presence, number, and mean diameter of the MEFs were recorded. Statistical analyses compared data between both sides and sexes. Results: 714 sides from 357 patients (177 male, 180 female) were analyzed. The patients’ ages ranged from 7 to 83 years, with a mean age of 25.6. MEFs were found in 329 patients, representing 92.15% of the total. The diameters of the MEFs ranged from 0.6 mm to 5.0 mm on the right side (mean 1.80 mm) and from 0.6 mm to 4.4 mm on the left side (mean 1.96 mm). Up to 3 MEFs were identified on the right side, and a maximum of 6 on the left. No significant differences in MEF presence were observed between sexes or between the left and right sides (p > 0.05). Conclusion: This study reveals a high prevalence and notable anatomical variations in the MEF, with MEFs larger than previously reported. At least one MEF was detected in 92.15% of cases, emphasizing the importance of comprehensive preoperative evaluation.