The variability of the mastoid foramen

Abstract

Purpose of the study. The aim of the present work was to study the variability of the mastoid foramen.

Material and methods. 74 skulls of adults, taken from the fundamental museum of Department of Human Anatomy and Medical Terminology of Azerbaijan Medical University, were studied. Cranioscopic and craniometrical methods were used. The presence or absence of mastoid foramen, its number, sizes on the right and left sides and location (in the occipitomastoid suture, in the temporal bone in front of the suture, in the occipital bone behind the suture) were studied.

Results. The results show that the mastoid foramen was observed in 86.5% cases. On 35 skulls the mastoid foramen was found on both right and left sides. Unilateral location of the mastoid foramen was found on 29 skulls (18 skulls on the right, 11 skulls on the left). Bilateral absence of the mastoid foramen was revealed on 10 skulls. Double mastoid foramen was found on 7 skulls. Diameter of mastoid foramen on external surface of skull is 1.0-6.0 mm on the right and 1.0-5.0 mm on the left. On the right side the mastoid foramen was located in the occipitomastoid suture (40.4%), in the temporal bone in front of the suture (52.6%), in the occipital bone behind the suture (7%). On the left side the mastoid foramen was located in the occipitomastoid suture (40.8%), in the temporal bone in front of the suture (51%), in the occipital bone behind the suture (8.2%).

Conclusions. Frequency, sizes and location of the mastoid foramen is variable. Obtained results may be interesting for anthropologists and have practical importance during surgery in this region.