Asterion localization - variability of the location for surgical and anthropological relevance.

This work aimed to study the variability in location of the asterion in a Polish population, which may be important for both surgical and anthropological procedures. In surgical approaches to the posterior cranial fossa, the asterion is of great importance as a reference landmark. Its accurate localization may be impeded by the presence of additional, irregular sutural bones. Dry adult human skulls (n = 113, 60.2% male and 39.8% female) were analyzed for asterion location in relation to the reference points (mastoidale, bregma, porion, inion, lambda, opisthion). The asterion exhibits wide variation in location. The range of ± 2 SD of measured distances demonstrated broad variation intra and interindividually (15.9-27.8 mm for male skulls and 13.1-24.6 mm for female skulls). Distances from the asterion to the reference landmarks were longer for males compared to females (p < 0.05), and some distances were longer for people of lower socioeconomic status. Because of its lesser variation, measurements to three reference landmarks (mastoidale, bregma and frontotemporale) may be particularly important for surgical purposes. Defining accurately the safe area for asterion is important but problematic. Because of the complex relations between bony landmarks, preoperative imaging assistance is required, and the asterion should only be used as auxiliary, not as a key superficial cranial landmark in surgical interventions.