Inner Surface of Pterion in Terms of Surgical Approaches: An Anatomical Cadaveric Study

Abstract

Objective:Aim of this study was to evaluate the morphometric features and the inner surface of the pterion in terms of surgical procedures for neighboring anatomical structures.Methods:Thirty five skeletally mature craniums were included in the present study. Fifteen of the craniums were belonged to cadavers, 20 of the craniums were dry bones. All specimens were obtained from the department of anatomy. Type of pterion and distance of midpoint of pterion to palpable surface landmarks were noted. Inner surface of pterion was marked by translumination of a laser pointer. Overlap of pterion with important anatomical structures and its closest distance to them was evaluated.Results:The most common type of pterion was sphenoparietaltype (80%) and the least common type was epipterical (1.4%) type. The mean thickness of the calvaria on the pterion was 4.2±016 mm. Pterion is located approximately 4 cm superior and 2.5 cm anterior to midpoint of arcus zygomaticus; 3 cm superior and 1.5 cm posterior to tuberculum marginale; 7 cm superior and 6.5 cm anterior to the tip of processus mastoideus. In 61.4% (n=43) of samples, inner surface of pterion was found to be associated with groove of a. meningea media. In 81.4% (n=57) of specimens, inner projection was coincided with sinus sphenoparietalis. Foramen spinosum was located posteroinferior to inner projection and the mean closest distance was 39.8±6.53 mm. Meckel cave was located posteromedial to inner projection and the mean closest distance was 40.6±3.18 mm.Conclusion:Sinus sphenoparietalis and frontal branch of a. meningea media are the main anatomical structures overlapping with internal aspect of pterion. In order to minimize complications, these anatomical structures should be kept in mind during pterional craniotomies.

Keywords

• pterion
• arteria meningea media
• sinus sphenoparietalis