Anatomical consideration of pterion and its related references in Thai dry skulls for pterional surgical approach.

Objective: Pterion is a crucial surgical landmark for surgical approaches to the middle meningeal artery particular lesions, and tumors in the brain. The present study aimed to analyze the types of the pterion and its location related with nearby landmarks in dry skulls. In addition, variations of pterion in sex, age, and skull side were compared.

Material And Method: Bilateral sides of 268 adult human Thai dry skulls were investigated Pterion types were classified as sphenoparietal, frontotemporal, epipteric, or stellate. To localize the pterion, linear distances were measured from the center of the pterion to neighboring landmarks.

Results: The results showed the two most common types of the pterion, the sphenoparietal (81.2%), and the epiteric (17.4%). Externally, the pterion was commonly located 38.48 +/- 4.38 mm superior to the zygomatic arch and 31.12 +/- 4.89 mm posterior to the frontozygomatic suture. Internally, it was located 38.94 +/- 3.76 mm lateral to the optic canal and 11.70 +/- 4.83 mm from the sphenoid ridge. Sex influenced the occurrence of thepterion type, while sex, skull side, and age affected its location. Mean skull thickness at the pterion was 5.13 +/- 1.67 mm.

Conclusion: The pterion is predominantly sphenoparietal type and is typically located 39 mm superior to the zygomatic arch, 31 mm posterior to the frontozygomatic suture, 39 mm lateral to the optic canal and 12 mm from the sphenoid ridge. The data obtainedfrom the present study should be clinically useful for localizing the position of pterion.