Pterion: Morphometry and Surgical Significance

ABSTRACT

Introduction: Pterion is a H-Shaped formation of sutures and cranio-metric point on the lateral side of skull. It is marked by the junction of frontal, parietal, greater wing of sphenoid & squamous temporal bone. Objective: The study is aimed to determine prevalence of types of pterions, presence of epipteric bone. We also tried to find pterion’s relationship with anterior branch of middle meningeal artery Materials and methods: Study was done in department of Anatomy, GMCH-32, Chandigarh on 40 adult dried skulls without calvaria, of unknown age, gender and race. The skulls with broken lateral wall were excluded. Skulls were examined for 1. A. prevalence of pterion shape B. Prevalence of bilaterality of similar shape of pterion. C. Prevalence of unilateral variation of pterion on two sides of skull. 2. Epipteric bone A. Presence of epipteric bone B. relation to the suture on both sides. 3. Distance of pterion center point to frontozygomatic suture and upper border of zygomatic arch. 4. relationship of pterion on external and internal surface of skull and on inner side its relationship with anterior branch of Middle meningeal artery. Observations In the present study 3 types of pterions i.e., Sphenoparietal, stellate, frontotemporal were observed. Sphenoparietal was found to be present bilaterally 40% on both sides. Frontotemporal & stellate were 2.5%. Sphenoparietal type of pterion was 55% on right side & 67.5% on left side. frontotemporal type of pterion was 5% on right side & 2.5% on left side, stellate type was 7.5% on right side & 2.5% on left side. epipteric bone were present in pterion on right side in 32.5% & on left side 27.5%. Pterion was lying approximately 3.5 cm above the zygomatic arch and 2.83 cm behind the posterior margin of frontozygomatic suture. Conclusion: in our study the commonest type of pterion shape was Sphenoparietal. This type was most common to be present bilaterally. Epipteric bone was found in Sphenoparietal type both unilaterally & bilaterally. The anterior branch of MMA was closest and farthest in stellate type.