Anatomic position of the Pterion among Indians for lateral skull approaches

Background: This study was conducted to determine the position of the pterion in south Indian skull. The pterion is point of suturai confluence seen in the norma lateralis of the skull where frontal, parietal, temporal and sphenoid bones meet. The importance of the pterion is its relation to the middle meningeal artery, Broca's motor speech area on the left side and surgical interventions relating to pathologies of the sphenoid ridge and optic canal. The position of the pterion exhibits population based variations. Method: Specific measurements were taken on both sides of 125(83 male and 42 female) Indian skulls. Results: The pterion was 38.43±3.58mm above the mid point of the zygomatic arch(MPZ). The MPZ on right side was 39.01±3.54mm and 37.85±3.57mm on left side. The distance from the centre of the pterion to the frontozygomatic suture(FZS) was 34.40±4.70 mm. The FZS on right side was 34.78±4.84mm and 34.02±4.50mm on left side. Male had statistically higher pterion compared to female being 39.13±3.56mm and 37.53±3.01mm above the mid point of the zygomatic arch respectively. Conclusions: This information may be useful in planning prior to surgery especially where neuronavigation divices equipments are scarce.