Varying positions and anthropometric measurement of supraorbital and supratrochlear canal/foramen in adult human skulls.

The supratrochlear and supraorbital notches and foramina have been studied in 312 adult skulls of known age and sex. Out of them, in males 49.4% had bilateral supraorbital notches and 13.5% had bilateral foramina, 18.91% had a notch on one side and a foramen on the other side. Bilateral supratrochlear notch was present in 5.4% skulls, 9.65% skulls had bilateral supratrochlear canals and 8.49% had unilateral supratrochlear foramina/ notch on one or the other side. In females, 32% had bilateral supraorbital foramina and 30.18% had bilateral supraorbital notches. 37.7% had unilateral foramen/notch. Supratrochlear canal was present in 13.2% skulls on one or the other side. Bilateral notch was present in 2 skulls (3.77%) only. There was a significant difference between the frequency of supraorbital foramina and notches in males whereas there was no significant difference between the two in females. The distances of the notches/foramina from the midline and also from the temporal crest were measured. The distance of the supraorbital and supratrochlear foramen from the supraorbital rim was measured. There was no significant difference between the two genders. Knowledge of the anatomy of the region is important for those doing forehead and brow lift surgery in order to avoid injuring the neurovascular bundles passing through these notches and foramina, hence the gender wise present study. The methods of study and clinical relevance are discussed.