Position of superciliare in relation to the lateral iris: testing a suggested facial approximation guideline

It has been suggested in the literature that superciliare is located directly above the most lateral point of the iris and that this association may be of use in facial approximation. However, the relationship between the lateral iris and superciliare has not been tested and its accuracy remains unknown. This study aims to determine the accuracy of this relationship using metric and non-metric analysis. The horizontal distance from superciliare to the lateral iris was measured, using photogrammetric methods, in Australians of European extraction (27 males, 48 females), central/south-east Asian extraction (20 males, 19 females) and individuals from other population groups (7 males, 7 females). Results indicate that superciliare position is best approximated by the lateral iris in females. On average, superciliare fell lateral to the lateral iris by 4.8 mm, S.D. 3.4 mm in males, and 1.2 mm, S.D. 5.4mm in females. In approximately 70-80% of the sample, the superciliare fell between the exocanthion and the pupil center on both sides. It is suggested that the proposed guideline that the lateral iris is equal to superciliare is not very accurate, especially for males. Also the large standard deviations indicate that the position of superciliare is highly variable. The above measures should, on average, give a more accurate prediction of superciliare in contrast to the lateral iris border, and therefore, they should be used in facial approximation. However, the large variation in superciliare position should be acknowledged.