Sex assessment of medieval Norwegian skeletons based on permanent tooth crown size

The excavation of the Library site in Trondheim uncovered the medieval cemetry of St. Olav's church containing 388 skeletons, of which 248 had skulls with teeth. Sex assessment was based on osteological criteria, and for 145 skeletons sex classification was performed with a high degree of certainty. The remaining 103 were classified as uncertain male, uncertain female and sex undetermined. Mesio‐distal and facio‐lingual crown widths of permanent teeth in the group of reliably assessed males and females were used in sex‐discriminant analyses. A combination of two or more teeth was less effective in discrimination than using one tooth alone. This was due to missing data in the combined variable sets and thereby loss of cases. Missing variables were due to post‐mortem tooth loss, attrition or large deposits of calculus. The teeth were ranked according to their power in sex discrimination. The left maxillary first molar (26) represented by its facio‐lingual dimension was the best sex discriminator (classified 85 per cent of the cases correctly), followed by the right maxillary first molar (16) also represented by its facio‐lingual dimension (classified 77 per cent correctly). With only one variable in the discriminant function, a critical value could be calculated and tabulated for each tooth. This was used in sex assessment of the osteologically undetermined and uncertain groups. Only variables that could sex classify correctly at least 70 per cent of the cases with the Jack‐knife procedure were used. Sex assessment could be made for 16 of 24 (66.7 per cent) of the osteologically sex‐undetermined adult individuals and for 21 of 44 (47.7 per cent) of the children. Of 35 osteologically uncertainly sex‐assessed skulls, only nine (six men and three women) corresponded with dental classification.