In the field of forensic odontology, judgement and identification of
unknown bleached bone skulls is an important function. However, as it is possible for
teeth to drop out after death, in such cases characterized hard tissue findings may be im-
portant. In this report we note relatively rare hard tissue findings in 3 cases. Case 1 was
a frontal suture (metopism) in a 36-year-old male, Case 2 was a so-called Os Incae, and
Case 3 was an exostosis. The frequency of metopism in Japanese adults is about 6.9%,
Os Incae in males is 3.1% and 2.2% in females, while exostosis is 7-15.6%. It is consid-
ered that metopism, Os Incae and exostosis may play important roles in identification, es-
pecially if an X-ray photograph of the skull has been taken during that person's lifetime