The pink teeth phenomenon has been observed in cases of hanging and drowning, but the relationship of this phenomenon with cause of death has not been positively affirmed. To date, teeth with a pinkish tone have been simply regarded as pink teeth. However, we speculated that classification and evaluation of the degree and region of discoloration with reference to how color is classified in prosthodontic dentistry may produce novel findings regarding the pink teeth phenomenon. Therefore, we classified the degree and region of discoloration on teeth into three grades and attempted to evaluate the relationship of grade with various cadaveric factors in 68 cases of pink teeth. The degree and region scores of discoloration did not show significant differences in terms of sex, age, cause of death, and place of discovery, but the degree of discoloration in terms of time after death showed a significant increase at 6 months (p < 0.01) and a significant decrease after 7 months (p < 0.05), while the region score also showed a significant decrease after 7 months. Furthermore, in 18 cases of drowning, the degree of discoloration significantly increased with time after death (p < 0.01). Thus, it was clarified that time after death was most strongly related to the pink teeth phenomenon, suggesting cadaveric decomposition may affect the occurrence of pink teeth. Further investigation in cases of early postmortem changes would be required to determine whether pink teeth in putrefactive cadavers have utility in medico–legal assessments.

This study sought to clarify the characteristics and trends of physical elder abuse and the status of collaboration between forensic medicine departments and related institutions in Japan. Questionnaires were sent to 82 forensic medicine departments and 2857 institutions randomly selected from hospitals, municipalities and public community general support centers. The survey period was February to June 2021, including an extension period for collection. Responses from 675 facilities were analyzed. The most common finding in cases of physical elder abuse at forensic medicine departments was subcutaneous hemorrhage on the head (85.7%), with mixed old and new injuries most commonly observed in the lower limbs (70%). There were few cases in which there was collaboration between forensic medicine departments and other institutions. Among the issues identified, there is a need to provide related institutions with information obtained in forensic medicine departments. A new collaboration system is needed to achieve this.