Development of formulae for dental age estimation using digital radiographs in the Mongolian population.

This study aimed to examine the applicability of the pulp/tooth ratio (PTR) method for age estimation in Mongolian populations using panoramic radiographs and derive new regression formulae. Moreover, we aimed to assess the accuracy of these formulae in other subjects from the Mongolian population and compare them with the other formulae derived from different Asian populations. The total sample size of the study was 381. The formulae were derived from the examination of panoramic radiographs of 271 individuals aged 15-62 years. Following Cameriere's method, PTR was calculated for the upper and lower canine teeth. Linear regression analyses were performed between the actual age and that obtained from upper-lower canine PTR and established formulae for age estimation. To verify the formulae, two types of test samples were collected: 73 panoramic radiographs and 37 periapical radiographs. The estimated age was calculated using our new formulae and three other formulae derived from Asian populations. The correlation coefficient between the actual age and that obtained by PTR was significantly negative for both canines. According to our new regression formulae, the differences between the estimated age and actual age showed a bell-shaped curve distribution in both test groups. While using the other formulae derived from the Asian population, the distribution patterns obtained were significantly different in the Mongolian population. This study was the first to examine the relationship between actual age and PTR in Mongolian population, and these results advance the field of forensic science in Mongolia.

Analysis on unidentified cases in which dental information was collected from 2014 to 2019 in Miyagi Prefecture, Japan.

This study aimed to summarize the characteristics of unidentified cases in which dental information was collected during 2014-2019 in Miyagi Prefecture and to discuss the challenges and social characteristics of dental identification in routine forensic work. Cases were selected and examined from the database of dental charts collected at Tohoku University and the database of the Miyagi Prefectural Police. The annual percentage of cases with matched dental findings ranged from 19.2 - 37.1%, and 80.6% of the cases were identified within four days using dental information. The most common age group was the 50-70 s. Males were more common in the 20-70 s, whereas females were more frequent in the 80-90 s age group. Utilization of dental information was lower for cases involving young people and those over 90 years of age. The number of unidentified cases and unspecified death cases in the central block was significantly higher than other regions. However, there were no significant differences in sex, age, and season between each region. Spearman's rank-order analysis of the unspecified deaths showed a strong correlation with the monthly average temperature (ρ = 0.89, p < 0.01). Within the limitations of this study, the results provide valuable information on the long-term progress of routine dental identification work and could be useful as a reference for a statistical survey. Future research must examine the role of dental information in forensic identification by exploring the role of more specific background characteristics among autopsy cases.