Comparison of the accuracy of two different methods in dental age estimation

Age estimation plays a crucial role in forensic medicine, particularly in countries facing significant refugee-related challenges. There are many parameters used for age estimation. The aim of this study is to evaluate the visibility of the pulp and periodontal ligament space in the mandibular third molar using cone beam computed tomography (CBCT) images and to compare the effectiveness of these two methods in chronological age estimation, specifically in assessing the 18-21 age thresholds.

CBCT images of 359 patients (189 females, 170 males), aged between 16 and 29 were analyzed by three independent observers. Patients with a history of trauma and/or surgery in the maxillofacial region, developmental anomalies or pathologies in the mandible, or systemic diseases affecting growth and development were excluded. Additionally, third molars with incomplete root development, developmental or acquired dental anomalies, pulp calcification etc. were excluded from the study. After recording the patients' age and sex, the mandibular third molars were classified according to the Olze (visibility of the root pulp) and Guo classification (visibility of the periodontal ligament) into grades 0, 1, 2, and 3. Each observer re-evaluated the CBCT images of 140 randomly selected patients two weeks later to assess intra-observer reliability.

The simple correlations between Olze and Guo grades were examined regardless of sex, the relationship between both methods and age was found to be significant and positive (Olze vs age r = 0.493 and p < 0.001, Guo vs age r = 0.445 and p < 0.001). Additionally, for both the Olze and Guo methods, it was observed that as the grade increased, mean age also increased at a statistically significant level (p < 0.001). Olze and Guo's grades changed statistically significantly in the 18 and 21 age thresholds in total (p < 0.001). When both methods were evaluated on a grade basis, it was seen that both Olze and Guo grade 0 increased statistically significantly in the under-18 age group, while Olze Grade 1 and Grade 2, and Guo Grade 2 increased statistically significantly in the 18 and over age group (p < 0.001). Olze method's cutoff value was found to be > 0, and Guo method's cutoff value was found to be > 1 in distinguishing between those under 18 and over. Both Olze and Guo's methods were found to be more successful in predicting the 18-year-old threshold.

Although they offer a high probability of being accurate, both Olze and Guo classifications do not provide 100 % accuracy in determining the 18 and 21 age thresholds in forensic dental age estimation. However, for both the Olze and Guo methods, the mean age increased as the grade increased. Both the Olze and Guo methods were found to be successful in estimating the 18 and 21 age thresholds.