The applicability of the Willems et al. model was verified on a collected sample of Malay (Malaysian nationality) children. This sample was split in a reference sample to develop a Malay-specific prediction model based on the Willems et al. method and in a test sample to validate this new developed model. Next, the incorporation of third molars into this model was analyzed. Panoramic radiographs (n = 1,403) of Malay children aged between 4 and 14.99 years (n = 702) and subadults aged between 15 and 23.99 years (n = 701) were collected. The left mandibular seven permanent teeth of the children were scored based on the staging technique described by Demirjian and converted to age using the Willems et al. method. Third molar development of all individuals was staged based on the technique described by Gleiser and Hunt modified by Kohler. Differences between dental age and chronological age were calculated and expressed in mean error (ME), mean absolute error (MAE), and root mean square error (RMSE). The Willems et al. model verified on the collected Malay children overestimated chronological age with a ME around 0.45 year. Small differences in ME, MAE, and RMSE between the verified Malay-specific prediction model and the Willems et al. model were observed. An overall neglected decrease in RMSE was detected adding third molar stages to the developed permanent teeth model.
Knowledge of the position of the mental foramen is important both when administering regional anesthesia and performing periapical surgery in the mental region of the mandible. This study determines the position of the mental foramen in a selected Malay population. One hundred and sixty nine panoramic radiographs of Malay patients retrieved from a minor oral surgery waiting list were selected to identify the normal range for the position of the mental foramen. The foramen was not included in the study if there was any mandibular tooth missing between the lower left and right first molars (36-46). The findings indicated the most common position for the mental foramen was in line with the longitudinal axis of the second premolar (69.2%) followed by a location between the first and second premolar (19.6%). The right and left foramina were bilaterally symmetrical in three of six recorded positions in 67.7% patients. The mental foramen was most often in line with the second premolar.