Applicability of Willems methods and Demirjian's four teeth method for dental age estimation: Cross sectional study on Tunisian sub-adults.

This study aims to evaluate and compare the applicability of three dental methods for age estimation, including Demirjian's four teeth, Willems I, and Willems II methods in a sample of Tunisian children. Panoramic radiographs of 500 children (241 females, 259 males) aged between 5 and 15 years were examined. The mean absolute error (MAE) was performed to assess the accuracy of age estimation. Independent samples t-test was employed to compare the differences, the chronological age minus dental age (CA-DA), between sexes for the three methods. All of the three methods underestimated the chronological age on the average, and almost for all age groups. The discrepancy between the chronological age and the estimated age was most frequently observed for ages above 8 years for all methods. In our study, the Demirjian's four teeth method underestimated the chronological age by 0.45 years for males and 0.32 years for females, with no significant difference (p=0.124). Whereas the Willems I method is indicted for underestimating the chronological age by 0.40 years for males, and by 0.69 years for females. Willems II method underestimated age by 0.91, and 0.64 years for males and females, respectively. It is established that the Demirjian's four teeth method was more accurate in estimating the dental age than the Willems I and II methods, with a mean absolute error of 0.76 years for males and 0.79 years for females (MAE=1.10, and 0.98 years for the Willems I/1.02, and 0.92 years for the Willems II). According to the results, it is highly recommended that the Demirjian's four teeth method should be applied when estimating the dental age in Tunisian males and females. In forensic cases, when the sex is unknown or doubted, the Willems II method could be appropriate.

Age assessment in canine and premolar by cervical axial sections of cone-beam computed tomography.

Age estimation in adults is a challenge in both anthropological and forensic situations compared to sub-adults age estimation. The present study explored, for the first time, the cervical zone of single rooted teeth. The deposition of secondary dentin is responsible for a decrease in the volume of the dental pulp cavity with aging, and therefore is often used as an age indicator. The current study aimed at estimating the chronological age among adults by measuring the pulp/dentin area ratio (physiological ratio) by axial sections at cervical region of maxillary canine and mandibular second premolar. The sample consisted of 120 cone beam CT images of 120 Tunisians whose age ranged from 22 to 67, from the database of a private clinic of radiology. The first axial section of chosen teeth without enamel was selected. Linear regression models were derived for canine, premolar and for all variables to predict the age. They indicated that dentin deposition on canine and premolar have almost the same correlation with age (r=-0.838 and -0.837 respectively). The residual standard errors (RSE), when these regression equations applied for the entire sample, were ranged between 8.27, 8.29 and 7.06 for canine, premolar and for all variables respectively. Tested for younger ages (from 22 to 44years) the RSE decreased considerably and thus ranged between 4.32, 4.72 and 4.05. The outcomes of this study show that the physiological ratio is a useful variable for assessing age with a satisfying accuracy.