Correlation between chronological age and developmental status of third molars [A Radiographic Evaluation]

Determining chronological age of individuals is an investigation key in legal medicine. The aim of this study was radiographic evaluation of correlation between chronological age of Iranian people and developmental status of third molar tooth based on Demirjian staging method. This cross-sectional and diagnostic study was accomplished in Radiology department, Dental School, Shahid Beheshti University of Medical Sciences in Tehran [2004-2005]. [35] young adults, 15-25 year-old, attended the study. ID cards and radiographic evaluation were used for data collection. The radiographs were studied by a legal medicine resident and an oral and maxillofacial radiologist. Determining the developmental stages of third molar teeth was based on Demirjian method. Statistical calculations were carried out by Levene, t, Wilcoxon's signed rank, Mann-Whitney, Friedman tests and Kendal correlation coefficients [tau-b]. The distribution of different development stages of Demirjian method increased by development of third molars. There was a significant statistical discrepancy between boys and girls for the lower left third molar tooth [P < 0.001]; males were in a higher development rank. According to Calton system, he relation between Demirjian method and age was average in maxillary third molar teeth and was strong in mat dibular third molar teeth. The maxillary third molars were generally in a higher development rank compared to mandibular third molar teeth [Friedman test, X2 -44.2 14, P < 0.001]. Among four molar teeth, only developmental stage of lower left third molar was diagnosed to be effective [R 0.7 14, R2=0.51, adjusted R2 0.507, F =209.047, P < 0.001]. Only stage [H] of Demirjian method that the distal canal is closed can b: predicted with 99% precision whether the person will be 18 or above 18 years old

Comparison between two developmental staging methods of third molars [Demirjian versus Engstrom] and their correlation with chronological age

Determining chronological age of individuals is an investigation key in legal medicine, to recognize the age of those without the date of birth or of those who have problems in birth registration and also the age of criminals under or above 18. The aim of this study was to compare between two developmental staging methods of third molars [Demirjian vs. Engstrom] and their correlation with chronological age of population. This cross-sectional and diagnostic study was accomplished in department of radiology, faculty of dentistry, university of Shaheed Beheshti in Tehran [2004-2005]. Samples were composed of 350 young adults, 15-25 year-old, attending department of radiology. The radiographs were studied by a legal medicine resident and an oral and maxillofacial radiologist in order to determine developmental stages of third molars according to two methods of Demirjian and Engstrom. Statistical calculations were carried out by Levene, T, Wilcoxon's signed rank, Mann-whitney, Friedman tests and Kendal correlation coefficients [tau-b]. The frequency of different developmental stages of Demirjian and Engstrom methods was increased by development of third molars. In Demirjian method there is only a significant statistical difference between males and females in case of the left mandibular third molar, in a way that males were in a higher developmental rank. In Engstrom method, in case of the right and left mandibular third molars, the males were in a higher developmental rank, and in maxillary third molars there were no difference between males and females. According to Calton system about correlational coefficients, the relation between Demirjian method and age was average in maxillary third molars, and was strong in mandibular third molars. These results were similar to the results of Engstrom method but correlational coefficients in case of each tooth, were lower in Engstrom method in comparison to Demirjian. In order to determine the chronological age, Demirjian method was better than Engstrom