Evaluation of third molar development with chronological age by demirjian's method

SİRKECİ S. Evaluation of third molar development with chronological age by Demirjian's method. Hacettepe University Health Sciences Institute Specialty Thesis in Pediatric Dentistry, Ankara, 2018. The aim of this study was to evaluate the development of third molar and its relationship to chronological age in subjects aged 5-18 years according to Modified Demirjian's method. A retrospective study was performed on 1249 patients' panoramic radiographs. The radiographs were evaluated by two independent observers. Intra-class correlation coefficient was performed to calculate the intra- and inter-observer agreement. Spearman correlation coefficients and Chi-square tests were performed to assess the correlation between third molar development and chronological age. T-test was used to evaluate the effect of teeth locations. All data were analyzed with SPSS software package (SPSS Inc. Chicago). Statistical significance was defined as P< 0.05. A strong correlation was found between third-molar development and effect of age (p<0.05). Third molar crypt formation was observable as early as 6 years old and as late as 14 years old. Gender difference had no significant effect on third-molar development (p>0.05). The effect of jaw difference was observed only at 7, 8, 9, 10 and 11 ages (p<0.05). At these ages, mandibular third molars were more advanced than their counterparts in maxilla. Crown and root completion occurred as early as 9 and 18 years, respectively. Keywords: Third molar development, Chronological age, Demirjian method.