The Reliability of Fishman, Demirjian and Nolla Methods in Predicting the Chronological Age for 8-16 Years Old Yemeni Children

Abstract

Background: Prediction of chronological age by skeletal and dental age estimating methods is a useful mean for orthodontic diagnosis and treatment planning and forensic dentistry. The aim of the present descriptive cross-sectional study is to assess the reliability of Fishman, Demirjian and Nolla methods in estimating the chronological age for Yemeni children. Materials and Methods: Orthopantomographs and left hand-wrist radiographs were taken for 358 Yemeni children (193 boys and 165 girls) 8 - 16 years old. Skeletal and dental ages were calculated and compared with chronological age using SPSS version 21, statistical significance was predetermined at P<0.05. Results: The mean chronological, skeletal, and dental ages were 12.00±2.25 years, 12.39±1.65 years, 11.43±2.42 years, for Demirjian and 11.32±2.65 years, for Nolla, respectively. Intraclass correlation coefficient-ICC showed strong correlation between chronological and skeletal age and between chronological and dental age, estimated by both Demirjian and Nolla methods (P<0.001). Wilcoxon signed test showed Fishman method significantly underestimated the chronological age by 0.23±1.19 in both genders (P=0.02) and 0.44±1.26 years in boys (P=0.001), and insignificantly underestimated the chronological age by 0.02±1.08 years in girls (P=0.898). Demirjian method significantly underestimated the chronological age by 0.58±1.25 years in both genders, 0.73±1.30 years in boys and 0.40±1.17 years in girls (P<0.001). Nolla method significantly underestimated the chronological age by 0.68 ±1.25 years in both genders, 0.59 ±1.28 years in boys and 0.78 ±1.21 years in girls (P<0.001). Regression equations were formulated with the best of fit for the three methods. Conclusions: Chronological age of Yemeni children was highly correlated to skeletal age estimated by Fishman method and dental age estimated by Demirjian and Nolla methods. The three methods underestimated the chronological age of Yemeni children. Fishman method was accurate among girls and Nolla method in both genders older than 13 years.