Comparing London Dental Atlas and Demirjian Accuracy Across Varying BMIs

Objectives: Timing of dental development is affected by body mass index (BMI) as some studies found, with high BMI children having accelerated (precocious) dental development. Most research investigating this question used Demirjian method for dental age estimation. The London Atlas of dental development (LA) showed better measures of accuracy as some data suggested although it hasn’t been tested in regard to BMI. The aim of this study is to test and compare Demirjian’s method and (LA) on a spectrum of BMIs.
Methods: Dental age was assessed using Demirjian’s and (LA) on a diverse convenience sample of OPGs from the Pediatric and Orthodontic Clinics at UIC. Age- and sex-specific BMI percentiles were calculated for each child based on recorded height/weight. Mean difference of dental age and chronological age (Bias) was tested using a two-tailed t-tests.
Results: Total sample was 90 individuals (50 female; 40 male) ages 6-11. Intra-rater reliability was high (Demirjian: 0.86; (LA): 0.95). Both methods systematically over-estimated age with Bias of (Demirjian: 0.385 years, SD +-0.614 years; (LA): 1.11yr, SD +-0.78yr). Bias held true in males (Demirjian: 0.41yr, SD +-0.615yr; (LA): 0.928yr, SD +-0.79yr) and females (Demirjian: 0.347yr, SD +-0.619yr; (LA) 1.24yr, SD +-0.765yr). Both methods were statistically significantly different from one another (p<0.001). In regard to BMI classes (Underweight; Normal; Overweight; Obese), (LA) consistently overestimated age to the same degree on all classes.
Conclusions: In our limited sample, Demirjian’s method showed better measures of accuracy than (LA). Our results suggest that the choice of dental age estimation method should be considered when testing different groups (e.g., BMI category) and should ideally be verified using multiple methods. Additional verification of inter-rater reliability is needed to support these preliminary results.