Dental age assessment on panoramic radiographs in a Swiss population: a validation study of two prediction models

Dental age assessment methods are widely used for age estimation. This study aimed to analyse the accuracy of a meta-analysis method to estimate dental age in Swiss individuals and to detect potential limitations of the method. Precision of repeated tooth staging using Demirjian's classification on maxillary and mandibular teeth was also assessed.

Panoramic radiographs of 50 Swiss white healthy children were analysed. Developing teeth on the left maxilla and mandible and all third permanent molars were staged following Demirjian's classification. Dental age was calculated for each subject, using a random effects model and a fixed effect model, and compared with chronological age.

The mean error of the dental age ranged between -3 and +1 months for both the calculation models. Dental age calculated with the fixed effect model overestimated the age of the subjects (average + 0.10 y, ranging from -1.95 y to +2.16 y) compared with their chronological age, whereas the random effects model underestimated the age (average -0.32 y, ranging from -2.24 y to +1.61 y).

Demirjian's method allowed a precise repeated staging of maxillary and mandibular developing teeth. For both calculation models, dental age correlated well, on average, with chronological age of Swiss subjects younger than 12 years. The random effects model showed a better accuracy for these subjects than the fixed effect model. However, both models underestimated the chronological age in subjects older than 12 years.