Analyzing the interobserver variability in stages of tooth development with orthopantomogram (OPG)

Abstract

The development of teeth in human body follows a definitive chronological sequence. The different stages of formation of teeth have been used to evaluate the maturity and age of an individual. In dentistry, this estimation has been widely used to assess the growth for planning treatment. The legal system also uses this chronology to estimate the age of an individual, as there are various laws governing the adult and the juvenile in different countries, and dental age estimation has been widely used standard of age estimation when there are no legal records of age available. The aim was to study the agreement of the scoring pattern between different individuals while using the most popular techniques of Demirjian and Nollas for scoring for the age of an individual. To assess the accuracy and correlation of agreement between individuals for the various stages of tooth development as proposed by Demirjians and Nolla. To propose a system that is easily reproducible of the two.To assess the need for automation of the scoring system to eliminate human judgemental errors. 50 doctors were asked to score the OPG of 6 patients for the demirjians and nollas age assessment. They were assessed for agreement of various stages with the result closest to the age at the time of radiograph. The results were tabulated and tested statistically using interclass correlation co efficient and their statistical significance assessed. Both the tests had good correlation among clinicians for teeth 1st premolar and 1st molar. Rest of the teeth has mixed results. Demirjians had better correlation co efficient than the nollas technique. The differences in identification of the stages was statistically significant. Demirjians showed more agreement between the practitioners than Nollas but has statistically significant differences. This precludes the need for an automated system which will ensure reproducible scoring and age assessment.