Qualitative and quantitative assessment of tooth wear in young individuals

Objectives: To assess the degree of tooth wear in children and adolescents by application of a qualitative wear index and by quantitative measurement on digital models. The hypothesis was that the quantitative method would be sensitive to reliably measure tooth wear. Methods: Existing digital models (n = 24) gathered from a prospective clinical study were analysed. The models were obtained at two time points (11-17 months apart) from a cohort of young individuals (11-16 years old) with permanent dentition. Dental wear was scored per sextant on the models according to the qualitative criteria by two examiners and was then quantified on reference teeth (central incisors, canines and first molars). Data were analysed using Cohen's kappa coefficient, Kruskal-Wallis tests followed by Mann-Whitney U, and correlation tests, all with a significance level of 0.05. Results: According to the qualitative assessment, all subjects showed signs of tooth wear and the severity of scores was higher in the anterior dentition (P <= 0.003). Inter-examiner reliability was 0.652 (P < 0.001) while intraexaminer reliability was 0.618 and 0.571 (P < 0.001), respectively. The quantitative analysis showed median tooth wear of 0.09 mm (range: 0 - 0.56 mm). There was no significant correlation between the quantitative measurements of tooth wear and age, sex assigned at birth, time span between scans, or sum of index scores. Conclusions: The quantitative method was sufficiently sensitive to reliably measure tooth wear on digital models in >= 92 % of the investigated teeth. The use of the qualitative wear index on digital models proved dubious due to moderate intra- and inter-reliability ratings. Clinical significance: Our results show increased prevalence and severity of tooth wear in children and adolescents, which raise concern about the current lifestyle habits in our society. Intraoral scanning can be used to quantify tooth wear at an early stage and thus help design individual strategies to prevent further tooth loss.