Maturational changes of the normal occlusion: A 40-year follow-up.

INTRODUCTION

In this study, we aimed to evaluate the changes in dental arch dimensions, tooth size, and incisor crowding in subjects with normal occlusion over a 40-year period.

METHODS

A sample of 82 white subjects with normal occlusion evaluated in adolescence and early adulthood was recruited for a third evaluation in their sixth decade of life. The final sample included dental casts of 22 subjects (12 men, 10 women) obtained at mean ages of 13.3, 17.8, and 60.9 years. The following variables were measured on the digital casts: mesiodistal tooth size; clinical crown height; arch length, width, and perimeter; palatal depth; crowding; overjet; overbite; and curve of Spee. Interphase changes were evaluated using repeated measures analysis of variance, followed by Tukey tests (P <0.05).

RESULTS

Increases of clinical crown height in the posterior teeth and incisor crowding were found. Decreases of mesiodistal tooth size, mandibular intercanine width, arch length, arch perimeter, overbite, and curve of Spee were observed. Palatal depth increased from 13 to 17 years of age. No changes were observed for overjet.

CONCLUSIONS

Subjects with normal occlusion had changes in tooth size and alignment, overbite, and arch dimensions from adolescence to late adulthood.