Influence of tooth crown size on malocclusion.

INTRODUCTION

Malocclusion is an increasingly common, multifactorial problem. The most prevalent malocclusion results from excess tooth size compared with the size of the supporting bone; this creates a tooth-size arch-size discrepancy. Although the causes of malocclusion are obscure in most instances, a contributing factor appears to be tooth size. The goal of this study was to test whether the dimensions of the crowns of the permanent teeth differ in young men with naturally good occlusions compared with those who required orthodontic treatment.

METHODS

Tooth crown dimensions (mesiodistal and buccolingual) were measured in 2 samples of American white men. One group (n = 42) had naturally good occlusion; the other group (n = 90) required orthodontic treatment to correct tooth-size arch-size discrepancy.

RESULTS

The means of 23 of the 24 tooth crown dimensions-involving the 14 tooth types (central incisor through first molar) in both arches-were significantly larger in subjects with malocclusions than in those with good occlusions. Multivariable analysis showed that mesiodistal size of the maxillary lateral incisor was the most significant difference between the 2 samples, but this might reflect the composition of the sample (maxillary lateral incisor size is notoriously variable in white men).

CONCLUSIONS

Tooth size is not necessarily the foremost cause of malocclusion in a patient, but it should be evaluated.