Predictors of variation in mandibular incisor enamel thickness

Abstract

Background: Interproximal reduction of mandibular incisor enamel often is performed as an adjunct to orthodontic alignment. The authors conducted a study to determine factors contributing to variations in incisor enamel thickness.

Methods: The authors compared enamel thickness between mandibular central and lateral incisors, between mesial and distal surfaces, between male and female subjects (N=40 each) and between African-American and white subjects (N=40 each). The authors also evaluated correlations between overall tooth width and enamel thickness.

Results: The authors found significantly greater enamel thickness in lateral incisors, on distal tooth surfaces and in black subjects (P<.0001 for each); they found no differences between male and female subjects. They found that wider teeth were associated with greater enamel thickness (P<.01) but that the amount of thickness varied greatly among subjects (range: 0.44-1.28 millimeters).

Conclusions: Thicker enamel was found on the distal aspect of lateral incisors, in black subjects and in wider teeth. The authors observed, however, that the variations in thickness are not fully explained by these factors alone.

Clinical implications: If substantial enamel reduction is planned as part of dental treatment, the authors recommend that clinicians use calibrated radiographs to measure the thickness of their patients' enamel surfaces because of the extensive variation in enamel thickness among and within people.