The influence of labiolingual and mesiodistal anterior tooth dimensions on interarch relationships: A modified anterior Bolton analysis.

INTRODUCTION: Tooth size and morphology of anterior teeth influence interarch relationships. The Bolton analysis uses tooth width to calculate a sum of mandibular to maxillary tooth width ratios necessary for proper occlusion. Several parameters not factored in the Bolton analysis influence occlusion, such as tooth thickness. This study sought to use 3D modeling to develop and assess a tooth size analysis that encompasses labioligual thickness as well as mesiodistal width of anterior teeth.

METHODS: The role of tooth thickness in interarch relationships was studied using simulations in a 3D modeling software (Suresmile). To develop a new chart of interarch ratios based on tooth thickness, a series of simulations were produced with varying tooth thicknesses and widths. The new ratios were evaluated on records from 50 patients.

RESULTS: Findings from the simulations suggest that the ideal tooth thickness remains approximately 2 mm if the overall tooth width of the dentition increases and the interarch anterior ratio is maintained. The thickness-adjusted anterior mandibular to maxillary tooth ratio ranges from 0.70-0.79 depending on the tooth thickness. This thickness-adjusted ratio provides a superior prediction for the sum of anterior tooth width compared with the Bolton analysis.

CONCLUSION: Tooth thickness affects interarch tooth width ratios and anterior occlusion. A thickness-adjusted ratio can be used to more accurately predict anterior tooth dimensions necessary to achieve proper occlusion.