Lateral Incisors Ratio as a Substitute for Bolton Index

Aim: An appropriate occlusal relationship, when there is a significant tooth size discrepancy between the lower and upper dental arches, is impossible. In this way, it is necessary to assess the Bolton's anterior and overall ratios. But it seems too difficult to Measure ۲۴ teeth for each patient routinely. in this research our aim was to find an appropriate substitute for the Bolton ratio. Material and Methods: One hundred pairs of dental casts were selected and the mesiodistal width of each tooth was measured by a sharpened gauge. Then correlation between lateral ratio (mesiodestal width of lower lateral incisors/ upper lateral incisors) and Bolton's anterior ratio (AR) and overall ratio (OR) was evaluated by paired T test and regression models. Results: Mean overall ratio was ۹۱:۳ %, anterior ratio ۷۹.۰% and lateral ratio ۸۸.۴%correspondingly. No significant difference was found between males and females. A well correlation was found between LR and AR (r=۰.۷۰) and OR. Conclusion: Strong correlation between LR and AR and OR was established. Mean value of ۸۸.۴% for LR was correspondent to normal Bolton ratios. (IJO ۲۰۰۶; ۱: ۵۳ - ۵۷)

Keywords:

Lateral incisors ratio , Tooth Size Discrepancy , occlusal relationship