Original Article

Determination of Bolton Tooth Size Ratios and Prevalence of Tooth Size Discrepancies in Dental Malocclucions


  • Sercan Akyalçın
  • Servet Doğan
  • Banu Dinçer
  • Aslıhan M. Ertan Erdinç
  • Gökhan Önçağ

Turk J Orthod 2005;18(3):235-242

The aim of this study was to determine the prevalence of tooth size discrepancy and average Bolton tooth size ratios in a group of orthodontic patients with skeletally Class I jaw relationship and normal vertical growth. A total of 850 cases were examined and according to selection criteria and 3 study groups were formed as 48 Angle Class I, 60 Angle Class II and 44 Angle Class III subjects resulting in a final sample of 152 subjects. The material comprised the standardized lateral cephalograms and dental casts obtained from the individuals before the treatment. Analysis of variance was performed to compare the mean ratios of Bolton analysis as a function of Angle classification and gender. In order to deter -mine the prevalence of tooth size imbalances among the three malocclusion and the two gender groups, chi-square tests were performed. No statistically significant differences were determined for the mean values of Bolton's anterior and overall ratios among the groups and genders. No statistically significant differences were observed in Bolton's anterior and overall tooth size prevalence among the malocclusion groups and between the two genders. However, the prevalence of Bolton's anterior and overall tooth size discrepancies was found very high in our sample. The presence of high prevalence of tooth size discrepancies in an orthodontic patient population suggested that the measurement of inter-arch tooth size ratios before the treatment might be clinically beneficial for treatment outcome and future expectations.

Keywords: Bolton ratios, Dental malocclusions, Tooth size discrepancies