Introduction: The purpose of this study was to determine the applicability of Wayne Bolton’s original anterior and overall ratios when evaluating inter-arch tooth size discrepancies for subjects of Filipino descent living in Canada. Methods: Overall and anterior Bolton ratios were calculated for 57 Filipino patients who had undergone non-extraction Invisalign treatment at private orthodontic clinics in Canada. All 57 patients had either finished treatment or were projected to finish with an ideal class I occlusion without any interproximal reduction according to their ClinCheck® simulation. To compute the Bolton ratios, mesiodistal tooth widths were digitally measured on virtual casts using OrthoCad® software. Results:
There were no statistically significant differences between the anterior or overall ratios calculated for the study sample and the original Bolton Ratios published in 1958(p=.808). Additionally, there were no significant differences when comparing females versus males on Bolton ratios(p>0.05). However, there was a moderately low reliability for Bolton anterior ratios given by ClinCheck® compared to anterior ratios calculated based on manual measurements by the primary investigator (ICC=.594). Conclusions: Wayne Bolton’s original overall and anterior ratios from 1958 are applicable when diagnosing inter-arch tooth-size discrepancies for Filipino-Canadian patients, regardless of gender. For better accuracy, anterior Bolton ratios should be calculated based on direct measurements of mesiodistal tooth widths rather than relying on tooth widths presented by ClinCheck®