Analysis of Tooth Size Discrepancy (Bolton Ratio) among Orthodontic Patients at Combined Military Hospital (CMH), Dhaka

Objective: The prime purpose of this study is to determine the mean overall ratio (OR) and anterior ratio (AR) of the Bolton analysis among the patients reported to orthodontist at Combined Military Hospital Dhaka, and to evaluate the clinical significance of the estimated tooth size discrepancies, the dependence of Bolton ratio on gender, teeth width variability, and to estimate the Bolton ratio changes that mostly have influence on teeth. Materials and Methods: The sample comprised 67 diagnostic models (22 male and 45 female) from the ages 13 to 30 years with fully erupted and complete permanent dentitions from first molar to first molar, which were selected randomly from 300 consecutively treated orthodontic patients. The mesiodistal tooth sizes were measured using digital calipers, and recorded on a data analysis sheet along with patient's specific information. Data were complied and analyzed by using SPSS version 15.0. Results: It was determined that in 82.08% of the cases (55 patients) normal Overall Bolton ratio was found (no tooth size discrepancies), 14.93% of patients (10 patients) - had wider upper than lower teeth, 2.99% (02 patients) , the opposite. Estimated Anterior Bolton ratio was normal in 58.2% (39 patients) of the cases, in 32.84% (22 patients) - upper front teeth appeared to be wider than lower front teeth, in 8.96% (06 patients), the opposite. Significant tooth size discrepancies in both posterior and anterior segments were detected in 10.44% of examined patients (91.3 ± 3.86), in 37.31% - only in the anterior part of the dentition (77.2 ± 3.30). Conclusions: Both the values of Bolton overall ratio and anterior Ratio of the samples were identical to that of Bolton's, but showed marked variation between male and female. Bolton Ratio was mostly influenced by the width differences of the maxillary lateral and central incisors and mandibular first maolars.