Introduction: Prerequisite of orthodontic treatment depends on the diagnosis. There are many diagnostic aids. One of them important is correct assessment of inter-arch and intra-arch tooth relationship. Inter-arch tooth ratio (Bolton’s) is one which is important to build normal overjet and normal occlusion. For this analysis most researchers used GV BLACK’S table for sake of mesiodistal dimensions of teeth. The present study aimed at establishing individual tooth size for Patna population and reliability of Bolton’s ratio to this particular population and to determine sexual dimorphism. Methods-Measurements were taken from 51 male & 52 female with Class1 molar and canine relationship with ideal overjet and overbite having not treated by orthodontist. Vernier Caliper used to measure the greatest mesiodistal diameter of the teeth. From the obtained data descriptive statistical analysis was done. Result- Increased anterior (77.79±3.08) and overall ratio (99.3±2.1) were found in relation to Bolton’s ideal ratio. Conclusion-But differences of ratios was not statistically significant. Bolton’s standard can be applied to Patna population irrespective of ethnic or sex back ground.
