To evaluate the norms using Bolton's analysis in North Eastern Indian population and to compare the gender difference.The cross-sectional study comprised of 120 dental students aged 18–25 years with Angle's class I occlusion, normal overjet–overbite, normal growth and development, normal maxillary and mandibular arches with all teeth; excluding third molars, history of previous orthodontic or surgical treatment, restoration, prosthesis, tooth anomalies in form, structure and development, significant medical history and history of trauma. The mesio-distal diameter of each tooth was measured. Measurements were used to evaluate Bolton's overall and anterior ratios. Descriptive statistics like mean and standard deviation (SD) were used. The p-values less than 0.05 were treated as significant. Unpaired “t” test was used for comparison between male and female subjects.The mean anterior ratio was 79.16±2.19 and overall ratio was 90.64±2.00. The mean overall ratios were almost same in both males (90.51±2.23) and females (90.78±1.74) with no significant gender difference (p=0.471). Similarly, the mean anterior ratios showed almost same in both males (79.30±2.34) and females (79.02±2.03) with no significant gender difference (p=0.486).It would be useful in diagnosis and treatment planning for the subjects with malocclusion in this reason. It would also aid in comparing with the standard Bolton's values. Also, both the ratios derived from the sample can be applied irrespective of gender.
