Establishment of soft tissue norms for sagittal discrepancy for maxilla and mandible in central Gujarat population

Abstract

Objective: To establish the cephalometric norms of ‘Zero meridian line’ and ‘Mew line’ to assess the sagittal discrepancy in the maxilla and mandible of subjects in the Central Gujarat population Materials and methods: The sample was screened from the records from the hospital. 100 individuals (50 males, 50 females) of the age group between 18-50 years, native of Central Gujarat, with acceptable pleasing profile, no skeletal asymmetry, normal Class I occlusion having ideal anterior bite, less than 2 mm crowding and no history of previous orthodontic treatment were selected for the study. Lateral cephalograph were taken in natural head position. The linear measurements between points of soft tissue pogonion to the Zero Meridian line (vertical line dropped from soft tissue nasion) and distance of Mew line (the biting edge of the upper front teeth to the tip of the nose) was taken on cephalograms. Result: Mean value for soft tissue pogonion to the Zero meridian line on cephalograms was 0.2 mm for female and 0.8 mm for male and mean value for Mew line on cephalograms was 39 mm for female and 42 mm for male subjects. Conclusion: Normal value for soft tissue pogonion to the Zero meridian line is 0.8 + 1.8 mm for males and 0.2 + 1.7 mm for females, and normal value for Mew line is 41.2 + 3.2 mm for male and 39.4 + 2.2 mm for female in Central Gujarat population. Values other than normal suggests skeletal sagittal discrepancy of maxilla and/or mandible, which is helpful in diagnosis and treatment planning.