Evaluation of facial and dental midline deviations in children

Background: The diagnosis of den to-facial asymmetry has been discussed significantly, but the esthetic significance of facial and dental midline symmetries has been inconclusive with respect to upper and lower arch dentition. Aim: The purpose of the present study is to evaluate the extent of deviation of dental midline from the facial soft tissue midline and its association with different malocclusions. Materials and Methods: This cross sectional double blind study was conducted in a randomly selected sample of 500 children of 12-17 years. The molar relation and the presence of any malocclusions were noted. Impressions of both maxilla and mandibular arches were made in each subject and study cast were prepared. The following three points were marked on the face: bridge of the nose, base of the upper lip and chin to determine the facial midline. The dental midline(DMD) was assessed by verifying the coincidence of the vertical lines between the central incisors in the maxillary and mandibular arch. Results: All the data obtained was subjected to statistical analysis using chi square test. The study population consisted of 500 subjects, for statistical convenience the group of the subjects were divided into three groups 12-13 years, 14-15 years, 16-17 years. The coincidence of facial and dental midline (FDMC) was found to be statistically significant in 12-13, 14-15 years age groups (pvalue-0.00). No statistical significance was found in 16-17 years age group. Conclusion: FDMC and minor discrepancies as less as 2mm should be considered as normal and an important objective in orthodontic treatment planning.