The Relationship between Mandibular Midline Deviation and Tooth Wear, DMFT and TMD Findings

Aim: The purpose of this study was to determine if there is an association between a deviation of the mandibular frenal dental midline and DMFT, tooth wear and TMD findings. Introduction: Research has looked at the association between deviation of the dental midline and the impact on esthetics. There also has been some research dealing with the question of discrepancies in growth of the maxilla and mandible and right versus left side of the face. Some research has focused on midline deviation and its effect on the Temporomandibular Joint (TMJ) and the muscles associated with this joint as it relates to parafunction. There have been no studies which evaluated the effect of midline deviation and its effect on the teeth irrespective of parafunction. This study sought to find any association between these two variables. Methods: Fifty patients were selected from a general dental practice with varying degrees of mandibular frenal midline deviation. Based on previous research we determined that those with frenal midline deviation of 1mm or less to be within normal limits and those 1.5mm or greater to have excessive deviation. Each patient had clinical photographs, impressions and models of their teeth with bite registration taken in the maximum intercuspal position (MIP), and a clinical exam of teeth and the stomatognathic system based on the research diagnostic criteria for temporomandibular disorders(RDC/TMD). Results: Eighteen male and 32 female patients were selected with an average age of 48 and 42 respectively. Of these patients 23 had deviation 1mm or less and 27 had deviation 1.5mm or more. It was determined that there was a statistically significant difference in tooth wear between those with deviation 1mm or less and those with deviation 1.5mm or greater (p<0.0001), with less tooth wear in those with no deviation. There was also a significant association between tooth wear and side, with more wear on the ipsilateral side when compared to the contralateral side (p<0.0001). No significant association wasfound between midline deviation and TMD findings. Conclusion: Our research concludes that there is a statistically significant difference in tooth wear and DMFT findings in those with deviation of the frenal midline 1.5mm ormore in comparison to those who have deviation 1mm or less.