Evaluation of the Relationship between Occlusal Interference and Bruxism

Statement of Problem: Bruxism is an oral habit consisting of involuntary rhythmic or spasmodic nonfunctional gnashing, grinding, or clenching of teeth, in other than chewing movements of the mandible, which may lead to occlusal trauma, tooth wear and fracture of the teeth. It would be useful to determine the relationship between occlusal interferences and bruxism in order to prevent its development by occlusal interference adjustment. Purpose: This study evaluates the relationship between occlusal interferences and bruxism. Materials and Methods: For this study, 59 subjects (22 males and 37 females) including 28 bruxers and 31 nonbruxers were selected after filling a questionnaire based on the exclusion criteria. Occlusal interferences in the centric relation and eccentric movements in the two groups were evaluated and recorded. Data were analyzed by SPSS software (Version 16) using Chi-square test. Results: The results showed that there was a statistically significant relationship between bruxism and protrusive interferences ( p <0.05) while there was no statistically significant relationship in the centric relation and other eccentric movements ( p >0.05). Conclusion: According to the results of this study, due to the relationship between some types of occlusal interferences (protrusive interferences) and bruxism, it would be useful to examine occlusal contacts in bruxing patients to eliminate probable causative or contributing occlusal factors.