Effect of Occlusal Splint on Mandibular Movement: a Pilot Study

Method: Nine individuals with diagnosed bruxism and no signs and symptoms of TMD were included in this pilot study. An occlusal relaxation splint was made by a standardized procedure in a fully adjustable articulator (Protar Evo 7, Kavo, Germany) for each subject. Recordings for fabrication of splints and for mandibular range of movements were obtained by an electronic ultrasound measuring device (Arcus Digma II, Kavo, Germany), by using the kinematic axis as the posterior reference point. Measurements were made initially and after 2, 4, 8 and 12 weeks of wearing the splint. Each subject performed opening and closing, laterotrusion to the left and right and Posselt`s movement in the sagittal and horizontal axis, based on which opening incisal, opening left condyle, opening right condyle, laterotrusion left and laterotrusion right were calculated as parameters for mandibular range of movements.

Result: The mean values of all tested variables increased slightly with increasing of the follow-up time. Laterotrusion left had the highest and opening right condyle the lowest increase. The results of variance analysis showed no statistically significant difference among the groups of the tested parameters at the significance level of p<0.05.

Conclusion: The results of the study show that occlusal splint increases the range of mandibular movements in every parameter. Lack of statistically significant difference can be explained by the fact that the splint is a symptomatic therapy for bruxism and that the subjects had no signs and symptoms of TMD. This study shall be extended by increasing the number of subjects and introducing a control group for establishing the exact effect of the splint on mandibular movements.