Abstract
Purpose: The effect of a mouthguard (MG) on the temporomandibular joint remains unclear. In this study, we aimed to clarify how differences in the occlusal MG support affect condylar displacement during clenching, by determining and examining the condylar displacement during maximal voluntary clenching (MVC) for three different kinds of occlusal support.
Methods: The study consisted of ten healthy adults (mean age:27 years) with healthy natural dentition. Three different kinds of occlusal MG support were prepared (Type 77 provided occlusal contact for all teeth, from the anterior teeth to the second molar; Type 66 provided occlusal contact up to the first molar; and Type 47 provided only posterior occlusal contact). Condylar displacement during MVC was determined by the Win Jaw system® (ultrasonic motion analyzer) for the intercuspal position (ICP) and while wearing the three kinds of MG support.
Results: Compared to ICP, the extent of condylar displacement during MVC was significantly greater for superior displacement of Type 77 and Type 66.Furthermore, compared to ICP data, anteroposterior displacement was significantly greater for Type 66,and was significantly greater for Type 66 and Type 47, compared to Type 77.
Conclusion: It was also found that loss of anterior or posterior occlusal support decreased anteroposterior stability. There was significant individual variation in the distance and direction of condylar displacement under each occlusal support condition. This study could not identify which occlusal support condition was better.
