A change of occlusal conditions after splint therapy for bruxers with and without pain in the masticatory muscles.

Bruxism has been suggested as an initiating or perpetuating factor in a certain subgroup of temporomandibular disorders (TMD), however, the exact association between bruxism and TMD remains unclear. This study aimed to demonstrate the difference in responses between bruxism and a subgroup of TMD to a full-arch maxillary stabilization splint from the standpoint of an occlusal condition. This study was conducted to verify the null hypothesis that there were no differences between bruxer groups with and without myofascial pain (MFP) with respect to the changes in occlusal conditions after the use of a splint. Thirty bruxers with MFP and 30 without MFP participated. Occlusal conditions were examined before and after splint therapy, and occlusal changes following the use of a splint were compared between the two groups. The frequency of occlusal changes after splint therapy was significantly higher in the MFP bruxer group than the non-MFP bruxer group (p < 0.05) for the occlusal conditions investigated in the present study. However, no statistical differences were found with regard to each occlusal condition. This result may show the variety of splint effects and may demonstrate a heterogeneous aspect to bruxism and myofascial pain.