Disocclusion guides in occlusal splints on temporomandibular disorders and sleep bruxism: a systematic review

To determine the best disocclusion guidance in occlusal splints (OSs) to manage and treat temporomandibular disorder (TMD) and sleep bruxism (SB).The research was conducted on 7 major electronic databases and 3 gray literature sources. We included randomized trials, nonrandomized clinical trials, and before-and-after studies. The risk of bias (RoB) was assessed by Joanna Briggs Institute of Critical Appraisal Tools. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to grade the certainty of evidence.Qualitative synthesis included 16 surveys reporting data from 620 participants. Canine guidance (CG) was widely searched. Bilateral balanced occlusion (BBO) and CG significantly decreased pain levels compared with the placebo splint. Comparing between OS and absence of therapy, only CG was assessed and showed significant improvements on mouth opening, pain, sleep quality, and muscle activity. When compared different guide types among themselves, no significant improvement was founded in any evaluated outcome. Three studies presented high RoB, 7 presented moderate RoB, and 6 presented low RoB.It is suggested there is not enough evidence to support that there are any specific kind of guidance responsible for improving evaluated outcomes on TMD and SB.