Conservative therapy in patients with anterior disc displacement without reduction using 2 common splints: a randomized clinical trial.

Purpose: We performed a comparative evaluation of different types of splint therapy for anterior disc displacement without reduction (ADDWR) of the temporomandibular joint.
Patients and Methods: Seventy-four patients agreed to participate (65 females and 9 males). All patients were examined using a clinical temporomandibular joint disorder examination protocol, including muscle palpation, mandibular range-of-motion measurement, and joint sound detection. Additionally, the patients marked their pain (during chewing, mandibular movements, and rest position) and limitation levels on a visual analog scale. Bilateral magnetic resonance images were acquired, confirming ADDWR in at least one joint. After clinical examination and imaging, randomized splint therapy was provided: 38 patients received a centric splint, while 36 received a distraction splint. After 1, 3, and 6 months of therapy, outcome was evaluated using the Wilcoxon signed rank test for matched pairs. Success after 6 months was defined as improvement in active mouth opening of greater than 20% and pain reduction (on chewing) of at least 50%. Success was statistically verified using logistic regression test.
Results: The improvements in mouth opening were significant in both groups. The improvements in pain on chewing, pain during other functions, pain at rest, functional limitation on chewing, and other functions were also comparable in both groups. However, the logistic regression test suggested that patients using centric splints were treated more successfully than the others (confidence interval, 1.014 to 8.741, odds ratio = 2.785).
Conclusions: Centric splints seem to be more effective than distraction splints. Therefore, before the surgical treatment of ADDWR, centric splints should be used instead of distraction splints.