Effects of Anterior Repositioning Splint on Temporomandibular Joint Positional and Morphological Parameters and Facial Symmetry in Patients With Temporomandibular Disorders and Functional Mandibular Deviation: A Prospective Study.

BACKGROUND: Anterior repositioning splint (ARS) alleviates temporomandibular disorders (TMD) by sagittal correction of jaw via cusp-to-fossa relation, which can also correct transverse positional deficiency. Therefore, ARS may have therapeutic effects on mandibular deviation (MD) related TMD. OBJECTIVES: To investigate the temporomandibular joint (TMJ) positional and morphological parameters and facial symmetry in patients with MD and evaluate the therapeutic effects of ARS treatment on these parameters in patients with TMD and functional MD. METHODS: CBCT, MRI, and 3D facial images of patients with or without MD were compared in the case-control study. Effects of ARS treatment were evaluated and compared at pre-treatment (T0), the therapeutic occlusal position (T1) and post-treatment (T2) in the prospective study. RESULTS: Forty patients (20 MD, 20 control) were recruited for the case-control study. Bilateral condylar height of the MD group was smaller than that of the control group, with the deviated side smaller than the contralateral side. Condylion Y-axis and X-axis of the deviated side were larger than those of the contralateral side. Disc-condyle angle and internal distance of the disc of the contralateral side were larger than those of the control group. 18 patients (15.40 ± 4.30 years) were included in the prospective study. Y coordinate of the condyle and disc-condyle angle reduced in T1 compared to T0. External distance of the disc of both sides and Condylion Z-axis and Y coordinate of the condyle of the contralateral side decreased in T2 compared to T0. CONCLUSION: Mandibular deviation is accompanied by asymmetry in TMJ and facial soft tissues. ARS treatment might contribute to improving TMJ positional symmetry, implying its potential therapeutic value for patients with TMD and functional mandibular deviation.