Is there a link between tinnitus and temporomandibular disorders?

STATEMENT OF PROBLEM: The frequent concurrence of tinnitus and temporomandibular joint and masticatory muscle disorders (TMD) has led to the assumption that a possible relationship exists between these 2 conditions. PURPOSE: The present prospective clinical study was conducted to assess the possible association between tinnitus and TMD and to investigate the effect of stomatognathic therapy on tinnitus distress. MATERIAL AND METHODS: The prevalence of TMD and tinnitus was investigated in a consecutive series of 951 patients at the Department of Prosthetic Dentistry at the University Medical Center Regensburg, Germany. Patients with TMD and simultaneous tinnitus were included in the prospective clinical trial (n=25). Baseline examination comprised a detailed functional analysis, diagnosis of temporomandibular joint and masticatory muscle disorder, and a tinnitus questionnaire. All the participants received individual dental functional therapy (oral splints, physiotherapy). The effects of functional therapy on TMD and tinnitus symptoms were examined 3 to 5 months after the initiation of dental functional therapy. Means (standard deviations) were calculated, and 1-way ANOVA was used to investigate statistical differences (α=.05). The differences of the 2 binary outcomes were compared with the Pearson χ(2) test, and the relative risk was calculated. RESULTS: Prevalence of tinnitus was found to be 8 times higher in participants with TMD (30 of 82 [36.6%]) than in participants without TMD (38 of 869 [4.4%]). All the participants with unilateral TMD and unilateral tinnitus showed these conditions on the same side. Stomatognathic therapy improved tinnitus symptoms in 11 of 25 participants (44%). CONCLUSIONS: The results of this study and the prospective clinical trial showed a significant correlation between tinnitus and TMD. The observed treatment outcome suggests that dental functional therapy may have a positive effect on TMD-related tinnitus

Real-time MRI of the temporomandibular joint at 15 frames per second: A feasibility study.

The purpose of this study was to develop and evaluate a novel method for real-time MRI of TMJ function at high temporal resolution and with two different contrasts. Real-time MRI was based on undersampled radial fast low angle shot (FLASH) acquisitions with iterative image reconstruction by regularized nonlinear inversion. Real-time MRI movies with T1 contrast were obtained with use of a radiofrequency-spoiled FLASH sequence, while movies with T2/T1 contrast employed a gradient-refocused FLASH version. TMJ function was characterized in 40 randomly selected volunteers by sequential 20 s acquisitions of both the right and left joint during voluntary opening and closing of the mouth (in a medial, central and lateral oblique sagittal section perpendicular to the long axis of the condylar head). All studies were performed on a commercial MRI system at 3 T using the standard head coil, while online reconstruction was achieved with a bypass computer fully integrated into the MRI system. As a first result, real-time MRI studies of the right and left TMJ were successfully performed in all 40 subjects (80 joints) within a total examination time per subject of only 15 min. Secondly, at an in-plane resolution of 0.75 mm and 5 mm section thickness, the achieved temporal resolution was 66.7 ms per image or 15 frames per second. Thirdly, both T1-weighted and T2/T1-weighted real-time MRI movies provided information about TMJ function such as disc position, condyle mobility and disc-condyle relationship. While T1 contrast offers a better delineation of structures during rapid jaw movements, T2/T1 contrast was rated superior for characterizing the articular disc. In conclusion, the proposed real-time MRI method may become a robust and efficient tool for the clinical assessment of TMJ function

Multi-slice real-time MRI of temporomandibular joint dynamics.

OBJECTIVES: The purpose of this work was to improve the clinical versatility of high-speed real-time MRI studies of temporomandibular joint (TMJ) dynamics by simultaneous recordings of multiple MRI movies in different sections. METHODS: Real-time MRI at 3 T was realized using highly undersampled radial FLASH acquisitions and image reconstruction by regularized nonlinear inversion (NLINV). Multi-slice real-time MRI of two, three or four slices at 0.75 mm resolution and 6 to 8 mm thickness was accomplished at 50.0 ms, 33.3 ms or 25.5 ms temporal resolution, respectively, yielding simultaneous movies at 2 × 10, 3 × 10 or 4 × 10 frames per second in a frame-interleaved acquisition mode. Real-time MRI movies were evaluated by three blinded raters for visibility of the anterior and posterior border of disc, shape of the disk body and condyle head as well as movement of the disc and condyle (1 = excellent, 5 = no visibility). RESULTS: Effective delineation of the disk atop the mandibular condyle was achieved by T1-weighted images with opposed-phase water-fat contrast. Compared to 8 mm sections, multi-slice recordings with 6 mm thickness provided sharper delineation of relevant structures as confirmed by inter-rater evaluation. Respective dual-slice and triple-slice recordings of a single TMJ as well as dual-slice recordings of both joints (one slice per TMJ) received the highest visibility ratings of ≤ 2 corresponding to high confidence in diagnostic content. CONCLUSIONS: The improved access to TMJ dynamics by multi-slice real-time MRI will contribute to more effective treatment of temporomandibular disorders