A comparative study of audiology and cone beam computed tomography in TMD patients with otological symptoms through occlusal splint therapy

Abstract

INTRODUCTION: To investigate the changes of audiological tests and the cone beam computed tomography (CBCT) measurements of temporomandibular joint (TMJ) and middle-inner ear structure after occlusal splint therapy in temporomandibular disorders (TMD) patients with otological symptoms, and explore the etiological mechanism between TMD and otological symptoms.

METHODS: The 25 subjects aged 18 to 40 years who diagnosed with TMD combined the otological symptoms enrolled in the study.They all had received orthodontic treatment in the outpatient clinic of the orthodontic department in Beijing Stomatological Hospital. All the subjects underwent the audiological tests of pure tone audiometry (PTA) and CBCT before and after the occlusal splint therapy.

RESULTS: After the stabilization occlusal splint therapy, subjects with improvement or complete remission in TMD and otological symptoms accounted for 84% and 80% in all subjects respectively. There were statistically differences in the distances between condylar center (CoC) and sella (S) in sagittal and vertical directions before and after treatment, and statistically difference between ATM and S in sagittal direction. The threshold of PTA at 8000Hz were negatively correlated with the sagittal displacement of condyle and positively correlated with the coronal displacement of condyle. The thickness of top 1/3 of anterior wall of tympanum in sagittal were positively correlated with the threshold of PTA at 4000Hz.

CONCLUSION: The changes in the TMJ position through occlusal splint therapy might cause the changes in structure of middle-inner ear, which might be one of the reasons for the improvement in otological symptoms.