Clinical implications of magnetic resonance imaging in temporomandibular disorders patients presenting ear fullness

OBJECTIVES/HYPOTHESIS

The aim of this study was to investigate whether findings detected by temporomandibular joint magnetic resonance imaging (TMJ-MRI) can provide pathognomonic evidence of temporomandibular disorders (TMD) in patients with nonspecific ear fullness (EF). The association of nonspecific EF with clinical characteristics of TMD based on TMJ-MRI findings was examined.

STUDY DESIGN

Retrospective analysis.

METHODS

Thirty-four subjects (42 ears) who had no detectable otologic problems as a cause of EF were enrolled in this study. Each subject underwent TMJ-MRI to identify pathology of the TMJ as a possible cause of nonspecific EF. All subjects participated in the re-evaluation process following TMD treatment.

RESULTS

Anatomical abnormalities in TMJ-MRI, irrespective of TMD signs, were observed in 34 of the 42 ears (80.9%), such as degenerative change of the TMJ (16 ears), articular disc displacement (11 ears), and joint effusion (seven ears). Specific abnormalities of the TMJ were associated with nonspecific EF, and this symptom showed improvement following individualized TMD treatment in those with internal derangement and/or effusion of the TMJ. However, abnormal TMJ-MRI findings were also observed in seven of nine ears with no TMD signs, and there was no significant association between the presence of TMD signs and abnormal TMJ-MRI findings (χ² = 0.075, P = .784).

CONCLUSIONS

Patients presenting with nonspecific EF may have TMD, which can be effectively diagnosed using TMJ-MRI. The present study revealed the causal relationship between nonspecific EF and abnormal TMJ findings based on MRI. Individualized TMD treatments based on TMJ-MRI led to improved treatment outcomes with special regard to nonspecific EF LEVEL OF EVIDENCE: 4. Laryngoscope, 128:1692-1698, 2018.

Evaluation of Round Window Stimulation Performance in Otosclerosis Using Finite Element Modeling

Round window (RW) stimulation is a new type of middle ear implant's application for treating patients with middle ear disease, such as otosclerosis. However, clinical outcomes show a substantial degree of variability. One source of variability is the variation in the material properties of the ear components caused by the disease. To investigate the influence of the otosclerosis on the performance of the RW stimulation, a human ear finite element model including middle ear and cochlea was established based on a set of microcomputerized tomography section images of a human temporal bone. Three characteristic changes of the otosclerosis in the auditory system were simulated in the FE model: stapedial annular ligament stiffness enlargement, stapedial abnormal bone growth, and partial fixation of the malleus. The FE model was verified by comparing the model-predicted results with published experimental measurements. The equivalent sound pressure (ESP) of RW stimulation was calculated via comparing the differential intracochlear pressure produced by the RW stimulation and the normal eardrum sound stimulation. The results show that the increase of stapedial annular ligament and partial fixation of the malleus decreases RW stimulation's ESP prominently at lower frequencies. In contrast, the stapedial abnormal bone growth deteriorates RW stimulation's ESP severely at higher frequencies.