Endoscopic-Assisted Repair of Spontaneous Temporomandibular Joint Herniation Through a Transcanal Approach

Temporomandibular joint herniation into the external auditory canal presenting as clicking tinnitus: A case report

BACKGROUND

Herniation of the temporomandibular joint (TMJ) into the external auditory canal (EAC) due to a bony defect in the EAC is rare. Such bony defects can be secondary to inflammation, neoplasm, trauma. In rare instances, TMJ herniation can occur when the Huschke foramen is constantly exposed. TMJ herniation can induce clicking tinnitus, otalgia, conductive hearing loss, and otorrhea, but can also present with no symptoms. This study reports a case of TMJ herniation.

CLINICAL PRESENTATION

A male patient presented with clicking tinnitus that had developed 3 years ago. Dome-shaped soft tissue was found on the anterior EAC wall, which protruded and depressed with mouth movement. The patient underwent surgical reconstruction of the bony defect with titanium mesh, and the symptoms resolved after surgery.

CONCLUSION

This case highlights the importance of surgical reconstruction of a bony defect in the EAC using appropriate materials.

Finding the Silver Bullet for Persistent Foramen Hushke

We report a case of persistent foramen Hushke and embark on a literature search from 1990 to 2021. The search was done using electronic databases of PubMed and Google Scholar using the MESH words 'TMJ herniation', 'persistent foramen Hushke', 'TMJ prolapse', 'EAC dehiscence', and 'ear canal mass'. A total of 37 other case reports were included after excluding duplicates and non-English publications. The most common presentations, treatment modalities, complications, and outcomes were discussed. Common presentations include otalgia, tinnitus, otorrhea, and aural fullness. Surgical intervention shows a good outcome, whereas conservative treatment shows a mixed response. Despite the overwhelming success of surgical interventions in treating symptomatic persistent foramen of Hushke, it is still early to establish a guideline to manage these patients, as this condition is rare and presents with variable symptoms. More high-quality studies and a long-term follow-up of the patients may be essential to observe and compare the outcome and recurrence rate of temporomandibular joint (TMJ) herniation.

Robotic and Microrobotic Tools for Dental Therapy

Robotic and microrobotic tools such as dental operating microscopes and dental endoscopes are being used extensively in dental therapy, which have a significant impact on dental therapy and education. Herein, this paper reviews the state of the art of robotic and microrobotic tools for dental therapy. This article starts with a brief introduction of current robotic and microrobotic tools for dental therapy and then displays their applications in various dental problems; strengths and weaknesses are also surveyed. Lastly, the conclusion and outlook are discussed, referring to the emerging dental clinic problems and demands. This review is expected to provide guidelines for the therapeutic application of robotic and microrobotic tools and to promote the development of robots in dentistry.

Parotidectomy in the management of squamous cell carcinoma of the external auditory canal

PURPOSE

To investigate optimal approaches for appropriate removal of the parotid gland in the management of squamous cell carcinoma (SCC) of the external auditory canal (EAC) at different tumor stages.

METHODS

In total, 39 patients with SCC of EAC treated at the Second Affiliated Hospital of Nanchang University between September 2003 and April 2019 were enrolled in this study. All patients underwent lateral temporal bone resection or subtotal temporal bone resection. Total parotidectomy was performed in patients with direct parotid invasion. Superficial parotidectomy was performed in patients with parotid node metastasis and patients with advanced stages without evidence of parotid involvement.

RESULTS

The mean follow-up period was 68.7 months. Local recurrences or distant metastases occurred in five patients (12.8%). The 5-year overall survival rate was 78.4%. The 5-year survival rate was 100% in early stage (T₁ and T₂) patients, and 58.9 and 50.0% in patients staged III and IV, respectively. Direct parotid invasion was observed in only advanced-stage patients, while parotid node metastasis was noted in both early and advanced-stage patients preoperatively. There were no significant differences (χ² = 0.1026; p = 0.749) between different tumor primary locations. However, soft tissue or preauricular organs became vulnerable once the anterior wall was infiltrated or eroded.

CONCLUSION

Parotid management is important for achieving safer and wider tumor-free margins. Total parotidectomy should be mandatory for all advanced-staged (T₃ and T₄) patients. An optimal decision for parotid management in early stages depends on the infiltration or erosion of the anterior wall of the EAC.

Temporomandibular joint herniation into the middle ear: A rare cause of mastication-induced tinnitus

A 75-year-old patient complained of mastication-induced clicking tinnitus on the left side, and otoendoscopic examination revealed that the left tympanic membraneTM was outwardly bulged by clenching her teeth. Temporal bone computed tomography demonstrated that the posteromedial bony wall of the glenoid was partially dehiscent, allowing herniation of soft tissue contents of temporomandibular joint into the middle ear. Increased middle ear pressure due to soft tissue herniation can induce left tympanic membrane bulging and accompanying clicking tinnitus. Herniation of temporomandibular joint soft tissue into the middle ear should be considered as a differential diagnosis when clicking tinnitus is evoked by mastication.