The temporomandibular joint (TMJ) is in contact with the temporal bone, and as a neighboring organ, TMJ disease manifests itself in the same way as otolaryngological diseases. Therefore, dentists and otolaryngologists should be concerned about common symptoms near the TMJ and ear related diseases. It is important for both departments to understand diseases near their respective areas in terms of primary care. From an otolaryngological point of view, symptoms related to the TMJ area include otalgia, ear fullness, discomfort in the ear, hearing loss, tinnitus, hyperacusis, vertigo, neck pain, discomfort in the throat, neck mass, etc. Acute otitis externa, acute otitis media, chronic otitis media (cholesteatoma), sudden sensorineural hearing loss, chronic sinusitis, allergic rhinitis, acute tonsillitis, acute parotitis, neck tumor, and laryngopharyngeal reflux disease are considered important as major differential diseases. We discuss the characteristics and details of diseases that dentists take into consideration to differentiate TMJ disorders from otolaryngological diseases based on their symptoms.

In their daily practice, dentists regularly treat patients with complaints of occlusal discomfort. Oral and maxillofacial examinations typically identify abnormalities in occlusal conditions, prosthetic devices, and temporomandibular joints. Dentists then remove the abnormalities in an effort to improve the symptoms of the patients. However, this study encountered certain patients without objective findings or whose symptoms did not improve even after eliminating abnormalities that were determined to be the cause of the symptoms. As such, these patients become distressed due to the lack of resolution despite being treated at several dental institutions.

Occlusal discomfort syndrome is a generic term for multiple diseases that may cause occlusal discomfort. Such cases have been called "phantom bite syndrome" or "occlusal dysesthesia." In 2013, the Japan Prosthodontic Society proposed a broader concept of occlusal discomfort syndrome and tentatively grouped symptoms into narrow and broad classifications, where the narrow sense reflects the abovementioned concept, such as phantom bite syndrome or occlusal dysesthesia.

The present study developed a disease classification (2021), a special questionnaire, and a biaxial rating form (2021) to identify patients with occlusal discomfort syndrome from the viewpoint of the bio-psycho-social model. Based on this information, this study developed a "Treatment flowchart for patients with occlusal discomfort syndrome (2021) " as a guideline for general dentists when treating patients with occlusal discomfort syndrome.

The purpose of the flowchart is to help improve the health of patients by using it as a treatment guideline.

Oral appliances (OA) are widely used in daily clinical practice as a reversible and conservative therapy for masticatory muscle pain and sleep bruxism (SB). However, there is insufficient evidence for their therapeutic effect. Hence, the objectives of this randomized clinical trial were to clarify the effects of OA on masticatory muscle pain and SB activity. Sixteen patients who were referred to the TMD clinic at Kyushu University Hospital with masticatory muscle pain and SB participated in this study. They were randomly allocated to either the splint group, who wore OA during sleep, or the control group. Electromyographic activity of the masseter muscle during sleep was recorded at baseline, immediately after, and 1, 4, and 6 weeks after the insertion of OA. At baseline and 6 weeks after starting the treatment, masticatory muscle pain was evaluated by a visual analog scale and muscle palpation, and Oral Health Impact Profile-49 (OHIP-49) scores were recorded. There were statistically significant differences in the muscle palpation index and OHIP-49 total score between the OA and control groups. There was a significant reduction in SB events immediately after wearing OA, but no change at 1, 4, or 6 weeks after starting the treatment. A simple correlation between SB activity and pain parameters was not found. In conclusion, OA had positive effects on both masticatory muscle pain and SB, but effects on SB were transient.

We report a case of Ehlers-Danlos syndrome treated by eminectomy for an articular eminence of the temporomandibular joint. The patient was a 34-year-old woman who was referred to us from the orthopedic department in our hospital for treatment of left condylar dislocation and pain of the left temporomandibular joint. The patient had experienced the symptom every day since junior high school and performed self-reduction each time. Dislocation had occurred two or three times per day after reaching adulthood. Radiographic findings showed flattening of the part of the left articular eminence. MRI findings showed no reduction of the left articular disc at both the closing and opening positions. Eminectomy of the left temporomandibular joint was performed. There has been no recurrence of the dislocation for a year after the eminectomy, and jaw movement remains good.