The method of manually reducing (manipulating) temporomandibular dislocation began with Edwin Smith Papyrus of the BC era and has thus been known for a long time. A variety of reduction methods have been reported, including Hippocrates' method of reducing from in front of the patient, Borchers' method of reducing from behind the patient, a method of picking up the ears, a method using a lever such as a cork, and a method by striking. Findings have also been presented. Symptoms at the time of dislocation have also been observed in detail, and dislocations have been classified. The bandage method after reduction appears to be widely used.

According to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD), which was published in 2014 and includes the item "Headache attributed to TMD", TMD experts are expected to diagnose this headache. However, when TMD experts (dentists) apply this diagnostic system in clinical settings, there is difficulty in differentiating it from other headaches.

Various headaches mimic "Headache attributed to TMD"; this article describes Medication-overuse headache (MOH) as a diagnostic pitfall for dentists.

MOH is a headache developing in patients with primary headache who take excessive amounts of therapeutic agents, eventually developing a chronic pattern of headache. These headaches usually resolve after discontinuing the offending drugs.

The characteristics of MOH headache include a continuous dull/aching pain, occurring from dawn or early morning and continuing all day. When the pain expands to the anterior part of the head, it is occasionally felt as temporomandibular or masticatory pain.

It is important to determine the half of headache sufferers who experience daily headache who are suffering from MOH. If a patient experiences daily headache, detection of MOH requires thorough elicitation of the history, particularly the drug history.

Typical treatment involves discontinuing the offending drug, while simultaneously focusing on preventative treatment against both withdrawal headache from the causal drug, and the original headache.

When "headache attributed to TMD" coexists with MOH, cooperation with a headache expert is necessary to obtain relief in the most direct manner.

There are few reports of epidemiological investigations on jaw movements in school children. We longitudinally surveyed the range of mouth opening and the clicking sounds of a total of 7,378 students in elementary and junior high school over the 10-year period from 2002 to 2011, in Niigata Prefecture. Based on these data, we studied the relationship between the range of maximum mouth opening and the body height as they grew up (in 382 students), and prevalence of clicking sound on TMJ at each age (in 133 students). The results were as follows:

1. After the 4th grade of elementary school, there was no relation between the range of maximum mouth opening and the body height.

2. The first occurrence of clicking sound on TMJ was recognized in children of the lower grades of elementary school, but it was recognized more frequently in junior high school students.

3. Regarding continuation of the clicking sound, the rate of transient cases was 49.0%. The clicking sound continued for more than two years in 28.3% of cases, and recurrence was seen in 18.9%.

We report a case of temporomandibular joint (TMJ) ankylosis caused by psoriatic arthritis. The patient was a 35-year-old male. He developed erythema of the skin and was diagnosed with psoriasis vulgaris, at approximately 30 years of age. He was referred to the Department of Oral and Maxillofacial Surgery at Tokyo Medical and Dental University Hospital of Dentistry in 1994, with the chief complaint of bilateral TMJ pain and difficulty in opening the mouth. The mouth-opening range was 32 mm. Conservative treatment based on mouth-opening exercises was initiated, but the pain did not improve. Therefore, we performed bilateral discectomy and arthroplasty of the TMJs. The mouth-opening range improved to 39 mm. However, 5 years after the surgery, the mouth-opening range decreased to 18 mm. Bilateral osseous ankylosis of the TMJs was found, so we performed bilateral TMJ mobilization. For 17 years since the surgery, he has continued mouth-opening exercises and psoriasis treatment, and his jaw movement remains good.