A Case Report of Severe Osteoarthritis Affecting the Temporo-Mandibular Joint (TMJ) Improved with Dental Occlusal Management by Means of the Bi-Digital O-Ring Test

[Purpose] Osteoarthritis is a degenerative joint disease. In severe case, this disease sometimes leads to significant loss of subarticular bone in the condyle of the TMJ. Once serious bone loss occurs in the condyle, the occlusion becomes extremely unstable and tends to change significantly. The jaw and chin will be distorted and the teeth will not fit properly. The occlusion becomes uneven. The unstable occlusion will cause an increase in muscle activity and will cause more force to travel through the teeth and TMJ. This will put more force and torque on the already damaged joint causing more breakdown. For this reason, the occlusal management of severe osteoarthritis affecting the TMJ is considered to be one of the most difficult dental treatments. We would like to report a case of our conservative therapy for a TMJ osteoarthritis patient, with dental occlusal approach by means of the Bi-Digital O-Ring Test (OMURA, Y. 1977-2002; BDORT) . [Case] A 64-year-old female, who was working at a children’s sporting school came to our dental office with severe pain in her right TMJ. The pain had been lasting for 6 months and seemed to be getting worse. She was aware of a single click and grinding sound in her right TMJ. Especially opening motion accentuated her pain. She could open her mouth about 33mm. Interincisally, and had been taking liquid diet and little bit of soft food because of the pain. In her past dental history, 4 upper front teeth were restored with porcelain crown 30 years ago. Since then, she felt quite uncomfortable all the time. Because these front teeth were over retracted and the anterior tooth contact became narrow and tight. We found, by MRI-Examination, anterior disc displacement without reduction in the Both sides of TMJ. In the left condyle hi-level bone deformity was found, and in the right condyle there were Osteitis and bone absorption. Fig.1 Clinical Characteristics and MRI View Right TMJ: Painfull Left TMJ: Painless Condyle: Severe Deformation Right Molars: Open Bite The Jaw and Chin: Shifted Left Side Left Molars: Heavy Contact [Treatment and Results] Anti-inflammatory medications were prescribed for 2 weeks. The patient was instructed to restrict the movement of her mouth with in painless limit and to take only soft diet. At first, a piece of anterior positioning appliance was worn (4 weeks), and then stabilization type was also worn. The first purpose of anterior positioning appliance was to decrease overloading of the joint structures. The purpose of stabilization mould was to search the patient’s own acceptable treatment position of mandible. For 5 months, she was treated only by appliance therapy and some equilibration. Dr.Yoshiro Fujii’s occlusal adjustment by means of BDORT was done every other week throughout the treatment. Around 4 or 5 months later, she said the pain of TMJ decreased, and she could open her mouth about 40mm interincisally, which enabled her to eat same rice as the other member of the family ate. When she visited our office one year later, she reported that most of the TMJ pain had resolved and she could eat toast, beef steak and “sushi” with both side molar teeth. [Conclusion] In order to decide “The Adapted centric posture” of intractable T.M. Disorders, BDORT are the indispensable guiding principle for dentists.