Kazuhiro Yamada

Matsumoto Dental University, Japan

It has been reported that etiology of temporomandibular joint disorders (TMD) has been thought to be multifactorial and an imbalance between tolerance of host in TMJ and mechanical stress to temporomandibular joint (TMJ) causes TMD. Treatment options include patient education and self-care, cognitive intervention, pharmacotherapy, physical therapy, orthopedic appliances, occlusal therapy, and surgery. In practice, they should be used in combination depending on the needs of the patients. When multiple contributing factors are present, and especially if the condition is chronic, a pain management program with a team of clinicians may be needed. All management programs should be time-limited and not left open-ended.On the other hand, many patients with disc displacement (reducing and non-reducing) or TMD can perform painless jaw function with the disc displaced. The internal derangement of the TMJ often exhibits a natural progression of compensatory adaptation and remodeling. Even with progression to osteoarthritic changes, the outcome is typically benign with acceptable masticatory function. However, the inhibition of mandibular growth and idiopathic changes of mandibular position (progressive Class II relation) due to osteoarthritis has been reported. These active condylar resorption causes the mandibular retrusion. These patients has the low tolerance of condyle to the loading, the orthognathic surgical treatment for them will be difficult. Although it has been reported that hormonal balance, disease, trauma, parafunction, psychological factors and occlusion are associated with condylar bony change, the cause of these idiopathic condylar resorption remains unclear.
I have been treating patients with TMD and also been studying on the relations of mandibular movement, clinical symptoms and craniofacial morphology to TMJ pathology to investigate the factors for idiopathic condylar resorption.My presentation will shows the etiology, diagnosis and treatment for mandibular retrusion patients with TMD, especially osteoarthritis as well as some case presentations with helical computer tomography and magnetic resonance images. It will also give you the criteria for high risk in patients with osteoarthritis.