Splint therapy is a major type of conservative therapy for patient with temporomandibular joint disorders. In particularly, application of splint is useful therapy for anterior disc displacement with reduction case because mandibular position to be obtained in treatment goal as disc recapture position. However, the relationship between the disc and condyle are normal only when the splint is placed to maintain the mandibular position guided by the splint. Therefore, it is important to stabilize the mandibular postion guided by the splint as much as possible by using prosthetic or orthodontic technique for reconstructing normal occlusion. We report a case in which a patient was given orthodontic treatment 17 years ago and seemed to obtain functional occlusion. However, in the passed ten year after posttreatment, the patient had bilateral internal derangement of temporomandibular joint of disc displacement with reduction. Based on axiograph and MRI findings, we considered that clicking during mouth closing occurred in the mandibular position in which the displaced disc returned to the normal position on the condyle, and performed splint therapy, by which disappearance of clicking and subjective symptoms were obtained. We stabilized occlusion by the splint and tooth movement, setting the mandibular position as the position to be obtained in the treatment goal, and reconstructed occlusion was obtained with disappearance of all clinical symptoms. We retained the finally obtained mandibular position using a functional appliance (FA), and retention was maintained three years and nine months after post treatment.
At present, it is considered that lesion spread from infected root canal can be cured under normal conditions if proper root canal treatment is performed. However, if lesion is not on the root apex but on the lateral face, it is necessary to take heed of the types of operation as well as post-operation course. At this paper, I would like to report a clinical case of trying to save a tooth with severe lateral lesion.