Disk-repositioning onlays in the treatment of temporomandibular joint disk displacement: comparison with a flat occlusal splint and with no treatment.

Sixty-three patients with an arthrographic diagnosis of disk displacement with reduction were randomly assigned to three treatment groups: (I) onlays to maintain disk repositioning, (II) flat occlusal splint, or (III) untreated controls. Guidance for construction of the disk-repositioning onlays was established during arthrography to obtain a recaptured disk position relative to the condyle. The onlays were cemented to the teeth and maintained the new intercuspal position anteriorly and inferiorly. The flat occlusal splint was used at night only and was adjusted to maintain a maximal occlusal contact in centric relation and centric occlusion. Clinical examinations were performed before and after 6 months of treatment. The disk-repositioning onlays improved joint function and reduced joint and muscle pain when compared with the flat occlusal splint and with nontreatment. The signs and symptoms in the flat occlusal splint group were no different from those in the control group. It is concluded that disk-repositioning onlays are effective in reducing pain and dysfunction associated with disk displacement with reduction in patients in whom the disk can be maintained in a normal relationship to the condyle with the aid of such onlays. The symptoms, however, returned when the onlays were removed after 6 months; this raises the question of whether a permanent change in the intercuspal position is necessary for long-term success.