The purpose of this study was to determine whether disc reduction occurred in patients with closed lock after mandibular manipulation (MM) and to analyze the factors that influenced the result.
Two hundred fifteen patients with closed lock received MM. Of these, 74 patients (79 joints) were assessed by means of magnetic resonance imaging (MRI) for disc reduction. The results of the MRI were compared with the findings from the clinical and radiographic examinations.
According to the MRI assessment, only 18% (14 of 79) of the joints had successful disc reduction. The unsuccessfully treated joints had severe joint pain, disc displacement, condylar bone change, and disc deformity.
The results of this study suggest that successful reduction of the disc by MM is rare. They also suggest that MM is least effective in the advanced stages of internal derangement, when the disc becomes deformed.