Retaining of the medially displaced condyle and disc in the surgical treatment of type III temporomandibular joint ankylosis

Purpose: To evaluate the effectiveness of retaining of the medially displaced condyle and disc in the surgical treatment of type III temporomandibular joint ankylosis.
Patients and methods: Eight patients with type III temporomandibular joint ankylosis, according to Sawhney(6) classification were included in this study. 5 males and 3 females, their ages in between 12 to 42 years with a mean of 33 years. All the patients were evaluated preoperatively both clinically (determination of maximal inter-incisal opening in mm, assessment of mandibular deviation, presence of pain on the affected joint, examination of occlusion and examination of function of the facial nerve) and radiographically (using axial, coronal and three dimensional computerized tomograms) to determine the presence of ankylosis on the lateral aspect of the TMJ and to determine the presence of medially displaced condyle. All the clinical and radiographic parameters were performed immediately, 3 months, 6 months and finally one year after surgery.
Results: Regarding to the maximal inter-incisal opening, there was improvement in mouth opening, as the mean of inter-incisal distance preoperatively was 6mm and increased after one year postoperatively to 35 mm. The visual analogue pain scale (VAS) revealed no pain after one year, from surgery in all patients. All patients showed presence of proper postoperative occlusion according with no occlusal disturbances nor presence of deviation in mouth opening toward the affected side, as the condyle was preserved and height of the ramus of the affected side was maintained during the follow up periods. No permanent damage to the facial nerve had been detected in any case. Radiographic evaluation revealed proper remolding of the reconstructed joint, no evidence of bony overgrowth no recurrence of ankylosis in all operated joints and the medially displaced condyle articulates properly with the base of the skull, medial to the glenoid fossa.
Conclusion: Retaining of the medially displaced condyle and disc during surgical treatment of type III TMJ ankylosis seems to be safe and efficient method as:- 1) The bony resection was far easier than conventional methods, as all work was carried out on lateral side of the joint. 2) There was less chance of bleeding and so, the surgery was relatively safe. 3) Preservation of the disc makes no need to use any interpositional material. 4) Preservation of the condyle leads to maintaining the ramus height and also the retained condyle can fulfilsits role in mandibular growth and function. 5) There is no need to reconstruct the joint with autogenous or alloplastic material.