Modified gap arthroplasty and Myrhaug's incision as a treatment option in management of temporomandibular joint ankylosis: a study of 10 cases.

PURPOSE OF THE STUDY The purpose of this study was to evaluate effectiveness of modified gap arthroplasty procedure and modified Myrhaug's preauricular incision for treating bony temporomandibular joint (TMJ) ankylosis. MATERIALS AND METHODS A total of 10 cases were included in the study with Sawhney's type III and IV TMJ ankylosis. Study consisted of 6 males and 4 females. Three cases were treated for bilateral ankylosis and 7 were treated for unilateral ankylosis. All the patients were treated with modified gap arthroplasty and modified Myrhaug's incision was used. In this modification, osteotomy cuts were modified in such a way that coronoid process was also removed simultaneously along with the osteotomized ankylosed mass in one piece. RESULTS All the patients were followed up for 5 years and none of them presented with recurrence. Two patients had transient paresis to zygomatic and temporal branch of facial nerve and none had permanent damage to the nerve. Seven patients had mouth opening more than 25 mm (p) when followed for 5 years. Anterior open bite was seen in 4 patients and deviation of the jaw on ipsilateral side was noted in 2 patients. CONCLUSION Modified gap arthroplasty gave successful results in the follow-up period and eliminated the need of separate coronoidectomy. Use of modified Myrhaug's preauricular approach, provided excellent visibility particularly of the elongated coronoid process, minimized bleeding, prevented damage to the vital anatomical structures surrounding the joint and gave acceptable cosmetic results. CLINICAL SIGNIFICANCE The modified incision has been found to be reducing intra- and postoperative morbidity as well as provides excellent accessibility. The modified osteotomy technique eliminated the need for separate coronoidectomy thus significantly reducing the operating time.