Sternoclavicular Joint Transfer in the Management of Temporomandibular Joint Ankylosis- A case report

Temporomandibular joint ankylosis is a clinical condition resulting in loss of jaw function and retardation of growth. The main objectives of the treatment for Temporomandibular joint ankylosis are to increase mouth opening, restore joint function, initiation of mandibular growth, improve the patient’s facial esthetic profile and prevent reankylosis. To release of ankylotic mass and gap is filled up with interpositional material. We reported a case of temporomandibular joint ankylosis in a 15 years old girl, whose treatment was done in the Department of Oral and Maxillofacial Surgery,Bangabondhu Sheikh Mujib Medical University, with sternoclavicular joint transfer which is very rare in our country and this was nearly fulfill treatment objective.


Introduction
Temporomandibular joint ankylosis is one of the most distressing clinical conditions resulting in loss of jaw function and impairment of growth. The Temporomandibular joint ankylosis leads to facial asymmetry resulting in psychosocial problems in the affected patients. Unilateral ankylosis is associated with chin deviation to the affected side, vertical deficiency of the maxilla and the mandible on the side of defect, retrognathic mandible with short ramus, convex facial profile, absent or deficient cervico-mental angle, fullness of face on affected side, flatteneing on unaffected side, and prominent antigonial notch. The intra oral features includes occlusal cant with deviation of maxillary and mandibular midlines toward the affected side, class II malocclusion although class I occlusion may occasionally be seen, posterior cross bite, severe oral hygiene problems leading to caries and dental problems. Treatment for Temporomandibular joint ankylosis are to improve mouth opening, restore joint function, allow for mandibular growth, improve the patient's facial profile and prevent reankylosis. 1 The etiology of recurrence of ankylosis has been postulated to be failure to have aggressive physiotherapy, poor compliance by the patient. Kaban postulated that recurrence could be due to inadequate excision of ankylotic mass .2 In view of the technical difficulties and high incidence of recurrence the surgical management of temopormandibular joint ankylosis poses a significant challenge to both the surgeons and the patients. The various techniques for surgical correction of TMJ ankylosis are gap arthroplasty, interpositional arthroplasty, and joint reconstruction. 3 Numerous materials have been suggested for reconstructing of TMJ. Traditionally, the costochondral grafts have been used for reconstruction of TM Joint in ankylosis patients, but because of the unpredictable growth, warpage, and fracture of the costochondral grafts have created a background for dissatisfaction and prompted a search for an alternative. 4 It is observed that in humans the sternoclavicular joint and temporomandibular joint are similar anatomically and physiologically. 5 This similariy of the joints have encouraged the surgeons to use SCG as an alternative to costochondral grafts. The good functional outcome reported in the literature using SCG as interpositional material supports its usage.

Case Report
A 15-year-old girl was referred to oral and maxillofacial surgery department for treatment of right TMJ ankylosis. Her right mandible become hypoplastic. she gave history of birth trauma . Clinical examination revealed an obviously hypoplastic mandible with a class II dental relationship. The mandibular midline was 3 mm to the right of the facial midline but the occlusal plane was not canted. Maximum intraincisal opening was 1mm (Fig:1), there was no palpable movement over the right TMJ and only slight rotation on the left side. Prominent antigonial notch on the right side. Radiographic investigations confirm bony ankylosis of the right TMJ with elongation of the right coronoid processes. Following treatment plan was carried out-1. Surgery: Gap arthroplasty, Ipsilateral coronoidectomy, Harvesting of sternoclavicular joint graft and rigid internal fixation.

Physiotherapy: Aggressive use of continuous passive movement (CPM)
The surgery was done under general anesthesia with tracheotomy intubation. Submandibular and preauricular approach was used to reach the site of ankylotic mass. Right sided gap arthroplasty and coronoidectomy were done. Same sided sternoclavicular joint graft was selected for harvest and harvesting was done through infraclavicular transverse incision. Harvesting graft was replaced in the gap (Fig.2) and fixed to right ramus with 2 bicortical screws. Care was taken to maintain vertical height of ramus. Then lateral pteregoid muscle was sutured with sternoclavicular joint graft. Closing was done layer by layer. Immediately 2 days after surgery her mouth opening was 30 mm, there was no posterior gaging and anterior open bite, all TMJ movement were slightly present.
In the follow up visit her mouth opening was increase (35 mm) (Fig 3), occlusion is satisfactory , chin throat angle was decrease so improvement of facial esthetics, her chest x-ray reveled partially bone formation of harvested site of clavicle, patient satisfaction is very high.

Discussion
TMJ ankylosis is a distressing clinical condition causing complex problems as inability to open the mouth, chewing difficulties, speech impairment, facial asymmetry, airway compromise as well as a psychological stress to the patients. The main objectives of the treatment for Temporomandibular joint ankylosis are to increase mouth opening, restore joint function, initiation of mandibular growth, improve the patient's facial esthetic profile and prevent re-ankylosis. 1 The various techniques for surgical correction of TMJ ankylosis are gap arthroplasty, interpositional arthroplasty and Joint reconstruction. 3 In this case report unilateral ankylosis was considered for case selection. Unilateral TMJ ankylosis presents with, a short ramus, flat gonial angle, deviation of chin to affected side and hence there is a need to provide a graft with    15 Sarnet and Laskin postulated that SCJ and TMJ are similar anatomically and physiologically. The SCJ articulation has a growth centre, interarticular fibro articular disc that simulates the disk of the TMJ.
In this case, there was a complete regeneration of clavicle minimizing donor site morbidity. The post operative complications were nil except for a mild scar in the donor site, which was acceptable. The postoperative mouth opening was highly satisfied with a maximum mouth opening of more than 35mm. The growth of the reconstructed TM joint was evaluated with orthopantomogram, & CT scan. The complete regeneration of the SCG was also observed with chest x ray. The reconstruction of TMJ with SCG has been proved to be successful in this reported case.

Conclusion
The outcome revealed that anatomic resemblance of SCG to TMJ and there was no donor site morbidity. The mouth opening was normal (more than 35mm) during the follow up period after the reconstruction of the TMJ with SCG. The patients were subjectively satisfied with the outcome. With an impressive benefit , the sternoclavicular graft could be a versatile and viable alternative to surgeons in reconstruction of TMJ and relatively simple to carry out with minimal complications and good results.