Abstract
The authors present a review of seven patients (eight joints) with temporomandibular ankylosis treated between 2007 and 2008. The aim of this retrospective study was to present the experience of using full thickness skin-subcutaneous fat grafts, harvested from the patient’s abdomen as interpositional material after gap arthroplasty. All patients presented with osseous ankylosis and were graded according to Topazian’s classification. Postoperative follow up ranged from 12 to 24 months. Maximal inter-incisal opening (MIO) on presentation ranged from 0 to 8 mm, which stabilized to 27–44 mm at follow up. There was no evidence of re-ankylosis. This study found merit in the use of autogenous full thickness skin-subcutaneous fat graft as an interpositional material for up to 2 years following ankylosis release.
Over the past decade, a variety of techniques have been proposed to prevent postoperative fibrosis and recalcitrant bone formation after gap arthroplasty for temporomandibular joint (TMJ) ankylosis. Ankylotic bone can be likened to heterotopic, exuberant callus that replaces the gleno-temporal articulation, impedes function and has the capacity for aggressive regrowth. Current surgical management aims to restore joint function by interpositional gap arthroplasty and joint reconstruction. The use of the word ‘function’ as applied to the TMJ is controversial as it refers to two objective measurements: inter-incisal opening and contralateral excursive movements. Several authors support aggressive resection and the use of an interpositional material to convert the ankylotic joint into a functioning pseudoarthrosis . Post resection, the functional joint activity relies primarily on the ostectomy created and the choice of interpositional material. In the literature, interpositional materials range from indigenous pterygomassetric slings, temporalis muscle and fascia, auricular cartilage, fascia lata, free fat dermis, and full thickness skin grafts to alloplastic materials such as silastic and silicone . The rationale behind interpositional arthroplasty is that the presence of dead space after extensive resection of callus leads to haematoma formation with subsequent organisation. Local pluripotent stem cells may then be induced to differentiate into fibroblasts and osteoblasts, with deposition of collagen and bone. A decrease in vascularity and oxygen tension occurs in the surrounding tissues, favouring the transformation of fibrous tissue into cartilage and bone .
The objective is to create a functioning pseudoarthrosis that prevents recurrence and provides adequate joint mobility.
Autologous dermis fat, full thickness skin grafts, and cartilage have been used as interpositional grafts in the surgical management of TMJ ankylosis with varying success . C hossegros et al. compared various autologous materials (skin, temporal muscle, irradiated costal cartilage) for interpositional arthroplasty for the treatment of TMJ ankylosis. Twenty-five patients (32 joints) were evaluated, with follow up ranging from 3 to 10 years. Ninety-two percent results were obtained in cases using full thickness skin graft, 83% in cases using temporal muscle, and irradiated costal cartilage yielded poor results.
C hossegros et al. conducted a retrospective study of 31 patients treated for TMJ ankylosis with full thickness skin graft interposition with good postoperative results and with only one case developing an epidermoid cyst. Skin quality was implicated in the occurrence of this complication as the patient manifested with severe acne.
D imitroulis interposed dermis fat grafts in 11 patients for the management of TMJ ankylosis and found that the interposition of dermis fat was effective in the prevention of re-ankylosis. They reported consistently good results at 6-year follow up, with only one case of re-ankylosis. M ehrotra et al. studied dermis fat versus temporalis fascia in the management of TMJ ankylosis in children. Maximal inter-incisal opening (MIO) in the dermis fat group was significantly higher than in the temporalis fascia group (the probable aetiology being postoperative muscle scarring).
In an endeavour to derive benefits from two accepted interpositional materials, the present authors used full thickness skin-subcutaneous fat grafts in the surgical management of TMJ ankylosis.
Materials and methods
A retrospective clinical evaluation of seven consecutive patients (eight joints) was conducted. There were two men, four women and one child with a mean age of 27.2 years (range 14–39 years). Four patients had a history of multiple surgery for ankylosis release at various centres in rural India. Three patients were cases of post-traumatic adult ankylosis. At presentation, the MIO ranged from 0 to 8 mm. The patients’ TMJ ankyloses were assessed clinically and radiographically. Complete ankylosis was graded according to radiographic findings as described by T opazian ; two cases were grade 1, four cases were grade 2 ( Figs 1 and 2 ), and one case was grade 3.
Details on the cause, duration, extent, MIO, secondary osseous changes, and previous surgery were evaluated. Four patients who had undergone previous surgery for ankylosis release presented with extensive fibrosis, scarring and no details of previous surgery. The authors were unable to gauge whether temporalis flap/fascia had been used previously. For the patients with post-traumatic adult ankylosis, it was decided to preserve the temporalis/fascia to facilitate a secondary rescue procedure, should any complications arise from the use of a full thickness skin-subcutaneous fat graft.
All the patients underwent gap arthroplasty ( Figs 2 and 3 ) with subsequent interpositioning with full thickness skin-subcutaneous fat grafts harvested from the lower abdomen ( Figs 4 and 5 ). Patients were operated on between 2007 and 2008 and were followed up for a minimum period of 12–24 months after surgery.
