1.BRIEF RESUME OF THE INTENDED STUDY:

1.1NEED FOR THE STUDY:

The Temporomandibular joint (TMJ) ankylosis is a pathological condition of the joint with restriction or total failure of the joint movement, limited mouth opening, disturbance of mandibular development in growing period of life, and serious disfigurement of an individual’s appearance, oral hygiene and functions. The speech, swallowing and chewing functions of such patients are affected to a major extent. The treatment of TMJ ankylosis poses a significant challenge because of technical difficulties and a high incidence of recurrence. Various soft tissue grafts like dermis fat pad,collagen membrane and local soft tissue flaps like temporalis fascia,temporalis muscle are used in the surgical management of temporomandibular joint ankylosis.

The rationale for using dermis-fat as an interpositional graft following osteoarthrectomy and a gap arthroplasty is three-fold. Firstly, the donor site in the thigh provides ample tissue to fill the dead space left within the joint cavity following disc removal. Secondly, the dermis-fat acts as a simple space filler for the joint cavity so as to prevent direct contact between the condylar head and glenoid fossa. And finally, the attached dermis helps to keep the fat intact to prevent fragmentation, as it is carefully trimmed before placing into the joint cavity as one piece. The purpose of this study is to investigate the fate of dermal fat pad as a interpositional graft in Tempromandibular joint ankylosis.

1.2REVIEW OF LITERATURE:

The aim of this retrospective clinical study is to present the clinical experience of using dermis-fat interpositional grafts in the surgical management of temporomandibular joint (TMJ) ankylosis in adult patients. Eleven adult patients who presented with ankylosis of the TMJ were identified and included in the study. All patients underwent a TMJ gap arthroplasty which involved the removal of a segment of bone and fibrous tissue between the glenoid fossa and neck of the mandibular condyle. The resultant gap was filled with an autogenous dermis-fat graft procured from the patient’s groin. All patients were followed up for a minimum of 2 years. Five of the 11 patients were found to have osseous ankylosis while 6 patients had fibroosseous ankylosis. Two patients had bilateral TMJ ankylosis that were also treated with costochondral grafts which were overlaid with dermis-fat graft. The average interincisal opening was 15.6 mm on presentation which improved to an average of 35.7 mm following surgery. Patients were followed up from 2 to 6 years post-operatively (mean 41.5 months) with only 1 re-ankylosis identified out of the 13 joints treated This study found that the use of the autogenous dermis-fat interpositional graft is an effective procedure for the prevention of re-ankylosis up to 6 years following the surgical release of TMJ ankylosis.1

The purpose of this study was to investigate the radiological fate of the dermis-fat graft within the temporomandibular joint (TMJ) using magnetic resonance imaging (MRI). Fifteen patients with dermis-fat grafts placed in 17 TMJs following surgery for severe internal derangement were divided into 3 equal groups according to the time lapse between TMJ surgery and the MRI investigation: 0–6 months, 7–23 months and 2 or more years. The radiological presence of fat was found within the joint or surrounding the condyle in all 17 operated joints. The interpositional material found within the radiologically defined joint space was mainly grey (Grade 3, 12 joints), suggesting tissue change to other than fat, i.e. scar or granulation tissue. Two joints showed interpositional material entirely composed of fat (Grade 1), while 3 joints showed heterogenous material composed of fat interspersed with grey tissue (Grade 2). There was no statistically significant difference in size of fat graft between the time intervals studied. Fat was present in similar quantities within or surrounding all joints regardless of the time lapse since surgery. Intermittent compressive forces of the joint may act as a negative influence on the growth and maintenance of fat tissue within the joint space itself. 2

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 skinsubcutaneous 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.3

The aim of this critical review is to determine what constitutes an ideal disc replacement material and whether any of the existing materials reported in the literature satisfy the requirements of an effective disc substitute following temporomandibular joint (TMJ) discectomy. Over the last half century a myriad of interpositional materials have been used in the TMJ but nearly all have been less than successful. The disasters that followed the early use of alloplasticinterpositional implants in the 1980s prompted the increased use of autogenously grafts in the 1990s. Whilst studies by the author on the use of dermis-fat grafts have been largely positive, there are still concerns that make the dermis-fat graft a less than ideal interpositional material for use in discectomized joint cavities. In reviewing the literature, it is clear that there is still no ideal interpositional material that satisfies all the criteria for replacement of a missing articular disc following TMJ discectomy.4

The histological fate of abdominal dermis–fat grafts implanted into the temporomandibular joint (TMJ) following condylectomy was studied. 21 rabbits underwent left TMJ discectomies and condylectomies, 6 were controls (GroupA;no graft used);15(Group B;autogenous abdominal grafts) transplanted into the leftTMJ. Animals were sacrificed after 4, 12 and 20 weeks. Specimens of the TMJ were histologically and histomorphometrically evaluated. At 4weeks,fat necrosis was clear in all specimens. The dermis component survived and formed cysts with no necrosis.By 12 weeks, viable fat deposits appeared with no evidence of necrotic fat. At 20 weeks, large amounts of viable fatwere present in GroupBspecimens. GroupAhad nofat, although the missing condyles regenerated. In the presence of viable fat, Group B showed little condyle regeneration 20weeks aftercondylectomy. Non-vascularised fat grafts do not survive transplantation, but stimulate neoadipogenesis. The fate of thedermis component of the graft is independent of the fat component. Fat in the joint space disrupts the regeneration of a new condylar head. Neoadipogensis inhibits growth of new bone and cartilage. This has clinical implications for TMJ ankylosis management and preventing heterotopic bone formation around prosthetic joints.5

1.3OBJECTIVES OF THE STUDY

The purpose of this study is to evaluate the fate of dermal fat pad as an interpositional graft in surgical management of Temporomandibular joint ankylosis and radiological evaluation of the graft using OPG, Immediate postoperative MRI and MRI between 7-20 months along with USG at the end of 3 months.

2.MATERIALS AND METHODS

2.1SOURCE OF THE DATA:

The study will be conducted in Department of oral and maxillofacial surgery. P.M.N.M Dental College & hospital, Bagalkot.

2.2METHOD OF COLLECTION OF DATA:

Seven patients reporting to the Department of Oral & Maxillofacial Surgery for the treatment of tempromandibular joint ankylosis will be included in this study. The clinical preoperative examination will focus on amount of mouth opening present, type, either unilateral or bilateral & duration of ankylosis. All the patients will undergo osteoarthrectomy and gap arthroplasty followed by placement of dermal fat pad as interpositional graft and further evaluated by OPG, MRI and USG.

INCLUSION CRITERIA:

1.Unilateral or bilateral ankylosis

2.Bony or fibrous ankylosis

3.Patients willing to participate in this study.

EXCLUSION CRITERIA:

  1. Medically compromised patient and not fit to be taken under general aneasthesia
  2. Patients who have undergone any temporomandibular joint surgeries earlier.
  3. Patients reporting with trismus other than temporomandibular joint ankylosis

2.3DOES THE STUDY REQUIRE ANY INVESTIGATIONS OR INTERVENTIONS TO BE CONDUCTED IN PATIENTS OR OTHER HUMANS:

  1. OPG
  2. MRI
  3. USG
  4. Complete blood examination
  5. Pre-operative and post-operative photographs

2.4HAS ETHICAL CLEARANCE BEEN OBTAINED FROM YOUR INSTITUTION :

Yes

3.LIST OF REFERENCES

1.The interpositional dermis-fat graft in the management of temporomandibular joint ankylosis. G. Dimitroulis .Int. J. Oral Maxillofac. Surg. 2004; 33:755–760.

2.The radiological fate of dermis-fat grafts in the human temporomandibular joint using magnetic resonance imaging. G. Dimitroulis, N. Trost, W. Morrison.Int. J. Oral Maxillofac. Surg. 2008; 37: 249–254.

3.The Versatility of full thickness skin-subcutaneous fat grafts as interpositional material in the management of Temporomandibular Joint Ankylosis.A. Thangavelu, K.SantoshKumar, AVaidhyanatham, M.Balaji, R.Narendra.Int.J.Oral Maxillofac. Surg.2011; 40:50-56.

4.A critical review of interpositional grafts following temporomandibular joint discectomy with an overview of the dermis-fat graft. G. Dimitroulis.Int. J. Oral Maxillofac. Surg. 2011; 40: 561–568.

5.Histological fate of abdominal dermis–fat grafts implanted in the temporomandibular joint of the rabbit following condylectomy. G. DimitroulisJ. Slavin, W. Morrison.Int. J. Oral Maxillofac. Surg. 2011; 40: 177–183.