Temporomandibular joint ankylosis-"Knowing when not to operate": Case report and qualitative systematic review of literature.

Temporomandibular joint ankyloses (TMJA) may manifest in patients with several predisposing systemic conditions. A case of extraarticular TMJA is presented in a patient diagnosed with fibrodysplasia ossificans progressive (FOP) is presented. The features, diagnosis, and management of TMJA superimposed on this condition are presented through a qualitative systematic review of literature.

The Application of Pre-operative Three-Dimensional Models in the Management of Mandibular Pathology: Is it Really Useful? An Institutional Study.

AIM: To assess the usefulness of 3D models for the surgical management of mandibular pathology requiring resection with continuity defects reconstructed using reconstruction plates. PATIENTS AND METHOD: A bidirectional study was conducted in 40 patients, 20 each in group 1 and 2. Group 1 included those patients taken up for resection with continuity defects and reconstruction using reconstruction plates without using 3D models and Group 2 included those patients managed similarly with 3D models. Pre-operative pathological model and mirrored model was fabricated for accurate placement and pre-bending of plates and determining the position and length of the screws. The level of understanding of the patients with regards to the diagnosis and extent of the disease (VAS 0-10), treatment planning (VAS 0-10), accuracy of fixation by a blinded surgeon (VAS 0-5), operative time, change in the mouth Opening, occlusal disturbance, implant-related complications was assessed as outcome measures and tested statistically. RESULTS: The level of understanding of the patients with regards to the diagnosis and extent of the disease, treatment planning, operative time and accuracy of fixation was found to be statistically significant with superior performance in Group 2. No statistical significance was elicited in the change in mouth opening. No limitation in the mandibular range of movements and occlusal disturbance was found in any patient. No implant-related complications were found during the follow-up. CONCLUSION: 3D model fabrication can serve as a valuable adjunct in improving clinical outcomes with minimal operating time, increased patient compliance and radiological accuracy of fixation.

Novel hypotheses related to Temporomandibular joint derived from Ankylosing spondylitis.

Ankylosing spondylitis (AS) is a seronegative arthropathy that affects fibrocartilaginous joints leading to arthritis and eventually ankylosis. Temporomandibular joint (TMJ), a fibrocartilaginous joint is affected to a lesser extent than the other joints, very rarely precipitating TMJ ankylosis. No explanation exists for the same in the present literature. Several hypothesis have been presented to explain this phenomenon of rarity of TMJ ankylosis in AS. The presence of an intraarticular disc acts as a physical barrier to the ankylotic process. However, in cases with AS, that present with TMJ ankylosis, this hypothesis needs several clarifications since the intraarticular disc is a constant phenomenon in TMJ. The cause of TMJ ankylosis in these cases might be explained by two hypotheses. Firstly, Pathological condylar loading in some cases; secondly, an application of the orthopaedic concept of functional enthesis to the TMJ disc and thirdly, an application of the concept of enthesis organ to TMJ. Using these hypotheses, important concepts on the anatomy and evolution of TMJ can be derived with evidence from literature. The intraarticular disc may be considered as an involuted tendon of the lateral pterygoid muscle which not only attaches to the mandibular condyle but also to the temporal bone via a elastic fiber mediated enthesis extending to the malleus through the discomalleolar ligament. The fibrocartilaginous changes that occur on the undersurface of the disc may support the concept of functional enthesis and provide a reverse evidence for the disc being a tendon. The evidence presented from extant monotremes may also throw light on the embryological development of the articular disc. These evidences are more of an anecdote than being focussed. Several scientific experiments, studies and data collection needs to be carried out to validate them. The proof of these hypotheses will be of use in establishing the development and role of the articular disc in TMJ function and TMJ disorders, including AS. The understanding of the role of the articular disc is important since many firstly, TMJ disorders are being treated by discectomy with good results, apparently rendering the disc vestigial and secondly, in the era of tissue engineering where efforts are being made to artificially produce articular disc and its analogues.

Evaluation of Total Alloplastic Temporomandibular Joint Replacement in TMJ Ankylosis.

INTRODUCTION: Total joint reconstruction using autologous or alloplastic materials is one of the treatment options for the reconstruction of the affected joint in TMJ ankylosis. The clinical results of alloplastic TM joint replacement (Biomet Microfixation system) that was carried out for the treatment and reconstruction of TMJ ankylosis have been summarised. MATERIALS AND METHODS: A retrospective analysis of eight cases clinically and radiographically diagnosed as TMJ ankylosis with minimal facial asymmetry presenting beyond the growth period and willing for at least 12 months of follow-up who have been taken up for gap arthroplasty and reconstruction using Biomet Microfixation TMJ replacement system was carried out. Follow-up of these patients was carried out at regular intervals and assessed on the following criteria: maximal interincisal mouth opening, TM joint pain on the affected side (on VAS), lateral mandibular excursions to the unaffected side deviation on mouth opening, occlusal discrepancy and neuromotor deficit of peripheral branches of facial nerve. RESULTS: The mean maximal interincisal mouth opening pre-surgery and 1 year post-surgery was 2 and 31.8 mm, respectively. The mean lateral excursive movement to the unaffected side was found to be 5.5 mm with mean deviation on mouth opening to be 4.6 mm. No pain, occlusal discrepancy or neurological deficit existed at the end of 1 year. CONCLUSION: Biomet Microfixation system is a viable treatment option for reconstruction of TMJ in cases of ankylosis with no major complications.