Assessment of Discectomy and Eminectomy for Temporomandibular Joint Derangement: Manitoba Experience Bachelor of Science in Dentistry (B.Sc. Dent) Thesis By: Harmeet Manghera B.Sc. Dent 2019 Supervisors: Dr. Reda F. Elgazzar and Dr. Adnan Shah Dental Diagnostic and Surgical Sciences Oral and MaxilloFacial Surgery TABLE OF CONTENTS ACKNOWLEDGEMENTS …….……...…………………………………………………..….… 3 ABSTRACT …………………………………………………………………………………..…..4 INTRODUCTION …………………………………….………………………………………….5 PATIENTS AND METHODS………………………………………………...………………….7 RESULTS………………………………………………………………………..……………......9 DISCUSSION…………………………………………………………………………...……….13 CONCLUSION…………………………………………………………………….…………….17 REFERENCES…………………………………………………………………………………. 18 2 Acknowledgements I wish to express my sincere gratitude towards my mentors Dr. Elgazzar and Dr. Shah, in the department of DDSS/OMFS, for their encouragement and supervision during this project. I am also grateful to Dr. Bhullar, the Associate Dean of Research, for running the BSc (Dent) Program through the Faculty of Dentistry, University of Manitoba. This project was partially supported by the Canadian Association of Oral and Maxillofacial Surgeons. HSC and SOGH Health Records personnel provided the resources needed to complete this thesis. It would not have been possible without their help. I am thankful for my parents for providing moral support and encouragement along the journey. 3 Abstract Temporomandibular joint disorder (TMD) is caused by the loss of function of the intra- articular tissues, leading to a failure in the biomechanics of the joint. Non-surgical modalities and less invasive surgical procedures such as arthroscopy are usually employed to manage patients with TMD in their earlier stages of the disease. Many patients respond well to such modalities while others fail to show satisfactory improvement. Hence, they qualify to be treated with more invasive open joint surgery such as arthroplasty. The aim of this study was to assess the surgical outcomes of temporomandibular joint (TMJ) arthroplasty, discectomy and eminectomy for the management of the refractory TMD cases. The retrospective chart review was conducted on TMD patients who were diagnosed and treated with arthroplasty, eminectomy and discectomy at the Health Sciences Centre (HSC) and the Seven Oaks General Hospital (SOGH) between the years of 2011 and 2017. The University of Manitoba Research Ethics Board (REB) provided approval for the project. A data capture sheet was created for data collection. Pre-operative, intra-operative and post-operative information was recorded. Eight (22%) males and 28 (78%) females incorporated the study group with ages ranging from 17 to 68 years with a mean of 40.4 years. The follow up period ranged from 1 to 29 months with a mean of 8.6 months. All patients had adequate recovery after receiving the arthroplasty supplemented with post-operative physiotherapy. Majority of these patients showed a noticeable increase in the range of jaw motion and a reduction in pain. No major complications were reported, a few minor complications were observed including numbness of the ear, transient weakness of the surrounding muscles due to impingement or stretching of the facial nerve and minor scar formation on the skin. The results show that TMJ arthroplasty is an effective and definitive surgery for the treatment of refractory TMD. Key Words: TMJ Internal Derangement, TMD, TMJ Arthroplasty, Discectomy, Eminectomy 4 Introduction Temporomandibular Joint Disorder (TMD) is used to define pain/dysfunction due to abnormalities in the TMJ, masticatory muscles and all supporting structures. Although a standardized treatment does not exist, alleviating pain and improving function of the temporomandibular joint through a conservative approach is the main goal when treating TMD. It is for this reason that open joint surgery is usually a last resort when attempting to save the TMJ. It was found that nearly 5-33% of the general population show subjective symptoms of TMD between the age of 20-40.1 A disc is situated between the condyle and articular eminence, which allows for smooth motions when opening and closing. Complications arise when the disc becomes displaced preventing lateral and protrusive movements and limiting the maximal opening of the jaw.2 Various treatment options exist ranging from simple medical treatments to complex surgeries. When medical techniques such as patient education, physiotherapy, behavioural stress management, occlusal adjustment or splint therapy fail, surgical intervention is indicated. Arthroscopy and arthrocentesis are two examples of minimally invasive techniques that show high success rates in various studies. Several studies in the past indicated that arthroscopic lysis and lavage in closed lock patients showed success rates in approximately 80-86% of all patients.3 Arthrocentesis and arthroscopy is used in fewer than 10% of patients that present with TMD. Of this 10%, arthroscopy is capable of removing symptoms in 70-86% of the cases, with only 10% of this group requiring open joint surgery.4 Arthroplasty involves the surgical approach to the TMJ structures via an incision in the skin, called the preauricular incision.5 Eminectomy or eminoplasty involves partial or total 5 removal of the anterior articular eminence using surgical bur and bone files; discectomy involves the elimination of all mechanical interferences within the joint caused by TMJ meniscus and is indicated in more severe cases.6 To replace the disc, grafts and alloplastic materials such as silicone, dermis, cartilage and myofascial grafts have been used in the past with unacceptable complications. It is argued that disc replacement isn’t necessary following discectomy.7 Teflon-Proplast and most grafts proved to show little success in the past few decades, leading to the investigation of abdominal fat grafts versus temporalis myofascial flap, in hopes of finding a more effective material. Problems exist with abdominal fat grafts as they degrade over time due to a lack of vascularization. Discectomy shows better results compared to eminectomy regardless of whether it is performed with the inclusion of an abdominal fat graft. The abdominal fat graft provides evidence of cushioning the condyle within the articular but shows contradicting evidence when compared to the temporalis myofascial flap graft.7 There is no perfect solution to treating temporomandibular joint disorder as the pain and/or dysfunction due to abnormalities in the temporomandibular joint, masticatory muscles and all supporting structures can be treated in a variety of effective ways.5,7 New methods continue to be studied and tested in alleviating pain and improving the function of the TMJ. Aim of the Study: The purpose of this study was to determine the effectiveness of arthroplasty, eminectomy and discectomy in the treatment of TMD patients in Manitoba. 6 Patients and Methods The retrospective chart review was conducted on TMD patients who were diagnosed both clinically and through MRI with arthroplasty, eminectomy and discectomy at the Health Sciences Centre (HSC) and the Seven Oaks General Hospital (SOGH) between the years of 2011 and 2017. The University of Manitoba Research Ethics Board (REB) provided approval for the project. This study was conducted in order to determine whether or not arthroplasty including discectomy and eminectomy is an effective surgery to alleviate pain and various other symptoms associated with TMD. The age, gender and occupation of each individual patient were recorded. The clinical examination recorded symptoms of pain and the ranges of motion. While the MRI results were recorded specific to each side of the TMJ as normal, anterior disc displacement with or without reduction, or osteoarthritis. Exclusion criteria were applied to subjects who had missing information concerning their clinical examination, MRI results or the etiology of their TMD. Eight males and 28 females made up the study group with ages ranging from 17 to 68 years with a mean of 40.4 years. After a follow up period, a clinical examination was once again conducted, where symptoms of pain, as well as the ranges of motion were reassessed. The follow up period ranged from 1 to 29 months with a mean of 8.6 months. Internal derangement was recorded for the left and right sides of the TMJ using the Wilkes Classification System2 (Table 1). A grade of I-V was given for each patient. A data capture sheet (Figure 1) was formed with patient, pre-operative, intra-operative and post-operative information. To ensure the patients remained anonymous, each patient was designated a unique code number, with a master key to identify patients if needed. In order to assist with the coding, the initials of each patient as well as their age and gender were recorded. Data were analysed using MiniTab18. 7 Table 1. Wilkes Staging of Internal Derangement of TMJ.7 Stage Clinical Imaging I. Painless clicking Slightly forward disc, reducing No restricted motion Normal osseous contours II. Occasional painful clicking Slightly forward disc, reducing Intermittent locking Early disc deformity Headaches Normal osseous contours III. Frequent pain, Joint Anterior disc displacement, reducing early progressing to non-reducing tenderness, Headaches, late Locking, Restricted motion Moderate to marked disc thickening Painful chewing Normal osseous contours IV. Chronic pain, headache Anterior disc displacement, non-reducing Restricted motion Marked disc thickening, abnormal bone contours V. Variable pain Anterior