GAP Australasian-Dentist-Mar Apr 2019

Category 94 AustrAlAsiAn Dentist INTRODUCTION the temporomandibular Joint (tMJ) has been the domain of Dental Practitioners for over half a century. in that time, the management of temporomandibular disorders (tMD) has had a significant dental focus with dental occlusion at the very centre of most therapeutic approaches. unsurprisingly, tMJ surgery has always been an option of last resort, especially as the majority of Dental practitioners remain oblivious to the role of surgery in the management of intractable joint pathology. As a surgeon specializing in the field of tMJ surgery, i see tMD as an orthopaedic rather than a dental disorder (Dimitroulis, 2018). to clarify this point, my definition of tMD is as follows; TMD is a musculoskeletal disorder of mandibular movement that adversely affects the smooth, pain-free function of the mandible resulting in poor oral function and reduced quality of life. in line with this more focused definition, there are essentially two components to tMD; the muscles of mastication and the tMJ. the tMJ, like any other functioning joint in the body, may be afflicted by a range of diseases and disordersrangingfromacuteinjuriessuchas a sprain, to chronic degenerative disorders such as osteoarthritis. Osteoarthritis is a progressive, degenerative joint condition that causes joints to become painful and stiff when the cartilage is damaged and worn so it loses its smooth cushion surface and becomes rough and uneven. Osteoarthritis afflicts about 1.8 million Australians and can affect in any joint in the body, such as the hip, knee, spine and even the tMJ. in a German study of 307 tMD patients aged between 20-49yr, 25% were shown to have clinical signs and Mri evidence of tMJ osteoarthritis (Benhardt et al 2007). tMJ osteoarthritis is, therefore, not an uncommon disorder in our society yet most Dental Practitioners remain oblivious to the high prevalence of this disease amongst their own patients. the most common symptoms of tMJ osteoarthritis are listed in table 1 and the risk factors for tMJ osteoarthritis are listed in table 2. there are a multitude of treatment options currently available for tMJ osteoarthritis which range from anti-inflammatory medication, both systemic and topical, to acupuncture, heat packs, jaw physiotherapy, and of course, occlusal splint therapy. On the other hand, glucosamine, fish oil, chondroitin and stem cells have either been not properly evaluated or not shown to be effective, so caution is advised. some people with tMJ osteoarthritis may eventually require surgery when non-surgical measures fail to provide adequate relief. A total prosthetic joint replacement is often the only surgical option available which has lasting benefits because none of the damaged or diseased joint components in an osteoarthritic joint can be salvaged, and so need to be removed. if the resected tMJ is not replaced with a prosthesis, it can result in significant malocclusion and lower facial asymmetry. the aim of this article is to present some clinical examples of tMJ total joint replacements in patients with tMJ osteoarthritis who failed to respond to non-surgical measures. CASE 1 the first case is that of a 35yo female who had 4 years of conservative management for ongoing pain and dysfunction related to the right tMJ. not only was the pain in the right tMJ getting worse, but the anti-inflammatory medication was playing havoc with her stomach. By the time she was seen by the author she had already undergone two courses of occlusal splint therapy, acupuncture and botox injections. she had seen a specialist jaw physiotherapist in the preceding three months who recommended she seek a surgical opinion, and hence shewas referred to the author for further assessment. An update OPG x-ray (fig. 1) showed significant degeneration of the right mandibular condyle which was subsequently confirm on conebeam Ct scan as severe right tMJ degenerative joint disease (fig. 2). As the patient had exhausted most of her non-surgical options, she decided to proceed with right tMJ prosthetic total joint replacement using the fully customized 3D printed OMX tMJ prosthesis. to build the custom tMJ prosthesis, a Ct scan (1mm slices) was taken of her jaws and midface and the file converted to DiCOM format. the Ct lInICal Osteoarthritis of the Temporomandibular Joint By George Dimitroulis Consultant Oral & Maxillofacial surgeon, st.Vincent’s Hospital Melbourne & epworth-Freemasons Hospital George Dimitroulis PAINFUL JOINTS – especially during jaw function: eg. chewing or talking STIFFNESS – resulting in reduced mouth opening or jaw locking LOSS OF FLEXIBILITY – difficulty protruding and moving jaw side to side GRATING OR CRACKLING SOUNDS IN THE JOINT – referred to as crepitus SWELLING – sometimes noticed just in front of the ears WEAKNESS OR WASTING – of muscles around the joint ACUTE JOINT INJURIES – accidents, sporting mishaps, assault CHRONIC INJURIES – bruxism, recurrent subluxation/dislocation FEMALE GENDER – much higher risk for TMJ osteoarthritis AGE – the risk of TMJ osteoarthritis increases with age FAMILY HISTORY – some families have a genetic predisposition to TMJ joint disease MEDICAL RELATED – Rheumatoid/Psoriatic arthritis, Previous TMJ surgery, traumatic anaesthetic intubation Table 1: Clinical symptoms of TMJ Osteoarthritis Table 2: Risk factors for TMJ Osteoarthritis