Temporomandibular disorders are considered a heterogeneous group of psychophysiological disorders of the stomatognathic system (Okeson 1985, Okeson 1993) covering a broad spectrum of muscular, skeletal or both, clinical problems (Nagamatsu-Sakaguchi, Minakuchi et al). They are often initiated by pain, joint sounds and limited function / mandibular movement, and are considered one of the main causal factors of non-dental orofacial pain (Rossetti et al., 2008, Makino, Masaki et al.; Magnusson 1999). Conservative and non-invasive treatment is considered as the one of choice at an early stage, since the symptomatology is usually reduced through the combined use of occlusal appliences, physiotherapy and medication. (De Leeuw, American Academy of Orofacial Pain et al., 2008) The dislocations of the articular disc are the most common arthropathy and are characterized by several stages of clinical dysfunction involving an abnormal interrelationship of the disc condyle complex (more often an anterior or anteromedial disc displacement) (Isberg-Holm and Westesson 1982 ). Pain (in acute cases), changes in mandibular movement pattern and joint noise are the most frequent symptoms.~The causes of disc displacements are not completely established. It has been postulated that, in most cases, the elongation or rupture of the condyle-disc ligaments allows displacement of the disc. (Stegenga, de Bont et al., 1991) Changes in lubrication and synovial fluid quality have also been suggested as possible etiological agents (Nitzan 2001). The presence of osteoarthritis may also precipitate changes in the condyle-disc complex. (De Leeuw, American Academy of Orofacial Pain et al., 2008) In addition to the intervention of the dentist with occlusal appliance (among other resources), mandibular physiotherapy aims to reduce musculoskeletal pain, promote muscle relaxation, reduce muscle hyperactivity, improve muscle control and function, and maximize joint mobility . In addition to the electrotherapeutic means there are several manual therapy techniques directed to TMJ that aim the joint decompression, fibrosis reduction and adhesions at the level of structures such as ligaments or joint capsule, recaptation of the articular disc or adaptation of the retrodiscal tissues. We are talking about intraoral techniques such as condylar distraction or specific exercises of joint mobility or muscle strengthening. (Craane, Dijkstra et al., 2012) In the specific case of joint disc displacements, the condylar distraction technique is one of the most used therapeutic resources. It is a technique that aims to increase the space between the mandibular condyle and the joint fossa of the temporal, decompressing the joint and promoting the adaptation of the articular tissues and / or the disc reuptake. It is a technique almost exclusively performed by the physiotherapist and / or dentist, with repeated applications over an extended period of treatment that can reach several weeks or months, difficult to perform by the patient at home (De Leeuw, American Academy of Orofacial Pain et al, 2008). There are currently only ambulatory mandibular exercise devices that aim to increase the range of mandibular movement through rotation, rototranslation, and condylar translation (eg, TheraPace Jaw Motion Rehab System, TheraPacer Jaw CPM ). None of these devices distracts the joint, so in cases of acute displacement of the disc, with the presence of retrodiscal pain, they may even be counterproductive. Thus, the development of an apparatus capable of performing or assisting patients in the condylar distraction maneuver could prove to be a valuable aid in the treatment of these conditions, increasing patient adherence and reducing costs related to a long treatment time.
Articular Disc Displacements are the most common TMJ arthropathy and the articular distraction technique is one of the most common therapeutic resources. It is a technique almost exclusively performed by the physiotherapist and / or dentist, with repeated applications over an extended period of treatment, that can reach several weeks or months, difficult to perform manually by the patient on an ambulatory basis. Currently there are no ambulatory mandibular exercise devices that aim to execute articular distraction. Thus, the objective of this work was to study, design and develop a device capable of performing and / or assisting patients in the articular distraction maneuver.