[[https://doi.org/10.3390/app12031224](https://doi.org/10.3390/app12031224)]([https://doi.org/10.3390/app12031224](https://doi.org/10.3390/app12031224))  
Footnote 13: email: [PERSON] [PERSON]; [PERSON] [PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON] Measuring Changes in Jaw Opening Forces to Assess the Degree of Improvement in Patientslife-threatening, up to 70% of people experience signs or symptoms of TMD at some point in their life. TMD has also been associated with impaired general health and socioeconomic factors, as symptoms can become chronic and difficult to manage [8; 9]. The main signs and symptoms of TMDs are pain and tenderness in the masticatory muscles or around the temporomandibular joint (TM), altered jaw function, reduced range of movement of the mandible, and locking and joint noises, as well as associated ear and headache symptoms [10; 11]. The most frequent type of TMD in the adult population is myofascal pain (42%), followed by disc displacement (32.1%) and arthralgia (30%) [12]. The diagnosis of TMDs is not always straightforward, and patients with TMD may seek help from many different experts, such as dentists (including oral surgeons, oral medicine specialists, oral and maxillofacial surgeons, orthodontists, and prosthodontists) or ear, nose, and throat (ENT) surgeons, in search of pain relief, before achieving proper diagnosis and treatment [6; 12]. An early diagnosis can often bring a marked improvement to chronic symptoms in the head, neck, and jaw. Until now, several protocols have been used to diagnose and classify TMDs. The Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) protocol is the most commonly used in TMD diagnosis [13]. The DC/TMD protocol is based on indirect and subjective measures that rely on the patient's history and clinical examination; it is time-consuming, involves a face-to-face interview, and has a low diagnostic accuracy [14]. Imaging techniques such as dental X-ray imaging, computed tomography scans, magnetic resonance imaging (MRI), and arthroscopy, which evaluates the joint's bone morphology and pathology, are used to diagnose TMDs [14; 15]. However, imaging techniques are expensive, and several studies have shown that a poor agreement was found between clinical diagnosis and MRI findings in TMD patients [16; 17; 18]. In our previous study, we showed that a novel jaw-opening-forces measuring device could be used as a potential diagnostic tool to screen TMDs [19; 20]. The treatment goals for TMD focus on relieving pain, restoring normal masticatory and jaw function, and improvement in quality of life [21]. Treatment for TMD traditionally has included self-management instructions, physical therapy, pharmacotherapy, physiotherapy, occlusal appliance therapy, and trigger-point injection [21; 22; 23]. Despite improvements in diagnostic techniques and treatment advances in the long-term management of TMDs, clinical tools to assess the degree of improvement in TMD patients are still lacking. Presently, the improvement in TMD patients is measured through questionnaires based on pain scales, which are prone to bias [14; 24]. This observational study aimed to evaluate whether changes in jaw-opening forces can be used as an adjunct quantitative measure to identify TMDs and assess the clinical improvement following diagnosis and treatment in TMD patients. The test hypothesis is that jaw-opening forces will increase in the TMD patients after treatment.