Digitally Trained Applied Relaxation for Treatment of Temporomandibular Pain

Background and significance More than 30% of people worldwide suffer from chronic pain, which causes human suffering for the individual and burdens the society financially. Musculoskeletal diseases are the most functionally impairing diseases in Europe. Masticatory muscle/jaw joint pains and dysfunctions (temporomandibular disorders, TMD) located in the face and head area are the second most common musculoskeletal pain conditions after low back pain. Various biopsychosocial risk factors, such as stress, depressive symptoms, anxiety, and sleep problems are related to chronic pain, including TMD pain. On the other hand, treating sleep disorders can also alleviate pain. Psychological stress and disturbances in the regulation of the pain mechanism related to chronic pain can manifest as dysfunction in the autonomic nervous system (ANS) activity. Compared to healthy people, TMD patients have impaired response of the ANS activity as indicated by higher heart rate, lower heart rate variability and lower baroreflex. Oral prafunctions, such as awake bruxism (tooth clenching during awakefulness) are also common in individuals with TMD and may share common psychosocial background factors with TMD, such as somatic symptoms, depression and anxiety.

Treatment of TMD aims to relieve pain and improve function. Usual treatment methods are counselling and guidance, muscle exercises, manual therapy, and occlusal splint therapy. Motivation and activation of the patient instead of the patient "receiving" passive treatment is important. Structured self-care methods should also be developed and evaluated considering cost-effectiveness. The Current Care Guidelines of pain emphasize the use of patient's own coping strategies. Relaxation training is mentioned as one of these methods, in addition to information, cognitive coping methods, and physical exercises.

Applied relaxation (AR) is a self-management method developed on the basis of Jacobson's progressive relaxation. The method is based on step-by-step training during a six-week programme where the person gradually learns the skill of relaxing his/her body in about 30 seconds. Learning this skill can be compared, for example, to learning to ride a bicycle, where the skill eventually becomes automatic.

AR has been used in treatment of various psychological and somatic conditions, such as anxiety disorders, panic disorders, dental fear, stress problems, gynaecological pain problems, tinnitus, musculoskeletal pains, as well as TMD symptoms, based on a previous randomised controlled trial. As a method that activates the patient and is easy to use independently, AR has several advantages compared to other coping or imagination-based methods. The patient is guided to control his/her reactions and sensations of the ANS by relaxing the body and/or muscle groups. The time needed for relaxation gradually decreases from 20 minutes to less than a minute and transforms from conscious to unconscious through active practice. This method is generally used in the treatment of chronic pain, mostly in specialised medical care units in group meetings under the guidance of a health care professional. There is a need for digital technology for training of AR, which could target it at a wider group of patients.

For training of AR a web application, named Relappy, was developed in University of Oulu and Oulu University Hospital in company collaboration as well as using the expertise on the field of psychology. The Relappy contains instructions, self-instructed exercises and exercise diaries for independent training of AR.

The aim of this randomized controlled study (RCT) is to evaluate the effect of digitalised AR training (by using Relappy) on TMD pain and comorbid symptoms, such as other musculoskeletal pain, psychological symptoms (depression/ anxiety symptoms, unspecific physical symptoms, sleep problems), and oral parafunctions (including sleep and awake bruxism).

Based on the previous knowledge, it can be hypothesized that digitalized AR training relieves TMD pain, other musculoskeletal pain, psychosocial burden, stress-related symptoms as well as oral parafunctions more effectively as compared to "traditional TMD treatment". It can also be seen as lowering of the sympathetic activity in ANS parameters.

As a high-quality clinical study, this RCT trial generates new knowledge for cost-effective treatment of TMD, musculoskeletal pain symptoms, and stress-related symptoms. It emphasizes the patient´s own responsibility and activation, instead of mere "doctor´s tricks", which mostly do not have any far-reaching effects. The study will also offer tools for prevention of stress-related symptoms/ diseases and thus support the welfare and healthcare.

Impact The present high-quality RCT study generates new knowledge on the effectiveness of self-care methods for treatment of TMD and its comorbid symptoms, such as other musculoskeletal pain, psychosocial burden and sleep problems. The merit also comes from that comorbid symptoms are evaluated besides TMD pain, thus considering the larger view of the patient´s condition. It also gives additional value by generating new, clinical-based science, as these is still relatively low number of RCTs in the field of TMD and self-care procedures in pain management.

Training of AR using the Relappy gives many benefits for the users. They get important knowledge about their general health and themselves. This knowledge helps users to achieve positive changes in their lives and to cherish their healthy life habits, which have further effects on working life, relationships and self-confidence. Well-being will improve, and the burden for health care will decrease as the users can themselves do treatment/preventive actions. Although the traditional group meetings of AR have their advantages, digitalisation would offer an efficient and flexible use of the method, also considering the accessibility of the treatment, the patient's time use, healthcare resources and sustainable development (traveling to the office decreases). This would also promote equality, as training of AR can be offered to larger patient groups and non-patients. The online application would enable the AR training to be more widely available, both geographically and temporally, and would reduce the burden on the nursing staff.

Based on the previous randomised controlled trial, AR (trained as traditional group meeting) was more effective in promoting comprehensive wellbeing as compared to occlusal splint treatment. Therefore, it is expected that if actively used, Relappy would achieve corresponding results; not only relieving local TMD pain but also decreasing other body pain and psychosocial burden. Improvement of the quality of sleep is also expected.

The digitally trained AR is expected to give several positive outcomes for individuals suffering from chronic pain by decreasing pain-related disability, improving sleep quality, and promoting psychological well-being. This method can be used in addition to other treatments as part of comprehensive, individualised treatment. The use of Relappy could also prevent the onset of symptoms and development of chronic pain conditions when used regularly and specifically in various stress-related situations. The AR method has no adverse effects.

If shown to be effective, this method can be adopted by clinicians as part of comprehensive, individual treatment of pain patients. The results of the project will be disseminated to the stakeholders, i.e., the wellbeing services counties in Finland.

The expected economic impact is the reduction of healthcare costs by avoiding invasive treatments and medications and by decreasing the number of visits. In Finland, 7-9% of the population need TMD treatment, corresponding to 440,000 people. In the latest comprehensive Healthy Finland Survey in 2023 the preliminary results showed that 7% of Finnish adults (aged 20 years or older) reported of using occlusal splint, corresponding 313,600 people (yet unpublished data). The total cost of one occlusal splint as "traditional" treatment for TMD is approximately 500 euros (including cost for dental technician and salaries for health care personnel), resulting in costs of 156.8 million euros. The occlusal splint may at best be used for a few years and must be renewed thereafter. AR training with the aid of Relappy is expected to replace the occlusal splint at least to some extent, roughly estimating 25% of those in need for treatment, corresponding 96,259 people. When regularly trained, the possible benefit for the patients would be long-lasting.

Besides TMD, Relappy can be used for other pain conditions as well. In 2022, musculoskeletal diseases were the most common reason to seek treatment in health care and also the most common cause of disability retirement. In Finland, musculoskeletal symptoms and diseases cost several billion euros annually. Direct costs include treatment visits, medications, and rehabilitation. Indirect costs are caused by sick leaves, decreased productivity, and unemployment. In 2022 in Finland, musculoskeletal diseases caused costs amounting to 235.2 million euros due to sick leaves and 346.6 million euros due to retirement. The costs of medications due to musculoskeletal diseases were 64.2 million euros. The use of Relappy is expected to decrease these costs, offering safe, non-medication treatment.

Implementation

Preliminary data Before RCT, Relappy was tested by volunteers in a pilot study. The study participants were recruited by e-mail advertisement from the staff and dental students in University of Oulu and Eastern Finland. Feedback on the use of the online service was collected from the participants. In addition, the research subjects answered the same questionnaires as the patients of the clinical study (see section Clinical study). The subjects' self-assessed degree of relaxation before and after the exercises is saved on the server.

Altogether 54.5% responders (n=26) had noted positive changes in their well-being. Based on the questionnaire, the total number of physical symptoms (p=0.017, ANOVA test) and body pain sites (p=0.006) decreased after Relappy training, as compared to the baseline. A tendency of decrease in depression symptoms was also noted (p=0.059). There was also a tendency for improvement of distinct sleep parameters (sleep onset duration, sleep duration), based on the sleep diary Oneiros.

Clinical study The goal of the present study is to evaluate the effectiveness of Relappy on TMD pain symptoms, psychosocial burden factors, sleep quality and oral parafunctions in TMD pain patients of the Finnish Student Health Service (health care units in Oulu and Turku) and two well-being servives counties in Finland (North Ostrobothnia, Oulu, and North Savo, Kuopio), based on a clinical randomised controlled trial (RCT).

The sample is selected from patients who seek treatment due to TMD-related pain symptoms. Subjects are randomly divided into two treatment groups, the AR group and the stabilization splint group. Allocation into groups is performed using a randomization method performed by a computer program.

The exclusion criteria are as follows:

* serious general illnesses such as rheumatism, schizophrenia or other serious mental illness * pregnancy

The inclusion criteria are as follows:

• presence of TMD pain diagnosis (myalgia, myofascial pain with referral, arthralgia and/or headache attributed to TMD), based on a validated, international Diagnostic Criteria for TMD Axis I criteria

The sample size was calculated using a power calculation. It has been estimated that the difference between two NRS (Numerical Rating Scale, 0-10) points is calculated as a clinically significant pain reduction in the assessment of pain intensity. A mean difference of 2 points (SD 3.5) between groups (at 80% power, statistical significance p\<0.05) is obtained with a sample size of 39 patients in each group

• Body pain symptoms [Срок оценки: From baseline until 1 year after baseline]
• Depression symptoms [Срок оценки: from baseline until 1 year after baseline]
• Physical symptoms [Срок оценки: from baseline until 1 year after baseline]
• Anxiety symptoms [Срок оценки: from baseline until 1 year after baseline]
• Sleep quality [Срок оценки: from baseline until 1 year after baseline]
• Sleep diary [Срок оценки: from baseline until 1 year after baseline]
• Heart rate variability [Срок оценки: from baseline until 1 year after baseline]
• Baroreflex sensitivity (BRS) [Срок оценки: from baseline until 1 year after baseline]
• Body composition (Inbody) [Срок оценки: from baseline until 1 year after baseline]