Abstract
Introduction
Painful temporomandibular disorders (pTMD) is a subgroup of TMD, which refers specifically to cases with persistent pain symptoms, often associated with significant functional and psychosocial impact.
Purpose
To investigate the outcome of patients with persistent pTMD five years after multidisciplinary investigation.
Patients and Methods
The present study was a five-year follow-up study of 74 patients with pTMD. Baseline data were available for 72 patients. At follow-up, 68 patients were invited to participate, but only 32 responded. A questionnaire equal to the baseline questionnaire, was sent to the patients. It investigated pain duration and pain intensity (General Pain Intensity questionnaire [GPI]), mandibular function (Mandibular Functional Index Questionnaire [MFIQ], two- question Coping Strategies Questionnaire [CSQ]), general health status, psychosocial factors, previous treatments. The follow up included the extent to which they have been followed up by their general medical practitioner (GMP) and whether their TMD symptoms have changed.
Results
32 out of 74 patients responded. Pain intensity and pain-related suffering had improved significantly, but mandibular function and restricted jaw movements remained unchanged. Follow-up by general medical practioners was rated poorly.
Conclusion
Patients who responded to the five-year follow-up reported reduced pain intensity and pain-related suffering compared with baseline, while restricted jaw movements were found to be unchanged. Symptom duration alone showed no clear association with future pain severity and suffering in this sample. Changes in quality of life after multidisciplinary assessment seemed to vary across life domains. Given the low response rate at follow-up, the findings should be interpreted with caution and may not be representative of the entire original cohort.
Keywords: catastrophizing, multidisciplinary, orofacial pain, persistent pTMD, psychosocial factors, mandibular function
Introduction
Temporomandibular disorder (TMD) is a collective term for pain and dysfunction in the temporomandibular joint (TMJ), and in the muscles that regulate the opening and closing function of the mandible.1
The Prospective Evaluation and Risk Assessment (OPPERA) study demonstrated the characteristics of TMD. The study shows that there is a higher prevalence of psychosocial factors such as somatic awareness, catastrophic thinking, pain, and stress in TMD patients, compared to healthy individuals.2,3 In accordance with the biopsychosocial model of chronic pain, painful TMD (pTMD) is understood to have multidimensional effects on pain, function, and psychosocial outcomes.4
The National Unit for Orofacial Pain (NUOP) at Haukeland University Hospital (HUH), Bergen, Norway was established in 2017. It builds on the interdisciplinary National TMD Project initiated in 2013 as a commission from the Norwegian Directorate of Health. NUOP provides assessment by both odontology and medical specialists of patients with persistent orofacial pain in a tertiary care setting, applying a biopsychosocial framework. The purpose of this initiative was to characterize the patient group and develop national guidelines for the assessment and treatment of TMD. A key publication from 2016 presented interdisciplinary assessments of 60 patients with persistent painful TMD (pTMD).5 Subsequent research has expanded these findings, including a three-year follow-up study demonstrating that high pain intensity at baseline is a significant risk factor for long-term symptoms. Together, these efforts have helped establish NUOP as a national center for complex orofacial pain and pTMD, providing a foundation for ongoing research on long-term follow-up and treatment outcomes.6 However, despite these contributions, evidence regarding outcomes beyond three years remains limited in literature. Given the chronic and fluctuating nature of pTMD, longer follow-up periods may provide additional insight into whether early changes are sustained, improved, or deteriorated over time.
The present study is a five-year follow-up of one of two cohorts of patients with pTMD who were interdisciplinary examined. Our results were compared with findings from the previous three-year follow-up study of the other cohort, a multidisciplinary evaluation conducted in the period 2013–2015. As baseline data for both cohorts were collected using identical protocols within the same clinical setting, this allows for meaningful comparison across follow-up periods despite differences in duration. In accordance with the biopsychosocial model of chronic pain, outcomes were assessed across pain intensity, mandibular function, and psychosocial factors to capture the multidimensional impact of pTMD. This study therefore aims to extend current knowledge on long-term outcomes in pTMD by examining whether findings observed at three years persist, change, or evolve over a five-year period following multidisciplinary assessment. A five-year follow-up was chosen to extend the observation period beyond previously reported three-year outcomes while maintaining methodological comparability within the same clinical cohort and reducing the risk of participant loss during longer follow-up periods.
Aims
The primary objective was to assess changes in signs and symptoms of pTMD at the five-year follow-up. Additional objectives included assessing patients’ physical function, psychological health and social life, and patients’ evaluation of follow-up treatments recommended by the multidisciplinary team. The final objective was to identify possible risk factors for persistent painful TMD.
Materials and Methods
Study Design
The present study was a longitudinal five-year follow-up study of 74 pTMD patients who participated in a national Norwegian TMD Project at HUH in Bergen, 2015–2018. Figure 1 represents the participants at the follow-up. At HUH the patients were assessed by a multidisciplinary evaluation team including both medical and odontology specialists.
Figure 1.
Flow Chart Representing the Drop-Out of Participants in the Study Population.
Notes: The figure represents the participants at the follow-up (n=32). Out of the total 74 TMD patients who were multidisciplinary examined at HUH, 72 patients answered the baseline questionnaires, since 2 patients dropped out. Out of the 72 TMD patients at baseline, 3 patients had died, and 1 patient had moved abroad. Therefore, only 68 TMD patients received invitations to participate in the follow-up. Out of the total 68 patients, 32 patients participated in the Five-Year Follow-Up.
Abbreviation: TMD, Temporomandibular disorder.
Initially, 60 patients were selected for interdisciplinary assessment as the primary study cohort. However, due to high patient demand, the Norwegian Directorate of Health decided to expand the project, resulting in an additional 74 patients with TMD being included. This additional group of 74 patients is the cohort we have investigated.
Results from the previous three-year follow-up study consisting of the first 60 patients were used to be compared to the present group.
Ethics
Ethical approval was obtained by the Regional Ethical Review Southeast (2015/930) for the initial evaluation, and for the present study (2020/8685), in accordance with the Helsinki Declaration (1964). Written informed consent was received from all patients enrolled in study.
Participants
The study population consisted of 74 patients with pTMD. Two patients dropped out, resulting in 72 patients completing the baseline questionnaires. Between baseline and follow-up, three patients died and one patient moved abroad. Consequently, 68 pTMD patients received invitations to participate in the follow-up, of whom 32 chose to participate.
The inclusion criteria were that patients had reached the age of 18 years at baseline and had pTMD. Exclusion criteria were non-TMD-related orofacial pain, drug dependence, psychiatric diagnoses, and unresolved financial disability claims. Patients were included consecutively on an ongoing basis. The patients were diagnosed by the team according to a beta version of the TMD guidelines from the Norwegian Directorate of Health published in 2016, which are comparable to the diagnoses included in the Diagnostic Criteria for TMD (DC/TMD).7,
Our study population consisted of patients diagnosed with pTMD, a subgroup of TMD characterized by persistent pain often associated with significant functional and psychosocial impact. TMD is an umbrella term encompassing a range of musculoskeletal disorders affecting the masticatory system and in addition TMJ with different entities.
Baseline Data
The baseline evaluation was performed by a multidisciplinary team at Haukeland University Hospital (HUH) in Bergen, Norway in the period 2015–2018.
Before the clinical examination, patients were asked to complete a comprehensive questionnaire about their symptoms and health related questions.
The baseline questionnaire covered general health, history of diseases and medications, pain and other symptoms, psychosocial factors, physical function, symptoms, and adverse events (e.g facial trauma).
Pain intensity was measured using a General Pain Intensity Questionnaire (GPI). To these questions, the patients answered on a scale from 0–10, where 0 was no pain and 10 was the most intense pain the patient could imagine. A two-question Coping Strategies Questionnaire (CSQ), each with a scoring range of 0–6, was used to measure the patients coping with chronic pain and pain catastrophizing. Mandibular function was reported using a Mandibular Function Questionnaire (MFIQ), where the claims were rated from 0–4, where 0 represented “no difficulties” and 4 “was impossible without help”.
The patients were examined thoroughly by an interdisciplinary team consisting of six specialists, both dental and medical, with more than 10 years of experience in pain medicine. There was an oral and maxillofacial surgeon, a dental specialist in orofacial pain from the Oral and maxillofacial department. From the Pain clinic a pain physician, a physiotherapist and a clinical psychologist all of them specialized in pain medicine. Two radiologists were also in the team, one medical and one dental radiologist, and every second week we had rounds. On top of that we had consultations with a neurologist and an orthodontist when needed. At the final consultation, the results of the assessment were presented to the patient with an explanation of why they were in pain, followed by counseling including treatment suggestions that were discussed with the patients and their relatives. The proposed treatment plan was reported to their GMP with a request for a follow up. A description of the multidisciplinary work and a characterization of the patient group with persistent pTMD have previously been published.8–11
Five-Year Follow-Up
Approximately five years after baseline, the patients were contacted via telephone and asked if they wanted to participate in a follow-up study. Those who agreed received a comprehensive questionnaire by e-mail. The questionnaire was similar to the baseline one with the addition of questions regarding their satisfaction with the follow-up by their GMP and regarding the progression of their TMD symptoms. This was scored on a five-point scale, from much improved too much worse, and their general health on at scale from 0 to 100, where 0 was “the worst health you can imagine” and 100 was “the best health you can imagine”. The follow-up study also included questions regarding TMD treatments received and the outcome of the treatments. “TMD symptoms” presented is how the patients have experienced the development of their TMD symptoms after the assessment. TMD symptoms include dysfunction and pain related to masticatory muscles and/or jaw joints with surrounding structures. Not all participants completed every section of the questionnaires, resulting in some missing data. Consequently, the sample size varies slightly between the different tables and analyses depending on the available responses for each variable.
The term physical health, psychological health, economy, chewing/eating and social life in the five-year follow-up refers to the impact that TMD-related symptoms have had on the patients’ subjective perception of their physical health, psychological health, economy, chewing/eating and social life following the clinical evaluation. If the patients did not answer the questionnaire, they were reminded by telephone.
Statistical Methods
Our statistical analyses were performed in IBM SPSS Statistics version 28. Data from the first evaluation were considered baseline values for comparison with follow-up values. Mean, median, range and standard deviation were calculated for continuous variables. Ordinal variables, such as the TMD-related domains (economy, physical health, psychological health, chewing/eating and social life), were subjected to correlation analysis (Spearman correlation). For comparison of GPI, CSQ and MFIQ scores between baseline and follow-up, a Wilcoxon matched-pairs signed-rank test was performed.
Results
Baseline Registrations
Baseline characteristics of all patients (n=72), responders at the follow up (n=32) and non-responders at follow-up (n=40) are presented in Table 1. The baseline values being represented in the table are sex ratio, the mean age of patients, and the pain duration at baseline, measured in years.
Table 1.
Drop Out Analyses of Response to Follow-Up Questions 5 Years After Interdisciplinary Evaluation and Guidance/Treatment for pTMD
| Baseline All Patients | Five-Year Follow-Up Responders | Five-Year Follow-Up Non-Responders | |
|---|---|---|---|
| Number of patients | 72 | 32 | 40 |
| Sex ratio F:M | 13:5 | 13:3 | 13:7 |
| Age years mean, (range) | 46, (19–73) | 51, (30–73) | 42, (19–73*) |
| Pain duration years mean, (range) | 11, (1–40) | 11, (1–31) | 12, (2–40) |
| CSQ mean, (range) | 7, (0–12) | 8, (2–12) | 8, (0–12) |
| GPI max mean, (range) | 8, (2–10) | 8, (4–10) | 8, (2–10) |
| GPI suffer mean, (range) | 8, (2–10) | 7, (3–10) | 8, (2–10) |
Notes: The table presents responders at baseline, how many patients that responded to the follow up and how many patients that dropped out since baseline. Age, pain duration, CSQ and GPI are compared between the groups. The p-value of *p<0.05 was considered significant, in this case age differed between the groups.
Abbreviations: CSQ, Coping Strategies Questionnaire; GPI, General Pain Intensity Questionnaire.
Out of the 72 patients who had completed the baseline questionnaire 32 patients (44.4%) responded to the five-year follow-up questions. The drop out analysis (Table 1) showed that the responders were significantly older than the non-responders (mean age 51 vs 42 years).
Occupation
At the five-year follow-up most of the patients were retired (41.9%), followed by patients being disabled to work (16.1%). The third most reported work situation was patients receiving work assessment allowance (12.9%). Three patients (9.6%) reported that they had full time jobs, 3 patients (9.6%) had part-time jobs over 50%, and 2 patients had part-time jobs under 50% (6.4%). One patient was on work-leave (3.2%).
TMD Symptoms
The TMD symptoms were unchanged in 6 patients (18.8%) and improved or worsened in 12 patients each, respectively (37.5%) for both groups.
Economy, Physical Health, Psychological Health, Chewing/Eating and Social Life
The correlation between economy, physical Health, psychological health, chewing, eating and social life is presented in Table 2. The analyses revealed several significant associations between self-reported outcome domains five years after the interdisciplinary evaluation. The strongest correlation was observed between physical health and social life (p = 0.000). Positive correlations were also found between social life and economy (p = 0.001), social life and psychological health (p = 0.002), and physical health and chewing/eating function (p= 0.001) (Table 2).
Table 2.
Correlation Between Economy, Physical Health, Psychological Health, Chewing/Eating and Social Life in 31 Patients 5 Years After Interdisciplinary Evaluation and Guidance/Treatment for pTMD
| Domain | N | Sign. Correlations |
|---|---|---|
| Economy | 31 | Physical health (p=0.005**) |
| 31 | Psychological health (p=0.001**) | |
| 24 | Social life (p= 0.001**) | |
| 31 | Chewing/eating (p=0.027*) | |
| Physical health | 31 | Economy (p=0.005**) |
| 24 | Social life (p=0.000***) | |
| 31 | Chewing/eating (p=0.001***) | |
| Psychological health | 31 | Economy (p=0.001**) |
| 24 | Social life (p=0.002**) | |
| Chewing/eating | 31 | Economy (p=0.027*) |
| 31 | Physical health (p=0.001***) | |
| Social life | 24 | Economy (p=0.001**) |
| 24 | Physical health (p=0.000***) | |
| 24 | Psychological health (p=0.002**) |
Notes: This descriptive analysis is based on participant responses regarding changes in five domains after a multidisciplinary evaluation for temporomandibular disorder (TMD): economy, physical health, psychological health, chewing function, and social life. Each domain was rated on a 3-point scale: 1 = worse, 2 = unchanged, 3 = improved. Sample size varies between N = 24 and N = 31 due to missing data in the social life domain. The p-values of *p<0.05, **p<0.01 and ***p<0.001 were considered significant.
Abbreviations: N, number; TMD, temporomandibular disorder.
Pain Intensity and Suffering from Pain
Maximum pain intensity (p = 0.004) and the highest level of suffering from pain (p = 0.003) decreased significantly from baseline to the five-year follow-up (Table 3).
Table 3.
Results from Psychosocial- and Functional Related Questionnaires in 32 Patients 5 Years After Interdisciplinary Evaluation and Guidance/Treatment for pTMD
| GPI Minimum (0–10) |
GPI Maximum (0–10) |
GPI Suffer (0–10) |
GPI Accept (0–10) |
CSQ (0–12) | MFIQ (0–28) | |
|---|---|---|---|---|---|---|
| First examination | ||||||
| Mean | 3.2 | 8.6 | 7.7 | 2.9 | 7 | 13.3 |
| Median | 3 | 9 | 8 | 3 | 8 | 13.5 |
| Range | 0–5 | 6–10 | 4–10 | 1–5 | 0–11 | 4–23 |
| SD | 1.4 | 1.3 | 1.5 | 1.0 | 2.9 | 5.1 |
| n patients | 32 | 32 | 31 | 31 | 32 | 32 |
| Five-Year Follow-up | ||||||
| Mean | 3.3 | 7.7 | 6.7 | 3.3 | 7.6 | 13.3 |
| Median | 3 | 8 | 7 | 3 | 7 | 12 |
| Range | 0–10 | 4–10 | 3–10 | 0–7 | 2–12 | 3–28 |
| SD | 1.9 | 1.5 | 1.9 | 1.5 | 2.5 | 6.7 |
| n patients | 32 | 32 | 32 | 32 | 31 | 31 |
|
p-value Five-Year Follow-Up (Wilcoxon matched) |
0.9 | 0.004** | 0.003** | 0.223 | 0.367 | 0.615 |
Notes: Results from the questionnaires (CSQ, GPI and MFIQ) are presented at baseline and at the five-year follow-up. Higher scores indicate more prominent difficulties. The table also shows the number of patients who completed the questionnaires at both baseline and the five-year follow-up. A p-value of **p <0.01 was considered statistically significant.
Abbreviations: MFIQ, Mandibular Function Index Questionnaire; SD, Standard Deviation.
No statistical differences were found in minimum pain intensity from baseline to the five-year follow-up (p = 0.9) nor the option of the highest pain intensity that patients would accept living with (p = 0.223).
Functional and Psychosocial Related Questionnaire
The MFIQ (p = 0.615) or CSQ score (p = 0.367) did not show any difference at the five-year follow-up compared to the baseline level (Table 3).
Satisfaction with GMPs Follow-Up on Treatment Recommendations
Only 4 patients (12.5%) were satisfied with the follow-up by their GMP in the five-year follow-up study, 6 patients (18.8%) were not satisfied with the follow-up, and 10 patients (31.3%) did not know. 12 patients (37.5%) reported that their GMP did not follow-up at all.
TMD Related Treatments and Outcome
The patients’ self-reported treatments of TMD are presented in Table 4. It should be noted that the patients could have had several different treatments regarding their TMD. All types of treatments had at least one patient who had experienced a positive effect in their TMD symptoms, except medication of antidepressants. In total there were 23 patients who reported a positive effect of at least one treatment in the five-year follow-up group.
Table 4.
Reported Treatment During the Follow Up Period in 32 Patients 5 Years After Interdisciplinary Evaluation and Guidance/Treatment for pTMD
| Treatment of TMD | Positive Effect on TMD from Treatment | |||
|---|---|---|---|---|
| (32 Patients) | (23 Out of 32 Patients) | |||
| n1 | % | n2 | % (n2/n1 x 100) | |
| Analgesics (unspesific) | 27 | 84.4 | 12 | 44.4 |
| Antidepressants | 10 | 31.3 | 0 | 0.0 |
| Anxiolytics | 8 | 25.0 | 2 | 25.0 |
| Sleep Drugs | 14 | 43.8 | 8 | 57.1 |
| Physiotherapy | 22 | 68.8 | 4 | 18.2 |
| Surgery | 5 | 15.6 | 2 | 40.0 |
| Psychologist | 12 | 37.5 | 3 | 25.0 |
| Dental Splint | 29 | 90.6 | 8 | 27.6 |
| Dental Treatment | 9 | 28.1 | 3 | 33.3 |
| Self-Treatment/Exercises | 31 | 96.8 | 7 | 22.6 |
Notes: Data from the first column (“Treatment of TMD”) refers to the number and percentage of patients (out of 32) who reported type of TMD-treatment received throughout the follow-up period. The right column (“Positive effect on TMD from treatment”) refers to the number and percentage who reported a positive effect out of their reported treatment of TMD.
Subgroup Analysis
The patients were divided into three subgroups: those who reported improvement of their TMD symptoms at the 5-year follow-up, those who reported no change, and those who reported worsening of their symptoms. No significant differences were found between the groups in baseline variables.
Discussion
The present study is a five-year follow-up of a highly selected group of patients with persistent pTMD, with an average pain duration of 11 years at the time of investigation.
The group of pTMD patients who reported improved TMD symptoms also reported reduced maximum pain and pain-related suffering. This trend was also seen in the previous three-year follow-up study from our research group.6 Our findings suggest that symptom relief is associated with both pain intensity and the level of suffering. Previous longitudinal studies have shown that higher pain intensity is associated with a poorer prognosis for TMD.12 One study also found that greater pain-related suffering is linked to more long-term symptoms and a worse prognosis and on the other hand reported that symptom improvement was correlated with pain reduction.13
Interestingly, some patients without reported symptom changes still experienced reduced suffering at five-year follow-up, possibly reflecting improved coping strategies, greater acceptance, or reduced stress and other lifestyle factors. Overall, these findings are consistent with the importance of considering individualized approaches considering both physical and emotional factors. For a more accurate assessment of TMD-related pain, two key factors may be relevant: maximum pain intensity and suffering from pain. Together, these reflect different aspects of the pain experience and provide a more comprehensive understanding of the condition’s impact.
Considering self-reported health related and socioeconomic variables, lowest mean scores were observed for economy and physical health, reflecting a tendency toward deterioration in these areas. Psychological health showed a slight improvement, while chewing function and social life were perceived as mostly unchanged but with a slight inclination toward worsening. Due to the five-year follow-up time, these findings will, however, most likely be affected by factors not related to TMD, such as changes in general health status, lifestyle modifications, or aging, which were not included in the study.
Improvements following TMD assessment often occurred in parallel across domains. Strong and statistically significant associations were observed between physical health and social life, suggesting that participants who experienced improvements in physical health also tended to report improvements in social functioning. Strong positive correlations were also observed between social life and psychological health, social life and economy, and physical health and chewing/eating function. Overall, these findings suggest that long-term improvements following interdisciplinary management of pTMD may occur across biopsychosocial domains rather than in isolation.
Catastrophizing, as measured by CSQ, increased slightly from 7.0 at baseline to 7.6 at five-year follow-up but was not statistically significant. Nevertheless, the consistently high level of catastrophizing observed over time is clinically relevant. In contrast, previous findings from the three-year follow-up indicated a reduction in catastrophizing scores, suggesting that this subgroup may differ in important ways. The lack of significant change over five years may partly be explained by the small population and the low response rate at follow-up, which increases the risk of selection bias. It is possible that patients who continued to report high levels of catastrophizing were more likely to respond, potentially affecting the results. Previous studies suggest that individuals who accept higher levels of pain may cope better, partly due to reduced stress and less catastrophic thinking, leading to greater symptom improvement.8–10 Incorporating coping strategies into treatment may therefore be beneficial. Managing psychosocial factors such as catastrophic thinking is also crucial for optimal outcomes in chronic facial and jaw pain.14 The persistently elevated catastrophizing scores indicate that long-term monitoring and psychological support may be relevant for patients with long-term pTMD. This finding enhances the importance of addressing cognitive and emotional aspects of chronic pain in clinical follow-up and treatment planning.
The results also revealed an inability of the primary health care system to implement treatment recommendations from the multidisciplinary team. Satisfaction with follow-up by the GMPs was low.
An important methodological consideration is the distinction between the terms “physical health” and “psychological health” used in the five-year follow-up, and the broader term “general health” used in the three-year follow-up. In contrast to the three-year follow-up, the five-year follow-up did not ask the patients directly about how their general health had developed following the assessment. Instead, they were asked to what extent the TMD-related symptoms had affected their physical and psychological health after the assessment. Consequently, these measures are not directly comparable across the two follow-up periods.
The five-year follow-up have several limitations affecting result interpretation. In summary, the small sample size, low response rate, and reliance on self-reported data limit the interpretation of the results, particularly regarding correlations and subgroup analyses. These findings should therefore be considered exploratory and be interpreted with caution. The accuracy and validity of self-reported questionnaires are uncertain, as prior research shows discrepancies between physician evaluations and patient responses.15 The study was limited by a low response rate (44%) compared to the three-year follow-up, possibly due to a longer follow-up period. Additionally, no clinical re-examination was conducted following completion of the questionnaire, which should be considered a methodological limitation. Low response rates are common in long-term pain studies due to health, relocation, or loss of interest. While this limits its wider relevance, the response rate in this study aligns with long-term pain cohorts. For instance, a recent study on individuals with chronic low back pain with 4 to 15 years follow-up reported a response rate of only 35%, underlining the difficulty of maintaining participant engagement over extended periods.16–19
Responders in both the three- and five-year follow-ups were older than non-responders. This may be due to older adults having more spare time because of retirement and fewer work responsibilities, as shown in Statistics Norway’s time use survey.20, Increased availability may make them more likely to participate, while younger individuals may have competing priorities like work or family. Although this improves representation of older demographics in longitudinal research, it may introduce selection bias, as their experiences may not reflect those of younger, busier individuals.20
Respondents in both the three- and five-year follow-ups had higher female representation than the non-respondents. This may be less problematic, as TMD is more common in women who also have higher risk of developing the condition.21 Thus, the follow-up study reasonably reflects the typical TMD population.
The long period between baseline and follow-up can introduce bias. Several factors could have affected the results and led to interpretation bias, such as changes in general health, natural symptom variation, or other treatments that can affect the results and make it difficult to attribute any changes in health status directly to the treatment or intervention considered in the study. Lack of control over adherence to follow-up in accordance with the recommended treatment plan, or other treatments, may also influence outcomes.
Two fifths of patients reported overall improvement in their TMD symptoms in the five-year follow-up. This may be related to follow-up and treatment being the responsibility of the GMP, who may lack expertise in TMD, or that treatment was not sustained long enough to have lasting effects. This may further support the role of multidisciplinary evaluation and treatment by recommended specialists.5,14,22,23
Few follow-up studies exist for persistent pain patients, but interdisciplinary assessment focused on the biopsychosocial model consistently shows positive effects. While pain often persists, interdisciplinary teams help patients to understand why they have pain and help them develop better coping strategies.23 This supports interdisciplinary pain rehabilitation which could probably also be a cost-effective treatment for chronic pain.24
Conclusion
In this sample of patients with persistent pTMD, maximum pain intensity and pain-related suffering were reduced five years after multidisciplinary assessment. Restricted jaw movements were found to be unchanged. Symptom duration alone showed no clear association with future pain severity and suffering in this sample. Findings suggest that changes in quality of life may vary across life domains. Significant associations between physical health, psychological health, social life, economy, and chewing/eating function indicate that long-term outcomes in pTMD may reflect interactions between biopsychosocial domains and should be considered in long-term management of persistent painful TMD.
We were unable to identify any risk factors for developing persistent pTMD. However, the study has significant methodological weaknesses such as low response rate, small sample size along with no control group. The findings, especially regarding correlations and subgroup analyses, should therefore be interpreted with caution.
Future research may benefit from further exploring maximum pain intensity and suffering as key indicators of treatment effects along with a control group especially in follow up studies.
Acknowledgments
The authors want to thank all patients for participating. We also want to thank Professor Stein Atle Lie for his involvement in the statistical analysis. Artificial intelligence (Chat GPT4) has been used in proofreading the manuscript.25
Disclosure
The authors report there are no conflicts of interest in this work.
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