Is there a higher prevalence of tinnitus in patients with temporomandibular disorders? A systematic review and meta-analysis

Quality of life and level of physical activity of individuals with temporomandibular disorders with and without otological symptoms: Secondary analysis of a cross-sectional study

BACKGROUND AND PURPOSE

Otological symptoms (OS) are highly prevalent in individuals with temporomandibular disorders (TMD). Individuals with TMD and OS have more neck disability and decreased deep neck muscles endurance when compared to individuals without OS. However, no studies have evaluated whether OS is associated with lower Quality of Life (QoL) and worse levels of physical activity. This study aimed to evaluate the QoL and level of physical activity of individuals with TMD with and without OS.

METHODS

In this cross-sectional study, 62 individuals with TMD were allocated into 2 groups: TMD with OS (n = 36) or TMD without OS (n = 26). Self-reported complaints of dizziness, vertigo, tinnitus, earache, ear fullness, or hypoacusis were considered as OS. QoL was assessed with the WHOQOL-Bref and physical activity with the IPAQ-SF. Independent t-test and chi-squared test were used for analysis between-groups. Effect sizes were reported using Cohen's d. A Pearson correlation was used to compare the number of OS and QoL scores. A significance level of p < 0.05% and 95% confidence intervals were considered statistically significant.

RESULTS

The total generic scores for QoL were not different between-groups (p = 0.076), but individuals with TMD with OS had lower satisfaction (p = 0.015; d: 0.63) and physical domain (p = 0.015; d: 0.64) scores with a moderate effect size. In TMD with OS, 69.4% of individuals were irregularly active and 50% for the TMD without OS, with no statistical significance (p > 0.05). The number of OSs was inversely and weakly associated with the QoL total score.

CONCLUSION

Individuals with TMD and OS are associated with worsened QoL (physical domain and satisfaction) when compared to individuals with TMD without OS. The higher the number of OS, the worse the QoL score. Individuals with TMD with and without OS had similar levels of physical activity, but a high prevalence of irregularly active and sedentary individuals within TMD diagnosed population was found.

Evaluation of tinnitus in patients with Temporomandibular Disorders through Axis II of the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) and the Tinnitus Handicap Inventory (THI)

BACKGROUND

Tinnitus is a quite common and bothersome disorder that results in a perceived sound or noise, without an external origin, often causing notable psychological distress. Some interconnections between tinnitus, bodily pain perception, and psychological well-being were previously reported, thus the relationships between tinnitus and temporomandibular joint (TMJ)-related muscle issues, resulting in somatosensory tinnitus, must be deeply investigated. This study aims to assess the prevalence of tinnitus in patients with temporomandibular disorders (TMD) and to examine the correlation between tinnitus and scales assessing the severity of TMD as well as psychological-related parameters.

MATERIALS AND METHODS

In this cross-sectional study, a total of 37 adults with TMD symptoms were enrolled. Diagnostic data were collected using the Axis II of the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) and the Tinnitus Handicap Inventory (THI) questionnaire. Statistical analysis included descriptive assessments and significance was set at p < .05.

RESULTS

Individuals with tinnitus and TMD reported a significantly higher number of body pain areas, indicating a link between tinnitus and increased bodily pain perception. Tinnitus did not significantly impact TMJ-related functions. Significantly higher levels of psychological distress were observed in individuals with tinnitus, as evidenced by elevated scores in depression, generalised anxiety and somatic symptoms.

CONCLUSION

Tinnitus is a complex condition with significant effects on health and well-being, requiring an interdisciplinary approach for effective evaluation and care. The study provides deep insights into the prevalence of tinnitus in TMD patients, underscoring the need for comprehensive treatment strategies addressing both TMD and tinnitus.

A global bibliometric analysis on the relationship between tinnitus and temporomandibular disorders

BACKGROUND AND OBJECTIVES

This global bibliometric review aimed to investigate trends in publications relating to tinnitus and TMD.

METHODS

A search was performed in eight databases (June/2022), by independent researchers with relevant keywords about tinnitus and TMD, without restriction of date or language. Original research or case report/series evaluating prevalence, association and risk related to tinnitus and TMD were included. Independent examiners selected studies by title and abstract and performed data extraction. Data about publication and researchers, study population, objective, study design and diagnostic criteria for tinnitus and TMD were exported to VintagePoint® for bibliometric analyses. Data about the direct association between tinnitus and TMD were extracted.

RESULTS

One hundred and seventeen articles from 25 countries were included, most observational (68.4%) and evaluating association (N = 60; 44.8%). Among the 60 studies of association, 22 (36.6%) presented results of a direct association between the presence/absence of tinnitus and the presence/absence of TMD. Brazil (19.5%) and the United States (12.7%) were the countries with the most publications, and Dentistry (48.6%) was the main publication area. A growth in publications in Dentistry was observed in the past 30 years and in the past 10 years in Medicine. Half of the studies included the elderly population (50.2%). The main diagnostic criterion for both tinnitus (37.8%) and TMD (28%) was general questionnaires and/or self-report.

CONCLUSION

There is a growing trend in publications relating to tinnitus and TMD, especially in Dentistry, with a predominance of observational and association studies in the elderly population using questionnaires and/or self-report. More research with robust diagnostic methods and other study designs should be encouraged in the future.

Occurrence of Cervical Spine Pain and Its Intensity in Young People with Temporomandibular Disorders

Background: The main aim of this cross-sectional study was to compare the occurrence and severity of cervical spine pain in young adults diagnosed with TMDs with a healthy control group (without TMDs). Methods: The study was conducted from June to July 2023. Inclusion criteria were age (18-30 years), cervical spine pain (for at least 1 month), and consent to participate in the study. The study was conducted based on RDC/TMD protocol, an original questionnaire, and a physiotherapeutic examination focused on detecting TMDs. The cervical pain level was assessed using the Visual Analogue Scale (VAS). Thus, a total of 95 subjects were registered for the trials, 51 people (53.7%) constituted the control group (without TMDs), while 44 (46.3%) people constituted the study group (with TMDs). Results: The mean age of people participating in the study was 22.2 ± 2.2 years in the study group and 22.5 ± 3.1 years in the control group. The largest group was people aged 21-25 (n = 51 people, 53.7%). Patients from the study group more often experienced pain in the stomatognathic system during palpation (both in the muscle, joint, and musculoskeletal groups) and had reduced mobility of the temporomandibular joints in every movement (p < 0.001). People from the study group were also characterized by less mobility of the cervical spine (p < 0.05), apart from extension movement (p > 0.05). The analysis showed that of the 95 people participating in the study, 85.4% reported problems in the cervical spine area (n = 81), of which almost all people in the study group struggled with this problem (n = 43, 97.7%). It was found that cervical spine pain was significantly more common in people with TMDs (p < 0.05, chi2 = 10.118, df = 1, rc = 0.31). The level of pain was significantly higher in people from the study group (p < 0.001, chi2 = 45.765, df = 4, rc = 0.57). Conclusions: Our research has shown that the occurrence of cervical spine pain is more common in the group of young people with temporomandibular disorders (TMDs). In young people, this problem is rarely recognized and properly treated.

Effectiveness of Physical Therapy Interventions for Temporomandibular Disorders Associated with Tinnitus: A Systematic Review

Temporomandibular disorders (TMDs) refers to different clinical conditions affecting the temporomandibular joints, masticatory muscles, and adjacent structures. Although TMDs signs and symptoms (e.g., pain and limited mouth opening) are common, otological symptoms, such as tinnitus, might also be present. This study aims to summarize the evidence of the effectiveness of physical therapy interventions in individuals with TMDs associated with tinnitus. Randomized controlled trials investigating the effectiveness of physical therapy in individuals of both genders aged 18 or older with TMDs associated with tinnitus were included. The electronic search was performed in the following databases: MEDLINE, EMBASE, CINAHL, PEDro and CENTRAL. A total of four studies were included. All studies showed that physical therapy reduced the intensity of tinnitus, and two trials showed a decrease in the pain intensity caused by TMDs, an increase in the pressure pain thresholds in the masticatory muscles and an improvement of mandibular function. Two studies presented a low risk of bias. Despite a low certainty of the evidence, this review showed that physical therapy reduces the intensity or severity of tinnitus associated with TMDs. Results may support future research on the topic and evidence-based practice by recommending the best physical therapy approach for patients, clinicians, researchers, and health system managers.

Effects of Physical Interventions on Subjective Tinnitus, a Systematic Review and Meta-Analysis

Increasingly, patients suffering from subjective tinnitus seek help from physical therapists. Numerous randomised controlled trials (RCTs) have investigated the effect of physical interventions commonly used in physical therapy practice on subjective tinnitus. This systematic review and meta-analysis aimed to analyse the effects of physical interventions on tinnitus loudness, tinnitus annoyance, and scores on the Tinnitus Handicap Index (THI). Four databases were searched from inception up to March 2022. A total of 39 RCTs were included in the systematic review, and 23 studies were appropriate for meta-analyses. Risk of bias assessments were also performed. Interventions analysed in at least five studies were summarised, including transcutaneous electrical nerve stimulation (TENS), laser therapy, and acupuncture. Random-effects meta-analysis models were used, and effect sizes were expressed as Hedge's standardised mean differences (SMD) with 95%CI's. The quality of three-quarters of the studies was limited due to insufficient allocation concealment, lack of adequate blinding, and small sample sizes. Large, pooled effects sizes were found for acupuncture (SMD: 1.34; 95%CI: 0.79, 1.88) and TENS (SMD: 1.17; 95%CI: 0.48, 1.87) on THI as well as for acupuncture on tinnitus loudness (VAS Loudness (SMD: 0.84; 95%CI: 0.33, 1.36) and tinnitus annoyance (SMD: 1.18; 95%CI: 0.00, 2.35). There is some evidence that physical interventions (TENS and acupuncture, but not laser therapy) may be effective for tinnitus. However, the lack of high-quality studies and the risk of bias in many studies prohibits stronger conclusions.

Pain, deep neck flexors performance, disability, and head posture in individuals with temporomandibular disorder with and without otological complaints

BACKGROUND

Otological complaints (OC) are highly prevalent in subjects with temporomandibular disorders (TMD) and so is the risk of neck dysfunctions.

OBJECTIVE

To evaluate pain, deep neck flexor (DNF) performance, disability, and head and neck posture of individuals with TMD with and without OC.

METHODS

In this cross-sectional study, 57 individuals were divided into a group with TMD and OC (n= 31) and a group with TMD without OC (n= 26). Self-reported pain intensity, masticatory and neck muscles pressure pain thresholds, DNF performance, neck disability, and head and neck posture were evaluated. Data were compared between groups using the independent t test and Mann-Whitney test with Bonferroni correction for multiple comparisons. Effect sizes were evaluated using Cohen's index.

RESULTS

The TMD with OC group presented less muscle activation [26 (24-28) vs. 24 (24-26) mmHg; p< 0.05], less endurance [105 (46-140) vs. 44 (28-78) points; p< 0.05], and greater neck disability (8.15 ± 5.89 vs. 13.32 ± 6.36 points; p< 0.05). No significant difference was observed in self-reported pain, head and neck posture, or pressure pain thresholds.

CONCLUSION

Individuals with TMD with OC presented decreased DNF performance and increased neck disability compared to individuals with TMD without OC.

Association of temporomandibular disorders severity with otologic and concomitant pain symptoms in Asian youths

OBJECTIVE

To investigate the presence/severity of TMDs among Asian youths and examine the associations between TMD severity, otologic, and concomitant pain symptoms.

METHODS

Youths (17-24 years old) were recruited from a local polytechnic. The presence/severity of TMDs was determined with the Fonseca Anamnestic Index (FAI), while otologic/concomitant pain symptoms were appraised with the Maciel's Symptoms Checklist (MSC). Demographic, FAI, and MSC data were evaluated using Kruskal Wallis, chi-square, and relevant post-hoc tests (α = 0.05).

RESULTS

Among the participants (n = 200) enrolled, 40.5% had no TMD, whereas mild, moderate, and severe TMD were present in 43.5%, 12.5%, and 3.5%, respectively. Participants with moderate/severe TMDs had significantly more otalgia, tinnitus, vertigo, dizziness, ear pruritus, hearing loss, ear fullness, headache, eye, neck, and back pain than those with no TMDs (p < 0.001).

CONCLUSION

Otologic and concomitant pain symptoms were associated with TMDs and appear to increase with progressive TMD severity.

Association of periodontitis with tinnitus: A population-based cohort study in Taiwan

AIM

Tinnitus, ringing in the ears, is speculated to be driven by inflammation. This study examined whether periodontitis is a risk factor for tinnitus using Taiwan's National Health Insurance Research Database.

MATERIALS AND METHODS

Among the 79,456 patients who visited for dental concerns, 11,055 patients who were diagnosed with periodontitis and underwent periodontal treatment between 2000 and 2015 were enrolled in Group 1. After matching for sex, age, and index year, 11,055 patients with periodontitis who received no treatment were enrolled in Group 2. Similarly, 11,055 participants without periodontitis were included as controls.

RESULTS

At the end of the follow-up, 412 and 404 participants in the two periodontitis groups and 321 participants in the control group had tinnitus. Cumulative risk for tinnitus in Group 1 or 2 was significantly greater than in the control group. More periodontitis patients than controls developed tinnitus (adjusted hazard ratios were 1.71 (95% confidence interval [CI]: 1.49-1.97, p < .001) and 1.64 (95% CI: 1.37-1.86, p < .001) in Groups 1 and 2, respectively). The risks were not significantly different between Groups 1 and 2. Similar findings were obtained after excluding data for the first 1 or 5 years.

CONCLUSIONS

The study findings indicate that periodontitis is associated with tinnitus.

Temporomandibular Disorders and Bruxism in Patients Attending a Tinnitus Clinic

The current study investigated the coexistence of temporomandibular disorder (TMD) and/or bruxism among 51 individuals seeking treatment in a tinnitus clinic. All participants completed a Hebrew version of the Tinnitus Handicap Inventory (THI), depression and anxiety questionnaires, and the diagnostic criteria TMD (DC/TMD) questionnaire. In addition to questionnaires, the participants underwent a clinical evaluation of the oral cavity, facial muscles, and the temporomandibular joint (TMJ). Thirty-four participants (66.7%) were diagnosed with bruxism, while TMD was found in 14 (27.5%) of the cases. Patients with both tinnitus, TMD and bruxism scored the highest in the anxiety questionnaire. The severity of depression was found to be significantly associated with the tinnitus severity. These results emphasize the clinical bond between tinnitus, TMD, and bruxism.

Is there a comorbid relationship between temporomandibular disorders and otologic signs/symptoms?: An umbrella review

OBJECTIVE

This umbrella review (UR) explored the possible associations between temporomandibular disorders (TMDs) and otologic signs/symptoms (OSs) and established the potential impact of TMD interventions on OSs.

METHODS

A systematic review of systematic reviews (SRs)/meta-analyses (MAs) was conducted according to the PRISMA guidelines and Joanna Briggs Institute UR protocol. Electronic search of the PubMed, Scopus, Web of Science, and Open Grey databases was conducted and the quality of the identified studies was assessed using the AMSTAR2 criteria.

RESULTS

Out of 923 and 157 articles screened for the first and second focus questions respectively, a total of 8 SRs/MAs fulfilled the eligibility criteria. The prevalence of OSs in TMD patients and contrariwise varied substantially up to 85.0-95.0%. Available evidence indicates that TMDs are associated with OSs, and TMD treatment reduced OSs.

CONCLUSION

Findings suggest that a comorbid relationship between TMDs and OSs exists, and therapeutic TMD interventions improve OSs.

High Pain Intensity is a Risk Factor of Non-Resolving TMD: A Three-Year Follow-Up of a Patient Group in a Norwegian Interdisciplinary Evaluation Program

Purpose

To investigate the outcome of patients with long-term refractory temporomandibular disorders (TMD) three years after a Norwegian interdisciplinary evaluation program with attention to patient satisfaction, function, pain, and psychosocial variables.

Patients and Methods

The study population consisted of 60 long-term refractory TMD patients who were investigated by a Norwegian interdisciplinary team. A questionnaire that covered medical history, function, pain, lifestyle factors, TMD-status and follow-up from their general medical practitioner (GMP) was sent to the patients three years after the evaluation. Questionnaires that assessed function (Mandibular Functional Index Questionnaire [MFIQ] and Roland Morrison Scale [RMS]), pain intensity (General Pain Intensity questionnaire [GPI]) and psychosocial factors (Hospital Anxiety and Depression scale [HADS]); a 2-item version of the Coping Strategies Questionnaire [CSQ]) were included in the package.

Results

Thirty-nine out of 60 TMD patients completed the questionnaires. Improvements in TMD symptoms were reported in 10 patients (26%), were unchanged in 16 patients (41%) and worsened in 13 patients (33%). Only 8 patients (21%) were satisfied with the follow-up of the suggested treatments from their GMP. Significant improvements of symptoms were noted in MFIQ (jaw function), GPI (including pain intensity at maximum and suffering from pain), and CSQ (pain related catastrophizing), in all 39 TMD patients as one group. However, a subgroup analysis showed that the significant improvements were mostly within patients who reported improvement of TMD symptoms. A high pain intensity at baseline was a significant risk factor (OR = 5.79, 95% CI: 1.34, 24.96) for patients who reported worsening of TMD symptoms at follow-up.

Conclusion

High pain intensity at baseline was a significant risk factor for poorer recovery three years after an interdisciplinary evaluation. Our data support the notion that improved coping with TMD pain includes both decreased pain intensity, CSQ and MFIQ scores.

Patients' perceptions on temporomandibular disorder treatment with hydrostatic oral splints - a pilot study

Objective

To evaluate temporomandibular disorder (TMD) treatment with a prefabricated, hydrostatic oral splint (HOS) based on self-reported patient’s symptoms using a standardized questionnaire.

Methods

Two hundred fifty-eight questionnaires from patients diagnosed with TMD and subsequently treated with HOS were collected from two independent private practices. Based on patient’s comfort the questionnaire recorded TMD symptoms and symptom regression. Descriptive and comparative statistics was carried out using SPSS.

Results

A total of 221 questionnaires were analyzed. Patients reported TMD symptoms such as pain (93.2%), TMJ clicking (66.1%), headache (25.8%), cervical spine disorders (23.5%), restricted mouth opening (22.6%) and tinnitus (11.8%). For most symptoms, improvement was reported mostly after two weeks, except for tinnitus, where positive effects were usually reported after four weeks.

Conclusion

HOS seem to be effective for immediate treatment of pain and other TMD symptoms. Based on the available data, a treatment period of four weeks can be recommended.

Association of temporomandibular disorders and tinnitus with health-related quality of life: A cross-sectional study using the Fifth Korea National Health and Nutrition Examination Survey

BACKGROUND

Few studies have examined the associations of temporomandibular disorders (TMDs) and tinnitus with health-related quality of life on a national level.

OBJECTIVE

We aimed to investigate the associations of TMDs, tinnitus and quality of life among the Korean population, aged 19 years or older.

METHODS

Data were obtained from the fifth Korea National Health and Nutrition Examination Survey (2012; N = 5786). TMDs, tinnitus and health-related quality of life were assessed using self-report data from EuroQol-5 Dimension. Participants were divided into four groups: no TMD and no tinnitus, TMD present but no tinnitus, no TMD but tinnitus present and both TMD and tinnitus present.

RESULTS

Among the participants, 21.88% had TMD, 24.93% had tinnitus, and 7.74% had both. The prevalence of most TMD and all types of tinnitus was higher among females than among males. The group with both TMD and tinnitus reported the highest percentage of problems in the usual activity, pain/discomfort and anxiety/depression dimensions. Moreover, the odds ratio (OR) for lower quality of life was significantly higher in the group with both TMD and tinnitus compared to the group without TMD and tinnitus: mobility (OR = 1.527, 95% confidence interval [CI]: 1.014-2.300), pain/discomfort (OR = 2.072, 95% CI: 1.570-2.735), anxiety/depression (OR = 1.692, 95% CI: 1.034-2.767), EQ-5D score (OR = 1.651, 95% CI: 1.121-2.431) and EQ-VAS (OR = 1.682, 95% CI: 1.246-2.269).

CONCLUSION

The presence of both TMD and tinnitus has a considerable impact on HRQoL in the Korean population. In our study, the group with both TMD and tinnitus showed lower HRQoL than without TMD and tinnitus group. These results emphasise the need for a multilateral and comprehensive approach to address these disorders and provide baseline data for developing appropriate interventions.

Is there an association between otologic symptoms and temporomandibular disorders?: An evidence-based review

BACKGROUND

The aim of this article is to discuss the scientific evidence available on the the pathophysiology and management of otologic complaints in patients with temporomandibular disorders (TMDs).

TYPES OF STUDIES REVIEWED

The authors conducted an electronic search in MEDLINE, Web of Science and ScienceDirect and retrieved all the relevant peer-reviewed journal articles available in English on the topic. No time restriction was applied.

RESULTS

No consensus exists on the management of otologic symptoms in patients with concomitant TMD. The scientific evidence suggests that conservative or reversible TMD therapy might provide relief. However, this evidence is scarce and low, thus further studies with larger sample sizes and better designed methodological frameworks are needed. Until such evidence is available, dentists and orofacial pain specialists should treat TMD patients using current guidelines and refer those with otologic symptoms to an otolaryngologist.

PRACTICAL IMPLICATIONS

Given the wide range of potential pathophysiologies and treatments for each otologic symptom described in the TMD patient, close collaboration with otolaryngologists is essential to achieve the best patient care.

Sociodemographic profile and stages of Parkinson’s disease associated with predictors of Temporomandibular Disorder

ABSTRACT Purpose: to analyze the predictors of temporomandibular disorder in people with Parkinson’s disease, verifying their associations with sociodemographic aspects and stages of the disease. Methods: a study based on secondary data from research conducted in 2017 with 110 people with Parkinson’s disease. They were assessed with the Research Diagnostic Criteria for Temporomandibular Disorders and the Parkinson’s disease staging scale. The studied predictive variables for temporomandibular disorder were pain, crepitation, clicking, nighttime and daytime clenching/gnashing, uncomfortable/non-habitual bite, morning rigidity, and tinnitus. The sociodemographic aspects assessed were age, sex, schooling level, marital status, income, and stages 1 to 3 of the disease. The chi-squared odds ratio was used with a 95% confidence interval and significance level at p < 0.05. Results: an association was verified between nighttime clenching/gnashing and income (p = 0.006); tinnitus and income range from ½ to 3 (p = 0.003) and from 4 to 10 minimum wages (p = 0.004); and between tinnitus and stage 1 (p = 0.02). Conclusion: this study verified that the predictors associated with temporomandibular disorder in people with Parkinson’s disease were pain, clicking, crepitation, uncomfortable/non-habitual bite, and morning rigidity. It was verified that income and stage 1 of the disease had an association with nighttime clenching/gnashing and tinnitus.

Temporomandibular disorders, neck disability, and oral parafunctions in tinnitus patients: A cross-sectional epidemiological study from Southern Italy

OBJECTIVE

To assess the prevalence of temporomandibular disorders (TMD) in a sample of tinnitus patients and to determine the association between tinnitus, TMD, neck disability, and oral parafunctions.

METHODS

Seventy-nine tinnitus patients were enrolled and underwent standardized clinical examination for TMD. The tinnitus severity was measured with the Tinnitus Handicap Inventory (THI). The oral parafunctions were self-reported with the Oral Behavior Checklist (OBC). The neck disability was recorded with the Neck Disability Index (NDI).

RESULTS

More than half of the sample presented TMD, and the most frequent diagnosis was TMD pain. Higher THI was observed in TMD-pain individuals, compared to TMD-free (β 18.4; 95%CI 6.7, 30.1; p = 0.002). The OBC showed a significant low-to-moderate positive correlation with the THI (rho= 0.368, p = 0.001), while the NDI did not.

DISCUSSION

Standardized assessment of TMD and oral behaviors should be integrated into the routine diagnostic evaluations of tinnitus patients.

Influence of Clinical, Physical, Psychological, and Psychophysical Variables on Treatment Outcomes in Somatic Tinnitus Associated With Temporomandibular Pain: Evidence From a Randomized Clinical Trial

OBJECTIVE

To assess the influence of clinical, psychological, and psychophysical variables on treatment outcomes after application of exercise combined with education with/without manual therapy in people with tinnitus associated with temporomandibular disorder (TMD).

METHODS

A secondary analysis of a clinical trial was performed investigating the effectiveness of including cervico-mandibular manual therapy into an exercise combined with education program in 61 subjects with TMD-related tinnitus. Clinical outcomes including tinnitus severity and tinnitus-related handicap were assessed at 3 and 6 months post-intervention. Patients were assessed at baseline for clinical (tinnitus severity, tinnitus-related handicap, quality of life), physical (range of motion), psychological (depression), and psychophysical (pressure pain thresholds [PPTs]) variables that were included as predictors.

RESULTS

The regression models indicated that higher scores of tinnitus severity at baseline predicted better outcomes 3 and 6 months post-intervention (explaining 13% to 41% of the variance) in both groups. Higher scores of tinnitus-related handicap at baseline predicted better outcome of tinnitus-related handicap (45% variance) in the manual therapy with exercise/education group. Lower PPTs over the temporalis muscle at baseline predicted poorer clinical outcomes (10.5% to 41% of the variance) in both groups. Other predictors were sex and quality of life (6.7% variance) in the manual therapy group and PPTs over the masseter muscle (5.8% variance) in the exercise/education group.

CONCLUSION

This study found that baseline tinnitus severity and localized PPT over the temporalis muscle were predictive of clinical outcomes in individuals with TMD-related tinnitus following physical therapy. Other predictors (eg, sex, quality of life) were less influential.

Impact of Temporomandibular Joint Complaints on Tinnitus-Related Distress

There is increasing evidence of associations between the presence of temporomandibular joint (TMJ) disorders and tinnitus. It has been recently proposed that tinnitus patients with TMJ complaints could constitute a subtype, meaning a subgroup of tinnitus patients responsive to specific treatments. Tinnitus patients with TMJ complaints are often young women with somatosensory features of their tinnitus. Here, we investigate the socio-economic factors, phenotypic characteristics and psychological variables of tinnitus subjects from the Swedish Tinnitus Outreach Project, with (n = 486) or without (n = 1,996) TMJ complaints. The prevalence of TMJ complaints was greater in tinnitus subjects with severe tinnitus (36%) when compared to those with any tinnitus (19%), strongly indicating the contribution of TMJ problems to the severity of tinnitus. Comparing subgroups with or without TMJ complaints in the whole sample, differences were found regarding a large number of socioeconomic, phenotypic, and psychological characteristics. Subjects with TMJ complaints were more often women, more often reported stress as the cause of tinnitus, were more severely affected by tinnitus, scored worse in measures of psychological well-being and life quality, and were more often affected by problems tolerating sounds, headache, vertigo/dizziness, and neck pain. In addition, they more often reported pulsating and tonal tinnitus, somatic modulation of tinnitus, and aggravation of tinnitus by loud sounds and stress. When focusing the analysis in subjects with tinnitus as a big problem using the Tinnitus Functional Index cut-off ≥ 48, or with severe tinnitus according to the Tinnitus Handicap Inventory cut-off ≥ 58, the impact of somatosensory modulations and stress on tinnitus were greater in subjects with TMJ complaints in comparison to those without. In light of these results, we hypothesize that stress could contribute to the co-occurrence of TMJ problems and tinnitus and also to the development of severe tinnitus. Our study supports the need of involving dental care and stress management in the holistic treatment of patients with severe tinnitus.