Patterns of cervical and masticatory impairment in subgroups of people with temporomandibular disorders–an explorative approach based on factor analysis

Factors associated with patient-reported mouth opening activity limitations in individuals with persistent intra-articular temporomandibular disorders: A cross-sectional study exploring physical and self-reported outcomes

BACKGROUND

Individuals living with intra-articular temporomandibular disorders (IA-TMDs) often report limitations with mouth opening activities. While clinical measures such as active range of motion (AROM) and movement quality are often used to assess mouth opening function, it is unclear if and how these relate to patient-reported limitations and whether other factors such as kinesiophobia influence mouth opening activities in those with IA-TMDs.

OBJECTIVES

Compare clinical measures of mouth opening function in those with IA-TMDs to asymptomatic controls. In those with an IA/TMD, explore relationships between patient-reported mouth opening limitations, and mouth opening function and kinesiophobia.

DESIGN

Cross-sectional study.

METHOD

Clinical mouth opening function (AROM, movement quality, pain on movement/10, stiffness on movement/10) was compared between groups (n = 30 IA-TMD, n = 30 controls). Within the IA-TMD group, correlations between patient-reported mouth opening limitations (Patient specific functional scale), kinesiophobia (Tampa Scale for Kinesiophobia for Temporomandibular Disorders) and clinical measures of mouth opening function were explored.

RESULTS

Impairments in AROM (-4 mm, p = 0.04, d = 0.5), movement quality (p < 0.01, φ = 0.6), pain on movement (p < 0.01, d = 0.8) and stiffness on movement (p < 0.01, d = 1.6) were observed in the IA-TMD group compared to controls. Patient-reported mouth opening limitations and kinesiophobia were significantly correlated (r = -0.48, p < 0.01); no correlation was found between patient-reported limitations and clinical mouth opening measures (r < 0.3, p > 0.05).

CONCLUSIONS

Mouth opening function is impaired in IA-TMD. However, kinesiophobia appears more related to patient-reported mouth opening limitations than clinical impairments. Consideration of clinical, kinesiophobia and patient-reported limitation measures are necessary to direct management of IA-TMD in those presenting for care.

Pain-free bite force in a healthy population: Within-session test-retest reliability in different sitting positions

BACKGROUND

Pain-free bite force (PFBF) is a promising measure to evaluate bite function in temporomandibular disorders (TMDs), yet the reliability of the measure is unknown.

OBJECTIVES

Establish the (1) within-session test-retest reliability of PFBF in a healthy population for a single and mean of three trials in supported and unsupported sitting; (2) standard error of measurement (SEM) and minimal detectable change (MDC).

METHODS

Thirty healthy participants (n = 15 female, mean [SD] age = 34.4 [11.0] years) completed two sessions (30-60 min apart) comprising three PFBF trials on each side, in both supported and unsupported sitting, to provide data for 60 (30 participants × two sides) test-retest assessments. Test-retest reliability for the first trial and mean of three trials in each position were determined using intraclass correlation coefficients (ICCs), before calculating the corresponding SEM and MDC for males (M) and females (F) respectively.

RESULTS

Within-session reliability was considered excellent for a single trial in supported sitting (ICC = 0.85; SEM M/F = 99/84 N; MDC M/F = 275/232 N) and unsupported sitting (ICC = 0.91; SEM M/F = 72/59 N, MDC M/F = 200/163 N), and for a mean of three trials in supported sitting (ICC = 0.89; SEM M/F = 66/79 N, MDC M/F = 182/220 N) and unsupported sitting (ICC = 0.92; SEM M/F = 64/59 N, MDC M/F = 177/164 N).

CONCLUSION

Single and a mean of three trials in supported and unsupported sitting appear reliable methods to measure PFBF in a healthy population. Testing PFBF using a mean of three trials in unsupported sitting appears superior over other methods though due to higher test-retest reliability, and lower SEM and MDC. Future studies should examine the reliability of PFBF in TMD populations.

The effectiveness of cervical rehabilitation interventions for pain in adults with myogenic temporomandibular disorders: A systematic review and meta-analysis

OBJECTIVE

Little evidence exists for the most effective conservative treatment approach for adults with myogenic temporomandibular disorders (MTMD). We aim to assess the effectiveness of cervical rehabilitation interventions on pain intensity and sensitivity in adults with MTMD compared to comparison intervention such as placebo, sham treatment, education or no intervention.

METHODS

For this systematic review and meta-analysis, we searched PubMed, EMBASE, Medline, PEDro databases, forward and backward citations and grey literature studies through PROSPERO, clinical trials and data registries without language or date restrictions between inception and 1 December 2021. We selected randomised controlled trials (RCTs) based on adult populations with MTMD who had a cervical rehabilitation intervention which was defined as any conservative intervention targeting the anatomical structures of the cervical spine. The primary outcome measures for pain were self-reported pain intensity and pain sensitivity through the pressure pain threshold (PPT) of the masseter and temporalis muscles. Secondary outcome measures of maximal mouth opening (on MMO) were included. Included studies were assessed for bias with the Cochrane risk of bias tool for randomised trials. Evidence from RCTs was synthesised to determine treatment effect size as differences between standardised mean difference (SMD) for changes in pain intensity, PPT and MMO comparing adults with MTMD who were treated with cervical rehabilitation interventions compared to a control group. This study is registered on Prospero, number CRD 42021289299.

RESULTS

Our general search yielded 2647 studies where seven RCTs met eligibility criteria with low to some concerns in their risk of bias. Pain intensity (five studies, n = 223, SMD -0.98, 95% CI -1.67 to -0.28, I2 = 79%), PPT of the masseter muscle (six studies, n = 395, SMD 0.64, 95% CI 0.43 to 0.86, I2 = 90%) and the temporalis muscles (five studies, n = 295, SMD 0.76, 95% CI 0.07 to 1.45, I2 = 84%) showed large treatment effect estimates favouring cervical rehabilitation interventions compared to no treatment, sham cervical treatment, patient education or non-cervical neuromuscular techniques. Compared to control interventions, one type of cervical rehabilitation intervention, cervical manual therapy alone or in combination with a neck exercise program was associated with statistically significant, large treatment effect estimates on pain intensity (four studies, n = 203, SMD -1.52, 95% CI -2.50 to -0.55).

CONCLUSIONS

This review found that in the short-term, cervical rehabilitation interventions especially upper cervical MT alone or in combination with a neck exercise program are effective in improving multiple pain outcomes in adults with MTMD. However, further research is needed to measure the long-term effects of this type of intervention.

An investigation of the changes in mechanical properties of the orofacial and neck muscles between patients with myogenous and mixed temporomandibular disorders

OBJECTIVE

To investigate the possible changes in the mechanical properties of the orofacial and neck muscles in patients with temporomandibular disorders (TMD).

METHODS

The study included a total of 98 females. Females were divided into three groups as myogenous TMD, mixed TMD, and healthy controls. The frequency (indicator of muscle tone), stiffness, and decrement (related to muscle elasticity) values of the sternocleidomastoid, upper trapezius, cervical extensor, and masseter muscles were measured using a portable myotonometer.

RESULTS

The frequency, stiffness, and decrement values of the masseter muscle were higher in the mixed and myogenous TMD groups than those of the control group (p < 0.017). The mixed TMD group had higher frequency and stiffness values in the upper trapezius muscle compared with the control group (p < 0.017).

DISCUSSION

The results suggest that the mechanical properties of the oral and neck muscles may be affected in patients with TMD.

Evaluation of the Relationship Between Head Posture, Mandibular Movements and Emotional Tension

Introduction: The head, due to its structure and assigned functions, is a unique part of our body. In a number of studies, an association has been confirmed between the base of the head, the cervical spine, and temporomandibular joint disorders. Research objective: The aim of the study was to evaluate the correlation of spatial head position, temporomandibular joint mobility and emotional tension. Material and methods: The study comprised32 participants, aged 20 to 30 years. The position of the head in the sagittal and frontal planes was evaluated via the photogrammetric method. The mobility of the temporomandibular joints was assessed by measurements made with a ruler. Electrodermal activity was measured with the "Bitalino 3DP by BEEVERYCREATIVE" device, and stress intensity assessment was estimated using the PSS-10 scale. Results: A significant (p<0.01) linear correlation was found between electrodermal activity (EDA Min) and the values of angles describing head tilt (FHT1 and HTA). Higher EDA values are associated with higher angle values. No significant correlations (p>0.05) were found between mandibular mobility and EDA scores, or between mandibular mobility measurements and head position. Conclusions: The study revealed a relationship between head positioning and electrodermal EDA activity.

Strength of scapular elevation in women with TMD and asymptomatic women

Temporomandibular disorder (TMD) is recognized for its high prevalence, presenting characteristic signs and symptoms. Cervical spine pain is present in 70% of diagnosed TMD cases. Aim: To verify if women with TMD present changes in isometric muscle strength in the scapula elevation. Methods: This is an observational, cross-sectional study. Thirty-five women, aged 22.89±2.04 years, were divided into the TMD group (TMDG), diagnosed with TMD according to the DC/TMD, and control group (CG), with asymptomatic individuals. The volunteers accessed a online link by the smartphone in order to answer questions on personal data, the Fonseca Anamnestic Index (FAI), Neck Disability Index (NDI), and Masticatory preference. In all participants, evaluation of the force of the scapula elevation muscles was performed, using a load cell model MM-100 (Kratos® SP, Brazil). Data were analyzed descriptively using the maximum, mean, and standard deviation and a two-way ANCOVA test was applied for all variables. A significance level of 5% was considered. Results: There were no statistically significant differences between the TMDG and CG for the maximal and mean muscle strength of scapular elevation. There were statistically significant differences in FAI (p <0.001*) between the CG and the TMDG. Conclusion: Based on the results, it was not possible to confirm the hypothesis that women diagnosed with TMD present lower isometric strength during scapular elevation (right/left).  

Association of cervical spine signs and symptoms with temporomandibular disorders in adults: a systematic review protocol

OBJECTIVE

The objective of this systematic review is to assess the evidence of association of cervical spine signs and symptoms with temporomandibular disorders (TMD). This will help to lend credence to mechanisms supporting the association in order to improve care strategies for this condition.

INTRODUCTION

The association of cervical spine impairments (in relation to neck posture, cervical spine mobility, muscle tenderness, muscle activity, and neck disability) with TMD has been widely discussed in the literature. Clarification of this relationship is important for health professionals to better assess and treat TMD.

INCLUSION CRITERIA

Eligible studies will include participants aged 18 years and over, with a diagnosis of TMD from the Research and Diagnostic Criteria for Temporomandibular Disorders or a revised version. Exclusion criteria will be participants with previous temporomandibular joint surgery, history of trauma or fracture in the temporomandibular joint or the craniomandibular system; serious comorbid conditions such as cancer, rheumatic disease, and neurological problems; primary cervical spine disorders such as disc herniation or spinal degenerative changes; or systemic disease such as ankylosing spondylitis.

METHODS

The search for articles will be conducted in the databases PubMed, PEDro, CINAHL, Web of Science, and Embase, without language or time restrictions. Two independent reviewers will review the title, abstract, and full texts of identified studies; select studies against the inclusion criteria; assess the methodological quality of eligible studies using critical appraisal tools; and perform data extraction. Relevant quantitative data will be pooled with statistical meta-analysis, when possible.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42019123698.

Evaluation of Soft Tissue Mobilization in Patients with Temporomandibular Disorder-Myofascial Pain with Referral

The aim of the study was functional evaluation of soft tissue mobilization in patients with temporomandibular disorder-myofascial pain with referral. The study group consisted of 50 individuals-37 females and 13 males. The average age was 23.36 ± 2.14 years. All subjects were diagnosed with myofascial pain with referral (diagnostic criteria for temporomandibular disorders). Soft tissue mobilization was applied three times. Electromyography of selected masticatory muscles was performed six times-before and after the treatment. After each mobilization, a decreasing tendency of muscular activity was observed in the entire study group. The Friedman test indicated that mobilization altered the activity of the right temporal muscle (p = 0.00010), both masseters (p = 0.0000), right sternocleidomastoid (p = 0.00251), left sternocleidomastoid (p = 0.00033), and right and left digastric muscles (p = 0.00045 and p = 0.00000, respectively). With respect to symmetry a statistically significant difference was noted in the case of the sternocleidomastoid muscles (p = 0.00729). In conclusion, soft tissue mobilization seems to be effective in the relaxation of masticatory muscles in patients with temporomandibular disorders. Our findings proved that soft tissue mobilization does not improve the symmetry and synergy of the masticatory muscles limited by dental occlusion.

Relationship between specific temporomandibular disorders and impaired upper neck performance

Upper neck impairments are more prevalent in patients with temporomandibular disorders (TMDs) but the differences between specific types of TMDs are unclear. This study evaluated the distribution of such impairments among different forms of TMD. In total, 116 participants (86 women and 30 men, age range 21-75 yr) were investigated. Forty-two individuals had no TMDs and were assigned to the control group. The remaining 74 patients were assigned to one of three groups based on the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) findings: pain-related (n = 37); intra-articular (n = 17); or mixed (combined pain-related and intra-articular) (n = 20). Analyses of impairments included between-group comparisons of key parameters of upper neck performance (active/passive mobility and muscular capabilities) and pain (subjective neck disability and pain sensitivity). Patients in the pain-related and mixed TMD groups were found to have decreased upper neck mobility in the cervical flexion-rotation test compared with patients in intra-articular and control groups, as well as poorer capabilities of the deep neck flexor muscles in the cranio-cervical flexion test compared to the control group. It was concluded that patients with pain-related TMD diagnoses are more likely to experience significant upper-neck hypomobility and poor muscular capabilities than patients with intra-articular diagnoses of TMD.

Cervical spine range of motion, posture and electromyographic activity of masticatory muscles in temporomandibular disorders

Abstract Introduction: Temporomandibular joint disorders (TMD or TMJD) involve clinical problems and symptoms affecting the temporomandibular joint (TMJ) and associated structures. The temporomandibular joints are anatomically connected to the cervical region, where cervical spine movements occur simultaneously to masticatory muscle activation and jaw movements. Objective: Our study sought to assess the relationship between the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD), surface electromyography (sEMG) of the masticatory muscles, posture and cervical flexibility in women with TMD. Method: Fifty women with an average age of 27.0 ± 6.37 years, diagnosed with TMD according to RDC/TMD, were assessed for craniocervical posture, cervical flexibility and sEMG of the masticatory muscles. Results: There were no differences in jaw function limitations, depression, pain level and its interference in work ability and daily activities, posture and sEMG between TMD diagnoses or between muscle classification (p > 0.05). Depression scores were higher among participants with biarticular dysfunction (p = 0.023). The group with bruxism exhibited a higher pain level at assessment (p = 0.001) and a greater reduction in work ability (p = 0.039). Subjects with muscular and mixed TMD showed less cervical rotation to the right when compared with those with articular TMD. Conclusion: There was no difference in posture or sEMG values for TMD diagnoses, joint and muscle dysfunctions and the presence of bruxism. Muscle dysfunction is associated with reduced cervical rotation to the right. Jaw function limitations did not interfere in posture or sEMG and depression was associated with pain.

Multiple diagnoses, increased kinesiophobia? - Patients with high kinesiophobia levels showed a greater number of temporomandibular disorder diagnoses

OBJECTIVES

The aim of this study was to empirically derive subgroups according to pain-related fear of movement beliefs using cluster analysis within a sample of TMD patients and asymptomatic volunteers.

METHODS

129 volunteers participated in this cross-sectional study (34.78, standard deviation [SD]: 12.49 years; 92 TMD patients and 37 symptom-free volunteers). Mechanical pain sensitivity through pressure pain threshold (PPT) on orofacial and remote sites, kinesiophobia, pain catastrophizing, anxiety and depression were assessed. A cluster analysis was used to derive subgroups according to kinesiophobia scores (TSK/TMD).

RESULTS

Three subgroups were derived: cluster 1 (high kinesiophobia [n = 53], TSK score: 33, SD[standard deviation] = 2.9), cluster 2 (moderate kinesiophobia [n = 50], TSK score: 26.2, SD = 2.14) and cluster 3 (no/low kinesiophobia [n = 26], TSK score 12.12, SD = 2.08) which included patients with higher overall PPT and lower scores on psychosocial variables. The group with high kinesiophobia showed high levels of pain catastrophizing, anxiety, and orofacial pain-related disability compared to the other subgroups and mechanical pain hyperalgesia in remote site compared to the low-kinesiophobia group. Also, we found a greater prevalence of triple diagnosis for the high-kinesiophobia subgroup compared to the moderate kinesiophobia group - odds ratio: 12.6 (95% confidence interval [CI]: 3.31-43.52, p < 0.01).

CONCLUSION

These results suggested that patients with TMD and higher levels of kinesiophobia beliefs may show a more complex clinical feature, with high psychosocial distress, widespread mechanical pain sensitivity, and a more complex TMD disorder. In this way, we suggest a relationship between the number of TMD diagnoses and kinesiophobia severity.