Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) for Clinical and Research Applications: recommendations of the International RDC/TMD Consortium Network* and Orofacial Pain Special Interest Group†

Inter-tester reliability of selected clinical tests for long-lasting temporomandibular disorders

OBJECTIVE

Clinical tests used to examine patients with temporomandibular disorders vary in methodological quality, and some are not tested for reliability. The purpose of this cross-sectional study was to evaluate inter-tester reliability of clinical tests and a cluster of tests used to examine patients with long-lasting temporomandibular disorders.

METHODS

Forty patients with pain in the temporomandibular area treated by health-professionals were included. They were between 18-70 years, had 65 symptomatic (33 right/32 left) and 15 asymptomatic joints. Two manual therapists examined all participants with selected tests. Percentage agreement and the kappa coefficient (k) with 95% confidence interval (CI) were used to evaluate the tests with categorical outcomes. For tests with continuous outcomes, the relative inter-tester reliability was assessed by the intraclass-correlation-coefficient (ICC3,1, 95% CI) and the absolute reliability was calculated by the smallest detectable change (SDC).

RESULTS

The best reliability among single tests was found for the dental stick test, the joint-sound test (k = 0.80-1.0) and range of mouth-opening (ICC3,1 (95% CI) = 0.97 (0.95-0.98) and SDC = 4 mm). The reliability of cluster of tests was excellent with both four and five positive tests out of seven.

CONCLUSION

The reliability was good to excellent for the clinical tests and the cluster of tests when performed by experienced therapists. The tests are feasible for use in the clinical setting. They require no advanced equipment and are easy to perform.

Isolated Arthritis of the Temporomandibular Joint as the Initial Manifestation of Juvenile Idiopathic Arthritis

OBJECTIVE

To describe characteristics of patients with juvenile idiopathic arthritis (JIA) presenting with isolated arthritis of the temporomandibular joints (TMJ).

METHODS

Patients with JIA with isolated TMJ arthritis from 4 large tertiary pediatric rheumatology centers were included. Demographic and clinical data were analyzed using descriptive statistics.

RESULTS

Fifty-five patients were identified (65% bilateral presentation). Six patients developed arthritis in other joints (median time 6 mos); 4 patients developed uveitis, all prior to arthritis. At last followup, 9% were still taking antirheumatic medications.

CONCLUSION

JIA TMJ arthritis can occur in isolation, and is probably underdiagnosed. Care providers including dentists and orthodontists should be aware of this presentation.

Spasmodic torticollis after orthognathic surgery

The treatment of malocclusions can involve orthognathic surgery. Although orthognathic surgery is a safe surgical procedure, low incidences of many complications have been reported such as infections, hemorrhage, nerve injuries, temporomandibular disorders (TMDs), and psychological problems. There are no reports in the literature of orthognathic surgery being associated with postural disorders although the link between dental occlusion and postural disorders is highlighted in numerous recent publications. This report describes the case of a young, healthy patient who presented with sustained spasmodic torticollis following orthognathic surgery. In addition, the physiopathological aspects of this atypical condition are discussed.

A two-year follow-up of surgical and non-surgical treatments in patients with masticatory muscle tendon-aponeurosis hyperplasia

This study re-examined the usefulness of surgery for the management of masticatory muscle tendon-aponeurosis hyperplasia (MMTAH) through a comparison of the outcomes between patients who underwent surgery and those who did not. The duration of follow-up was 2 years. Twenty-eight patients who attended the study hospital and were given a diagnosis of MMTAH were included. Nineteen patients underwent surgery (surgical group) and nine patients were instructed to open their mouths wide once a day and did not undergo surgery (non-surgical group). Maximum mouth opening, impairment of daily activities, satisfaction, and the status of mouth opening training were evaluated after surgery. The mean increase in mouth opening after 2 years was 20.2mm in the surgical group and 2.4mm in the non-surgical group. Adequate mouth opening training led to satisfactory results 2 years postoperative, and sustained mouth opening training for 6 months after surgery was a key factor for obtaining good outcomes. The general condition and personality of individual patients should be evaluated carefully before surgery to estimate whether or not they can endure the pain associated with postoperative mouth opening training. The results of this study suggest that the surgical procedure is useful for the management of MMTAH.

Temporomandibular Joint Involvement in Association With Quality of Life, Disability, and High Disease Activity in Juvenile Idiopathic Arthritis

OBJECTIVE

To evaluate the demographic, disease activity, disability, and health-related quality of life (HRQOL) differences between children with juvenile idiopathic arthritis (JIA) and their healthy peers, and between children with JIA with and without clinical temporomandibular joint (TMJ) involvement and its determinants.

METHODS

This study is based on a cross-sectional cohort of 3,343 children with JIA and 3,409 healthy peers, enrolled in the Pediatric Rheumatology International Trials Organisation HRQOL study or in the methotrexate trial. Potential determinants of TMJ involvement included demographic, disease activity, disability, and HRQOL measures selected through univariate and multivariable logistic regression.

RESULTS

Clinical TMJ involvement was observed in 387 of 3,343 children with JIA (11.6%). Children with TMJ involvement, compared to those without, more often had polyarticular disease course (95% versus 70%), higher Juvenile Arthritis Disease Activity Score (odds ratio [OR] 4.6), more disability, and lower HRQOL. Children with TMJ involvement experienced clearly more disability and lower HRQOL compared to their healthy peers. The multivariable analysis showed that cervical spine involvement (OR 4.6), disease duration >4.4 years (OR 2.8), and having more disability (Childhood Health Assessment Questionnaire Disability Index >0.625) (OR 1.6) were the most important determinants for TMJ involvement.

CONCLUSION

Clinical TMJ involvement in JIA is associated with higher disease activity, higher disability, and impaired HRQOL. Our findings indicate the need for dedicated clinical and imaging evaluation of TMJ arthritis, especially in children with cervical spine involvement, polyarticular course, and longer disease duration.

Frequency of temporomandibular disorders diagnoses based on RDC/TMD in a Polish patient population

OBJECTIVE

To assess the frequency and age distribution of Axis I and Axis II diagnoses among Polish patients with temporomandibular disorders (TMD).

METHOD

One hundred sixty-three (n = 163) consecutive adult patients seeking TMD treatment were assessed based on the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) guidelines. Descriptive statistics on the frequency of diagnoses and mean age of the diagnostic groups was performed.

RESULT

Frequency of muscle disorders, disc displacements, and other joint disorders was 56.9, 48.9, and 31%, respectively. Disc displacement was the most common diagnosis in younger patients. Severe somatization and depression were shown in 11.9 and 15.8% of patients, respectively. Only 10.5% of the patients showed severe pain-related impairment. Females tended to have higher psychosocial scores than males.

DISCUSSION

The frequency of Axis I TMD diagnoses in Polish patients is similar to other populations, whereas Axis II findings slightly differ from previous reports from other countries.

Concentrations of CTX I, CTX II, DPD, and PYD in the urine as a biomarker for the diagnosis of temporomandibular joint osteoarthritis: A preliminary study

OBJECTIVES

The aim of this study was to identify a marker for temporomandibular joint (TMJ) osteoarthritis (OA) diagnosis by comparing the concentrations of urinary pyridinoline (PYD), deoxypyridinoline (DPD), and C-terminal telopeptides type I collagen (CTX-I), and CTX-II of TMJ OA patients with those of a non-symptomatic group.

METHODS

PYD, DPD, CTX-I, and CTX-II concentrations in the urine of 36 non-symptomatic subjects and 31 TMJ OA subjects were analyzed.

RESULTS

The differences for only PYD and DPD were significant. In ROC analysis, PYD and DPD showed higher sensitivity and specificity than CTX-I and CTX-II. PYD and DPD concentrations in urine were significantly increased in TMJ OA patients and can therefore be used as a biomarker in the supplementary clinical diagnosis of TMJ OA.

DISCUSSION

The findings suggest that measurement of their concentration can be a supplementary method for clinical diagnosis of TMJ OA.

Class II Division 2 subdivision left malocclusion associated with anterior deep overbite in an adult patient with temporomandibular disorder

ABSTRACT The orthodontic treatment of patients with chief complaint of temporomandibular disorders (TMD) presents doubtful prognosis, due to the poor correlation between malocclusions and TMDs. The present case report describes the treatment of an adult patient with Angle Class II Division 2 subdivision left malocclusion associated with anterior deep overbite and TMD. This case was presented to the Brazilian Board of Orthodontics and Dentofacial Orthopedics (BBO), as part of the requirements to obtain the title of BBO Diplomate.

Effect of mechanical loading on the metabolic activity of cells in the temporomandibular joint: a systematic review

OBJECTIVES

The purpose of this systematic review was to elucidate how different modalities and intensities of mechanical loading affect the metabolic activity of cells within the fibro-cartilage of the temporomandibular joint (TMJ).

MATERIALS AND METHODS

A systematic review was conducted according to PRISMA guidelines using PubMed, Embase, and Web of Science databases. The articles were selected following a priori formulated inclusion criteria (viz., in vivo and in vitro studies, mechanical loading experiments on TMJ, and the response of the TMJ). A total of 254 records were identified. After removal of duplicates, 234 records were screened by assessing eligibility criteria for inclusion. Forty-nine articles were selected for full-text assessment. Of those, 23 were excluded because they presented high risk of bias or were reviews. Twenty-six experimental studies were included in this systematic review: 15 in vivo studies and 11 in vitro ones.

CONCLUSION

The studies showed that dynamic mechanical loading is an important stimulus for mandibular growth and for the homeostasis of TMJ cartilage. When this loading is applied at a low intensity, it prevents breakdown of inflamed cartilage. Yet, frequent overloading at excessive levels induces accelerated cell death and an increased cartilage degradation.

CLINICAL SIGNIFICANCE

Knowledge about the way temporomandibular joint (TMJ) fibrocartilage responds to different types and intensities of mechanical loading is important to improve existing treatment protocols of degenerative joint disease of the TMJ, and also to better understand the regenerative pathway of this particular type of cartilage.

Counterclockwise maxillomandibular advancement surgery and disc repositioning: can condylar remodeling in the long-term follow-up be predicted?

This study investigated predictive risk factors of condylar remodeling changes after counterclockwise maxillomandibular advancement (CCW-MMA) and disc repositioning surgery. Forty-one female patients (75 condyles) treated with CCW-MMA and disc repositioning had cone beam computed tomography (CBCT) scans taken pre-surgery, immediately after surgery, and at an average 16 months post-surgery. Pre- and post-surgical three-dimensional models were superimposed using automated voxel-based registration on the cranial base to evaluate condylar displacements after surgery. Regional registration was performed to assess condylar remodeling in the follow-up period. Three-dimensional cephalometrics, shape correspondence (SPHARM-PDM), and volume measurements were applied to quantify changes. Pearson product-moment correlations and multiple regression analysis were performed. Highly statistically significant correlation showed that older patients were more susceptible to overall condylar volume reduction following CCW-MMA and disc repositioning (P≤0.001). Weak but statistically significant correlations were observed between condylar remodeling changes in the follow-up period and pre-surgical facial characteristics, magnitude of the surgical procedure, and condylar displacement changes. After CCW-MMA and disc repositioning, the condyles moved mostly downwards and medially, and were rotated medially and counterclockwise; displacements in the opposite direction were correlated with a greater risk of condylar resorption. Moreover, positional changes with surgery were only weakly associated with remodeling in the follow-up period, suggesting that other risk factors may play a role in condylar resorption.

The medial pterygoid muscle: a stabiliser of horizontal jaw movement

There is limited information of the normal function of the human medial pterygoid muscle (MPt). The aims were to determine whether (i) the MPt is active throughout horizontal jaw movements with the teeth apart and (ii) whether single motor units (SMUs) are active during horizontal and opening-closing jaw movements. Intramuscular electrodes were placed in the right MPt of 18 participants who performed five teeth-apart tasks: (i) postural position, (ii) ipsilateral (i.e. right) jaw movement, (iii) contralateral movement, (iv) protrusive movement and (v) opening-closing movement. Movement tasks were guided by a target and were divided into BEFORE, OUT, HOLDING, RETURN and AFTER phases according to the movement trajectories recorded by a jaw tracking system. Increased EMG activity was consistently found in the OUT, HOLDING and RETURN phases of the contralateral and protrusive movement tasks. An increased RETURN phase activity in the ipsilateral task indicates an important role for the MPt in the contralateral force vector. Of the 14 SMUs active in the opening-closing task, 64% were also active in at least one horizontal task. There were tonically active SMUs at the postural jaw position in 44% of participants. These new data point to an important role for the MPt in the fine control of low forces as required for stabilisation of vertical mandibular position not only to maintain postural position, but also throughout horizontal jaw movements with the teeth apart. These findings provide baseline information for future investigations of the possible role of this muscle in oro-facial pain conditions.

Physiological effects of anterior repositioning splint on temporomandibular joint disc displacement: a quantitative analysis

Anterior repositioning splints (ARS) are used primarily for the management of temporomandibular joint (TMJ) anterior disc displacement with reduction (ADDwR). However, the exact physiological effects of ARS are still unclear. This study investigated the short and long-term effects of ARS on disc and condyle angles/positions by metric analysis. Twenty-two subjects diagnosed with ADDwR were recruited. Maxillary full-coverage ARS were fabricated, and MRI of TMJs was obtained before splint treatment, immediate post-insertion and 6 months after splint treatment. Disc-condyle relationship was determined by disc-condyle angle measurement. Disc and condyle positions were described as X-Y coordinates with the summit of glenoid fossa as the origin of the coordinates. Thirty-two TMJs were classified as ADDwR and 12 were normal. Upon ARS insertion, all TMJs with ADDwR got normal disc-condyle relationships. The condyles moved significantly forward and downward, while the discs moved significantly backward and upward. MRI at 6 months after treatment (without ARS insertion) indicated that only 40·6% (13/32) of the joints were maintained in the normal disc-condyle relationship. The majority of condyles returned to their pre-treatment positions, while the discs generally moved anteriorly again. The use of ARS resulted in forward and downward condyle movement, and a concurrent backward movement of the disc resulting in ideal spatial disc-condyle relationship. The stability of this relationship, however, could not be maintained in the majority of TMJs upon ARS removal. Findings explain the good short-term clinical outcomes with ARS and their relatively lower efficacy in the long term.

Mechanobehavioral Scores in Women with and without TMJ Disc Displacement

Cartilage fatigue may be a factor in the precocious development of degenerative changes in the temporomandibular joint (TMJ). This cross-sectional study estimated potential for cartilage fatigue via TMJ energy densities (ED) and jaw muscle duty factors (DF), which were combined to calculate mechanobehavioral scores (MBS) in women with (+) and without (-) bilateral TMJ disc displacement (DD). All subjects gave informed consent to participate and were examined using Diagnostic Criteria (DC) for Temporomandibular Disorders (TMD) and magnetic resonance (MR) and computed tomography (CT) images. Forty-seven subjects were categorized into +DD ( n = 29) and -DD ( n = 18) groups. Dynamic stereometry (MR images combined with jaw-tracking data) characterized individual-specific data of TMJ stress-field mechanics to determine ED (ED = W/ Q mJ/mm3, where W = work done, Q = volume of cartilage) during 10 symmetrical jaw-closing cycles with a 20-N mandibular right canine load. Subjects were trained to record masseter and temporalis electromyography over 3 days and 3 nights. Root mean square electromyography/bite-force calibrations determined subject-specific masseter and temporalis muscle activities per 20-N bite-force (T20 N, µV), which defined thresholds. Muscle DF (DF = % duration of muscle activity/total recording time) were determined for a range of thresholds, and MBS (ED2 × DF) were calculated. Intergroup differences in ED, DF, and MBS were assessed via analyses of variance with Bonferroni and Tukey honest significant difference post hoc tests. Average ED for contralateral TMJs was significantly larger ( P = 0.012) by 1.4-fold in +DD compared to -DD subjects. Average DF were significantly larger (all P < 0.01) for +DD compared to -DD subjects by 1.7-, 2.5-, and 1.9-fold for day, night, and overall, respectively. Daytime MBS were significantly larger (all P < 0.04) by up to 8.5-fold in +DD compared to -DD subjects. Significantly larger ED, DF, and MBS were shown in women with compared to women without bilateral TMJ DD.

The IL-1Ra gene variable number tandem repeat variant is associated with susceptibility to temporomandibular disorders in Turkish population

BACKGROUND

Temporomandibular joint disorders (TMD) are a group of disorders involving temporomandibular joint and related structures. Interleukine-1 receptor antagonist (IL-1Ra) is an important anti-inflammatory molecule that competes with other interleukin-1 molecules. This study was designed to investigate the possible association of the IL-1Ra VNTR variant with the risk of TMD in the Turkish population.

METHODS

Peripheral blood samples were collected from 100 patients with TMD (23 males, 77 females) and 110 healthy individuals (35 males, 75 females). Genotyping of IL-1Ra 86 bp VNTR variant was evaluated by gel electrophoresis after polymerase chain reaction (PCR).

RESULTS

Our results show that there is a statistically significant difference between TMD patients and control group with respect to IL-1Ra genotype distribution and allele frequencies. 1.2, 1.4, and 4.4 genotypes were more common in patients, while 2.2 and 3.3 genotypes were rarer (P<.000). Frequency of alleles 1 and 4 was higher in patient groups (P<.000), whereas alleles 2 and 3 had a lower frequency in patients with TMD (P<.000).

CONCLUSIONS

This is the first correlation study that evaluates the association between IL-1Ra gene VNTR variant and TMD. The VNTR variant related to IL-1Ra gene showed a strong pattern of association with TMD that may have a potential impact on disease counseling and management. Larger studies with various ethnicities are needed to establish the impact of IL-1Ra VNTR variant on risk of developing TMD.

Cognitive behavioral therapy for psychosomatic problems in dental settings

Cognitive behavioral therapy (CBT) has been applied for various problems, including psychiatric diseases such as depression and anxiety, and for physical symptoms such as pain. It has also been applied for dental problems. Although the effect of CBTs on temporomandibular disorders and dental anxiety are well documented, its effectiveness on other types of oral symptoms remain unclear. Little information comparing the different types of CBTs in the dental setting is currently available. Because dental professionals are often expected to conduct CBTs in the dental setting, it is important to develop proper training programs for dental professionals.

In this review article, we demonstrate and discuss the application of CBTs for psychosomatic problems, including temporomandibular disorders, dental anxiety, burning mouth syndrome, and other oral complaints in dental settings.

TMJ energy densities in healthy men and women

OBJECTIVE

Cartilage fatigue, due to mechanical work, may account for the early development of degenerative joint disease (DJD) in the temporomandibular joint (TMJ), and why women are three times more likely to be afflicted. This study tested for gender differences in mechanical energy densities in women and men with healthy TMJs.

DESIGN

Eighteen women and eighteen men gave informed consent. Research diagnostic criteria including imaging were used to ensure that subjects' TMJs were normal, without disc displacement or signs of DJD. Numerical modeling determined TMJ loads (F_normal). Jaw tracking and three-dimensional dynamic stereometry characterized individual-specific data of stress-field dynamic mechanics during 10 symmetrical jaw closing cycles. These data were used to estimate tractional forces (F_traction). Energy densities were then calculated, where: Energy Density = W/Q (W = work done or mechanical energy input = F_traction*distance of stress-field translation, Q = volume of cartilage). Two-way analysis of variance (ANOVA) and follow-up two-group comparisons tested mean energy densities for ipsilateral and contralateral TMJs in women vs men.

RESULTS

Mean energy densities ± standard deviations in ipsilateral and contralateral TMJs in women were 9.0 ± 9.7 and 8.4 ± 5.5 mJ/mm³, respectively, and were significantly larger (P = 0.004 and 0.001, respectively) compared to ipsilateral and contralateral TMJs in men, which were 5.6 ± 4.2 and 6.3 ± 4.2 mJ/mm³, respectively.

CONCLUSIONS

Energy densities were significantly larger in healthy TMJs of women than men. Larger TMJ energy densities during normal jaw functions could predispose earlier mechanical fatigue of the TMJ disc.

Electromyographic ratio of masseter and anterior temporalis muscles in children with and without temporomandibular disorders

OBJECTIVE

This study investigated differences in surface electromyography (sEMG) activity of the masseter and anterior temporalis muscles in children with and without temporomandibular disorders (TMD).

PARTICIPANTS

Thirty-four children aged 8-12 years were recruited, comprising 17 children with TMD and 17 without TMD (control group [CG]). The children were quasi-matched for sex, age, weight, and height. sEMG data were obtained using Myosystem^® Br-1 equipment with 12 channels to evaluate the bilateral masseter, anterior temporalis, and suprahyoid muscles. For sEMG analysis, raw and normalized root mean square (RMS) values were obtained at rest and during maximum clenching. The sEMG ratios of the raw RMS data of the bilateral masseter in relation to the anterior temporalis muscles (sEMG-M/AT ratio) were also assessed. Mann-Whitney tests (p ≤ 0.05) were used to compare sEMG ratio between TMD group and CG.

RESULTS

Significant prevalences of pain during chewing (53% vs. 0%, X² = 5.87, p = 0.01), TMJ pain (58% vs. 0%, X² = 6.67, p = 0.01), neck pain (58% vs. 18%, X² = 3.77, p = 0.05) and pain in the temples (47% vs. 6%, X² = 5.44, p = 0.02) were identified in the TMD group compared to CG. Our results revealed lower sEMG-M/AT ratios during maximum clenching (p = 0.01) in children with TMD compared to those in the asymptomatic CG.

CONCLUSION

The results showed that children with TMD preferentially used their temporalis muscles during maximum voluntary clenching, probably as a consequence of nociceptive inputs in order to obtain pain relief.

History of facial pain diagnosis

Premise Facial pain refers to a heterogeneous group of clinically and etiologically different conditions with the common clinical feature of pain in the facial area. Among these conditions, trigeminal neuralgia (TN), persistent idiopathic facial pain, temporomandibular joint pain, and trigeminal autonomic cephalalgias (TAC) are the most well described conditions. Conclusion TN has been known for centuries, and is recognised by its characteristic and almost pathognomonic clinical features. The other facial pain conditions are less well defined, and over the years there has been confusion about their classification.

Prevalence of Painful Temporomandibular Disorders and Correlation to Lifestyle Factors among Adolescents in Norway

AIM

To estimate the prevalence of painful temporomandibular disorders (TMD-P) among adolescents and to investigate correlations with health, environment, and lifestyle factors.

METHODS

For this cross-sectional case-control study, 562 patients were consecutively recruited at their yearly revision control from four dental clinics in Rogaland County, Norway. Patients completed a questionnaire on general health, socioeconomics, demographics, and lifestyle factors. Responses to two screening questions identified patients with TMD-P, who then underwent clinical examination to verify the TMD diagnosis. Pain intensity was assessed on a visual analogue scale. Patients without TMD-P constituted the control group and were not clinically examined.

RESULTS

7% experienced TMD-P. The female-to-male ratio is 3:1; median age is 17 years. Patients at urban clinics had higher prevalence compared with those at rural clinics. TMD-P patients had headache and severe menstrual pain compared to controls. They were more likely to live with divorced/single parents and less likely to have regular physical activity. Myalgia was present in 21 patients with TMD-P, arthralgia in nine, and myalgia and arthralgia in nine. Females had higher pain intensity than males.

CONCLUSIONS

A low prevalence of TMD-P was shown but was comparable to other studies. Sex, health, lifestyle, and environment factors were associated with TMD-P.

Efficacy of photobiomodulation therapy on masseter thickness and oral health-related quality of life in children with spastic cerebral palsy

The study aimed to evaluate the efficacy of photobiomodulation therapy (PBMT) on bilateral masseter muscle thickness and amplitude of mouth opening in children with spastic cerebral palsy (CP), and the impact on their oral health-related quality of life (OHRQOL). Three groups were included: experimental CP group (EG: n = 26 with oral complaints), positive control CP group (PCG: n = 26 without complaints), and negative control group (NCG: n = 26 without CP). In the EG, the masseter muscles on both sides were irradiated with an infrared low-level Ga-Al-As laser (λ = 808 ± 3 nm, 120 mW) using a 3 J/cm² energy dose per site, with a 20 s exposure time per site (spot area: 4 mm²; irradiance: 3 W/cm²; energy delivery per point: 2.4 J) six times over six consecutive weeks. Masseter thickness, assessed through ultrasonography, and the amplitude of mouth opening were measured in the EG before and after six applications of PBMT and once in the PCG and NCG. The Parental-Caregiver Perception Questionnaire (P-CPQ) was used to evaluate OHRQOL. ANOVA, chi-square, t tests, and multilevel linear regression were used for statistical analysis. In the EG, the study results revealed average increments of 0.77 (0.08) millimeter in masseter thickness (P < 0.05) and 7.39 (0.58) millimeter for mouth opening (P < 0.05) and reduction in all P-CPQ domains (P < 0.001), except for social well-being. The six applications of PBMT increased masseter thickness and mouth opening amplitude and reduced the impact of spastic CP on OHRQOL.

Validation of the Social support and Pain Questionnaire (SPQ) in patients with painful temporomandibular disorders

Background

The present study aimed to validate of Social support and Pain Questionnaire (SPQ) for use in Chinese patients with painful temporomandibular disorders (TMD).

Methods

The Chinese version of SPQ was produced by translation and cross-culturally adaptation of the original English version according to international guidelines. The Chinese version of SPQ was then distributed to a total of 118 patients with painful TMD. Reliability of the SPQ was evaluating using internal consistency and test-retest methods and validity of the SPQ was determined by construct validity and convergent validity. The exploratory factor analysis (EFA) was used to assess the construct validity of SPQ. And convergent validity was assessed by correlating the SPQ scores with the score of a global oral health question.

Results

The Chinese version of SPQ has a high internal consistency (Cronbach’s alpha value, 0.926) and good test-retest reliability ((intraclass correlation coefficient (ICC), 0.784). Construct validity was evaluated by EFA, extracting one factor, accounting for 74.8% of the variance. All factor loadings of the six items had exceeded 0.80. As regards convergent validity, the SPQ showed good correlation with the global oral health question.

Conclusion

These findings support that the Chinese version of SPQ can be used as a reliable and valid tool for Chinese patients with painful TMD.

Temporomandibular Joint Pain: Clinical Presentations and Response to Conservative Treatments in a Nigerian Tertiary Hospital

Aims and Objectives:

The aims of this study are to determine the prevalence, pattern of presentation, and response to conservative (medical) interventions among patients who presented with temporomandibular joint (TMJ) pain in a Nigerian teaching hospital.

Material and Methods:

Consecutive patients who presented in Oral Medicine and Periodontology Clinic of Obafemi Awolowo University Teaching Hospitals' Complex on account of TMJ pain from January 2015 to December 2015 were recruited for the study. They were all interviewed and examined. The severity of pain was recorded using visual analog scale (VAS). Patients were treated with medications and physiotherapy. They were reviewed at 2, 4, and 6 weeks. Those who could not make the appointment were contacted through phone. The findings were recorded and analyzed using STATA version 11.

Results:

A total of 401 participants were seen, 55 presented on account of TMJ pain. The mean age of patients with TMJ pain was 54 ± 16.9 with 60% being female. Pain was present in all participants; other signs include clicking joint sound (85%), jaw deviation (64%), attrition (24%), and reduced mouth opening (23%). The left joint was more frequently affected (75%). Following 6 weeks of conservative treatments, none of the respondents had VAS score of more than 3.

Conclusion:

The prevalence of TMJ pain was 13%. TMJ was found to be more common in participants above 50 years with female predilection. Pain was most common symptom seen, and response to conservative treatments as assessed using VAS following 6-week of treatment showed complete remission of the pain.

A pilot study of nocturnal temporalis muscle activity in TMD diagnostic groups of women

Temporomandibular disorder (TMD) incidences are believed to be related to parafunctional behaviours like teeth clenching. This pilot study aimed to (i) develop an automated clench-detection algorithm, and (ii) apply the algorithm to test for differences in nocturnal clenching in women with and without TMD. Subjects gave informed consent to participate. Adult women were categorised using Diagnostic Criteria for TMD according to presence/absence (+/-) of both TM joint disc placement (DD) and chronic pain (P) into two groups (+DD+P, -DD-P) with 12 subjects each. Surface temporalis electromyography was recorded during oral tasks performed by subjects at two laboratory sessions. The data were used to characterise muscle activity per N of bite force (μV/N) for each subject, develop the clench-detection algorithm and test its accuracy. Ambulatory surface temporalis electromyography was self-recorded by each subject over three nights and analysed using the algorithm and bite force (N) versus muscle activity μV/N calibrations. Bonferroni-adjusted homoscedastic t-tests assessed for significant between-group differences in clenching (P < 0·05). Sensitivity, specificity and accuracy of algorithm-detected laboratory clenches were all ≥96%. During self-recordings 95% of clenches had durations of <4 s and peak forces of <10 N in both groups. Mean clench durations were significantly longer (P = 0·042) in +DD+P (1·9 ± 0·8 s) than -DD-P subjects (1·4 ± 0·4 s). Mean temporalis duty factors (%clench time/total recording time) were significantly larger (P = 0·041) in +DD+P (0·47 ± 0·34%) than -DD-P (0·26 ±0·22%) subjects. Nocturnal temporalis muscle activities detected by a validated algorithm were longer per clench and recording time in +DD+P compared to -DD-P women.

Reevaluating Antidepressant Selection in Patients With Bruxism and Temporomandibular Joint Disorder

Temporomandibular joint disorder (TMD) is a broad pain disorder that refers to several conditions affecting the temporomandibular joint of the jaw and the muscles of mastication. As with most pain disorders, a high prevalence of depression and anxiety is associated with TMD. Research has shown that selective serotonin reuptake inhibitors (SSRIs), the first-line drug therapy for major depressive disorder, may not be suitable for TMD patients because SSRIs can induce teeth-grinding, otherwise known as bruxism. This is problematic because bruxism is believed to further exacerbate TMD. Therefore, the purpose of this literature review is to better understand the mechanism of SSRI-induced bruxism, as well as discuss alternative antidepressant options for treating depression and anxiety in patients with bruxism and TMD. Alternative classes of antidepressants reviewed include serotonin-norepinephrine reuptake inhibitors, tricyclic antidepressants, atypical antidepressants, and monoamine oxidase inhibitors. Findings indicate that dopamine agonists and buspirone are currently the most effective medications to treat the side effects of SSRI-induced bruxism, but results regarding the effectiveness of specific antidepressants that avoid bruxism altogether remain inconclusive.

Frequency of temporomandibular joint osteoarthritis and related symptoms in a hand osteoarthritis cohort

OBJECTIVE

The prevalence of osteoarthritis (OA) in the temporomandibular joints (TMJs) in hand OA patients is largely unknown. Our aims were to explore (1) The frequency of TMJ-related symptoms and clinical findings; (2) The TMJ OA frequency defined by cone beam computed tomography (CBCT); and (3) The relationship between TMJ-related symptoms/clinical findings and CBCT-defined TMJ OA, in a hand OA cohort.

METHODS

We calculated the frequencies of TMJ-related symptoms, clinical findings and diagnosis of TMJ OA by CBCT and clinical examination in 54 patients from the Oslo hand OA cohort (88% women, mean (range) age 71 (61-83) years). Participants with and without CBCT-defined TMJ OA were compared for differences in proportions (95% confidence interval (CI)) of symptoms and clinical findings. Sensitivity and specificity of the clinical TMJ OA diagnosis were calculated using CBCT as reference.

RESULTS

Self-reported symptoms and clinical findings were found in 24 (44%) and 50 (93%) individuals (93%), respectively, whereas 7 (13%) had sought healthcare. Individuals with CBCT-defined TMJ OA (n = 36, 67%) reported statistically significantly more pain at mouth opening (22%, 95% CI 4-40%), clicking (33%, 95% CI 14-52%) and crepitus (25%, 95% CI 4-46%). By clinical examination, only crepitus was more common in TMJ OA (33%, 95% CI 29-77%). Clinical diagnosis demonstrated low sensitivity (0.42) and high specificity (0.93).

CONCLUSIONS

CBCT-defined TMJ OA was common in hand OA patients, suggesting that TMJ OA may be part of generalized OA. Few had sought healthcare, despite high burden of TMJ-related symptoms/findings. Clinical examination underestimated TMJ OA frequency.

Depression and chronic pain in the elderly: links and management challenges

Aging is an inevitable process and represents the accumulation of bodily alterations over time. Depression and chronic pain are highly prevalent in elderly populations. It is estimated that 13% of the elderly population will suffer simultaneously from the two conditions. Accumulating evidence suggests than neuroinflammation plays a critical role in the pathogenesis of both depression and chronic pain. Apart from the common pathophysiological mechanisms, however, the two entities have several clinical links. Their management is challenging for the pain physician; however, both pharmacologic and nonpharmacologic approaches are available and can be used when the two conditions are comorbid in the elderly patients.

Persistent idiopathic facial pain

Background

Persistent idiopathic facial pain (PIFP) is a chronic disorder recurring daily for more than two hours per day over more than three months, in the absence of clinical neurological deficit. PIFP is the current terminology for Atypical Facial Pain and is characterized by daily or near daily pain that is initially confined but may subsequently spread. Pain cannot be attributed to any pathological process, although traumatic neuropathic mechanisms are suspected. When present intraorally, PIFP has been termed ‘Atypical Odontalgia’, and this entity is discussed in a separate article in this special issue. PIFP is often a difficult but important differential diagnosis among chronic facial pain syndromes.

Aim

To summarize current knowledge on diagnostic criteria, differential diagnosis, pathophysiology and management of PIFP.

Methods

We present a narrative review reporting current literature and personal experience. Additionally, we discuss and differentiate the common differential diagnoses associated with PIFP including traumatic trigeminal neuropathies, regional myofascial pain, atypical neurovascular pains and atypical trigeminal neuropathic pains.

Results and conclusion

The underlying pathophysiology in PIFP is still enigmatic, however neuropathic mechanisms may be relevant. PIFP needs interdisciplinary collaboration to rule out and manage secondary causes, psychiatric comorbidities and other facial pain syndromes, particularly trigeminal neuralgia. Burden of disease and psychiatric comorbidity screening is recommended at an early stage of disease, and should be addressed in the management plan. Future research is needed to establish clear diagnostic criteria and treatment strategies based on clinical findings and individual pathophysiology.

Temporal summation and motor function modulation during repeated jaw movements in patients with temporomandibular disorder pain and healthy controls

Temporal summation of nociceptive inputs may be an important pathophysiological mechanism in temporomandibular disorders (TMD) pain; however, it remains unknown how natural jaw function relates to underlying pain mechanisms. This study evaluated changes in pain and movement patterns during repeated jaw movements in patients with painful temporomandibular joints (TMJ) compared with healthy controls. Twenty patients with TMD with TMJ pain, and an anterior disk displacement without reduction and 20 age- and gender-matched healthy volunteers were included. Participants performed 20 trials (4 × 5 sessions) of standardized and repeated mandibular movements, and scored the movement-associated pain intensity on 0 to 10 numeric rating scale in addition to measurements of jaw movements. Patients with TMJ pain reported higher baseline pain compared to the control group for all types of jaw movements (P = 0.001) and significant increases in numeric rating scale pain scores by repetition of jaw movements (P < 0.001), which was not observed in the control group (P > 0.05). Jaw total opening distance (P = 0.030), maximum opening velocity (P = 0.043) and average closing velocity (P = 0.044) in the TMJ pain group were significantly reduced during the repeated movements. In the control group, however, total opening distance (P = 0.499), maximum opening velocity (P = 0.064), and average closing velocity (P = 0.261) remained unchanged, whereas average opening velocity (P = 0.040) and maximum closing velocity (P = 0.039) increased. The study demonstrates that repeated jaw movements constitute a sufficient and adequate stimulation for triggering temporal summation effects associated with significant inhibition of motor function in painful TMJs. These findings have practical implications for diagnosis of TMD pain and for more mechanism-driven management protocols in the future.

Extracellular Matrix Mediates BMP-2 in a Model of Temporomandibular Joint Osteoarthritis

Temporomandibular joint (TMJ) osteoarthritis (OA) is a complex disease that affects both cartilage and subchondral bone. It is accompanied by loss of extracellular matrix (ECM) and may be controlled by bone morphogenetic protein-2 (BMP-2). We analyzed the effect of BMP-2 in both cartilage and subchondral bone in a TMJ-OA animal model that is deficient in biglycan (Bgn) and fibromodulin (Fmod) (Bgn-/-Fmod-/-). Whole mandibles were dissected from 3-week-old wild-type (WT) and Bgn-/-Fmod-/- mice and incubated with and without 250 µg/mL BMP-2 for 2 days using an explant culture system. Condyle growth was measured by microCT and the expression levels of cartilage and bone-related genes were analyzed using RT-PCR or by immunohistochemistry from condyles that contained an intact cartilage/subchondral bone interface. Osteoclast activity was estimated by tartrate-resistant acid phosphatase (TRAP) staining and by TRAP, Rankl, and Adamts4 mRNA expression levels. Our results showed that most parameters examined were slightly up-regulated in WT samples treated with BMP-2, and this up-regulation was significantly enhanced in the Bgn-/-Fmod-/- mice. The up-regulation of both catabolic and anabolic agents did not appear to positively affect the overall growth of Bgn-/-Fmod-/- condyles compared to WT controls. In summary, the up-regulation of both anabolic and catabolic genes in the WT and Bgn-/-Fmod-/- TMJs treated with BMP-2 suggests that BMP increases matrix turnover in the condyle, and, further, that Bgn and Fmod could have protective roles in regulating this process.

Neuropathic orofacial pain: Facts and fiction

Definition and taxonomy This review deals with neuropathic pain of traumatic origin affecting the trigeminal nerve, i.e. painful post-traumatic trigeminal neuropathy (PTTN). Symptomatology The clinical characteristics of PTTN vary considerably, partly due to the type and extent of injury. Symptoms involve combinations of spontaneous and evoked pain and of positive and negative somatosensory signs. These patients are at risk of going through unnecessary dental/surgical procedures in the attempt to eradicate the cause of the pain, due to the fact that most dentists only rarely encounter PTTN. Epidemiology Overall, approximately 3% of patients with trigeminal nerve injuries develop PTTN. Patients are most often female above the age of 45 years, and both physical and psychological comorbidities are common. Pathophysiology PTTN shares many pathophysiological mechanisms with other peripheral neuropathic pain conditions. Diagnostic considerations PTTN may be confused with one of the regional neuralgias or other orofacial pain conditions. For intraoral PTTN, early stages are often misdiagnosed as odontogenic pain. Pain management Management of PTTN generally follows recommendations for peripheral neuropathic pain. Expert opinion International consensus on classification and taxonomy is urgently needed in order to advance the field related to this condition.

Classification: The key to understanding facial pain

It is indisputable that the global scientific advances in headache research, be it bench or bedside, have benefited enormously from the operational diagnostic criteria published in 1988. Today, this classification system is indispensable. The reason for this success is a low inter-rater variability. In general, orofacial pain conditions are less well characterised – with the noticeable exemption of temporomandibular disorder pain. Tremendous work has been put into changing this, and significant progress has been achieved – in particular, in terms of the clinical implications and overriding conceptual models for oro-facial pain. Scientific classifications have only one goal: To provide a scientific agreement about the main features of an object of research and a scientific consensus regarding the name. The main significance is not the fact that a good classification offers a detailed and accurate image of the reality. If we want to overcome the obstacles of different competing classification systems, we need to overcome specialisation borders. The key to success is to understand that such a definition does not mirror all possible clinical facets of a given pain condition but is simply a convention – that is, a consensus on a word used for a pain condition. Simply speaking, a classification creates a common language to be used by more than one profession. It will be crucial to define any given pain condition as precisely and rigid as possible, in order to ensure a homogenous population. Only this ensures a low inter-rater variability, which consequently allows combining and comparing research on a population across different professional settings. This is not easy for chronic facial pain without verifiable morphological cause or structural lesions, as these syndromes are often rather featureless. The new IASP classification of chronic pain is a big step forward to a better characterisation of such conditions, and will trigger future work on a new and operationalised classification of oro-facial pain.

Antinociceptive effect of natural and synthetic alkamides involves TRPV1 receptors

Objective

To establish the role of TRPV1 receptor in the antinociceptive effect of natural alkamides (i.e. affinin, longipinamide A, longipenamide A and longipenamide B) isolated from Heliopsis longipes (A. Gray) S.F. Blake and some related synthetic alkamides (i.e. N-isobutyl-feruloylamide and N-isobutyl-dihydroferuloylamide).

Methods

The orofacial formalin test was used to assess the antinociceptive activity of natural (1–30 μg, orofacial region) and synthetic alkamides (0.1–100 μg, orofacial region). The alkamide capsaicin was used as positive control, while capsazepine was used to evaluate the possible participation of TRPV1 receptor in alkamide-induced antinociception.

Key findings

Natural (1–30 μg) and synthetic (0.1–100 μg) alkamides administered to the orofacial region produced antinociception in mice. The antinociceptive effect induced by affinin, N-isobutyl-feruloylamide and N-isobutyl-dihydroferuloylamide was antagonized by capsazepine but not by vehicle.

Conclusions

These results suggest that alkamide affinin, longipinamide A, longipenamide A and longipenamide B isolated from Heliopsis longipes as well as the synthesized analogue compounds N-isobutyl-feruloylamide and N-isobutyl-dihydroferuloylamide produce their effects by activating TRPV1 receptor and they may have potential for the development of new analgesic drugs for the treatment of orofacial pain.

Clinical instruments and methods for assessing physical oral health: A systematic review

OBJECTIVE

This study aimed at exploring available clinical instruments and methods for assessing physical oral health, and at identifying those with sufficient diagnostic performance.

METHODS

A systematic literature search was conducted in Embase and MEDLINE. Identified instruments and methods were critically appraised, and quality of diagnostic performance was rated by two independent reviewers as A (sufficient diagnostic performance), B (either sufficient reliability or validity) or C (insufficient quality, or empirical results unsatisfactory and/or inconsistent). For all A-rated instruments and methods, an in-depth literature search was conducted to supplement and verify their effectiveness and accuracy.

RESULTS

A total of 141 instruments and methods were identified. Only 12 methods with sufficient diagnostic performance could be rated as A, 72 were rated as B, and 34 received a C-rating. Further 23 instruments and methods could not be rated due to lack of available information on diagnostic performance. Of all A-rated instruments, six were designed for tooth structure, two for periodontium, one for endodontium and three for temporomandibular joints and muscles.

CONCLUSION

Even though some instruments and methods exhibited good to excellent reliability and validity and can be recommended for research and clinical practice, they do not allow assessing all components of physical oral health. There is a need to identify and define standard instruments, and for components of physical oral health where methods with sufficient diagnostic performance are lacking, further research is required.

Temporomandibular Disorders and Headache: A Retrospective Analysis of 1198 Patients

Aim. Headache is one of the most common diseases associated with Temporomandibular Disorders (TMDs). The aim of this study was to evaluate, retrospectively, if headache influences TMD's symptoms. Material and Methods. A total sample of 1198 consecutive TMD patients was selected. After a neurological examination, a diagnosis of headache, according to the latest edition of the International Classification of Headache Disorders, was performed in 625 subjects. Patients were divided into two groups based on presence/absence of headache: Group with Headache (GwH) and Group without Headache (GwoH). Descriptive statistics and Chi-square index were performed. Results. Sociodemographic (gender, marital status, and occupation) and functional factors, occlusion (occlusal and skeletal classes, dental formula, and occlusal abnormalities), and familiar pain did not show a statistically significant correlation in either group. Intensity and frequency of neck pain, arthralgia of TMJ, and myalgia showed higher correlation values in GwH. Conclusion. This study is consistent with previous literature in showing a close relationship between headache and TMD. All data underlines that headache makes pain parameters more intense and frequent. Therefore, an early and multidisciplinary treatment of TMDs should be performed in order to avoid the overlay of painful events that could result in pain chronicity.

Personality traits are potentially associated with the presence of chronic temporomandibular joint pain in patients without effusion as determined by T-2 weighted magnetic resonance

OBJECTIVE

The study aimed at investigating personality traits in chronic temporomandibular joints (TMJ) pain patients with and without joint effusion.

METHODS

Two groups of chronic TMJ pain patients were recruited. The TMJ pain control group was composed of patients showing magnetic resonance imaging (MRI) signs of TMJ effusion, while the TMJ pain test group included patients with chronic TMJ pain seemingly not justified, due to the absence of MRI-detected disorders. A third set of pain free individuals was selected as a comparison group. All patients completed a personality assessment with the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) instrument, and the between-group differences were assessed for significance by performing an analysis of variance test.

RESULTS

Patients of the TMJ pain test group had higher scores than subjects belonging to the TMJ pain and pain-free control groups in almost all of the MMPI-2 clinical scales. A significant difference was shown for the scales related to concerns about physical health (Scale 1-Hs; F = 7.74; p = .001) and physical symptoms (Scale 3-Hy; F = 8.43; p = .001).

CONCLUSIONS

Chronic TMJ pain patients without MRI-detected TMJ effusion have a different personality profile than patients with TMJ effusion and pain-free individuals, regarding high levels of concerns about physical health and physical symptoms.

CLINICAL IMPLICATIONS

This study has important clinical implications for temporomandibular disorders practitioners, providing suggestions that symptoms in the TMJ area are not only related to a physical disorder. The possible existence of a psychologically modulated condition in patients who refer pain in the TMJ area without signs of effusion should be carefully taken into consideration.

Inflammatory 'double hit' model of temporomandibular joint disorder with elevated CCL2, CXCL9, CXCL10, RANTES and behavioural hypersensitivity in TNFR1/R2-/- mice

BACKGROUND

Patients with temporomandibular joint disorders (TMD), reactive arthritis and rheumatoid arthritis often have combined etiology of hereditary and microenvironmental factors contributing to joint pain. Multiple clinical and animal studies indicate 'double-hit' inflammatory insults can cause chronic inflammation. The first inflammatory insult primes the immune system and subsequent insults elicit amplified responses. The present 'double hit' study produced a chronic orofacial pain model in mice with genetic deletion of both TNFα receptors (TNFR1/R2-/-), investigating the main nociceptive signalling pathways in comparisons to wild type mice.

METHODS

An initial inflammatory insult was given unilaterally into the temporomandibular joint (TMJ). Secondary hypersensitivity was tested on the skin over the TMJ throughout the experiment. Three weeks later after complete reversal of hypersensitivity, a second inflammatory insult was imposed on the colon. Pharmacological interventions were tested for efficacy after week 10 when hypersensitivity was chronic in TNFR1/R2-/- mice. Serum cytokines were analysed at Days 1, 14, and Week 18.

RESULTS

The double hit insult produced chronic hypersensitivity continuing through the 4-month experimental timeline in the absence of TNFα signalling. P2X7 and NMDA receptor antagonists temporarily attenuated chronic hypersensitivity. Serum cytokine/chemokine analysis on Day 14 when CFA induced hypersensitivity was resolved identified increased levels of pro-inflammatory cytokines CCL2, CXCL9, CXCL10, RANTES and decreased levels of anti-inflammatory cytokines IL-1ra and IL-4 in TNFR1/R2-/- compared to WT mice.

CONCLUSIONS

These data suggest a causal feed-forward signalling cascade of these little studied cytokines have the potential to cause recrudescence in this orofacial inflammatory pain model in the absence of TNFα signalling.

SIGNIFICANCE

Using a mouse model of chronic inflammatory temporomandibular joint disorder, we determined that absence of functional TNFR1/R2 induces aberrant inflammatory signalling caused by other increased pro-inflammatory and decreased anti-inflammatory cytokines that could serve as blood biomarkers and may predict disease progression.