Diagnostic criteria for temporomandibular disorders-INfORM recommendations: Comprehensive and short-form adaptations for adolescents.

BACKGROUND: The Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) for use in adults is in use worldwide. Until now, no version of this instrument for use in adolescents has been proposed. OBJECTIVE: To present comprehensive and short-form adaptations of the adult version of DC/TMD that are appropriate for use with adolescents in clinical and research settings. METHODS: International experts in TMDs and experts in pain psychology participated in a Delphi process to identify ways of adapting the DC/TMD protocol for physical and psychosocial assessment of adolescents. RESULTS: The proposed adaptation defines adolescence as ages 10-19 years. Changes in the physical diagnosis (Axis I) include (i) adapting the language of the Demographics and the Symptom Questionnaires to be developmentally appropriate for adolescents, (ii) adding two general health questionnaires, one for the adolescent patient and one for their caregivers and (iii) replacing the TMD Pain Screener with the 3Q/TMD questionnaire. Changes in the psychosocial assessment (Axis II) include (i) adapting the language of the Graded Chronic Pain Scale to be developmentally appropriate for adolescents, (ii) adding anxiety and depression assessment that have been validated for adolescents and (iii) adding three constructs (stress, catastrophizing and sleep disorders) to assess psychosocial functioning in adolescents. CONCLUSION: The recommended DC/TMD, including Axis I and Axis II for adolescents, is appropriate to use in clinical and research settings. This adapted first version for adolescents includes changes in Axis I and Axis II requiring reliability and validity testing in international settings. Official translations of the comprehensive and short-form to different languages according to INfORM requirements will enable a worldwide dissemination and implementation.

Real time evaluation of awake bruxism behaviors in young asymptomatic students and its impact on the masticatory muscles.

STATEMENT OF PROBLEM: The relationship of awake bruxism with pain is still unclear. PURPOSE: The purpose of this clinical study was to evaluate awake bruxism behavior for 1 week in healthy young adults with ecological momentary assessment, assess its relationship with masticatory muscle tenderness, and the participation of endogenous analgesia. MATERIAL AND METHODS: A total of 150 healthy participants were provided with a smartphone application that sent 10 alerts at random intervals every day. The participants were instructed to report in real time which of the following awake bruxism behaviors best represented their current condition: relaxed jaw muscles, tooth contact, tooth clenching, tooth grinding, or jaw bracing. At baseline, participants underwent recordings of the pressure pain threshold and conditioned pain modulation of the masticatory muscles. Pressure pain threshold recording was also repeated on the last day of the study. A t test was used to compare the first and the last pressure pain threshold recording after 1 week with an ecological momentary assessment evaluation. The Pearson correlation test was performed to evaluate the correlation between variables (α=.05). RESULTS: Overall compliance was 75.9%. The average frequency of relaxed jaw muscles was 54.5%, tooth contact 29.4%, jaw bracing 5.8%, tooth clenching 9.7%, and tooth grinding 0.6%. The average frequency of a distinct awake bruxism behavior was 45.5%. A statistically significant increase in pressure pain threshold values was found (P=.001; P=.001; P=.045 for right and left anterior temporalis and left masseter, respectively). No significant correlation was found between the frequency of awake bruxism behaviors, the pressure pain threshold, and conditioned pain modulation (P>.05). CONCLUSIONS: The most prevalent behavior was tooth contact (29.4%). No relationship was found between awake bruxism behaviors and masticatory muscle tenderness or endogenous analgesia.

Painful Temporomandibular Joint Clicking: Genetic Point of View.

AIMS: To determine whether there is an association between gene polymorphisms and patients with painful temporomandibular joint (TMJ) clicking when compared to patients with painless TMJ clicking and a healthy control group. METHODS: In this pilot study, the genotypic and allelic frequencies of candidate single-nucleotide polymorphisms (SNP) were compared among 60 individuals divided equally into three groups: patients with painful TMJ clicking (n = 20); patients with painless TMJ clicking (n = 20); and healthy controls (n = 20). Participants were genotyped for the following SNPs using real-time polymerase chain reaction: MMP1 -16071G/2G, COMT Val158Met, TNFα -308, IL1ß +3954, IL6 -174, and IL10 -1082. The pressure pain threshold (PPT) of the TMJ was also assessed. All variables were compared among groups. RESULTS: Patients with painful TMJ clicking had a significant association and a higher frequency of MMP1 -16071G/2G (P = .042), COMT Val158Met (P = .030), and TNFα -308 (P = .016) when compared to the other groups, as well as a lower frequency of IL10 -1082. Considering PPT values, a progressively lower mean was found in individuals with painful TMJ clicking, followed sequentially by the painless TMJ clicking and the control groups. CONCLUSION: This pilot study showed that patients with painful TMJ clicking had a significant association with mutant genotypes related to degradation of extracellular matrix components, pain, proinflammation, and anti-inflammation. Furthermore, these patients also had significantly lower TMJ PPT values in all comparisons.

Diagnostic criteria for temporomandibular disorders in children and adolescents: An international Delphi study-Part 2-Development of Axis II.

BACKGROUND: Unlike the psychosocial assessment established for adults in the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD), a standardised psychosocial assessment for children and adolescents with TMD complaints has not yet been established. OBJECTIVES: To develop a new standardised instrument set to assess the psychosocial functioning in children and adolescents by adapting the psychosocial status and pain-related disability (Axis II) of the adult DC/TMD and by including new instruments. METHODS: A modified Delphi method was used to survey 23 international TMD experts and four international experts in pain-related psychological factors for consensus regarding assessment tools for psychosocial functioning and pain-related disability in children and adolescents. The TMD experts reviewed 29 Axis II statements at round 1, 13 at round 2 and 2 at round 3. Agreement was set at 80% for first-round consensus level and 70% for each of the second and third rounds. The psychological experts completed a complementary Delphi survey to reach a consensus on tools to use to assess more complex psychological domains in children and adolescents. For the psychological experts, the first round included 10 open-ended questions on preferred screening tools for depression, anxiety, catastrophising, sleep problems and stress in children (ages 6-9 years old) and adolescents (ages 10-19 years old) as well as on other domains suggested for investigation. In the second round, the psychological experts received a 9-item questionnaire to prioritise the suggested instruments from most to least recommended. RESULTS: The TMD experts, after three Delphi rounds, reached consensus on the changes of DC/TMD to create a form to evaluate Axis II in children and adolescents with TMD complaints. The psychological experts added tools to assess depression and anxiety, sleep disorders, catastrophising, stress and resilience. CONCLUSION: Through international expert consensus, this study adapted Axis II of the adult DC/TMD to assess psychosocial functioning and pain-related disability in children and adolescents. The adapted Axis II protocols will be validated in the target populations.

Effects of Botulinum Toxin Type A on the Psychosocial Features of Myofascial Pain TMD Subjects: A Randomized Controlled Trial.

AIMS: To determine the effects of botulinum toxin type A (BoNT-A) on the psychosocial features of patients with masticatory myofascial pain (MFP). METHODS: A total of 100 female subjects diagnosed with MFP were randomly assigned into five groups (n = 20 each): oral appliance (OA); saline solution (SS); and three groups with different doses of BoNT-A. Chronic pain-related disability and depressive and somatic symptoms were evaluated with the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) Axis II instruments at baseline and after 6 months of treatment. Differences in treatment effects within and between groups were compared using chi-square test, and Characteristic Pain Intensity (CPI) was compared using two-way ANOVA. A 5% probability level was considered significant in all tests. RESULTS: Most patients presented low pain-related disability (58%), and 6% presented severely limiting, high pain-related disability. Severe depressive and somatic symptoms were found in 61% and 65% of patients, respectively. In the within-group comparison, BoNT-A and OA significantly improved (P < .001) scores of pain-related disability and depressive and somatic symptoms after 6 months. Only the scores for pain-related disability changed significantly over time in the SS group. In the between-group comparison, BoNT-A and OA significantly improved (P < .05) scores of all variables at the final follow-up when compared to the SS group. No significant difference was found between the BoNT-A and OA groups (P > .05) for all assessed variables over time. CONCLUSION: BoNT-A was at least as effective as OA in improving pain-related disability and depressive and somatic symptoms in patients with masticatory MFP.

Is the therapeutic effect of occlusal stabilization appliances more than just placebo effect in the management of painful temporomandibular disorders? A network meta-analysis of randomized clinical trials.

STATEMENT OF PROBLEM: Occlusal devices, particularly the stabilization appliances, have been commonly used as treatment for painful temporomandibular disorders (TMDs). However, the mechanisms of action of these devices are still unclear, including the role of the placebo effect in the pain management. PURPOSE: The purpose of this network meta-analysis was to identify to what extent the degree of efficacy of stabilization appliances in the management of painful TMDs arises from the placebo effect only or whether it arises chiefly from an actual effect. MATERIAL AND METHODS: An electronic search was undertaken to identify randomized clinical trials (RCTs) published up to April 2020, comparing the efficacy of the stabilization appliances in patients with painful temporomandibular disorders, with nonoccluding appliances (active placebo), and untreated controls (passive placebo). Outcome variables were pain intensity at follow-ups, the proportion of participants reporting pain improvement, and the number needed to treat. The quality of evidence was rated as per the Cochrane tool for assessing risk of bias. Mean difference was used to analyze via frequentist network meta-analysis by using the STATA software program. RESULTS: Treatment with stabilization appliances showed a significant reduction in pain intensity when compared with the other groups; but, the lower pain intensity at follow-ups in favor of stabilization appliances when compared with nonoccluding appliances was not statistically significant. However, a significantly higher number of participants reported pain improvement after treatment with stabilization appliances when compared with those treated with nonoccluding appliances or untreated participants. CONCLUSIONS: This network meta-analysis showed no significant difference in reported pain intensity at follow-ups between the treatment of painful TMDs with stabilization appliances or nonoccluding appliances (active placebo). However, a significant difference in participants reporting treatment satisfaction with reduced pain, and a significantly lower number needed to treat in favor of stabilization appliances were found. Patient-reported treatment satisfaction probably included more domains than just pain intensity, such as improvements in physical functioning and psychosocial factors, and deserves further investigation. The authors concluded that stabilization appliances treatment efficacy is beyond the placebo effect.

Effect of Genetic Polymorphisms on Pain Sensitivity in the Orofacial Region: A Systematic Review.

AIMS: To systematically review the literature to assess whether genetic polymorphisms affect orofacial pain sensitivity in healthy individuals and in patients with chronic orofacial pain disorders. METHODS: Electronic searches were conducted to identify observational studies and clinical trials investigating the association between genetic polymorphisms and orofacial pain sensitivity in healthy individuals and/or patients with chronic orofacial pain disorders. Searches were carried out in PubMed, Embase, and Scopus databases using Medical Subject Headings and free terms. RESULTS: Seven studies fulfilled the eligibility criteria: four analyzed healthy subjects, two included chronic orofacial pain patients, and one included samples of healthy subjects and patients with neuropathic pain. The results showed that genes associated with mechanical and thermal pain sensitivity were mostly related to opioid, catecholaminergic, inflammatory, and dopaminergic pathways. CONCLUSION: Genetic polymorphisms related to opioid, catecholaminergic, inflammatory, and dopaminergic pathways were associated with sensitivity to thermal and pressure stimuli in the orofacial region. Therefore, genetic factors should be taken into account for an accurate interpretation of orofacial pain sensitivity. These results will allow for a better understanding of the etiopathogenesis of chronic pain affecting the orofacial region, and consequently for finding new therapeutic targets.

Role of inflammatory and pain genes polymorphisms in temporomandibular disorder and pressure pain sensitivity.

OBJECTIVE: The aim of this study was to assess the correlation of inflammatory and pain genes polymorphisms with the presence of temporomandibular disorder (TMD) patients and with pressure pain sensitivity. DESIGN: Data was collected from 268 consecutive subjects at Bauru School of Dentistry. Subjects aged younger than 20 years, with dental and neuropathic pain, sinusitis, cognitive and neurologic disorder were excluded. Included subjects were evaluated using the Research Diagnostic Criteria for Temporomandibular disorders and divided into two groups: TMD cases and healthy controls. Groups were submitted to pressure pain threshold (PPT) test for the temporomandibular joint, anterior temporalis and masseter muscles and genotyped for Val158Met, IL6-174, IL-1ß-3954 and TNFA-308. Student's t-test and Pearson chi-square test were used to comparisons between groups. A linear multiple regression was used to evaluate the influence of genetics variables on the PPT and a bivariate analysis was used to assesses the influence of genetics variables on pain sensitivity below the PPT cut off of the structures in TMD group. RESULTS: TMD group showed significantly lower PPT values for all structures when compared with control group (p < 0.001). SNP IL6-174 predicted higher pain sensitivity in the temporomandibular joint (p < 0.005) and in anterior temporalis muscle (p < 0.044) and SNP Val158Met in the masseter muscle (p < 0.038); when TMD group was divided according to PPT cut-off values the SNP Val158Met influenced increase pain sensibility in the masseter muscle. CONCLUSION: TNFA-308 was associated with TMD and SNP IL6-174 and SNP Val158Met influenced pain sensitivity of patients with TMD.

Experimental Psychological Stress on Quantitative Sensory Testing Response in Patients with Temporomandibular Disorders.

AIMS: To assess the modulatory effects of experimental psychological stress on the somatosensory evaluation of myofascial temporomandibular disorder (TMD) patients. METHODS: A total of 20 women with myofascial TMD and 20 age-matched healthy women were assessed by means of a standardized battery of quantitative sensory testing. Cold detection threshold (CDT), warm detection threshold (WDT), cold pain threshold (CPT), heat pain threshold (HPT), mechanical pain threshold (MPT), wind-up ratio (WUR), and pressure pain threshold (PPT) were performed on the facial skin overlying the masseter muscle. The variables were measured in three sessions: before (baseline) and immediately after the Paced Auditory Serial Addition Task (PASAT) (stress) and then after a washout period of 20 to 30 minutes (poststress). Mixed analysis of variance (ANOVA) was applied to the data, and the significance level was set at P = .050. RESULTS: A significant main effect of the experimental session on all thermal tests was found (ANOVA: F > 4.10, P < .017), where detection tests presented an increase in thresholds in the poststress session compared to baseline (CDT, P = .012; WDT, P = .040) and pain thresholds were reduced in the stress (CPT, P < .001; HPT, P = .001) and poststress sessions (CPT, P = .005; HPT, P = .006) compared to baseline. In addition, a significant main effect of the study group on all mechanical tests (MPT, WUR, and PPT) was found (ANOVA: F > 4.65, P < .037), where TMD patients were more sensitive than healthy volunteers. CONCLUSION: Acute mental stress conditioning can modulate thermal sensitivity of the skin overlying the masseter in myofascial TMD patients and healthy volunteers. Therefore, psychological stress should be considered in order to perform an unbiased somatosensory assessment of TMD patients.

Headache Exacerbates Pain Characteristics in Temporomandibular Disorders.

AIMS: To evaluate the impact of headache in adults with masticatory myofascial pain (MMP) on the outcome variables clinical pain (ie, self-reported pain intensity and pressure pain sensitivity), sleep quality, and pain catastrophizing. METHODS: A total of 97 patients with MMP were diagnosed with co-existing headache (MMPH group, n = 50) or without headache (MMP group, n = 47) according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). The outcome parameters were the Pittsburgh Sleep Quality Index (PSQI); the Catastrophizing Thoughts subscale of the Pain-Related Self-Statement Scale (PRSS-C); pressure pain thresholds (PPTs) of the masseter and anterior temporalis muscles; and self-reported facial pain intensity measured on a 0- to 10-cm visual analog scale (VAS). Student t test for independent samples (α = 1.2%) and factorial analysis of variance (ANOVA) (α = 5%) were used to analyze the data. RESULTS: The MMPH group showed significantly impaired sleep quality (mean ± standard deviation [SD] PSQI score 9.1 ± 3.5) compared with the MMP group (7.2 ± 3.4; P = .008). Subscale scores on the PRSS-C were significantly higher in the MMPH (2.1 ± 1.2) than in the MMP group (1.6 ± 1.4, uncorrected P = .048). Also, the PPTs (kgf/cm²) of the masseter and anterior temporalis muscles were significantly lower in the MMPH group (1.52 ± 0.53; 1.29 ± 0.43, respectively) than in the MMP group (2.09 ± 0.73; 1.70 ± 0.68, respectively; P < .001), with no differences in self-reported facial pain intensity. Factorial analyses further indicated that chronic migraine was associated with poorer sleep quality (P = .003) and that tension-type headache patients had lower PPTs in the anterior temporalis muscle (P = .041) in comparison with non-headache patients. CONCLUSION: Co-existence of headache further exacerbates clinical characteristics in patients with painful TMD, which implies involvement of common mechanisms and pathways of vulnerability in these patients.

Effects of Experimental Pain and Lidocaine on Mechanical Somatosensory Profile and Face Perception.

AIMS: To assess the effects of experimental muscle pain and topical lidocaine applied to the skin overlying the masseter muscle on the mechanical somatosensory profile and face perception of the masseter muscle in healthy participants. METHODS: A total of 28 healthy participants received a 45-minute application of a lidocaine or placebo patch to the skin overlying the masseter muscle followed by one injection of 0.2 mL sterile solution of monosodium glutamate. Measurements were taken four times during each session of quantitative sensory testing (QST) (T0 = baseline, T1 = 45 minutes after patch application, T2 = immediately after glutamate injection, and T3 = 25 minutes after the glutamate injection), and the following variables were measured: mechanical detection threshold (MDT), mechanical pain threshold (MPT), pressure pain threshold (PPT), pain report (pain on palpation, pain spreading on palpation, and pain intensity), pain drawing, and perceptual distortion. Multi-way within-subjects analysis of variance (ANOVA) was applied to the data. RESULTS: The highest MDTs were present at T2 (F = 49.28, P < .001), the lowest PPTs were present at T2 and T3 (F = 21.78, P < .001), and the largest magnitude and area of perceptual distortion were reported at T2 (F > 6.48, P < .001). CONCLUSION: Short-lasting experimental muscle pain was capable of causing loss of tactile sensitivity as well as perceptual distortion of the face, regardless of preconditioning with a topical lidocaine patch. Short-term application of a lidocaine patch did not significantly affect the mechanical somatosensory profile.

Pain from Dental Implant Placement, Inflammatory Pulpitis Pain, and Neuropathic Pain Present Different Somatosensory Profiles.

AIMS: To address the two following questions: (1) What kind of somatosensory abnormalities may be characterized in patients receiving dental implants (IMP), in ongoing inflammatory dental pulpitis (IP) patients, and in neuropathic pain (atypical odontalgia [AO]) patients? and (2) What sort of sensory and neural changes may result from dental implant placement surgery and pulpectomy? METHODS: A total of 60 subjects were divided into three groups: the IMP (n = 20), IP (n = 20), and AO groups (n = 20). Quantitative sensory testing (QST) was performed preoperatively (baseline) for all three groups and postoperatively at 1 month and 3 months after dental implant placement or pulpectomy (in the IMP group and IP group, respectively). Statistical analyses were completed with one-way and two-way analysis of variance and z score transformations (α = 5%). RESULTS: The main findings of this study indicated that: (1) Elevations in mechanical detection threshold (MDT) and in current perception threshold (CPT) related to C-fiber activation, indicating a loss of function, were found at baseline in IP patients; (2) Somatosensory abnormalities such as allodynia, reduced MDT and mechanical pain threshold (MPT), and impaired pain modulation were found in AO patients; (3) No somatosensory alterations after implant placement were found in the IMP group; and (4) Somatosensory alterations in the form of reduction in the CPT related to C-fiber activation were reported 3 months after pulpectomy in the IP group. CONCLUSION: This study showed that somatosensory abnormalities were evident in AO and IP patients, and somatosensory alterations were seen in IP patients even 3 months after pulpectomy. However, no somatosensory alterations were seen after implant placement.

Is the Nociceptive Blink Reflex Associated with Psychological Factors in Healthy Participants?

AIMS: To evaluate the possible association between the nociceptive blink reflex (nBR) and various pain-related psychological measures: the Anxiety Sensitivity Index-3 (ASI-3), the Fear of Pain Questionnaire III (FPQ-III), the Pain Vigilance and Awareness Questionnaire (PVAQ), the Somatosensory Amplification Scale (SSAS), the Pain Catastrophizing Scale (PCS), and the Situational Pain Catastrophizing Scale (S-PCS). METHODS: The nBR was evaluated in 21 healthy participants. It was elicited by a nociceptive-specific electrode placed over the entry zone of the right supraorbital nerve, infraorbital nerve, and mental nerve, as well as the left infraorbital nerve. The outcomes were (1) nBR measurements: (a) individual electrical sensory threshold (I0) and pain threshold (IP); (b) root mean square (RMS), area under the curve (AUC), and onset latencies of R2 responses; (c) stimulus-evoked pain on a 0 to 10 numeric rating scale (NRS); and (2) the ASI-3, the FPQ-III, the PVAQ, the SSAS, the PCS, and the S-PCS. Pearson correlation coefficient was used to evaluate the association between the means of nBR measurements from all sites and the questionnaires The significance level was set up after a Bonferroni correction (adjusted α = .8%). RESULTS: There was no correlation for any pair of variables at the adjusted significance level (P > .008). There was only a single significant correlation at the standard significance level (P < .05), where the pain intensity (NRS) at 50% of IP presented a positive and small to moderate correlation with the PCS (r = 0.43, P = .04). CONCLUSION: It appears that the nBR and its associated psychophysical measures are not associated with psychological factors in healthy participants.

Headache Attributed to Masticatory Myofascial Pain: Clinical Features and Management Outcomes.

AIMS: To describe the characteristics of headaches attributed to temporomandibular disorders (TMD) and assess the effects of two management strategies used for the management of TMD on headache intensity and frequency. METHODS: The initial sample (n=60) of this randomized controlled trial comprised patients with masticatory myofascial pain according to the Research Diagnostic Criteria for TMD (RDC/TMD), and headache. The patients were divided into two groups: group 1 received only counseling for behavioral changes, and group 2 received counseling and an occlusal appliance. A 5-month follow-up period included three assessments. TMD-related headache characteristics, eg, headache intensity (scored on a visual analog scale [VAS]) and frequency were measured by a questionnaire. Two-way analysis of variance, chi-square, Friedman, and Mann-Whitney tests were used to test for differences considering a 5% significance level. RESULTS: The main clinical features of headache attributed to masticatory myofascial pain were the long duration (≥4 hours), frontotemporal bilateral location, and a pressing/tightening quality. Forty-one subjects (group 1, 17 subjects; group 2, 24 subjects) were included in the final analysis. There was a reduction in headache intensity and frequency, with no significant differences between groups (P>.05). The mean (±SD) baseline VAS was 7.6 (±2.2) for group 1 and 6.5 (±1.6) for group 2; final values were 3.1 (±2.2) (P<.001) and 2.5 (±2.3) (P<.001), respectively. CONCLUSION: Headache attributed to masticatory myofascial pain was mainly characterized by long duration, frontotemporal bilateral location, and a pressing/tightening quality. Also, counseling and behavioral management of masticatory myofascial pain improved headache, regardless of the use of an occlusal appliance.

Correlation between pressure pain threshold and pain intensity in patients with temporomandibular disorders who are compliant or non-compliant with conservative treatment.

OBJECTIVE: To investigate the correlation between pain measurements performed using a visual analogue scale (VAS) and pressure pain threshold (PPT) in individuals with temporomandibular disorders who underwent conservative treatment. STUDY DESIGN: This prospective study assessed 78 individuals diagnosed with myofascial pain, and the treatment consisted of counseling and self-care therapy sessions. Pain was assessed by means of a VAS and PPT at baseline (T0), after 15 to 30 days (T1), and after 75 to 90 days (T2). The participants were divided into two groups: "Compliant Group" and "Non-Compliant Group." The data were analyzed by means of Spearman's correlation test and Friedman's analysis of variance by ranks. RESULTS: Correlations were not identified between the VAS and PPT values at time points-T0, T1, or T2-in any group. CONCLUSION: Although, VAS and PPT represent subjective features, such as the perception of pain, the hypothesis that high pain intensity levels are equivalent to high pain sensitivity levels was not demonstrated.

Influence of myofascial pain on the pressure pain threshold of masticatory muscles in women with migraine.

OBJECTIVE: To evaluate the influence of myofascial pain on the Pressure Pain Threshold (PPT) of masticatory muscles in women with migraine. METHODS: The sample comprised 101 women, ages ranging from 18 to 60 years, with an episodic migraine diagnosis previously confirmed by a neurologist. All patients were evaluated using Research Diagnostic Criteria for Temporomandibular Disorders to determine the presence of myofascial pain and were divided into 2 groups: group I (n=56), comprising women with a migraine, and group II (n=45), comprising women with a migraine and myofascial pain. Two more groups (49 asymptomatic women and 50 women with myofascial pain), matched for sex and race, obtained from a previous study, were added to this study. The PPT values of masseter and temporalis (anterior, middle, and posterior regions) muscles were recorded bilaterally using a pressure algometer. One-way analysis of variance and the Tukey test for pairwise comparisons were used in statistical analysis with a 5% significance level. RESULTS: We found that all groups had significantly lower PPT values compared with asymptomatic women, with lower values seen in group II (women with migraine and myofascial pain). Women with a migraine and myofascial pain showed significantly lower PPT values compared with women with a migraine only, and also when compared with women with myofascial pain only. DISCUSSION: Migraine, especially when accompanied by myofascial pain, reduces the PPT of masticatory muscles, suggesting the importance of masticatory muscle palpation during examination of patients with migraine.

Influence of the menstrual cycle on the pressure pain threshold of masticatory muscles in patients with masticatory myofascial pain.

OBJECTIVE: The aim of this study was to investigate the influence of the menstrual cycle and oral contraceptive (OC) intake on the pressure pain threshold (PPT) of masticatory muscles in patients with masticatory myofascial pain (MFP). STUDY DESIGN: The sample was composed of 36 women, divided into 4 groups, according to the presence of MFP and the intake of OC (15 patients had MFP [7 taking OC] and 21 were pain-free controls [8 taking OC]). The algometer-based PPT of masseter and temporalis, and the record of subjective pain by visual analog scale (VAS) were determined during 2 consecutives menstrual cycles at 4 phases (menstrual, follicular, periovulatory, and luteal). A 3-way ANOVA for repeated measurements, Kruskal-Wallis, Friedman, and Dunn tests, with a 5% significant level analyzed the data. RESULTS: PPT was significantly lower in MFP patients when compared with controls throughout the experiment (P < .001). The menstrual phases did not influence PPT (P > .05), while the intake of OC seems to raise PPT levels for the left temporalis (P = .01) and right masseter (P = .04). VAS was, in general, higher at the menstrual phase CONCLUSIONS: Different phases of the menstrual cycle have no influence on PPT values, regardless of the presence of a previous condition, as masticatory myofascial pain, while the intake of OC is associated with decreased levels of reported pain.