Specific and number of comorbidities are associated with increased levels of temporomandibular pain intensity and duration

Peptide set test: a peptide-centric strategy to infer differentially expressed proteins

MOTIVATION

The clinical translation of mass spectrometry-based proteomics has been challenging due to limited statistical power caused by large technical variability and inter-patient heterogeneity. Bottom-up proteomics provides an indirect measurement of proteins through digested peptides. This raises the question whether peptide measurements can be used directly to better distinguish differentially expressed proteins.

RESULTS

We present a novel method called the peptide set test, which detects coordinated changes in the expression of peptides originating from the same protein and compares them to the rest of the peptidome. Applying our method to data from a published spike-in experiment and simulations demonstrates improved sensitivity without compromising precision, compared to aggregation-based approaches. Additionally, applying the peptide set test to compare the tumor proteomes of tamoxifen-sensitive and tamoxifen-resistant breast cancer patients reveals significant alterations in peptide levels of collagen XII, suggesting an association between collagen XII-mediated matrix reassembly and tamoxifen resistance. Our study establishes the peptide set test as a powerful peptide-centric strategy to infer differential expression in proteomics studies.

AVAILABILITY AND IMPLEMENTATION

Peptide set test (PepSetTest) is publicly available at https://github.com/JmWangBio/PepSetTest.

A female-specific role for trigeminal dynorphin in orofacial pain comorbidity

ABSTRACT

Migraine is commonly reported in patients with temporomandibular disorders (TMDs), but little is known about the mechanisms underlying the comorbid condition. Here, we prepared a mouse model to investigate this comorbidity, in which masseter muscle tendon ligation (MMTL) was performed to induce a myogenic TMD, and the pre-existing TMD enabled a subthreshold dose of nitroglycerin (NTG) to produce migraine-like pain in mice. RNA sequencing followed by real-time quantitative polymerase chain reaction confirmation showed that MMTL plus NTG treatment increased prodynorphin ( Pdyn ) mRNA expression in the spinal trigeminal nucleus caudalis (Sp5C) of female mice but not in male mice. Chemogenetic inhibition of Pdyn -expressing neurons or microinjection of antidynorphin antiserum in the Sp5C alleviated MMTL-induced masseter hypersensitivity and diminished the MMTL-enabled migraine-like pain in female mice but not in male mice. Moreover, chemogenetic activation of Pdyn -expressing neurons or microinjection of dynorphin A (1-17) peptide in the Sp5C enabled a subthreshold dose of NTG to induce migraine-like pain in female mice but not in male mice. Taken together, our results suggest that trigeminal dynorphin has a female-specific role in the modulation of comorbid TMDs and migraine.

Chronic disease clusters are associated with prolonged, bothersome, and multisite musculoskeletal pain: a population-based study on Northern Finns

BACKGROUND

Chronic diseases often accumulate with musculoskeletal (MSK) pain. However, less evidence is available on idiosyncratic patterns of chronic diseases and their relationships with the severity of MSK pain in general MSK pain populations.

MATERIAL AND METHODS

Questionnaire-based data on physician-diagnosed chronic diseases, MSK pain and its dimensions (frequency, intensity, bothersomeness, and the number of pain sites), and confounders were collected from the Northern Finland Birth Cohort 1966 at the age of 46. Latent Class Analysis (LCA) was used to identify chronic disease clusters among individuals who reported any MSK pain within the previous year (n = 6105). The associations between chronic disease clusters, pain dimensions, and severe MSK pain, which was defined as prolonged (over 30 d within the preceding year), bothersome (Numerical Rating Scale >5), and multisite (two or more pain sites) pain, were analyzed using logistic regression and general linear regression models, adjusted for sex and educational level (n for the full sample = 4768).

RESULTS

LCA resulted in three clusters: Metabolic (10.8% of the full sample), Psychiatric (2.9%), and Relatively Healthy (86.3%). Compared to the Relatively Healthy cluster, the Metabolic and Psychiatric clusters had higher odds for daily pain and higher mean pain intensity, bothersomeness, and the number of pain sites. Similarly, the odds for severe MSK pain were up to 75% (95% confidence interval: 44%-113%) and 155% (81%-259%) higher in the Metabolic and Psychiatric clusters, respectively, after adjustments for sex and educational level.

CONCLUSIONS

Distinct patterns of chronic disease accumulation can be identified in the general MSK pain population. It seems that mental and metabolic health are at interplay with severe MSK pain. These findings suggest a potential need to screen for psychiatric and metabolic entities of health when treating working-aged people with MSK pain.Key messagesThis large study on middle-aged people with musculoskeletal pain aimed to examine the idiosyncratic patterns of chronic diseases and their relationships with the severity of musculoskeletal pain. Latent class cluster analysis identified three chronic disease clusters: Psychiatric, Metabolic, and Relatively Healthy. People with accumulated mental (Psychiatric cluster) or metabolic diseases (Metabolic cluster) experienced more severe pain than people who were relatively healthy (Relatively Healthy cluster). These findings suggest a potential need to screen for psychiatric and metabolic entities of health when treating working-aged people with MSK pain.

Craniofacial disorders and headaches. A narrative review

OBJECTIVES

Craniofacial- and headache disorders are common co-morbid disorders. The aim of this review is to provide an overview of the research discussing craniofacial pain, especially temporomandibular disorders, and its relationship and impact on headaches, as well as suggestions for diagnostic assessment tools and physical therapeutic management strategies.

METHOD

A narrative structured review was performed. A search was conducted in MEDLINE using terms related to craniofacial pain and headaches. Additionally, papers regarding this topic were also extracted from the authors' personal libraries. Any study design (i.e., RCT, observational studies, systematic review, narrative review) that reported the concepts of interest was included, using Covidence. Results were narratively synthesized and described.

RESULTS

From an epidemiological perspective, craniofacial pain and headaches are strongly related and often co-existing. This may be due to the neuroanatomical connection with the trigeminal cervical complex, or due to shared predisposing factors such as age, gender, and psychosocial factors. Pain drawings, questionnaires, and physical tests can be used to determine the cause of pain, as well as other perpetuating factors in patients with headaches and craniofacial pain. The evidence supports different forms of exercise and a combination of hands-on and hands-off strategies aimed at both the craniofacial pain as well as the headache.

CONCLUSION

Headaches may be caused or aggravated by different disorders in the craniofacial region. Proper use of terminology and classification may help in understanding these complaints. Future research should look into the specific craniofacial areas and how headaches may arise from problems from those regions. (249 words).

Temporomandibular Joint Disorder Comorbidities

Comorbidity is a distinct additional condition that either existed or exists during the clinical course of a patient afflicted by the condition/entity in question. The clinician attempting to manage temporomandibular joint disorder (TMD) and TMD pain must realize that recognition and management of the comorbidities are essential to the successful management of the same with optimal pain control. When TMD presents with multiple comorbidities, the task for the clinician becomes more complex. It is the hope of the authors that this condensed version of TMD-associated comorbidities acts as a primer for understanding the significance of the same in pain management.

Focus Groups to Inform the Development of a Patient-Reported Outcome Measure (PROM) for Temporomandibular Joint Disorders (TMDs)

BACKGROUND

Understanding symptoms of temporomandibular joint disorders (TMDs) can help doctors and patients document, monitor, and manage the disease and help researchers evaluate interventions. Patients with TMDs experience symptoms ranging from mild to severe, primarily in the head and neck region. This study describes findings from formative patient focus groups to capture, categorize, and prioritize symptoms of TMDs towards the development of a patient-reported outcome measure (PROM).

METHODS

We conducted ten focus groups with 40 men and women with mild, moderate, and severe TMD. Focus groups elicited descriptions of symptoms and asked participants to review a list of existing patient-reported outcomes (PROs) from the literature and patient advisor input and speak to how those PROs reflect their own experience, including rating their importance.

RESULTS

We identified 52 distinct concepts across six domains: somatic, physical, social, sexual, affective, and sleep. Focus groups identified the ability to chew and eat; clicking, popping, and other jaw noises; jaw pain and headaches; jaw misalignment or dislocation; grinding, clenching, or chewing, including at night; and ear sensations as most important. Participants with severe TMDs more often reported affective concepts like depression and shame than did participants with mild or moderate TMDs.

CONCLUSION

Findings support PROM item development for TMDs, including selecting existing PROMs or developing new ones that reflect patients' lived experiences, priorities, and preferred terminology. Such measures are needed to increase understanding of TMDs, promote accurate diagnosis and effective treatment, and help advance research on TMDs.

Are central sensitization symptoms and psychosocial alterations interfering in the association between painful TMD, migraine, and headache attributed to TMD?

OBJECTIVE

To determine if somatosensory function and symptoms related to central sensitization (CS) differed in individuals with painful temporomandibular disorders (TMD) according to the presence of migraine (MIG) or MIG + headache attributed to TMD (HAT).

MATERIALS AND METHODS

This study evaluated 92 adults (20-65 years), presenting painful TMD. Standard diagnostic criteria were applied to classification of painful TMD, MIG, and HAT. CS was assessed through the central sensitization inventory (CSI), wind-up ratio (WUR), pressure pain thresholds (PPT), and the conditioned pain modulation test (CPM). Psychosocial factors were evaluated by validated instruments.

RESULTS

There was a significant difference regarding gender, with more women in the group TMD + MIG + HAT (p = 0.028). TMD + MIG and TMD + MIG + HAT had significantly lower PPTs than the TMD group. No group differences were found for the WUR, CPM, or CSI. TMD + MIG + HAT had higher chronic pain intensity (p = 0.001), disability points (p = 0.045), graded chronic pain scale (p = 0.007), and higher somatization (NSPS) scores (p = 0.012), compared to the other groups.

CONCLUSION

Mechanical hyperalgesia was more pronounced in the group with the highest pain and somatization scores, while CPM and WUR did not differ between groups. Altered somatosensory function and CS may partially underlie the pathophysiology of overlapping TMD pain conditions, pointing towards additive effects of comorbid head pains.

CLINICAL RELEVANCE

Our results demonstrate the importance of considering the association of primary and secondary headaches during TMD assessment and its implications for maintaining the signs and symptoms of CS. This can influence the conduct of treatment, which must be multidisciplinary, and must include management of mechanisms related to CS.

Investigation of temporomandibular disorders in patients with fibromyalgia syndrome: A case-control study

INTRODUCTION

The aim of this study is to compare the frequency of temporomandibular disorders and to examine the temporomandibular pain and functionality levels between healthy female participants and female patients diagnosed with fibromyalgia.

MATERIALS AND METHODS

Our study included 300 participants. Patients were evaluated according to the Diagnostic Criteria for Temporomandibular Disorders: Assessment Instruments (DC/TMD). While evaluating the patients using DC/TMD, TMD Pain Screener and Symptom questionnaire were used within the scope of Axis I, and Graded Chronic Pain Scale, Jaw Functional Limitation Scale-8 (JFLS-8), Patient Health Questionnaire (PHQ-4) and Oral Behaviors Checklist were applied.

RESULTS

Bruxism, tooth grinding and masseter hypertrophy were found to be significantly higher in fibromyalgia patients compared to healthy volunteers (p<0.001). The pain screener, JFLS-8, PHQ-4 and OBC scores and GCPS levels were found to be increased in the fibromyalgia group compared to healthy individuals (p<0.001). Considering the post-examination diagnoses of the participants, the diagnoses of myalgia (p=0.022) and disc displacement with reduction (p<0.001) were significantly higher than healthy individuals.

CONCLUSIONS

Fibromyalgia is a common pathology, therefore, TMD symptoms, which are more difficult to diagnose and often missed, should be questioned in fibromyalgia patients and should be kept in mind in the management of fibromyalgia patients.

Does risk of obstructive sleep apnea have interaction with chronic facial pain?

OBJECTIVES

The main purpose of the present study was to investigate the associations between the risk of obstructive sleep apnea (OSA) and chronic orofacial pain in a nationally representative sample of the Korean population.

MATERIALS AND METHODS

Data from the 8th wave Korean national health and nutrition examination survey, which was conducted from 2019 to 2020 were analyzed. This study included 5,780 Koreans (2,503 males, 3,277 females) over 40 years of age. The presence of subjective chronic facial pain lasting more than 3 months was evaluated based on a self-reported questionnaire. The risk of OSA was determined using the STOP-BANG questionnaire. Data related to anthropometric and sociodemographic factors; diagnostic history of hypertension, depression, and OSA; level of health-related quality of life and stress awareness; health-related behaviors, including smoking and alcohol drinking; and sleep duration were collected. The participants were classified into two groups according to the presence of chronic facial pain.

RESULTS

The level of health-related quality of life and stress awareness showed significant differences between the two groups. The sleep duration on weekends also presented significant differences. No significant differences were observed in the presence of snoring and observed apnea, while participants with chronic facial pain showed significantly higher levels of tiredness between the groups. The risk of OSA evaluated by STOP-BANG questionnaire showed significant differences between groups; however, the risk of OSA seemed to be higher in participants without chronic facial pain.

CONCLUSION

The participants with chronic facial pain demonstrated decreased sleep duration, lower health-related quality of life, and increased stress and tiredness. Even though, the role of OSA in the development of chronic facial pain was inconclusive from the study, it is possible that ethnicity play a role in relationship between OSA and chronic facial pain.

Associations between obstructive sleep apnea and painful temporomandibular disorder: a systematic review

The relationship between obstructive sleep apnea (OSA) and diverse types of pain conditions have been proposed. However, no consensus on the relationship between OSA and painful temporomandibular disorders (TMDs) has been established. Therefore, this systematic review has been conducted to review the existing literatures and provide comprehensive synthesis of such literatures about OSA and painful TMDs using the evidence-based methodology. A literature search was conducted using two electronic databases, Scopus, and PubMed. Risk of bias was assessed using the risk-ofbias assessment tool for non-randomized study version 2.0. A total of 158 articles were screened from the initial search and eventually, 5 articles were included in this systematic review. One study adopted both the longitudinal prospective cohort and case-control designs and other 4 articles adopted the cross-sectional design. Two studies employed polysomnography (PSG) for the diagnosis of OSA and mentioned the results from the PSG. All crosssectional studies demonstrated higher OSA prevalence among patients with TMD, and one cohort study suggested OSA as a risk factor for TMD. OSA appears to have potential influences on the development of TMD; however, the role of TMD in the development of OSA remains to be unknown owing to the lack of high-quality evidences.

Pain Management and Rehabilitation for Central Sensitization in Temporomandibular Disorders: A Comprehensive Review

Temporomandibular disorders (TMD) are a group of musculoskeletal diseases affecting masticatory muscles and temporomandibular joints (TMJ). In this context, the chronic TMD could be considered as a condition with chronic primary orofacial pain, presenting as myofascial TMD pain or TMJ arthralgia. In this context, myogenous TMD may present overlapping features with other disorders, such as fibromyalgia and primary headaches, characterized by chronic primary pain related to dysfunction of the central nervous system (CNS), probably through the central sensitization. This phenomenon could be defined as an amplified response of the CNS to sensory stimuli and peripheral nociceptive, characterized by hyperexcitability in the dorsal horn neurons in the spinal cord, which ascend through the spinothalamic tract. The main objectives of the management of TMD patients are: decreasing pain, increasing TMJ function, and reducing the reflex masticatory muscle spasm/pain. The first-line treatments are physical therapy, pharmacological drugs, occlusal splints, laser therapy, extracorporeal shockwave therapy, transcutaneous electrical nerve stimulation, and oxygen–ozone therapy. Although all these therapeutic approaches were shown to have a positive impact on the central sensitization of TMD pain, there is still no agreement on this topic in the scientific literature. Thus, in this comprehensive review, we aimed at evaluating the evidence on pain management and rehabilitation for the central sensitization in TMD patients.

An online survey of pelvic congestion support group members regarding comorbid symptoms and syndromes

Objectives

Patients with pelvic congestion syndrome (PCS) often report overlapping somatic symptoms and syndromes. The objective of this study was to explore the prevalence of co-existing symptoms and self-reported syndrome diagnoses among women with PCS and to inform future research hypotheses.

Methods

A brief online survey was offered to members of a PCS support group website. Responses were assessed for self-reported co-existing symptoms and formal diagnoses, including: chronic fatigue syndrome, fibromyalgia, postural tachycardia syndrome, irritable bowel syndrome, migraines, interstitial cystitis, and temporomandibular joint dysfunction.

Results

Of a total of 6000 members, there were 398 respondents; 232 (59%) had not yet been treated for PCS. Among these, the most prevalent co-existing symptoms were as follows: severe fatigue (72%), dizziness (63%), IBS symptoms (61%), brain fog (33%), migraines (49%), polyuria or dysuria (41%), excessive sweating (31%), TMJ pain (31%), and loose skin or lax joints (18%). These are much higher than reported for the general female population. The most commonly self-reported comorbid syndrome diagnoses for the overall group of 398 were: irritable bowel syndrome (29%), fibromyalgia (13%), spinal nerve problems (18%), interstitial cystitis (10%), postural tachycardia syndrome (9%), hypertension (11%), chronic fatigue syndrome (10%), and Ehlers-Danlos syndrome (6%). Other than with hypertension, these rates are variably higher than in the general population.

Conclusion

Several self-reported co-existing symptoms and syndromes are more prevalent in members of a PCS support group relative to the reported prevalence in the general population. More formal investigation is warranted to evaluate this finding and to investigate potential etiologic links. Ehlers-Danlos Syndrome appears to be common in self identifying PCS women.

Fatigue in Adults with Chronic Arthralgia/Myalgia in the Temporomandibular Region: Associations with Poor Sleep Quality, Depression, Pain Intensity, and Future Pain Interference

AIMS

To examine associations between fatigue and poor sleep quality, depression symptoms, and pain intensity in an adult population with chronic arthralgia/myalgia in the temporomandibular region and to test whether fatigue predicted future pain-related interference above and beyond these other constructs.

METHODS

The sample included 40 participants with chronic arthralgia and/or myalgia in the temporomandibular region and 21 healthy controls. Participants self-reported fatigue (PROMIS fatigue score), sleep quality (PSQI), depression symptoms (PROMIS depression score), and average pain intensity and completed four weekly surveys of pain-related interference with daily activities.

RESULTS

The chronic arthralgia/myalgia group reported greater fatigue than healthy controls (t = 4.85, P < .001). Fatigue was significantly correlated with poor sleep quality (r = .46), higher depression symptoms (r = .41), and higher pain intensity (r = .46) in the chronic arthralgia/myalgia group, and these three variables together explained 39% of variance in fatigue. Greater fatigue-above and beyond sleep quality, depression symptoms, and average pain intensity-was associated with a higher average level of pain-related interference (β = 0.56, t score = 3.30, P = .002) over the following month. Depression symptoms, poor sleep quality, and pain intensity did not significantly predict pain interference above and beyond fatigue (all P > .05).

CONCLUSION

The results suggest that fatigue is a clinically relevant symptom distinct from depression, poor sleep quality, or pain intensity and may be related to worse pain outcomes over the following month in adults with chronic temporomandibular arthralgia/myalgia. Clinicians should assess, monitor, and treat fatigue to the best of their abilities when working with this population.

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

Purpose

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

Patients and Methods

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

Results

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

Conclusion

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

The prevalence of comorbid chronic pain conditions among patients with temporomandibular disorders: A systematic review

BACKGROUND

This systematic review was designed to evaluate the presence of comorbid conditions among patients with temporomandibular disorders (TMDs).

TYPES OF STUDIES REVIEWED

The authors reviewed studies that reported the prevalence or incidence of chronic pain conditions or psychiatric disorders (anxiety, mood, personality disorders) among patients with any type of TMD. The authors calculated sample size-weighted prevalence estimates when data were reported in 2 or more studies for the same comorbid condition.

RESULTS

A total of 9 prevalence studies and no incidence studies were eligible for review; 8 of the studies examined chronic pain comorbidities. Weighted estimates showed high prevalence of pain comorbidities across studies, including current chronic back pain (66%), myofascial syndrome (50%), chronic stomach pain (50%), chronic migraine headache (40%), irritable bowel syndrome (19%), and fibromyalgia (14%). A single study examined psychiatric disorders and found that current depression was the most prevalent disorder identified (17.5%).

CONCLUSIONS AND PRACTICAL IMPLICATIONS

There is a high prevalence of comorbid chronic pain conditions among patients with TMDs, with more than 50% of patients reporting chronic back pain, myofascial syndrome, and chronic stomach pain. Psychiatric disorders among patients with different types of TMDs were studied less commonly in this pain population. Knowledge of the distribution of these and other comorbid disease conditions among patients with different types of TMDs can help dentists and other health care providers to identify personalized treatment strategies, including the coordination of care across medical specialties.

Cerebral Perfusion and Sensory Testing Results Differ in Interstitial Cystitis/Bladder Pain Syndrome Patients with and without Fibromyalgia: A Site-Specific MAPP Network Study

Purpose

Fibromyalgia is a common co-morbidity in patients with interstitial cystitis/bladder pain syndrome. Quantitative sensory testing measures and regional cerebral blood flow measures have been noted to differ from healthy controls in both subjects with fibromyalgia and those with interstitial cystitis when studied independently. The present study examined such measures in subjects with the diagnosis of interstitial cystitis both with and without the co-diagnosis of fibromyalgia to determine whether differences in these measures may be associated with co-morbidity.

Patients and Methods

Female subjects with the diagnosis of interstitial cystitis with (n = 15) and without (n = 19) the co-diagnosis of fibromyalgia as well as healthy control subjects (n = 41) underwent quantitative sensory testing. A subset of these patients (9 with and 9 without fibromyalgia) underwent brain perfusion studies using arterial spin labeled functional magnetic resonance imaging. An analysis was performed of absolute regional cerebral blood flow of regions-of-interest when experiencing a full bladder compared with an empty bladder.

Results

Subjects with both interstitial cystitis and fibromyalgia were more hypersensitive than those without fibromyalgia as well as healthy controls in most sensory measures except heat. Subjects with interstitial cystitis, but no fibromyalgia, differed from healthy controls only in toleration of the ischemic forearm task. Other co-morbidities were more common in those subjects with both interstitial cystitis and fibromyalgia. Bladder fullness was associated with significantly greater whole brain gray matter blood flow in subjects with interstitial cystitis and fibromyalgia when compared with that of subjects with interstitial cystitis without fibromyalgia. Examination of regional cerebral blood flow in individual regions-of-interest demonstrated statistically significant differences between the subjects with interstitial cystitis with and those without fibromyalgia bilaterally in the thalamus, amygdala and hippocampus, as well as the right prefrontal cortex and greater responsiveness to changes in bladder fullness in the insula.

Conclusion

Quantitative sensory testing and brain perfusion data support that there are two phenotypes of interstitial cystitis patients, which can be differentiated by a co-diagnosis of fibromyalgia. This may affect responsiveness to treatment and suggest the utility of stratifying interstitial cystitis patients according to their co-morbidities.

Reasons for failure of total temporomandibular joint replacement: a systematic review and meta-analysis

The aim of this study was to evaluate the revision rate after total alloplastic temporomandibular joint replacement (TMJR) and determine whether there is a higher risk of revision surgery with stock or custom-fitted prostheses (the two most current TMJR prosthesis types). A systematic review was performed, with a search of PubMed, Google Scholar, and the Cochrane Library in November 2020. Overall, 27 articles were included in this study, describing Biomet and TMJ Concepts prostheses and including postoperative data on complications requiring a return to the operating room. A total of 2247 prostheses were analysed: 1350 stock Biomet prostheses and 897 custom-fitted TMJ Concepts and custom-fitted Biomet prostheses. The global revision rate was 1.19 per 100 prosthesis-years. The most common reason for revision was heterotopic bone formation. Stock prostheses appeared to have a lower risk of revision compared to custom prostheses: rate ratio 0.52 (95% confidence interval 0.33-0.81, P-value 0.003). Regarding causes of revision, the only significant difference between the types of devices was a higher rate of heterotopic bone formation for custom-made prostheses (P = 0.001). The results of this study revealed a low revision rate post TMJR revision, with stock devices even less prone to such risk. Nevertheless, these results can be explained by the fact that custom-made prostheses are more likely to be used for cases in which the anatomy is significantly abnormal or there is a history of multiple joint surgeries, which carry a greater risk of complications and heterotopic bone formation.

Review article: Physical and psychological comorbidities associated with irritable bowel syndrome

Irritable bowel syndrome (IBS) is one of the most common gastrointestinal disorders encountered by physicians in primary and secondary care. Patients with IBS commonly present with various extraintestinal complaints, which account for a substantial clinical and economic burden. The common extraintestinal comorbidities associated with IBS include anxiety, depression, somatisation, fibromyalgia, chronic fatigue syndrome, chronic pelvic pain, interstitial cystitis, sexual dysfunction and sleep disturbance. The presence of comorbidity in IBS poses a diagnostic and therapeutic challenge with patients frequently undergoing unnecessary investigations and interventions, including surgery. This review discusses the different physical and psychological comorbidities associated with IBS, the shared pathophysiological mechanisms and potential management strategies.

A comparison of the influencing factors of chronic pain and quality of life between older Koreans and Korean-Americans with chronic pain: a correlational study

BACKGROUND

Chronic pain is one of the most common health problems for older adults worldwide and is likely to result in lower quality of life. Living in a different culture may also influence chronic pain and quality of life in older adults. The purpose of this study was to explore how multifaceted elements affect chronic pain and quality of life in older Koreans living in Korea and in older Korean-Americans (KAs) living in the USA.

METHODS

We conducted a secondary data analysis of data from 270 adults aged 65 years or over (138 Koreans and 132 KAs). We compared the effects of multifaceted elements on pain and quality of life by testing structural equation models (SEMs) for each group, using a maximum likelihood estimation and bootstrapping.

RESULTS

SEMs for both Korean and KAs showed that age and depressive symptoms directly affected quality of life. The number of comorbidities and depressive symptoms had mediating effects on quality of life through chronic pain in both groups. In older Koreans only, perceived financial status directly affected quality of life. In older KAs only, sleep quality indirectly affected quality of life through chronic pain.

CONCLUSION

The data showed that multimorbidity and depressive symptoms play critical roles for explaining chronic pain in older Koreans and KAs and ultimately negatively influence quality of life. Future intervention program to improve quality of life in older adults with chronic pain should consider the different cultural aspects affecting quality of life for Koreans and KAs.

Comorbid Conditions in Temporomandibular Disorders Myalgia and Myofascial Pain Compared to Fibromyalgia

The impact of comorbidities in fibromyalgia (FM) and temporomandibular disorders (TMD) have been well documented, but whether TMD sub-diagnoses myalgia (MYA) and myofascial pain with referral (MFP) differ regarding comorbidity is unclear. We aimed to elucidate this by studying the presence and associations of comorbidities in FM, MFP and MYA. An extended version of the Diagnostic Criteria for TMD axis II questionnaire was used to examine demographics, pain and comorbidities in 81 patients with FM, 80 with MYA, and 81 with MFP. Patients with MFP and FM reported a higher percentage of irritable bowel syndrome (IBS), depression, anxiety, somatic symptoms, perceived stress, and insomnia compared to MYA. Patients with FM had more IBS, depression, and somatic symptom disorder versus MFP. After adjusting for confounding variables, participants with anxiety, somatic symptoms disorder, pain catastrophizing, and perceived stress, as well as a greater number of comorbidities, were more likely to have MFP than MYA, whereas FM participants were more associated with IBS, somatic symptoms and insomnia compared to MFP. The number of comorbidities was significantly associated with widespread pain but not pain duration, body mass index or being on sick leave. In conclusion, patients with MFP were more similar to those with FM regarding comorbidity and should be differentiated from MYA in clinical settings and pain management.

Reduction of headache intensity and frequency with maxillary stabilization splint therapy in patients with temporomandibular disorders-headache comorbidity: a systematic review and meta-analysis

This systematic review and meta-analysis aimed to analyze the effectiveness of maxillary stabilization splint (SS) therapy to reduce headache (HA) intensity and HA frequency in patients with temporomandibular disorders (TMD)-HA comorbidity. Randomized controlled trials (RCTs) using full-arch coverage, hard resin, and maxillary SS therapy were included. Electronic databases, including Cochrane Library, MEDLINE through PubMed, Web of Science, and EMBASE, were searched. The risk of bias was analyzed based on Cochrane's handbook. The search yielded 247 references up to January 28, 2020. Nine RCTs were included at a high risk of bias. The comparison groups included other splints, counseling, jaw exercises, medications, neurologic treatment, and occlusal equilibration. Four studies reported a statistically significant reduction in HA intensity, and five studies reported significant improvement in HA frequency from baseline at 2-12 months in patients with TMD-HA comorbidity treated with a full-arch hard maxillary SS. HA frequency in tension-type HA (TTH) comorbid with TMD diagnoses of myofascial pain (MFP) or capsulitis/synovitis improved significantly with SS than that with full-arch maxillary non-occluding splint (NOS) in two studies. Comparison groups receiving hard partial-arch maxillary splint nociceptive trigeminal inhibition (NTI) showed statistically significant improvements in HA intensity in patients with mixed TMD phenotypes of MFP and disc displacement comorbid with “general HA.” Comparison groups receiving partial-arch maxillary resilient/soft splint (Relax) showed significant improvements in both HA intensity and frequency in patients with HA concomitant with MFP. The meta-analysis showed no statistically significant difference in the improvement of pain intensity at 2-3 months with comparison of the splints (partial-arch soft [Relax], hard [NTI], and full-arch NOS) or splint use compliance at 6-12 months with comparison of the splints (partial-arch Relax and full-arch NOS) versus the SS groups in patients with various TMD-HA comorbidities. In conclusion, although SS therapy showed a statistically significant decrease in HA intensity and HA frequency when reported, the evidence quality was low due to the high bias risk and small sample size. Therefore, further studies are required.

Lack of correlation between central sensitization inventory and psychophysical measures of central sensitization in individuals with painful temporomandibular disorder

OBJECTIVE

To assess the correlation between the Central Sensitization Inventory (CSI) scores and the results of psychophysical tests and psychosocial questionnaires according to the presence of painful temporomandibular disorder (TMD).

DESIGN

It was a cross-sectional study involving 146 participants, aged 20-65 years. Painful TMD was classified using the Research Diagnostic Criteria for Temporomandibular Disorders. CSI was applied to assess "central sensitization-related symptoms", as has been suggested. Wind-up ratio, pressure pain threshold and conditioned pain modulation were used as psychophysical tests to evaluate signs and symptoms of central sensitization. Psychosocial factors were assessed by the presence of non-specific physical symptoms, depressive and anxiety symptoms. The sample was divided into two groups: Control (n = 31); Painful TMD (n = 115). Descriptive statistics characterized the sample. Correlation analysis were performed using Pearson's and Spearman's correlation coefficients (α = 5%).

RESULTS

Of the total sample, 78.8 % presented painful TMD, and the mean (standard deviation) age was 37.4 (±11.5) years. Anxiety symptoms (p = 0.028) and non-specific physical symptoms (p < 0.001) were more frequent in the painful TMD group than in controls. Painful TMD patients presented higher scores of the CSI (p < 0.001) and lower pressure pain thresholds (p ≤ 0.020) compared to controls. CSI scores were significantly correlated with psychosocial measures (p < 0.001) but not with psychophysical tests (p ≥ 0.089).

CONCLUSION

The CSI scores did not correlate with psychophysical measures of central sensitization but were positively correlated with the results of psychosocial questionnaires.

Neck associated factors related to migraine in adolescents with painful temporomandibular disorders

OBJECTIVE

Migraine is a comorbidity of painful temporomandibular disorders (TMDs). Both migraine and painful TMD have associations with neck pain and head posture. The aim of this study was to clarify the role of neck pain and head posture on the association between migraine and painful TMD in adolescents.

MATERIALS AND METHOD

In total 314 adolescents were included: 235 adolescents with only painful TMD (pTMD) and 79 adolescents with painful TMD and migraine (TMDMIG). Adolescents were diagnosed according to the Research Diagnostic Criteria for Temporomandibular Disorders and International Classification of Headache Disorders, 3rd edition. Head postures were identified using lateral cephalograms. Myofascial trigger points (TrPs) were evaluated in the temporalis, masseter, trapezius, sternocleidomastoid, sub-occipitalis, and splenius capitis muscles.

RESULTS

Multivariate logistic regression analysis confirmed the associations among the orofacial pain duration, number of active TrPs in the trapezius muscles, intensity of neck pain, and distance between the occiput and atlas and migraine in adolescents with TMD. The relationships among intensity of neck pain, number of TrPs in the cervical muscles, and head posture were more prominent in the TMDMIG than those in the pTMD.

CONCLUSION

Neck associated factors seemed to have relevance with migraine in adolescents with painful TMD.

The Prevalence of Psychiatric and Chronic Pain Comorbidities in Fibromyalgia: an ACTTION systematic review

Fibromyalgia (FM) is a chronic widespread pain condition that overlaps with multiple comorbid health conditions and contributes to considerable patient distress. The aim of this review was to provide a systematic overview of psychiatric and chronic pain comorbidities among patients diagnosed with FM and to inform the development of recommendations for the design of clinical trials. Thirty-one, cross-sectional, clinical epidemiology studies that evaluated patients diagnosed with FM were included for review. None of the reviewed studies reported on the incidence of these comorbidities. Sample size-weighted prevalence estimates were calculated when prevalence data were reported in 2 or more studies for the same comorbid condition. The most prevalent comorbidity across all studies reviewed was depression/major depressive disorder (MDD) with over half of the patients included having this diagnosis in their lifetime (weighted prevalence up to 63%). In addition, nearly one-third of FM patients examined had current or lifetime bipolar disorder, panic disorder, or post-traumatic stress disorder. Less common psychiatric disorders reported included generalized anxiety disorder, obsessive compulsive disorder, and specific phobias (agoraphobia, social phobia). There were fewer studies that examined chronic pain comorbidities among FM patients, but when evaluated, prevalence was also high ranging from 39% to 76% (i.e., chronic tension-type or migraine headache, irritable bowel syndrome, myofascial pain syndrome, and temporomandibular disorders). The results of the review suggest that depression and chronic pain conditions involving head/jaw pain and IBS were elevated among FM patients compared to other conditions in the clinic-based studies. In contrast, anxiety-related disorders were much less common. Addressing the presence of these comorbid health conditions in clinical trials of treatments for FM would increase the generalizability and real-world applicability of FM research.

A systematic review of the association between fibromyalgia and functional gastrointestinal disorders

BACKGROUND

Fibromyalgia and functional gastrointestinal disorders (FGID) including irritable bowel syndrome (IBS) are common conditions presenting in clinical settings and are more prevalent in women. While the relationship between IBS and fibromyalgia has been demonstrated, a review of the prevalence of the broader group of FGID in adults with fibromyalgia has not been undertaken. The aim of this review was to systematically review the published literature, identifying the comorbidity of FGID in people with fibromyalgia, and to discuss the clinical implications, limitations of current research and areas of interest for future research.

METHODS

Medline, Embase, CINAHL and Web of Science were searched during June 2019. Results were screened for original research articles meeting established criteria for identification of FGID in adults diagnosed with fibromyalgia.

RESULTS

A total of 14 studies involving 1340 adults with fibromyalgia, 363 healthy controls and 441 adults with other pathologies were included in this review. Only 1 of the 14 studies included surveyed the full range of FGID . Functional gut disorders were matched to Rome II criteria for reporting and comparison. In addition to increased abdominal pain and functional bloating or gas, IBS of mixed-pattern and constipation-types appear to be more prevalent than diarrhoea-predominant IBS in adults with fibromyalgia.

CONCLUSION

This review confirms previous reports that IBS is common in people living with fibromyalgia and suggests that IBS-mixed and constipation types predominate. An association with a range of FGID other than IBS is suggested, but data are limited. Research exploring the association between fibromyalgia and functional gastrointestinal dysfunction beyond IBS are warranted.

Evaluation of orofacial pain and psychological comorbidities in health sciences university students

Introduction: Orofacial pain (OP) is a common public health problem among the general population however, its distribution among the young population like students has not been evaluated so far. The objectives of this study were to investigate the self-reported prevalence, and characteristics of OP, and to evaluate its association with psychological comorbidities such as anxiety and depression. Materials and Methods: A questionnaire-based study was conducted on students studying health sciences programs at SEGi University, Malaysia. A well-designed, structured questionnaire was utilized to assess the prevalence and characteristics of OP. Hospital Anxiety and Depression (HAD) scale was used to evaluate the psychological status of the students. The collected data was subject to statistical analysis by using the SPSS version 22 software. Results: Overall 494 university students had participated in the study of which, 78% (n = 375) of students had suffered from OP and it was significantly higher among the female students (p < 0.03). Headache was the most common type of OP (66.2%) followed by pain in temple region (47.2%), in and around eyes (29.1%), facial region (23.3%), and tooth/gingival pain (20.9%). The association between the prevalence of OP and anxiety was statistically significant (p < 0.019). About 35.4% of the health sciences students had first OP episode started three months ago, 4.2% had daily pain, 14.3% suffered from continuous pain, and only 14% of the students had consulted professionals and 36.1% of them took medication. Conclusion: A significantly higher prevalence of self-reported OP was evident among the health sciences university students and students with different types of OP had higher anxiety and depression scores. Early recognition of OP symptoms and associated comorbidities must be considered for the prevention and successful management of these conditions to circumvent its negative academic impact on the students.

Is Irritable Bowel Syndrome Considered in Clinical Trials on Physical Therapy Applied to Patients with Temporo-Mandibular Disorders? A Scoping Review

The aim of the current scoping review was to identify if the presence of irritable bowel syndrome was included as eligibility criteria of participants included in clinical trials investigating the effects of physical therapy in individuals with temporomandibular pain disorders (TMDs). A systematic electronic literature search in the Web of Science database was conducted. Scientifically relevant, randomized clinical trials (those cited in other studies at least 5 times, or clinical trials published in high-impact journals, i.e., first and second quartiles (Q1-Q2) of any category of the Journal Citation Report (JCR)) evaluating the effects of any physical therapy intervention in patients with TMDs were included. The Physiotherapy Evidence Database (PEDro) scale was used to evaluate the methodological quality of the selected trials. Authors affiliated to a clinical or non-clinical institution, total number of citations, objective, sex/gender, age, and eligibility criteria in each article were extracted and analyzed independently by two authors. From a total of 98 identified articles, 12 and 19 clinical trials were included according to the journal citation criterion or JCR criterion, respectively. After removing duplicates, a total of 23 trials were included. The PEDro score ranged from 4 to 8 (mean: 6.26, SD: 1.48). Based on the eligibility criteria of the trials systematically reviewed, none considered the presence of comorbid irritable bowel syndrome in patients with TMDs. The comorbidity between TMDs and irritable bowel syndrome is not considered within the eligibility criteria of participants in highly cited clinical trials, or published in a high-impact journal, investigating the effects of physical therapy in TMDs.

Prognostic Indicators for Positive Treatment Outcome After Multidisciplinary Orofacial Treatment in Patients With Somatosensory Tinnitus

Introduction

Subjective tinnitus that is influenced by the somatosensory system is called somatosensory tinnitus (ST). When ST is related to the temporomandibular area, multidisciplinary orofacial treatment can reduce tinnitus severity. It is, however, unknown if we can predict this positive outcome. The aim of this study is to look for prognostic indicators that can predict a positive outcome after multidisciplinary orofacial treatment in patients with ST.

Methods

Patients were included when they were diagnosed with temporomandibular-related ST and received a maximum of 18 sessions of orofacial treatment during a 9-week program. Predictors for positive treatment outcome were identified using univariate and multiple logistic regression analyses with the Tinnitus Questionnaire (TQ) and the Tinnitus Functional Index (TFI) as dependent variables.

Results

The results of 101 patients were included in the analysis. Immediately after multidisciplinary orofacial treatment, a clinically relevant decrease in TQ score was significantly associated with “shorter duration of tinnitus” [odds ratio (OR) 0.99], “higher initial score on the TQ somatic subscale” (OR 1.52), and “painful palpation of the temporomandibular joint (TMJ)” (OR 2.46). After 9 weeks of follow-up, the “higher initial score on the TQ somatic subscale” remained as the sole predictor (OR 1.44). A clinically relevant decrease on TFI after 9 weeks of follow-up was predicted by “female gender” (OR 2.70), “younger age” (OR 0.96), “shorter duration of the tinnitus” (OR 0.99), “lower pressure pain thresholds (PPT) on TMJ” (OR 0.99), “lower PPT on sternocleidomastoid origin” (OR 0.99), and “better speech in noise perception” (OR 0.88). A multivariate model comprising “shorter duration of tinnitus” and “higher initial score on the somatic subscale of the TQ” correctly predicts the clinically relevant decrease in TQ score after treatment in 68.5%. A second multivariate model comprising “female gender,” “younger age,” and “shorter duration of the tinnitus” correctly predicts a clinically significant decrease on TFI after follow-up in 68.1%.

Conclusion

We were able to identify various prognostic indicators. “Younger female patients” with a “shorter duration of tinnitus” and a “higher initial score on the TQ somatic subscale” appear to have the best prognosis after multimodal orofacial therapy.

Newly graduated dentists' knowledge of temporomandibular disorders compared to specialists in Saudi Arabia

Background

General dentists are often the first healthcare professionals to see patients with orofacial pain (OFP). OFP conditions associated with the temporomandibular joint are often confused with dentoalveolar disorders, which leads to mismanagement. The objective of this study was to evaluate the level of knowledge of temporomandibular disorders (TMD) among newly graduated dentists compared to OFP specialists in Saudi Arabia.

Methods

This was a descriptive cross-sectional study utilizing an anonymous validated questionnaire assessing professional knowledge regarding TMDs in newly qualified dentists and OFP specialists. The questionnaire interrogated four domains including chronic pain/pain behavior, etiology, diagnosis/classification, and treatment/prognosis. OFP specialists were used as the reference group.

Results

A total of 393 dentists participated, a response rate of 67.6% in newly graduated dentists and 77.3% in OFP specialists. The degree of agreement between newly graduated general dentists and OFP specialists was highest for the “chronic pain and pain behavior” domain. The consensus among specialists was highest for the “treatment and prognosis” domain and the least for the “chronic pain and pain behavior” domain.

Conclusion

Newly graduated general dentists have limited knowledge of TMD in almost all domains compared to specialists. Given that a lack of knowledge of TMD can lead to clinical mismanagement, dental school curricula must address this important knowledge gap.

Graded exposure and orthopedic manual physical therapy for kinesiophobia and function in chronic temporomandibular dysfunction: A case report

BACKGROUND

This case report describes the successful use of multi-modal physical therapy (PT), including orthopedic manual physical therapy (OMPT) and graded exposure, in a patient with chronic temporomandibular dysfunction (TMD).

CLINICAL PRESENTATION

A 41-yr old female presented with a five-year history of bilateral chronic myofascial TMD and comorbid neck/right arm pain. The patient was treated for 12 weeks with a focus on OMPT and graded exposure. The patient demonstrated clinically significant improvements on the Tampa Scale of Kinesiophobia-TMD, maximal mouth opening, Global Rating of Change, and Jaw Functional Limitation Scale.

CLINICAL RELEVANCE

Mechanisms underlying chronic TMD are complex. Current evidence supports PT management of physical impairments; however, neglecting central drivers or psychosocial factors may result in suboptimal outcomes. Physical therapists are able to address both peripheral and central mechanisms of pain, and future research should examine the utilization of multi-modal PT to improve kinesiophobia and function in patients with chronic TMD.

A Pre-Existing Myogenic Temporomandibular Disorder Increases Trigeminal Calcitonin Gene-Related Peptide and Enhances Nitroglycerin-Induced Hypersensitivity in Mice

Migraine is commonly reported among patients with temporomandibular disorders (TMDs), especially myogenic TMD. The pathophysiologic mechanisms related to the comorbidity of the two conditions remain elusive. In the present study, we combined masseter muscle tendon ligation (MMTL)-produced myogenic TMD with systemic injection of nitroglycerin (NTG)-induced migraine-like hypersensitivity in mice. Facial mechanical allodynia, functional allodynia, and light-aversive behavior were evaluated. Sumatriptan, an FDA-approved medication for migraine, was used to validate migraine-like hypersensitivity. Additionally, we examined the protein level of calcitonin gene-related peptide (CGRP) in the spinal trigeminal nucleus caudalis using immunohistochemistry. We observed that mice with MMTL pretreatment have a prolonged NTG-induced migraine-like hypersensitivity, and MMTL also enabled a non-sensitizing dose of NTG to trigger migraine-like hypersensitivity. Systemic injection of sumatriptan inhibited the MMTL-enhanced migraine-like hypersensitivity. MMTL pretreatment significantly upregulated the protein level of CGRP in the spinal trigeminal nucleus caudalis after NTG injection. Our results indicate that a pre-existing myogenic TMD can upregulate NTG-induced trigeminal CGRP and enhance migraine-like hypersensitivity.

Oral Health and Fibromyalgia Syndrome: A Systemic Review

Fibromyalgia is a syndrome currently considered idiopathic and multifactorial rheumatic that causes an increase in muscle tension and is characterized by muscle pain and chronic fibrous tissues-widespread, fluctuating and migrating-associated with stiffness, asthenia, cognitive disorders, insomnia or sleep disorders, alterations in sensitivity to stimuli. In affected patients, there may be anxiety or depressive disorder development. The aim of this study is, with the help of an interdisciplinary team, to evaluate the correlations between this syndrome and oral health. A literature review was conducted, analyzing the most common scientific databases, more than 200 studies were obtained. Subsequently to the application of filters and revision by the authors, only 18 articles were considered eligible for this review. From the results, it is clear that the correlations between fibromyalgia and oral health mainly concern pain in the oro-maxillofacial district, especially in the temporomandibular joint. This certainly could help for faster diagnosis of the syndrome, which is currently difficult to identify.

Severity of irritable bowel syndrome in patients with temporomandibular disorders: A case-control study

Background

To assess the risk and severity of IBS in a population of TMD patients.

Material and Methods

Subjects for the study group were recruited from patients attending the Dental Clinic. Health controls (HC) were recruited among patients' friends and clinic staff. All subjects filled in the RDC/TMD questionnaire and the ROME III questionnaire for the diagnosis of IBS. The IBS Severity Scoring System (IBS-SSS) was used to evaluate the severity of each case of IBS. Categorical variables were compared through the Chi square test. The risk of having abdominal pain was analysed using logistic regression.

Results

Twenty-two (46.8%) cases of IBS were diagnosed among TMD patients, whereas only 4 (11.4%) were in the HC group. This difference was statistically significant (χ2(1)=11.6; p<.01). The differences in the distribution of IBS-SSS were statistically significant (χ2(3)=12.49; p<.05). The regression model resulted statistically significant (χ2(5)=24.08; p<.001, R2=.37): abdominal pain was significantly related to nonspecific physical symptoms independent of the other variables.

Conclusions

TMD patients had a greater risk of having IBS compared to HC. TMD patients presented also more severe form of IBS than HC. Key words:Temporomandibular disorders, irritable bowel syndrome, facial pain, case-control study.

Severity of irritable bowel syndrome in patients with temporomandibular disorders: A case-control study

BACKGROUND

To assess the risk and severity of IBS in a population of TMD patients.

MATERIAL AND METHODS

Subjects for the study group were recruited from patients attending the Dental Clinic. Health controls (HC) were recruited among patients' friends and clinic staff. All subjects filled in the RDC/TMD questionnaire and the ROME III questionnaire for the diagnosis of IBS. The IBS Severity Scoring System (IBS-SSS) was used to evaluate the severity of each case of IBS. Categorical variables were compared through the Chi square test. The risk of having abdominal pain was analysed using logistic regression.

RESULTS

Twenty-two (46.8%) cases of IBS were diagnosed among TMD patients, whereas only 4 (11.4%) were in the HC group. This difference was statistically significant (χ2(1)=11.6; p<.01). The differences in the distribution of IBS-SSS were statistically significant (χ2(3)=12.49; p<.05). The regression model resulted statistically significant (χ2(5)=24.08; p<.001, R2=.37): abdominal pain was significantly related to nonspecific physical symptoms independent of the other variables.

CONCLUSIONS

TMD patients had a greater risk of having IBS compared to HC. TMD patients presented also more severe form of IBS than HC. Key words:Temporomandibular disorders, irritable bowel syndrome, facial pain, case-control study.

Assessment of association between muscular diagnosis in temporomandibular disorders with mandibular kinematics

Objective: To study the association between mandibular kinematics and muscular diagnoses in temporomandibular disorders (TMD). Method: Retrospective, descriptive clinical study based on an analysis of 370 clinical records of muscle diagnoses in TMD. Statistical analysis was performed with the SPSS program. Results: Five different muscle diagnoses were considered. Myospasm and centrally mediated myalgia were discarded from the statistical analysis because of their low incidences. The diagnoses included in the analysis were protective co-contraction, myofascial pain, and myalgia. Decreased mandibular kinematics in the frontal and horizontal planes were related to myofascial pain. Mandibular kinematics with deflection in opening values decreased in the frontal plane, but intermediate or increased values in the horizontal plane were related to the protective co-contraction. Muscle pain with normal or increased mandibular kinematics was associated with a diagnosis of myalgia. Conclusion: Values of mandibular kinematics are correlated with the muscular diagnoses in TMD and are useful for diagnosis.

Benefits of implementing pain-related disability and psychological assessment in dental practice for patients with temporomandibular pain and other oral health conditions

BACKGROUND

Evidence in the field of dentistry has demonstrated the importance of pain-related disability and psychological assessment in the development of chronic symptoms. The Diagnostic Criteria for Temporomandibular Disorders offer a brief assessment for the diagnostic process in patients with orofacial pain (Axis II). The authors describe relevant outcomes that may guide general oral health care practitioners toward tailored treatment decisions and improved treatment outcomes and provide recommendations for the primary care setting.

METHODS

The authors conducted a review of the literature to provide an overview of knowledge about Axis II assessment relevant for the general oral health care practitioner.

RESULTS

The authors propose 3 domains of the Axis II assessment to be used in general oral health care: pain location (pain drawing), pain intensity and related disability (Graded Chronic Pain Scale [GCPS]), and psychological distress (Patient Health Questionnaire-4 [PHQ-4]). In the case of localized pain, low GCPS scores (0-II), and low PHQ-4 scores (0-5), patients preferably receive treatment in primary care. In the case of widespread pain, high GCPS scores (III-IV), and high PHQ-4 scores (6-12), the authors recommend referral to a multidisciplinary team, especially for patients with temporomandibular disorder (TMD) pain.

CONCLUSIONS

The authors recommend psychological assessment at first intake of a new adult patient or for patients with persistent TMD pain. The authors recommend the pain-related disability screening tools for all TMD pain symptoms and for dental pain symptoms that persist beyond the normal healing period.

PRACTICAL IMPLICATIONS

A brief psychological and pain-related disability assessment for patients in primary care may help the general oral health care practitioner make tailored treatment decisions.

As if one pain problem was not enough: prevalence and patterns of coexisting chronic pain conditions and their impact on treatment outcomes

INTRODUCTION

The presence of multiple coexisting chronic pain (CP) conditions (eg, low-back pain and migraines) within patients has received little attention in literature. The goals of this observational longitudinal study were to determine the prevalence of coexisting CP conditions, identify the most frequent ones and patterns of coexistence, investigate the relationships among patients' biopsychosocial characteristics and number of CP conditions, and determine the impact of coexisting CP conditions on treatment response.

PATIENTS AND METHODS

A total of 3,966 patients attending multidisciplinary pain-treatment centers who were enrolled in the Quebec Pain Registry were included. Patients completed self-report and nurse-administered questionnaires before their first visit and 6 months later. Results were analyzed using descriptive statistics, factor and cluster analyses, negative binomials with log-link generalized linear models, and linear mixed-effect models.

RESULTS

A third of patients reported coexisting CP conditions. No specific patterns of comorbidities emerged. The presence of coexisting CP conditions was associated with longer pain duration, older age, being female, and poorer quality of life. The presence of more than one CP condition did not have a clinically significant impact on treatment responses.

DISCUSSION

The novelty of the study results relate to the heterogeneity that was found in the patterns of coexistence of CP conditions and the fact that having multiple CP conditions did not clinically impact treatment response. These results highlight the need for future research that examines causes of coexistence among CP conditions across the spectrum of CP, as opposed to focusing on specific conditions, and to examine whether multiple CP conditions impact on additional domains, such as treatment satisfaction. These results highlight the importance of studying the pathophysiological mechanisms underlying the development of coexisting CP conditions, in order eventually to prevent/minimize their occurrence and/or develop optimal treatment and management approaches.

Diverse Physiological Roles of Calcitonin Gene-Related Peptide in Migraine Pathology: Modulation of Neuronal-Glial-Immune Cells to Promote Peripheral and Central Sensitization

The neuropeptide calcitonin gene-related peptide (CGRP) is implicated in the underlying pathology of migraine by promoting the development of a sensitized state of primary and secondary nociceptive neurons. The ability of CGRP to initiate and maintain peripheral and central sensitization is mediated by modulation of neuronal, glial, and immune cells in the trigeminal nociceptive signaling pathway. There is accumulating evidence to support a key role of CGRP in promoting cross excitation within the trigeminal ganglion that may help to explain the high co-morbidity of migraine with rhinosinusitis and temporomandibular joint disorder. In addition, there is emerging evidence that CGRP facilitates and sustains a hyperresponsive neuronal state in migraineurs mediated by reported risk factors such as stress and anxiety. In this review, the significant role of CGRP as a modulator of the trigeminal system will be discussed to provide a better understanding of the underlying pathology associated with the migraine phenotype.

High risk of temporomandibular disorder in irritable bowel syndrome: Is there a correlation with greater illness severity?

AIM

To investigate the prevalence and the risk of temporomandibular disorders (TMDs) in patients with irritable bowel syndrome (IBS) (including each subtype: constipation, diarrhoea, and mixed) compared to the general population.

METHODS

Between January 2014 and December 2015 we enrolled consecutively adult patients diagnosed with IBS at the outpatient clinic of the University of Salerno and healthy controls (HC) without IBS. At enrollment, we analyzed all patients for the presence of TMDs according to the Research Diagnostic Criteria for TMD.

RESULTS

We enrolled 91 IBS patients (23 IBS-D, 30 IBS-C and 38 IBS-M) and 57 HC in the study. We found a higher risk of having TMD (OR = 3.41, 95%CI: 1.66-7.01) compared to the HC. The risk of having TMD was independent of IBS-subtype. Multiple regression analysis showed that facial pain was positively related to abdominal pain and higher level of depression.

CONCLUSION

IBS patients had a more than three times greater risk of TMD compared to HC. The risk of having TMD was similar in different IBS subtypes. IBS patients that also fulfilled criteria for TMD seem to share along with chronic facial and abdominal pain a significant co-occurrence with psychiatric disorders and female preponderance.

High risk of temporomandibular disorder in irritable bowel syndrome: Is there a correlation with greater illness severity?

AIM

To investigate the prevalence and the risk of temporomandibular disorders (TMDs) in patients with irritable bowel syndrome (IBS) (including each subtype: constipation, diarrhoea, and mixed) compared to the general population.

METHODS

Between January 2014 and December 2015 we enrolled consecutively adult patients diagnosed with IBS at the outpatient clinic of the University of Salerno and healthy controls (HC) without IBS. At enrollment, we analyzed all patients for the presence of TMDs according to the Research Diagnostic Criteria for TMD.

RESULTS

We enrolled 91 IBS patients (23 IBS-D, 30 IBS-C and 38 IBS-M) and 57 HC in the study. We found a higher risk of having TMD (OR = 3.41, 95%CI: 1.66-7.01) compared to the HC. The risk of having TMD was independent of IBS-subtype. Multiple regression analysis showed that facial pain was positively related to abdominal pain and higher level of depression.

CONCLUSION

IBS patients had a more than three times greater risk of TMD compared to HC. The risk of having TMD was similar in different IBS subtypes. IBS patients that also fulfilled criteria for TMD seem to share along with chronic facial and abdominal pain a significant co-occurrence with psychiatric disorders and female preponderance.

Elevated levels of calcitonin gene-related peptide in upper spinal cord promotes sensitization of primary trigeminal nociceptive neurons

Orofacial pain conditions including temporomandibular disorder (TMD) and migraine are characterized by peripheral and central sensitization of trigeminal nociceptive neurons. The goal of this study was to investigate the role of calcitonin gene-related peptide (CGRP) in promoting bidirectional signaling within the trigeminal system to mediate sensitization of primary nociceptive neurons. Adult male Sprague-Dawley rats were injected intercisternally with CGRP or co-injected with the receptor antagonist CGRP_8-37 or KT 5720, a protein kinase A (PKA) inhibitor. Nocifensive head withdrawal response to mechanical stimulation was investigated using von Frey filaments. Expression of PKA, glial fibrillary acidic protein (GFAP), and ionized calcium-binding adapter molecule 1 (Iba1) in the spinal cord and phosphorylated extracellular signal-regulated kinase (P-ERK) in the ganglion was studied using immunohistochemistry. Some animals were co-injected with CGRP and Fast Blue dye and the ganglion was imaged using fluorescent microscopy. CGRP increased nocifensive responses to mechanical stimulation when compared to control. Co-injection of CGRP_8-37 or KT 5720 with CGRP inhibited the nocifensive response. CGRP stimulated PKA and GFAP expression in the spinal cord, and P-ERK in ganglion neurons. Seven days post injection, Fast Blue was observed in ganglion neurons and satellite glial cells. Our results demonstrate that elevated levels of CGRP in the upper spinal cord promote sensitization of primary nociceptive neurons via a mechanism that involves activation of PKA centrally and P-ERK in ganglion neurons. Our findings provide evidence of bidirectional signaling within the trigeminal system that facilitate increased neuron-glia communication within the ganglion associated with trigeminal sensitization.

Painful temporomandibular disorders and central sensitization: implications for management-a pilot study

The objective was to investigate the presence of cutaneous allodynia and hyperalgesia in the trigeminal and extra-trigeminal areas, as a surrogate for central sensitization (CS), in women with a painful temporomandibular disorder (TMD) and without other painful conditions. Painful TMDs, depression, and non-specific physical symptoms (NSPS) were classified according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). The amount of pain in the trigeminal and extra-trigeminal areas was determined using a visual analogue scale (0-100mm) after the application of a vibrotactile stimulus and assessment of the pressure pain threshold (PPT). Statistical tests (Fisher's, χ², and Mann-Whitney) were performed, with a significance level of 5%. The sample comprised 45 women (mean age 37.5 years; 16 with a painful TMD) who were free of any headache, fibromyalgia, or other painful condition. Painful TMD was associated with higher pain sensitivity and lower PPT values in the trigeminal (P<0.01) and extra-trigeminal regions (P<0.01). The presence of depression contributed significantly to increased pain sensitivity. The presence of hyperalgesia and allodynia in both the trigeminal and extra-trigeminal regions among women with a painful TMD indicated the presence of CS. Changes involving the central nervous system should be considered during the evaluation and management of patients with a painful TMD.

Headache in Behcet's disease: types and characteristics

BACKGROUND

Behcet's disease involves several systems in the body. Neurological involvement is identified by different symptoms. Headache is one of the common complaints of patients with Behcet's disease. It might be a part of neurological involvement or may arise independently in the course of disease. Studies with small sample size have resulted in various findings in this field. Since the prevalence of Behcet's disease is relatively high in Iran, this study was carried out to compare the features of headache between an acceptable number of patients with this rare disease and a control group.

METHODS

The current case-control study was performed to compare the features of headache between 312 patients with definite Behcet's disease who referred to a Behcet's clinic and healthy individuals. Patients with Behcet's disease were randomly selected. Controls were matched for age and sex. They were personally examined and interviewed meticulously using a questionnaire that met the standards of the International Headache Society classification for different types of headache.

RESULTS

The incidence of headache in the case and control groups was 28.3 % (n = 120) and 18.6 % (n = 59), respectively (p < 0.05; OR 2.73). Tension-type headache was observed in 12.2 % (n = 38) of cases which was significantly higher than control group (n = 6.3 %) (p = 0.011; OR 2.05). The most frequent type of headache in the case group was tension-type headache (12.2 %). In the control group, however, migraine without aura was the most common type (9.1 %). A correlation between ophthalmological involvement and headache was observed in 11 patients in the case group. In addition, a significantly higher systolic blood pressure was found in the case group compared to the controls (125.1 vs. 121.7 mmHg; p = 0.007). There was no major correlation between prednisolone consumption in patients with Behcet's disease and the type and frequency of headache.

CONCLUSIONS

Headache, especially tension-type headache, is more common in patients with Behcet's disease. This might be the result of specific types of uveitis-related and non-structural headaches seen in Behcet's disease.