Treatments for painful temporomandibular disc displacement with reduction: a network meta-analysis of randomized clinical trials.

There is currently no consensus on the best treatment for painful temporomandibular disc displacement with reduction (DDwR), and no network meta-analysis of randomized clinical trials (RCTs) comparing all types of treatment for this condition has been conducted. The objective of this study was to compare and rank all treatments for DDwR, including conservative treatments, occlusal splints, low-level laser therapy (LLLT), manual therapy, no treatment (control), arthrocentesis (Arthro) alone, Arthro plus intra-articular injection of platelet-rich plasma (Arthro-PRP) or hyaluronic acid (Arthro-HA), and Arthro plus occlusal splint. Predictor variables were pain intensity and maximum mouth opening (MMO). The mean difference with 95% confidence interval was estimated using Stata software. The GRADE system was used to assess the certainty of the evidence. Twenty RCTs reporting 1107 patients were identified in the literature search; 980 of these patients were included in the network meta-analysis. Direct meta-analysis showed that Arthro-PRP significantly reduced pain intensity compared to Arthro alone, while occlusal splint and manual therapy were superior to conservative treatment (all very low quality evidence). Arthro with intra-articular injection of PRP/HA ranked as the most effective treatment in terms of pain reduction, whereas LLLT ranked the best choice for increasing MMO for patients with DDwR. However, it is important to note that the evidence for the superiority of these treatments is generally of very low quality. Therefore, further high-quality research is needed to confirm these findings and provide more reliable recommendations for the treatment of DDwR.

Perceptions about Aging and Ageism from 14 Cross-sectional Cohorts of Undergraduate Dental Students.

BACKGROUND: Although positive and negative views of aging and older adults exist, how undergraduate dental students imagine their lives to be as they grow older remains to be fully explored. This study aimed at determining the self-perceived views of being 65, 75, or 85 y of age, as expressed by undergraduate dental students at the University of British Columbia (UBC), Vancouver, Canada. METHODS: A 14-y cross-sectional study design was utilized involving third-year undergraduate dental students at UBC's Faculty of Dentistry. Brief individual essays (150 words) encompassing students' self-perceived views were gathered as part of a dental geriatric course from 2009 to 2022; however, essays were not mandatory. Saldaña's inductive coding and thematic analysis of textual data were used. Themes and categories of information were identified and matched with their excerpts while aiming for data saturation. RESULTS: Over the 14-y period, 657 students were enrolled in UBC's undergraduate dental geriatric course, and 561 essays were collected. Inductive coding and thematic analysis identified 5 main themes and 11 categories. While themes included "oral health, general health, and the mind" and "me, myself, and familial relationships," the categories focused on "(un)able bodies" and "general health." Positive views about the aging process were shared, while less optimistic ideas-and even ageism-were apparent when students saw themselves as not employable or living in isolation. Positive and negative views were not bound by the students' academic year but might have been influenced by the COVID-19 pandemic. CONCLUSION: Although the number of older adults already surpasses the number of children in many countries, ageism appears to have permeated through students' views of 3 older ages. More positive yet realistic views of growing older were also shared. Follow-up studies are needed to explore the impact of dental education on decreasing ageism. KNOWLEDGE TRANSFER STATEMENT: As the proportion of older adults in the global population steadily grows, it is important to educate heath care providers about normal and pathologic aging to avoid ageism-stereotypes, prejudices, and discrimination against older adults. This cross-sectional study involved 14 cohorts of undergraduate dental students exploring their self-perceived views of growing older. Although positive and negative views of aging were shared, dental education must focus on decreasing ageism.

Plasma Cytokine Levels in Fibromyalgia and Their Response to 15 Weeks of Progressive Resistance Exercise or Relaxation Therapy.

The aims of this study were to compare circulating cytokines between FM and healthy controls and to investigate the effect on cytokine levels by 15 weeks of progressive resistance exercise or relaxation therapy in FM. Baseline plasma cytokine levels and clinical data were analyzed in 125 women with FM and 130 age-matched healthy women. The FM women were then randomized to progressive resistance exercise (n = 49) or relaxation (n = 43). Baseline IL-2, IL-6, TNF-α, IP-10, and eotaxin were higher in FM than in healthy controls (P < 0.041), whereas IL-1ß was lower (P < 0.001). There were weak correlations between cytokine levels and clinical variables. After both interventions, IL-1ra had increased (P = 0.004), while IL-1ß had increased in the relaxation group (P = 0.002). Changes of IFN-γ, IL-2, IL-4, IL-6, IL-8, and IL-17A were weakly correlated with changes of PPT, but there were no significant correlations between changes of cytokine and changes in other clinical variables. The elevated plasma levels of several cytokines supports the hypothesis that chronic systemic inflammation may underlie the pathophysiology of FM even if the relation to clinical variables was weak. However, 15 weeks of resistance exercise, as performed in this study, did not show any anti-inflammatory effect on neither FM symptoms nor clinical and functional variables. This trial is registered with ClinicalTrials.gov NCT01226784, registered October 21, 2010. The first patient was recruited October 28, 2010.

Increased levels of intramuscular cytokines in patients with jaw muscle pain.

BACKGROUND: The aim of this study was to investigate cytokine levels in the masseter muscle, their response to experimental tooth-clenching and their relation to pain, fatigue and psychological distress in patients with temporomandibular disorders (TMD) myalgia. METHODS: Forty women, 20 with TMD myalgia (Diagnostic Criteria for TMD) and 20 age-matched healthy controls participated. Intramuscular microdialysis was performed to sample masseter muscle cytokines. After 140 min (baseline), a 20-minute tooth-clenching task was performed (50% of maximal voluntary contraction force). Pain (Numeric rating scale 0-10) and fatigue (Borg's Ratings of Perceived Exertion 6-20) were assessed throughout microdialysis, while pressure-pain thresholds (PPT) were assessed before and after microdialysis. Perceived stress (PSS-10) and Trait Anxiety (STAI) were assessed before microdialysis. RESULTS: The levels of IL-6, IL-7, IL-8 and IL-13 were higher in patients than controls (Mann Whitney U-test; P's < 0.05) during the entire microdialysis. IL-6, IL-8 and IL-13 changed during microdialysis in both groups (Friedman; P's < 0.05), while IL-1ß, IL-7 and GM-CSF changed only in patients (P's < 0.01). IL-6 and IL-8 increased in response to tooth-clenching in both groups (Wilcoxon test; P's < 0.05), while IL-7, IL-13 and TNF increased only in patients (P's < 0.05). Patients had higher pain and fatigue than controls before and after tooth-clenching (P < 0.001), and lower PPTs before and after microdialysis (P < 0.05). There were no correlations between cytokine levels, pain or fatigue. Also, there were no differences in stress or anxiety levels between groups. CONCLUSIONS: In conclusion, the masseter levels of IL-6, IL-7, IL-8 and IL-13 were elevated in patients with TMD myalgia and increased in response to tooth-clenching. Tooth-clenching increased jaw muscle pain and fatigue, but without correlations to cytokine levels. This implies that subclinical muscle inflammation may be involved in TMD myalgia pathophysiology, but that there is no direct cause-relation between inflammation and pain.

Professional knowledge among Swedish and Saudi healthcare practitioners regarding oro-facial pain in children and adolescents.

Oro-facial pain (OFP) and temporomandibular disorders (TMD) in children and adolescents are a growing problem. To meet patients' healthcare needs, professionals must perform their work intuitively and with quality. Therefore, a high degree of professional knowledge is necessary. To investigate the professional knowledge regarding OFP/TMD in children and adolescents among Swedish and Saudi Arabian dental and medical specialists compared with Swedish OFP specialists. One questionnaire including the four domains Chronic pain and behaviour; Aetiology; Diagnosis and classification; Treatment and prognosis was distributed to 383 potential participants, that is physicians and dentists in Sweden and Saudi Arabia. The Swedish OFP/TMD specialists were used as a reference group. The response rates from Sweden and Saudi Arabia were 49% and 86%, respectively. The degree of agreement was highest in the domain Chronic pain and behaviour, especially for the Swedish groups. Regarding the other three domains, the agreement was modest to poor. In general, Swedish groups showed a higher agreement with Swedish OFP/TMD specialists than Saudi Arabian groups. This study shows that professional knowledge regarding OFP/TMD in children and adolescents is limited among Swedish and Saudi Arabian dental and medical professionals compared to Swedish OFP/TMD specialists. In Swedish groups, the professional knowledge is more accurate than in the corresponding Saudi Arabian. With these results in mind, and the frequent prevalence of OFP/TMD in children and adolescents, one can draw the conclusion that there is a need for modern medical education regarding OFP/TMD among both physicians and dentists, especially in Saudi Arabia.

NGF-induced mechanical sensitization of the masseter muscle is mediated through peripheral NMDA receptors.

Intramuscular injection of nerve growth factor (NGF) in healthy humans mimics some of the symptoms of myofascial temporomandibular disorders (M-TMD). We hypothesized that NGF induces a prolonged myofascial mechanical sensitization by increasing peripheral N-methyl-d-aspartate (NMDA) receptor expression, leading to an enhanced response of muscle nociceptors to endogenous glutamate. Behavioral experiments with an injection of NGF (25 µg/ml, 10 µl) into the masseter muscle reduced the mechanical withdrawal threshold for 1 day in male rats and 5 days in female rats. These results mirror the sex-related differences found in NGF-induced mechanical sensitization in humans. Intramuscular injection with the competitive NMDA receptor antagonist dl-2-amino-5-phosphonovaleric acid (APV, 0.020 g/ml, 10 µl) reversed the mechanical sensitization in male but not in female rats. NGF increased the number of NMDA receptor subtype 2B (NR2B)-expressing rat trigeminal masseter ganglion neurons in both sexes, which peaked at 3 days post injection. There was an association between the levels of NR2B expression and NGF-induced mechanical sensitization. The average soma size of NR2B-expressing neurons increased significantly. Increased expression of neuropeptides (CGRP and SP) was observed in NR2B-expressing masseter ganglion neurons in female but not in male rats. In healthy men and women, comparable basal expression levels of NR2B and SP were found in peripheral fibers from masseter muscle microbiopsies. This study suggests that NGF-induced sensitization of masseter nociceptors is mediated, in part, by enhanced peripheral NMDA receptor expression. Measurement of peripheral NMDA receptor expression may be useful as a biomarker for M-TMD pain.

Salivary cortisol and psychological factors in women with chronic and acute oro-facial pain.

The aim of this study was to compare the salivary cortisol level, pain intensity and psychological factors between patients with chronic and acute oro-facial pain (OP) and pain-free subjects. Twenty-seven females with chronic OP (a diagnosis of myofascial pain according to the Research Diagnostic Criteria for Temporomandibular Disorders with at least 6 months duration), 24 females with acute OP (<10 days duration) and 27 pain-free females participated. Morning saliva was collected from all participants for analyses of the cortisol level. The pain intensity was assessed on a 0-10 numeric rating scale. The participants were evaluated by the Symptom Checklist 90-revised for levels of depression and somatisation, and the Perceived Stress Scale. The cortisol levels among the three patient groups were similar with no significant group differences. The median (interquartile range) current pain level did not differ between chronic and acute OP and was, respectively, 5 (4) and 5 (3). Patients with chronic OP showed significantly higher scores for depression, somatisation and perceived stress compared with patients with acute OP (Ps < 0.001), but there were no significant differences between acute OP and controls. To conclude, there were no differences in cortisol level between groups, despite significant higher levels of depression, somatisation and perceived stress in patients with chronic OP. This shows that psychological distress has a more important role in chronic than in acute OP. However, the relation between pain, adreno-cortical activity and psychological distress is complex and warrants further investigation.

Influence of intramuscular granisetron on experimentally induced muscle pain by acidic saline.

The aim of this study was to investigate whether intramuscular administration of the 5-HT(3) receptor antagonist granisetron reduces experimental muscle pain induced by repeated intramuscular injections of acidic saline into the masseter muscles. Twenty-eight healthy and pain-free volunteers, fourteen women and fourteen men participated in this randomized, double-blind and placebo-controlled study. After a screening examination and registration of the baseline pressure-pain threshold (PPT), the first simultaneous bilateral injections of 0·5 mL acidic saline (9 mg mL(-1) , pH 3·3) into the masseter muscles were performed. Two days later, PPT and pain (VAS) were re-assessed. The masseter muscle was then pre-treated with 0·5 mL granisetron (Kytril(®) 1 mg mL(-1) pH 5·3) on one side and control substance (isotonic saline, 9 mg mL(-1) pH 6) on the contralateral side. Two minutes thereafter a bilateral simultaneous injection of 0·5 mL acidic saline followed. The evoked pain intensity, pain duration, pain area and PPT were assessed. The volunteers returned 1 week later to re-assess VAS and PPT. On the side pre-treated with granisetron, the induced pain had significantly lower intensity and shorter duration (P < 0·05) compared with the side pre-treated with control. A subgroup analysis showed that the effect of granisetron on pain duration was significant only in women (P < 0·001), while the effect on peak pain and pain area were significant in both sexes. The results showed no significant change in PPT. In conclusion, these results indicate that granisetron has a pain-reducing effect on experimentally induced muscle pain by repeated acidic saline injection.