Journal of Oral & Facial Pain and Headache, 01/2021

Aims: To investigate whether localized sensitization of the sternocleidomastoid (SCM) muscle using nerve growth factor (NGF) would affect masseter and anterior temporalis muscle sensitivity and pain profiles. Methods: A total of 28 healthy participants attended two sessions (T0 and T1). At T0, the maximum voluntary occlusal bite force (MVOBF), as well as pressure pain thresholds (PPT), mechanical sensitivity, and referred pain/sensations for the SCM, masseter, and temporalis muscles, were assessed. Participants also completed the Pain Catastrophizing Scale (PCS), the Pain Vigilance and Awareness Questionnaire (PVAQ), and the Neck Disability Index (NDI). After these assessments, 14 participants received an injection of NGF into the SCM, and 14 received an injection of isotonic saline solution. At T1 (48 hours postinjection), the participants were again submitted to the same evaluations. Results: NGF caused significant mechanical sensitization in the SCM (P < .025), but not in the masseter or temporalis muscles (P > .208). It also caused significant increases in NDI score (P = .004). No statistically significant differences were found for MVOBF, frequency of referred pain/sensations, or questionnaire scores (P > .248). Conclusion: These results suggest that 48 hours after localized sensitization of the SCM, the primary response is impairment of neck function, but not jaw function. Keywords: behavior, masticatory muscles, musculoskeletal pain, neck pain, nerve growth factor

Aims: To review randomized clinical trials on arthrocentesis for managing temporomandibular disorders (TMD) and to discuss the clinical implications. Methods: On March 10, 2019, a systematic search of relevant articles published over the last 20 years was performed in PubMed, as well as in Scopus, the authors’ personal libraries, and the reference lists of included articles. The focus question was: In patients with TMD (P), does TMJ arthrocentesis (I), compared to any control treatment (C), provide positive outcomes (O)? Results/ Conclusion: Thirty papers were included comparing TMJ arthrocentesis to other treatment protocols in patients with disc displacement without reduction and/or closed lock (n = 11), TMJ arthralgia and/or unspecific internal derangements (n = 8), or TMJ osteoarthritis (n = 11). In general, the consistency of the findings was poor because of the heterogenous study designs, and so caution is required when interpreting the meta-analyses. In summary, it can be suggested that TMJ arthrocentesis improves jaw function and reduces pain levels, and the execution of multiple sessions (three to five) is superior to a single session (effect size = 1.82). Comparison studies offer inconsistent findings, with the possible exception of the finding that splints are superior in managing TMJ pain (effect size = 1.36) compared to arthrocentesis, although this conclusion is drawn from very heterogenous studies (I2 = 94%). The additional use of cortisone is not effective for improving outcomes, while hyaluronic acid or platelet-rich plasma positioning may have additional value according to some studies. The type of intervention, the baseline presence of MRI effusion, and the specific Axis I diagnosis do not seem to be important predictors of effectiveness, suggesting that, as in many pain medicine fields, efforts to identify predictors of treatment outcome should focus more on the patient (eg, age, psychosocial impairment) than the disease. Keywords: arthrocentesis, disc displacement, osteoarthritis, temporomandibular disorders, temporomandibular joint

Aims: To test the feasibility and acceptability of a customized six-session cognitive behavioral therapy (CBT) group intervention for adults with recurrent trigeminal neuralgia (TN). Methods: Fifteen participants with TN were recruited from a specialist facial pain unit in London, United Kingdom. The effects of the group intervention were evaluated using validated self-report measures, which the participants completed before and after the intervention and at 1-month and 9-month follow-ups. A semi-structured interview was also used at the 1-year follow-up to gather qualitative feedback of the group intervention. Results: Participants reported an increase in confidence in managing everyday tasks in the presence of TN symptoms, a reduction in negative beliefs about pain, and an increase in engagement in meaningful activity. All patients completed the group intervention (100% retention rate). Qualitative feedback highlighted that the group CBT intervention was helpful, and no participants reported a worsening of mood or experience as a result of the intervention. Conclusion: The trends for improvement in several domains, plus the positive experiences of the participants, suggest that a CBT management program is acceptable and feasible for this population and should be further developed and implemented on a larger scale to determine its clinical efficacy. Keywords: cognitive behavioral therapy, facial pain, fear, pain management, multidisciplinary, patient satisfaction, quality of life, trigeminal neuralgia

Aims: To evaluate the diagnostic value of non–nerve-selective MRI sequences in posttraumatic trigeminal neuropathic pain (PTNP). Methods: This study retrospectively analyzed all MRI protocols performed between February 2, 2012 and June 20, 2018 commissioned by the Department of Oral and Maxillofacial Surgery, University Hospitals Leuven. Demographic, clinical, and radiologic data were extracted from the records of patients with an MRI in the context of PTNP. A contingency table was constructed based on the opinions of the treating physician and the radiologist who initially evaluated the MRI. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated. Results: The sample consisted of 27 women (65.9%) and 14 men (34.1%). The sensitivity and negative predictive value of MRI in PTNP were 0.18 and 0.77, respectively. Artifacts interfered with visualization of a possible cause of the trigeminal pain in 24.4% of MRIs. Almost all artifacts (90%) were caused by metal debris originating from the causal procedure or posttraumatic surgeries. MRI resulted in changed management for PTNP patients only once. Conclusion: The diagnostic value of non–nerve-selective MRI sequences for PTNP is low and has little impact on clinical management. Therefore, there is a need for dedicated sequences with high resolution and low artifact susceptibility for visualizing the posttraumatic injuries of the trigeminal branches. Keywords: magnetic resonance imaging, trigeminal nerve, trigeminal nerve injuries

Aims: To investigate the associations between temporomandibular disorders (TMDs) and sleep disorders in adult subjects. Methods: The PubMed, Embase, Evidence-Based Medicine Reviews, and ProQuest Dissertations & Theses databases were searched for studies published in English up to September 2019. Unpublished/gray literature and reference lists of identified articles were also examined. Inclusion criteria were male and female adults, presence or absence of a TMD based on the RDC/TMD or DC/TMD criteria, presence or absence of a sleep disorder according to the International Classification of Sleep Disorders, and any of the following study designs: cross-sectional, case-control, or longitudinal. Methodologic quality assessment was conducted using the National Heart, Lung, and Blood Institute quality assessment tools. Results: Twenty-two studies (11 cross-sectional, 9 case-control, 1 prospective cohort, and 1 mixed design) met the inclusion criteria. TMDs were assessed independently in relation to sleep bruxism (SB), obstructive sleep apnea (OSA), and sleep quality (SQ). All studies but one assessed TMDs using the RDC/TMD criteria. The relation between the TMD and the different sleep disorders was conflicting for SB and positive for OSA and SQ. Five studies were of good quality, and 17 were of fair quality. Conclusions: The evidence is inconclusive regarding the relationship between TMDs and SB and insufficient regarding the relationship with OSA. There is consistently fair evidence to support an association between TMD and SQ. This study highlights the need for higher-quality longitudinal studies to clarify the association between TMDs and sleep disorders. Keywords: adult, sleep apnea syndromes, sleep bruxism, systematic review, temporomandibular disorder

Aims: To clarify the mechanisms of hypersensitivity and spontaneous pain in intraoral structures in rats with diabetes mellitus (DM) accompanied by reduced saliva. Methods: Adult male Sprague-Dawley rats received a single injection of streptozocin (50 mg/kg) to induce DM. Saliva volume, intraoral hypersensitivity to menthol and capsaicin solutions, and head-withdrawal thresholds (HWTs) to noxious heat and mechanical stimulation of the tongue and whisker pad were measured. Results: On day 7 after streptozocin injection, rats with DM had a significantly reduced spontaneous saliva volume, polydipsia, capsaicin aversion of the intraoral mucosa, and a reduced HWT to noxious mechanical stimulation of the whisker pad skin. The HWT to noxious mechanical stimulation of the tongue reduced further on day 14 after streptozocin injection. These symptoms are similar to the orofacial and intraoral complaints of patients with DM. Meanwhile, reduction of HWT to noxious heat stimulation of the tongue and whisker pad were not observed. These results indicate that spontaneous intraoral mucosal pain and mechanical facial hypersensitivity are antecedent symptoms before mechanical hypersensitivity of the tongue. Conclusion: The mechanisms of saliva reduction, spontaneous intraoral mucosa pain, and mechanical hypersensitivity of intraoral and facial structures induced by DM involve both peripheral and autonomic neuropathies. Tongue hypersensitivity to noxious mechanical stimulation might be aggravated by xerostomia. Keywords: capsaicin aversion, diabetes mellitus, intraoral pain, mechanical hypersensitivity, xerostomia

Aims: To investigate perceived expressed emotion (EE) and self-esteem in adolescents with primary headaches and to assess the psychologic factors, especially perceived EE, that may play a mediating role in the relationship between pain severity and psychosocial quality of life (QoL). Methods: The sample of this single-center cross-sectional case-control study consisted of 102 adolescents with migraine without aura, 36 adolescents with tension-type headache (TTH), 62 age- and sex-matched healthy adolescents, and their parents. Perceived EE was evaluated with the Shortened Level of Expressed Emotion Scale (SLEES). The Rosenberg Self-Esteem Scale (RSS) was used to assess the self-esteem of the participants. Results: There were significant differences in both SLEES (F [2.199] = 7.913, P < .001) and RSS (F [2.199] = 8.138, P < .001) scores between the groups. When the two groups were compared in terms of SLEES score, adolescents with migraine and TTH had significantly higher levels of perceived EE and lower levels of self-esteem than their healthy peers. In mediation analyses, RSS and SLEES scores were found to be partial mediating factors in the relationship between pain severity and psychosocial QoL. Conclusion: Adolescents with migraine and TTH had higher perceived EE and lower selfesteem than their healthy peers. The most important result of this study was the demonstration that self-esteem and perceived EE can be two factors that play a mediating role in the relationship between headache and psychosocial QoL. Keywords: adolescents, migraine, perceived expressed emotion, self-esteem, tension-type headache

Aims: To investigate the effect of masticatory muscle contraction on the pressure pain threshold (PPT) of the lateral pole of the temporomandibular joint (TMJ) in patients with TMJ arthralgia and in asymptomatic individuals. Methods: A total of 72 individuals divided into two groups (group 1: patients with unilateral TMJ arthralgia [n = 36]; group 2: control group, asymptomatic individuals [n = 36]) were compared. The PPT of the lateral pole of the TMJ with and without concomitant masticatory muscle contraction was determined using a digital algometer in both groups. Paired and independent Student t test were used to compare the data within and between groups, respectively. A 5% significance level was used for all tests. Results: Higher TMJ PPT values with concomitant masticatory muscle contraction were found in both groups (P < .001). The amount of increase in PPT with contracted muscles was not significantly different between groups (P = .341), but the TMJ arthralgia group had significantly lower PPT values than the control group regardless of muscle contraction status (P < .001). Conclusion: Concomitant masticatory muscle contraction significantly increased the PPT of the lateral pole of the TMJ in relation to relaxed muscles, regardless of the presence of arthralgia. Keywords: pain, pressure pain threshold, temporomandibular joint, temporomandibular disorders