Capsaicin-induced secondary hyperalgesia differences between the trigeminal and spinal innervation.

This study compared the degree of secondary hyperalgesia and somatosensory threshold changes induced by topical capsaicin between spinal and trigeminal innervation. This crossover clinical trial included 40 healthy individuals in which 0.25 g of 1% capsaicin cream was randomly applied for 45 minutes to a circular area of 2 cm to the skin covering the masseter muscle and forearm in 2 different sessions, separated by at least 24 hours and no more than 72 hours (washout period).

Expectation of analgesia increases the inhibitory response of conditioned pain modulation in healthy participants who at baseline have a non-inhibitory profile.

Background: This study assessed the effect of expectation of analgesia on conditioned pain modulation (CPM) in healthy participants stratified into inhibitors and non-inhibitors.

Methods: A parallel CPM protocol was assessed on 21 women and 22 men across two sessions: baseline and expectation of analgesia, which was induced by a standardized audiovisual suggestion. The CPM assessment involved two different test stimuli (TS): mechanically controlled palpation and the pressure pain threshold, applied to two different regions: anterior temporalis and thenar eminence of the hand.

Auriculotemporal neuralgia overlapped with chronic orofacial myofascial pain: A case report of a challenging diagnosis.

Aim: Auriculotemporal neuralgia (AN) is a rare condition characterized by severe, stabbing, unilateral pain inadequately described in the literature. Often coexisting with other conditions sharing the same innervation, and this overlap complicates clinical interpretation, leading to diagnostic errors and inappropriate therapeutic choices. The absence of AN in headache and facial pain diagnostic criteria hampers access to crucial information for diagnostic reasoning.

Synovial Sarcoma of the Temporomandibular Joint and Infratemporal Fossa: A Case Report.

Temporomandibular joint (TMJ) and infratemporal fossa (ITF) tumors, even though rare, present diagnostic complexities due to their nonspecific symptoms. Synovial sarcoma comprises 5-10% of adult soft-tissue sarcomas and is uncommon in the head and neck and exceptionally rare in the TMJ/ITF region. We presented a case of monophasic synovial sarcoma affecting the left TMJ/ITF in a 24-year-old man with severe preauricular pain who was misdiagnosed with temporomandibular disorder for 3 years.

Central sensitization inventory is associated with psychological functioning but not with psychophysical assessment of pain amplification.

Background: The central sensitization inventory (CSI) is a questionnaire that has been widely used as a tool for assessing symptoms associated with sensitization. However, its ability to identify individuals with this phenomenon has recently been questioned. The aim of this study was to assess the correlation of CSI with psychosocial and psychophysical factors in patients with painful TMD diagnosed according to diagnostic criteria for temporomandibular disorders (DC/TMD) and asymptomatic controls, as well as to determine the influence of these variables on the CSI scores variations.

Impact of streptozotocin-induced diabetes on experimental masseter pain in rats.

This study aimed to assess the influence of streptozotocin (STZ)-induced diabetes on the nociceptive behavior evoked by the injection of hypertonic saline (HS) into the masseter muscle of rats. Forty male rats were equally divided into four groups: a) isotonic saline control, which received 0.9% isotonic saline (IS), (Ctrl-IS); b) hypertonic saline control, which received 5% HS (Ctrl-HS); c) STZ-induced diabetic, which received IS, (STZ-IS); d) STZ-induced diabetic, which received HS (STZ-HS).

Somatosensory alterations after single-unit dental implant immediate loading: A 1-year follow-up study.

Objective: This cohort study aimed to assess the incidence of somatosensory alterations after implant surgery using standardized quantitative and qualitative sensory testing.

Methods: 33 participants with single-tooth loss, undergoing immediate implant loading were included. Quantitative Sensory Testing (QST) and Qualitative Sensory Testing (QualST) were conducted at eight time points over a year (baseline to 1 year).

Referred pain is associated with greater odontogenic spontaneous pain and a heightened pain sensitivity in patients with symptomatic irreversible pulpitis.

Background: Symptomatic irreversible pulpitis often results in heightened reactions to thermal stimuli such as pain evoked by a cold stimulus, and spontaneous odontogenic pain (unprovoked pain).

Objective: This study primarily compared the clinical manifestations of odontogenic spontaneous pain and pain provoked by cold stimulus specifically focusing on their sensory discriminative characteristics (intensity, duration and quality) between symptomatic irreversible pulpitis patients with and without referred pain.

Methods: Twenty-three patients with symptomatic irreversible pulpitis with referred pain and 12 patients without referred pain were included in this cross-sectional study.

Nutrition and chronic musculoskeletal pain: A narrative review and directions for temporomandibular disorder research and management.

Background: Recent evidence suggests neuro-immune mechanisms may link dietary patterns to chronic painful conditions (CPC). In the research field of oro-facial pain (OFP), studies focuses primarily on dietary mechanical limitations due to pain and dysfunction.

Objective: This narrative review aimed to overview the role of nutrition on CPC, with emphasis on temporomandibular disorder (TMD), enlightening OFP researcher on dietary assessment possibilities and providing directions for studies in the field of OFP and nutrition.

Influence of psychometric and sleep quality features on painful mechanical sensitivity and pain modulation in patients with temporomandibular disorders.

Unlabelled: Investigating the collective impact of psychometric properties and sleep quality on pain sensitivity in temporomandibular disorder (TMD) patients could improve clinical management strategies.

Objective: Assessing whether combined psychometric properties and sleep quality impact painful mechanical sensitivity and pain modulation in TMD patients.

Materials And Methods: A cross-sectional study using secondary data analysis of 77 TMD patients and 101 controls.

Botulinum toxin-A effects on pain, somatosensory and psychosocial features of patients with refractory masticatory myofascial pain: a randomized double-blind clinical trial.

The antinociceptive effect of BoNT-A have been well documented in animal studies; however, results of few but well-designed randomized placebo-controlled clinical trials about BoNT-A efficacy in masticatory myofascial pain (MFP) are inconsistent. Therefore, the present randomized, double-blind, placebo-controlled clinical trial evaluated the efficacy of BoNT-A in patients with refractory MFP. Twenty-eight patients with pain reduction of less than 30% despite conservative treatment and with an average pain intensity of > 50 mm on the visual analogue scale (VAS) participated.

Prediction of duloxetine efficacy in addition to self-management in painful temporomandibular disorders: A randomised, placebo-controlled clinical trial.

Background: Conditioned pain modulation (CPM) is a potential predictor of treatment response that has not been studied in temporomandibular disorders (TMD).

Objectives: We conducted a randomised, double-blind, placebo-controlled trial (RCT) of duloxetine in addition to self-management (SM) strategies to investigate its efficacy to reduce pain intensity in painful TMD patients. Moreover, we investigated whether baseline CPM would predict the duloxetine efficacy to reduce TMD pain intensity.

Divergence between confidence and knowledge of endodontists regarding non-odontogenic pain.

Introduction: This study aimed to assess the self-reported levels of confidence and knowledge related to non-odontogenic pain among a group of Brazilian endodontists.

Methodology: A total of one hundred and forty-six endodontists affiliated with the Brazilian Society of Endodontics participated in the survey. The questionnaire, distributed via email or WhatsApp, contained inquiries designed to gauge self-perceived confidence and knowledge concerning non-odontogenic pain.

Secondary bruxism: A valid diagnosis or just a coincidental finding of additional masticatory muscle activity? A narrative review of literature.

Introduction: Bruxism is defined as a repetitive masticatory muscle activity that can manifest it upon awakening (awake bruxism-AB) or during sleep (sleep bruxism-SB). Some forms of both, AB and SB can be associated to many other coexistent factors, considered of risk for the initiation and maintenance of the bruxism. Although controversial, the term 'secondary bruxism' has frequently been used to label these cases.

Research routes on awake bruxism metrics: Implications of the updated bruxism definition and evaluation strategies.

Background: With time, due to the poor knowledge on it epidemiology, the need to focus on awake bruxism as a complement of sleep studies emerged.

Objective: In line with a similar recent proposal for sleep bruxism (SB), defining clinically oriented research routes to implement knowledge on awake bruxism (AB) metrics is important for an enhanced comprehension of the full bruxism spectrum, that is better assessment and more efficient management.

Methods: We summarised current strategies for AB assessment and proposed a research route for improving its metrics.

Catastrophizing and Hypervigilance Influence Subjective Sleep Quality in Painful TMD Patients.

To determine sleep quality and associated factors in a group of patients with painful TMDs. The medical records of 80 patients with arthralgia and/or myofascial pain were reviewed and compared to a healthy control group. Data about sex, age, subjective pain, physical activity, social activity, subjective sleep quality (Pittsburgh Sleep Quality Index [PSQI]), pain vigilance (Pain Vigilance and Awareness Questionnaire [PVAQ]), and pain catastrophizing (Pain Catastrophizing Scale [PCS]) were collected.

Ecological Momentary Assessment of Awake Bruxism Behaviors: A Scoping Review of Findings from Smartphone-Based Studies in Healthy Young Adults.

Background: The recent introduction of ecological momentary assessment (EMA) smartphone-based strategies has allowed achieving some interesting data on the frequency of different awake bruxism (AB) behaviors reported by an individual in the natural environment.

Objective: The present paper aims to review the literature on the reported frequency of AB based on data gathered via smartphone EMA technology.

Methods: On September 2022, a systematic search in the Pubmed, Scopus and Google Scholar databases was performed to identify all peer-reviewed English-language studies assessing awake bruxism behaviors using a smartphone-based Ecological Momentary Assessment.

Long-Term Effects of a Single Application of Botulinum Toxin Type A in Temporomandibular Myofascial Pain Patients: A Controlled Clinical Trial.

This study assessed the long-term effects of botulinum toxin type A (BoNT-A) in subjective pain, pain sensibility, and muscle thickness in persistent myofascial temporomandibular-disorder pain (MFP-TMD) patients. Fourteen female subjects with persistent MFP received BoNT-A treatment with different doses (10U-25U for temporalis muscle and 30U-75U for masseter muscle). The treatment was injected bilaterally in the masseter and anterior temporalis muscles in a single session.

Influence of genetic polymorphisms on mechanical pain sensitivity and endogenous pain modulation of trigeminal and spinal areas.

Background: Previous evidence indicates significant association between genetic polymorphisms and phenotypes related to pain sensitivity in patients with temporomandibular disorders (TMD). Despite the important advances in cataloguing diverse factors such as sleep disorders, anxiety and depression, the interrelated mechanisms of painful TMD aetiopathogenesis still need investigation.

Objectives: This case-control study aimed to evaluate the influence of genetic polymorphisms (rs6296, rs6295, rs1799971, rs4680, rs4633, rs4818) and psychosocial factors on the mechanical pain sensitivity and endogenous pain modulation in women with painful TMD and asymptomatic controls.

Who is the individual that will complain about temporomandibular joint clicking?

Background: Understanding the profile of the individual complaining of TMJ clicking can help in the clinical approach of these patients.

Objective: To identify clinical variables associated with individuals who complain about and seek treatment for TMJ clicking.

Methods: Seventy-two individuals, composed the sample: Group 1 - patients with a complaint of TMJ clicking who sought treatment; (n = 36); Group 2 - individuals with TMJ clicking who have no complaints about it (n = 36).

The hierarchy of different treatments for myogenous temporomandibular disorders: a systematic review and network meta-analysis of randomized clinical trials.

The best treatment modality for the management of painful temporomandibular disorders of muscular origin (M-TMD) with predictable outcomes based on solid evidence is still not well defined. Thus, the aim of this network meta-analysis (NMA) was to identify the best treatment for adult patients with M-TMD. An electronic search was undertaken from the inception of each database to August 2018, to identify randomized clinical trials (RCTs), which are comparing two or more of the following treatment modalities in patients with M-TMD: counseling therapy; occlusal appliances; manual therapy; laser therapy; dry needling; intramuscular injection of local anesthesia (LA) or botulinum toxin-A (BTX-A); muscle relaxants; hypnosis/relaxation therapy; oxidative ozone therapy; and placebo or no treatment.

Oral behaviors, bruxism, malocclusion and painful temporomandibular joint clicking: is there an association?

The present cross-sectional case-control study aimed to determine if there is an association between specific oral behaviors, sleep bruxism (SB), awake bruxism (AB), and painful temporomandibular joint (TMJ) clicking. Ninety individuals were dived into three groups; Group 1 (n = 30): painful TMJ clicking; Group 2 (n = 30): painless TMJ clicking; and Group 3 (n = 30): control group. The following clinical data were studied: oral behaviors (unilateral chewing, gum chewing, nail biting, foreign objects biting, leaning with jaw against the hand, and sleeping in a position that pressures the jaw), SB, AB (including the frequency in 10 days, evaluated by ecological momentary assessment), and malocclusions investigated based on clinical inspections (anterior open bite, posterior cross-bite, abnormal overbite/overjet, occlusal guidance, mediotrusive and/or laterotrusive interferences, retruded contact position to maximum intercuspation slide, missing posterior teeth).

Association of sleep quality and psychological aspects with reports of bruxism and TMD in Brazilian dentists during the COVID-19 pandemic.

Background: Dentists are exposed to contamination by SARS-CoV-2 due to dental interventions, leading to a state of alert and potential risk of negative impact in mental health and sleep quality, associated with Temporomandibular Disorder (TMD) and bruxism.

Objective: to evaluate the psychosocial status, sleep quality, symptoms of TMD, and bruxism in Brazilian dentists (DSs) during the COVID-19 pandemic.

Methodology: The sample (n=641 DSs) was divided into three groups (quarantined DSs; DSs in outpatient care; and frontline professionals), which answered an electronic form containing the TMD Pain Screening Questionnaire (Diagnostic Criteria for Temporomandibular Disorders - DC/TMD), the Pittsburgh Sleep Quality Index (PSQI), the Depression, Anxiety and Stress Scale (DASS-21), and the sleep and awake bruxism questionnaire.