BACKGROUND: Temporomandibular disorders (TMDs) encompass a spectrum of orofacial conditions characterised by pain and dysfunction in the temporomandibular joint and surrounding structures. Tobacco smoking has been posited as a potential factor influencing the prevalence and intensity of TMD. However, the nature and extent of this relationship remain unclear due to variations in study outcomes. This systematic review aimed to consolidate existing research findings to elucidate the association between tobacco smoking and TMD pain intensity.
METHODS: A comprehensive search of electronic databases was conducted to identify relevant studies published up to June 2023. Studies investigating the relationship between tobacco smoking and TMD pain were included. Data extraction was conducted by two reviewers. Quality assessment was performed using the New Castle-Ottawa scale. Review Manager 5.4 was used to quantitatively analyse the results.
RESULTS: The review included four studies employing similar TMD assessment techniques. All studies reported elevated TMD pain intensity among tobacco users, with non-smokers exhibiting lower pain intensity. The quality of the included studies was good. Meta-analytic results showed that TMD pain intensity was higher in the smokers group compared to the non-smokers group, with a weighted mean difference (WMD) of 0.65 (BPM) (95% CI: [0.10, 1.19], p = .02).
CONCLUSIONS: This systematic review provides a comprehensive synthesis of the existing literature on tobacco smoking and TMD symptoms. The findings underscore the multifaceted nature of the relationship between smoking and TMD pain, highlighting its clinical relevance and the need for tailored interventions. Further research is warranted to elucidate underlying mechanisms and potential moderating factors, contributing to a more nuanced understanding of this complex association.

This study provided an overview of the knowledge on the main sleep-related disorders and conditions affecting the prognosis of dental treatment: sleep bruxism (SB), obstructive sleep apnea (OSA), and gastroesophageal reflux disease (GERD). Current scientific evidence seems to suggest that these phenomena (ie, SB, OSA, GERD) belong to a circle of mutually relating sleep disorders and conditions where dental practitioners can play a key role in diagnosis and treatment.

Chronic orofacial pain disorders are common debilitating conditions, affecting the trigeminal system. Its underlying pathophysiological mechanisms are still unclear and the therapy is often unsatisfactory, therefore, preclinical models are crucial to identify the key mediators and novel treatment options. Complete Freund\'s adjuvant (CFA)-induced orofacial inflammatory allodynia/hyperalgesia is commonly used in rodents, but it has not been validated with currently used drugs. Here we tested the effects of the adjuvant analgesic/antiepileptic voltage-gated Na+ channel blocker complex mechanism of action topiramate in comparison with the gold standard antimigraine serotonin 5-HT1B/D receptor agonist sumatriptan in this model. CFA was injected subcutaneously into the right whisker pad of male Sprague-Dawley rats (250-300 g), then mechanonociceptive threshold values were investigated with von Frey filaments (3, 5, and 7 days after CFA injection). Effects of topiramate (30 mg/kg per os) and sumatriptan (1 mg/kg subcutaneous) on the adjuvant-induced chronic inflammatory orofacial allodynia were investigated 60, 120, and 180 min after the treatments each day. To determine the optimal concentration for drug effect analysis, we tested the effects of two different CFA-concentrations (1 and 0.5 mg/mL) on mechanonociceptive thresholds. Both concentrations of CFA induced a chronic orofacial allodynia in 60% of all rats. Although, higher CFA concentration induced greater allodynia, much more stable threshold reduction was observed with the lower CFA concentration: on day 3 the thresholds decreased from 18.30 g to approximately 11 g (low) and 5 g (high), respectively, however a slight increase was observed in the case of higher CFA concentration (on days 5, 7, and 11). In all investigation days, topiramate showed significant anti-allodynic effect comparing the pre and post drug dose and comparing the vehicle treated to the drug treated groups. Sumatriptan also caused a significant threshold increase compared to pre dose thresholds (day 3) and also showed a slight anti-allodynic effect compared to the vehicle-treated group (day 3 and 5). In the present study CFA-induced chronic orofacial allodynia was reversed by topiramate in rats validating the model with the adjuvant analgesic. Other than establishing a validated orofacial pain-related syndrome model in rats, new ways are opened for the repurposing of topiramate.

BACKGROUND: Inhibition of astrocytic energy metabolism alleviates neuropathic pain.
OBJECTIVE: To explore whether astrocyte-neuron lactate shuttle (ANLS) played any role in neuropathic orofacial pain.
METHODS: Rats with partial transection of the right infraorbital nerve (p-IONX) or sham operation were intrathecally injected with acetazolamide (a carbonic anhydrase inhibitor), bithionol (a soluble adenylyl cyclase inhibitor), α-cyano-4-hydroxycinnamic acid [α-CHCA, a monocarboxylate transporter (MCT) inhibitor] or vehicle once a day from postoperative day 1-14. The facial mechanical thresholds were tested on preoperative day 1 and 2 and postoperative days 1, 3, 5, 7, 10 and 14, expression of glucose transporters (GLUTs) and MCTs in the trigeminal subnucleus caudalis (Vc) were examined on the postoperative day 3 and neuronal activities in the Vc were examined in the p-IONX rats on postoperative days 3-5.
RESULTS: Compared with the sham group, the mechanical thresholds in the p-IONX group were significantly reduced at postoperative days 1-7, and the number of astrocytes expressing GLUT1 and MCT1/4, and neurons expressing MCT2 was significantly increased on postoperative day 3. In the p-IONX groups, neurons in the Vc were sensitised, and acetazolamide, bithionol and α-CHCA reversed the central sensitisation, significantly increased the mechanical thresholds at postoperative days 1-7 and decreased the number of astrocytes expressing GLUT1 and MCT1/4, and neurons expressing MCT2 at postoperative day 3 compared with those in the vehicle-treated rats.
CONCLUSIONS: Inhibition of ANLS alleviates p-IONX-related neuronal, behavioural and immunohistochemical changes, which suggests that ANLS plays an important role in trigeminal neuropathic pain.

BACKGROUND: The reduction in joint load is a potential beneficial factor in managing osteoarthritis of the temporomandibular joint (TMJ). This paper aims to compare the effectiveness of the intramuscular injection of botulinum toxin (BTX-A) as an adjunct to TMJ arthrocentesis plus viscosupplementation with arthrocentesis plus viscosupplementation alone in the management of TMJ osteoarthritis.
METHODS: A pilot clinical retrospective study examined TMJ osteoarthritis treatments. Patients were divided into two groups: Group A received BTX-A injections and arthrocentesis with viscosupplementation, while Group B received only arthrocentesis with viscosupplementation. The study assessed outcomes based on mouth opening (MO), pain at rest (PR), pain at mastication (PF), and masticatory efficiency (ME) at various time points (baseline (T0), 1 week (T1), 2 weeks (T2), 3 weeks (T3), and 4 weeks (T4)) up to 2 months after treatment.
RESULTS: The study included two groups, each with five patients. Group A received five weekly sessions of arthrocentesis plus viscosupplementation and a single BTX-A injection during the first arthrocentesis appointment. Group B underwent the five-session protocol of arthrocentesis plus viscosupplementation alone. MO, PF, PR, and ME improved quickly in T2 in both groups, but the improvement was of greater importance over the following weeks and lasted longer in Group A.
CONCLUSIONS: Arthrocentesis with viscosupplementation associated with BTX-A was found to be more effective than arthrocentesis alone in improving clinical outcomes. This suggests that patients with TMJ osteoarthritis and myofascial pain may benefit from reduced muscle tone and joint load.

BACKGROUND: Temporomandibular disorders (TMDs) frequently cause orofacial pain and dysfunction, with treatment options spanning from conservative therapies to invasive surgical procedures. The aim of this systematic review was to analyze and compare the efficacy and safety profiles of conservative, minimally invasive interventions and surgical procedures in patients diagnosed with TMDs and disc displacement.
METHODS: Following PRISMA recommendations, PubMed, Scopus, and Web of Science databases were searched for randomized clinical trials (RCT). Data were synthesized in a table and evaluated through the Cochrane risk of bias 2 (RoB 2) tool.
RESULTS: Thirty-eight RCTs, most with moderate RoB, were selected. Conservative approaches, including physical therapy and occlusal devices, led to an improvement in symptoms and function. Pharmacological treatments demonstrated effectiveness in reducing pain and improving function; however, they can have undesirable side effects. Minimally invasive and invasive treatments also demonstrated efficacy, although most trials did not show their superiority to conservative treatments.
CONCLUSIONS: The primary approach to TMDs should be a conservative, multimodal treatment plan tailored to patient complaints and characteristics. Treatment goals should focus on symptom control and functional recovery. Surgical treatment should be reserved for cases with a precise diagnosis and a clear etiology.

OBJECTIVE: The aim was to design accessible, simple, inexpensive protection for teeth and soft tissues during ETI, compare damage occurrence with and without protection, and investigate post-ETI orofacial pain symptoms.
METHODS: The selection procedure for adequate protection was carried out after which a reduced elastomer mouthguard was selected. Fifty patients were divided into 2 groups. In the first group, ETI was carried out using a mouthguard, while in the second group it was performed without it. The mouthguard was fabricated by anesthesiologists. After the ETI procedure, the patients and anesthesiologists were asked to complete a survey.
RESULTS: No difference in intubation severity and time required for intubation between the two groups was present. Seven patients from the non-mouthguard group suffered injuries during the ETI procedure. No injuries were present in the mouthguard group. In 92% of cases anesthesiologists agreed that mouthguards should be used during ETI. However, most of them (96% of cases) agree that the mouthguard should be used only when there is an increased risk of tooth loss and/or tooth damage. There was a significant ETI effect on the emergence of new orofacial pain cases.
CONCLUSIONS: The mouthguard adequately protected dental and soft tissues and did not affect the work of the anesthesiologist. A significantly higher number of patients experiencing temporomandibular joint and masticatory muscles pain after surgery indicates that ETI might be a risk factor for orofacial pain.

OBJECTIVE: Temporomandibular disorders (TMD) are the most common nonodontogenic cause of orofacial pain, leading to morbidity and impairment. TMD presents a diagnostic challenge due to many aetiologies that exhibit comparable symptoms and refer pain to the temporomandibular joint (TMJ) region. Patients may be referred to dental specialists without accounting for all pain sources. This study aims to identify radiographic confounders (RCs) that can be mistaken for TMD in patients undergoing TMJ assessment using cone-beam computed tomography (CBCT).
METHODS: A review of 369 CBCT oral maxillofacial radiology reports of the TMJ acquired between July 2020 and June 2023 was completed. Pertinent RCs were classified as endodontic lesions, impacted dentition, sinus pathologies, root fractures, soft tissue calcifications, and others. The chi-squared test assessed the significance of the relationship between RCs and patient variables.
RESULTS: A total of 283 RCs were identified in 202 of the 369 cases (54.7%). The most frequent findings included sinus abnormalities (32.5%), endodontic lesions (15.2%), impacted dentition (12.7%), and elongated/calcified stylohyoid process (9.2%). Significant associations were found between sinus pathologies with TMD signs (P = .009) and gender (P = .001).
CONCLUSIONS: Our results indicate that RCs that mimic TMD-related symptoms are prevalent in patients referred for TMJ CBCT imaging.
CONCLUSIONS: Clinicians should be aware of these RCs when diagnosing complaints related to the TMJ. We recommend clinicians first obtain dental clearance and investigate all other potential sources of a patient\'s complaint before initiating referrals to avoid unnecessary costs and delays in patient care.

BACKGROUND: COVID-19 infection shows variant symptoms apart from respiratory symptoms, including the orofacial pain. We aim to research the morbidity, characteristics and potential risk factors of orofacial pain associated with COVID-19 pandemic in China from December 2022 to early 2023.
METHODS: A cross-sectional survey was conducted in Fujian Province, China. The demographic and characteristic data of the subjects were collected and analysed.
RESULTS: A total of 1526 subjects responded to the survey. The morbidity of orofacial pain increased significantly before and after COVID-19 infection. (42.26% vs. 46.52%, P < .001) A total of 217 (14.22%) subjects with orofacial pain before COVID-19 infection reported the phenomenon of \"COVID-19 infection with orofacial pain\" (CIOP). Univariate and multivariate logistic regression showed that male (OR = 1.761, P < .001) and other symptoms of COVID-19 (OR = 1.494, P < .001) may be the risk factors for the aggravation of CIOP, while the time of first infection (OR = 0.580, P = .004) and preference for drinking tea or coffee (OR = 0.610, P = .003) may be the protective factors for the aggravation of CIOP. While, the subjects who did not concern about the spread of COVID-19 in oral treatment (OR = 0.639, P = .001), female (OR = 0.749, P = .03), education level (OR = 1.687, P < .001) and income level (OR = 1.796, P < .001), higher PSS-10 score (OR = 1.076, P < .001), and more drugs taken for infection (OR = 1.330, P < .001) were more willing to seek medical treatment.
CONCLUSIONS: The morbidity of orofacial pain appears to have increased significantly due to the COVID-19 epidemic; a number of factors can influence the CIOP including gender, infection period, and beverage preference\' psychological factors, gender, education and income level can also influence the intent to seek a dentist.

Virtual reality (VR) has emerged as a nonpharmacological adjuvant to manage acute and chronic pain symptoms. The goal of this survey study was to determine the acceptability of VR among chronic pain participants hailing from distressed and prosperous neighborhoods in the state of Maryland. We hypothesized that pain severity and interference vary in groups experiencing health disparities, potentially influencing VR\'s acceptability. From March 11 to March 15, 2020, we surveyed a cohort of clinically phenotyped participants suffering from chronic orofacial pain. Participants were asked to express their willingness to participate in a longitudinal VR study and their expectation of pain relief from using VR. Seventy out of 350 participants with chronic pain completed the survey (response rate: 20%). There was no difference in the likelihood of responding to the survey based on their neighborhood distress. Among survey respondents and nonrespondents, similar proportions of participants were from distressed neighborhoods. Among the respondents, 63 (90%) and 59 (84.3%) were willing to participate and expected to experience pain relief from the VR intervention, respectively. Age, sex, race, neighborhood distress, severity of pain, and prior VR experience did not influence willingness to participate in the VR trial or the expectations of VR-induced improvement. These findings suggest that VR as an adjuvant intervention is potentially accepted by chronic pain participants, irrespective of neighborhood-level social determinants of health.