'Temporomandibular disorders' is an umbrella term for disorders of the temporomandibular joints, the masticatory muscles, and the adjacent anatomical structures. On behalf of the International Network for Orofacial Pain and Related Disorders Methodology, this article gives an overview of key points for good clinical practice in the field of temporomandibular disorders. During an annual conference in March 2024, members of the aforementioned network drew up a list of 10 core principles. These core principles include knowledge about the causes, diagnosis and treatment of temporomandibular disorders. They summarize the current standard of care for the treatment of such conditions and are in keeping with the need to help increase the expertise of dentists working in general practice and to prevent incorrect treatment. The core principles can be regarded as a starting point for other national and international organisations to use to develop guidelines and recommendations for the treatment of temporomandibular disorders.

Supplemental Digital Content is Available in the Text.This study demonstrates that the ketogenic diet can be used as a complementary approach for treating opioid-induced hyperalgesia. Opioids are commonly prescribed to patients with chronic pain. Chronic opioid usage comes with a slew of serious side effects, including opioid-induced hyperalgesia (OIH). The patients with long-term opioid treatment experience paradoxical increases in nociceptive hypersensitivity, namely, OIH. Currently, treatment options for OIH are extremely lacking. In this study, we show that the ketogenic diet recovers the abnormal pain behavior caused by chronic morphine treatment in male mice, and we further show that the therapeutic effect of the ketogenic diet is mediated through gut microbiome. Our 16S rRNA sequencing demonstrates that chronic morphine treatment causes changes in mouse gut microbiota, specifically a decrease in short-chain fatty acids-producing bacteria, and the sequencing data also show that the ketogenic diet rescues those bacteria in the mouse gut. More importantly, we show that supplementation with short-chain fatty acids (butyrate, propionate, and acetate) can delay the onset of OIH, indicating that short-chain fatty acids play a direct role in the development of OIH. Our findings suggest that gut microbiome could be targeted to treat OIH, and the ketogenic diet can be used as a complementary approach for pain relief in patients with chronic opioid treatment. We only used male mice in this study, and thus, our findings cannot be generalized to both sexes.

OBJECTIVE:To present a list of key points for good Temporomandibular Disorders (TMDs) clinical practice on behalf of the International Network for Orofacial Pain and Related Disorders Methodology (INfORM) group of the International Association for Dental, Oral and Craniofacial Research (IADR). METHODS:An open working group discussion was held at the IADR General Session in New Orleans (March 2024), where members of the INfORM group finalized the proposal of a list of 10 key points. RESULTS:The key points covered knowledge on the etiology, diagnosis, and treatment. They represent a summary of the current standard of care for management of TMD patients. They are in line with the current need to assist general dental practitioners advance their understanding and prevent inappropriate treatment. CONCLUSIONS:The key points can be viewed as a guiding template for other national and international associations to prepare guidelines and recommendations on management of TMDs adapted to the different cultural, social, educational, and healthcare requirements.

The management of patients with orofacial pain and temporomandibular disorders is challenging. Recognizing the opportunity to advance patient care, in 2019 the National Academies of Science, Engineering, and Medicine (NASEM) convened representatives from the Food and Drug Administration, Medical Device Epidemiology Network (MDEpiNet), patient advocacy groups, oral and maxillofacial surgeons, and orofacial pain experts to identify specific steps to improve care for patients. In response, the American Association of Oral and Maxillofacial Surgeons (AAOMS) created the Special Committee on Temporomandibular Joint Care (SCTMJC) whose assignment was to develop contemporary evidence-based guidelines for the management of patients with orofacial pain and temporomandibular disorders. These guidelines represent the findings and recommendations of that committee.

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.RESULTS:Most of the literature focuses on bruxism in general or SB in particular, whilst knowledge on AB is generally fragmental. Assessment can be based on non-instrumental or instrumental approaches. The former include self-report (questionnaires, oral history) and clinical examination, whilst the latter include electromyography (EMG) of jaw muscles during wakefulness as well as the technology-enhanced ecological momentary assesment (EMA). Phenotyping of different AB activities should be the target of a research task force. In the absence of available data on the frequency and intensity of wake-time bruxism-type masticatory muscle activity, any speculation about the identification of thresholds and criteria to identify bruxers is premature. Research routes in the field must focus on the improvement of data reliability and validity.CONCLUSIONS:Probing deeper into the study of AB metrics is a fundamental step to assist clinicians in preventing and managing the putative consequences at the individual level. The present manuscript proposes some possible research routes to advance current knowledge. At different levels, instrumentally based and subject-based information must be gathered in a universally accepted standardised approach.

OBJECTIVE:This paper aims to present and describe the Standardised Tool for the Assessment of Bruxism (STAB), an instrument that was developed to provide a multidimensional evaluation of bruxism status, comorbid conditions, aetiology and consequences.METHODS:The rationale for creating the tool and the road map that led to the selection of items included in the STAB has been discussed in previous publications.RESULTS:The tool consists of two axes, specifically dedicated to the evaluation of bruxism status and consequences (Axis A) and of bruxism risk and etiological factors and comorbid conditions (Axis B). The tool includes 14 domains, accounting for a total of 66 items. Axis A includes the self-reported information on bruxism status and possible consequences (subject-based report) together with the clinical (examiner report) and instrumental (technology report) assessment. The Subject-Based Assessment (SBA) includes domains on Sleep Bruxism (A1), Awake Bruxism (A2) and Patient's Complaints (A3), with information based on patients' self-report. The Clinically Based Assessment (CBA) includes domains on Joints and Muscles (A4), Intra- and Extra-Oral Tissues (A5) and Teeth and Restorations (A6), based on information collected by an examiner. The Instrumentally Based Assessment (IBA) includes domains on Sleep Bruxism (A7), Awake Bruxism (A8) and the use of Additional Instruments (A9), based on the information gathered with the use of technological devices. Axis B includes the self-reported information (subject-based report) on factors and conditions that may have an etiological or comorbid association with bruxism. It includes domains on Psychosocial Assessment (B1), Concurrent Sleep-related Conditions Assessment (B2), Concurrent Non-Sleep Conditions Assessment (B3), Prescribed Medications and Use of Substances Assessment (B4) and Additional Factors Assessment (B5). As a rule, whenever possible, existing instruments, either in full or partial form (i.e. specific subscales), are included. A user's guide for scoring the different items is also provided to ease administration.CONCLUSIONS:The instrument is now ready for on-field testing and further refinement. It can be anticipated that it will help in collecting data on bruxism in such a comprehensive way to have an impact on several clinical and research fields.

INTRODUCTION:Bruxism has historically been of particular interest to the field of dentistry, primarily due to the inferred damage it may cause to the dentition and supporting periodontal structures. The definition of bruxism itself has undergone multiple changes over time. In addition, the effects of bruxism as it relates to oro-facial pain conditions has remained a debatable topic.PURPOSE:To review the available literature relating to bruxism and non-temporomandibular disorder (TMD) pain conditions.METHODS:A literature search was conducted with the assistance of an expert librarian. The following databases were reviewed: PubMed, MEDLINE, EMBASE and Google Scholar. For additional references, articles were also retrieved by hand search from the selected papers. Any articles that were not published in English, or the focus were related to temporomandibular disorders were excluded.CONCLUSIONS:While bruxism and certain headache conditions do tend to occur together frequently, evidence relating to any clear common pathophysiological mechanism has yet to be fully elucidated. Robust evidence as it relates to the relationship between bruxism and other non-TMD oro-facial pains is also lacking.

The human temporomandibular joint, is a ginglymo-arthrodial joint. The articular disk serves as a fibrous, viscoelastic structure that allows force distribution and smooth movement of the joint in its normal arrangement during mandibular movements. Most studies suggest that in the normal disk position the posterior band is located at the 12'o clock position within the glenoid fossa in the closed mouth posture. When the biomechanics of the joint is altered, the disk may be displaced creating an abnormal relationship between the disk, condyle, and the eminence that is often referred to as an internal derangement. This article reviews the various presentations of internal derangements.

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.

Purpose It has become more apparent that studies focusing on the effect of sex steroids on orofacial pain in humans and animals require careful attention to the methods of hormone replacement. As a result, the purpose of this review is to highlight differences in estrogen concentration and its effects on temporomandibular joint (TMJ) pain and behavior. Methods This literature review searched keywords TMJ, orofacial, pain, nociception sex steroids, estrous cycle, menstrual cycle estradiol, and progesterone. Results In the case of estrogen, the change in concentration was a consideration, as a rise in estrogen can lead to protective effects and a decrease in estrogen appears to exacerbate the pain response. The dosage and timing was important when administering sex steroids as many orofacial pain studies conducted on animals have used large pharmacologic dosages and/or have given the hormone in a nonphysiologic way that does not mimic natural secretion patterns. Conclusions The results demonstrate that when performing studies or experiments these factors can result in alteration of the pain or behavioral response, as well as, joint structure and inflammatory response. Therefore, these factors must be considered when designing experiments focused on determining the mechanisms of action for sex steroids.

The diagnostic process of pain in the oral, facial, and head region is often perceived as more difficult due the numerous, extensively innervated structures located in this area. To successfully manage the patient with these pain presentations, it is critical for the clinician to spend ample time procuring a good medical and dental history. A systematic approach to the physical examination will ensure that sufficient data are acquired without overlooking potentially important contributing factors. The use of adjunctive laboratory tests and imaging studies should be based on the findings in the history and examination.

Burning mouth syndrome (BMS) is a chronic disorder for which a definitive etiopathology is not known. The BMS patient often experiences a continuous burning pain in the mouth without any clinical signs. This confusing condition can create frustration for both patient and practitioner. Ultimately, it is important for the practitioner who treats head and face pain to become knowledgeable in the recognition of the many complexities and various presentations associated with BMS. In doing so, the practitioner can be better prepared to help patients cope with this confounding disorder and gain a better quality of life.