Masticatory Myofascial Pain Disorders.

Masticatory myofascial pain disorders (MMPD) are a common group of orofacial pain conditions affecting the muscles of mastication, with headache and cervical disorders as well as chronic widespread pain and psychosocial disorders being common comorbid conditions. As their pathophysiology is multifactorial in nature, a multimodal and interdisciplinary approach should be considered. Overall treatment goals include decreasing pain and disability, increasing mandibular range of motion, and improving quality of life. This article describes a complex case exhibiting common characteristics of MMPD while additionally reviewing the literature on classification, pathophysiology, and evidence-based treatment planning.

Head and Neck Cancer-Related Pain.

Pain is a common and most debilitating symptom of head and neck cancers (HNC). The prevalence of pain in HNC is nearly 70%. There are no universally accepted classification or diagnostic criteria for HNC-related pain, and currently, HNC-related pain is classified based on the underlying pathophysiological mechanism, the location of the tumor, and the protagonist of pain. The clinical presentation of HNC-related pain varies and can be similar to primary pain disorders. The management of HNC-related pain primarily consists of pharmacotherapy. However, in some cases, interventions may be needed. This article will present a case study and review the epidemiology, diagnostic criteria and classification, clinical features, pathophysiology, and HNC-related pain management.

Burning Mouth Syndrome.

Burning mouth syndrome (BMS) is a rare chronic neuropathic pain condition characterized by recurring burning pain or dysesthesia in the absence of any local or systemic causes of symptoms. The exact pathophysiology of BMS is unknown, but recent research suggests a medley of neuropathic, endocrinological, and psychosocial elements. This article presents a case history and reviews the epidemiology, diagnostic criteria, clinical features, diagnostic investigations, pathophysiology, and management of BMS.

Trigeminal Neuralgia.

Trigeminal neuralgia (TN) is a rare neuropathic pain disorder characterized by recurrent, paroxysmal episodes of short-lasting severe electric shock-like pain along the sensory distribution of the trigeminal nerve. Recent classification systems group TN into 3 main categories depending on the underlying pathophysiology. This article will present a case history and review the epidemiology, diagnostic criteria, classification, clinical features, diagnostic investigations, pathophysiology, and management of TN.

Pain Management for Dental Medicine in 2021: Opioids, Coronavirus and Beyond.

Over the past year our attention has inevitably been on the coronavirus pandemic, the health and welfare of our families, patients, and office staffs as well as the re-opening of our dental practices. In addition, the opioid crisis continues, is very likely to worsen as a result of the pandemic and continues to be a challenge to Dentistry. National public health issues and healthcare disparities continue and have created a global concern for providing evidence-based, adequate pain management in the dental setting. We have brought together a group of national thought leaders and experts in this field who will share their insights on the current state of opioid prescribing in Dentistry and describe some of the exciting work being done in advancing pain management. The learning objectives for this conference proceedings were: Describing the implications of current public health concerns for safe and effective pain management in dental medicine.Identifying risk factors and understanding the current guidelines for the use of opioid and non-opioid medications in dental medicine.Analyzing the interprofessional collaborations necessary for effective pain management in dental medicine.Recognizing the challenges and opportunities brought about by the COVID-19 pandemic for the dental profession.Applying evidence-based strategies for managing the complex pain patient in the dental setting.Appraising new and future modalities for the assessment and management of orofacial pain.

Ictal and interictal brain activation in episodic migraine: Neural basis for extent of allodynia.

In some patients, migraine attacks are associated with symptoms of allodynia which can be localized (cephalic) or generalized (extracephalic). Using functional neuroimaging and cutaneous thermal stimulation, we aimed to investigate the differences in brain activation of patients with episodic migraine (n = 19) based on their allodynic status defined by changes between ictal and interictal pain tolerance threshold for each subject at the time of imaging. In this prospective imaging study, differences were found in brain activity between the ictal and interictal visits in the brainstem/pons, thalamus, insula, cerebellum and cingulate cortex. Significant differences were also observed in the pattern of activation along the trigeminal pathway to noxious heat stimuli in no allodynia vs. generalized allodynia in the thalamus and the trigeminal nucleus but there were no activation differences in the trigeminal ganglion. The functional magnetic resonance imaging (fMRI) findings provide direct evidence for the view that in migraine patients who are allodynic during the ictal phase of their attacks, the spinal trigeminal nucleus and posterior thalamus become hyper-responsive (sensitized)-to the extent that they mediate cephalic and extracephalic allodynia, respectively. In addition, descending analgesic systems seem as "switched off" in generalized allodynia.

Trigeminal Autonomic Cephalalgia and Facial Pain: A Review and Case Presentation.

Trigeminal autonomic cephalalgias (TAC) are primary headache disorders that are characterized by severe unilateral pain along the distribution of the trigeminal nerve with corresponding activation of the autonomic nervous system. The clinical characteristics and presentation of TAC are unique; however, there may be an overlap of these features with other painful conditions affecting the orofacial region, which can be a diagnostic challenge for the clinician. This article reports a case history and discusses the differences between clinical characteristics of TAC and other painful orofacial conditions. Refractory pain conditions and the occurrence of episodic pain attacks with accompanying autonomic symptoms necessitate a thorough evaluation to rule out rare causes of head and face pain.

What Variables Are Associated With the Outcome of Arthroscopic Lysis and Lavage Surgery for Internal Derangement of the Temporomandibular Joint?

PURPOSE: Arthroscopic lysis and lavage surgery (AS) is an effective modality that can decrease pain and increase maximum interincisal opening (MIO) in patients with internal derangement (ID) of the temporomandibular joint (TMJ). However, some patients remain in pain or have limited mandibular range of motion despite AS. The purpose of this study was to determine the effectiveness, prevalence of adverse effects, and predictors of response to TMJ AS in patients with TMJ arthralgia and ID. MATERIALS AND METHODS: A retrospective cohort study was conducted using data of patients who had undergone AS by a single surgeon (D.A.K.) from September 2010 to April 2015 in the Department of Oral and Maxillofacial Surgery at Massachusetts General Hospital (Boston, MA). Variables, including demographic data, medical history, and clinical presentation, were extracted and analyzed. Criteria for surgical success were defined as a postoperative MIO of at least 35 mm and a postoperative pain level no higher than 3 on an 11-point Likert-type numeric verbal pain rating scale. Appropriate descriptive and analytic statistics were computed and significance was set at a P value less than .05. RESULTS: Of the 247 participants, 226 (91.5%) were women. The mean age of the sample was 38 ± 15.4 years. Successful surgical outcome was achieved in 62.3% of patients. Based on logistic regression analysis, higher initial mean pain score and concurrent use of benzodiazepines were the only variables that predicted an unsuccessful surgical outcome (P < .001; P = .005). Adverse effects were reported by 13.4% of patients, the most common being postoperative increase in pain (13.4%), temporary malocclusion (1.2%), and temporary paresthesia in the preauricular region (0.4%). CONCLUSION: The results from this study indicate that in patients with ID of the TMJ unresponsive to noninvasive treatments, high initial pain scores and concurrent use of benzodiazepines are correlated with an unsuccessful outcome after AS.

Facial pain associated with cardiac origin.

BACKGROUND: Ischemic heart disease manifests as pain on the left side, in the retrosternal or the precordial region, with subsequent radiation to the ipsilateral shoulder, face, and cervical region. Less frequently, it may manifest solely as face pain. CASE DESCRIPTION: A 57-year-old man sought care at the Massachusetts General Hospital Oral and Maxillofacial Pain Center with a symptom of pain in the mandibular left posterior region, in the medial aspect of the ipsilateral eye, and in the left side of the neck. The pain had started approximately 8 months previously as a mild, constant dull ache in the mandibular left posterior region. However, it became severe in intensity and sharp in quality and radiated toward the medical aspect of the ipsilateral eye and lateral neck region after intense physical activity. Results from comprehensive diagnostic evaluation and a series of diagnostic tests suggested that the facial pain was associated with cardiovascular disease. There was complete resolution of pain symptoms after the patient received appropriate pharmacotherapy. PRACTICAL IMPLICATIONS: Association of pain with exercise and termination of pain with rest and the presence of risk factors for cardiovascular disease necessitate a thorough investigation of rare and fatal causes of facial pain.

Effectiveness, Safety, and Predictors of Response to Botulinum Toxin Type A in Refractory Masticatory Myalgia: A Retrospective Study.

PURPOSE: Masticatory muscle pain disorders respond well to conservative therapy; however, in some patients the pain becomes refractory. Botulinum toxin type A (BoT-A) therapy has been shown to be an effective modality in the management of refractory headache disorders. Conversely, there are conflicting reports in the literature regarding the efficacy, safety, and predictors of therapeutic response to BoT-A therapy for management of refractory masticatory muscle pain. MATERIALS AND METHODS: We performed a retrospective chart review of patients who underwent at least 2 injection cycles of 100 U of BoT-A for refractory masticatory myalgia in the Department of Oral and Maxillofacial Surgery, Massachusetts General Hospital, between May 2012 and June 2016. Information regarding demographic, diagnostic, and therapeutic characteristics was extracted and analyzed. The χ2 test was used for analysis between independent and dependent variables. Forward step-wise-type logistic regression analysis was conducted to determine the predictors of outcome. RESULTS: Among 116 participants, 30.6% reported significant relief in pain for a mean period of 10.1 weeks. A total of 16.4% of participants reported at least 1 adverse effect. The effectiveness of the BoT-A therapy was found to be statistically associated with the presence of muscle hypertrophy (P = .004), range of motion (P = .02), concurrent use of opioid analgesics (P = .003), and local anesthetic trigger-point injections (P = .003). Logistic regression analyses suggested that the presence of muscle hypertrophy and occurrence of adverse effects were predictors of positive outcome. On the contrary, concurrent use of opioid analgesics was found to be a predictor for no or minimal relief. CONCLUSIONS: BoT-A therapy provides significant relief for approximately one third of patients with refractory masticatory muscle pain. Therapy is associated with a mild risk of adverse effects. The presence of muscle hypertrophy, occurrence of an adverse effect, and concurrent use of opioid analgesics were found to be predictors of outcome response.

Classification and Differential Diagnosis of Oral and Maxillofacial Pain.

Pain in the orofacial region is a common presenting symptom. The majority of symptoms are related to dental disease and the cause can readily be established, the problem dealt with, and the pain eliminated. However, pain may persist and defy attempts at treatment. Intractable oral or facial pain can be diagnostically challenging. To make a definitive diagnosis and initiate proper treatment, a rigorous protocol for evaluation includes a thorough history and an appropriate comprehensive clinical examination and diagnostic testing, including chief complaint, history of present illness, medical history, physical examination, diagnostic studies, including imaging, and psychosocial evaluation.

Cranial Neuralgias.

Advances in diagnostic modalities have improved the understanding of the pathophysiology of neuropathic pain involving head and face. Recent updates in nomenclature of cranial neuralgias and facial pain have rationalized accurate diagnosis. Clear diagnosis and localization of pain generators are paramount, leading to better use of medical and targeted surgical treatments.

Cortico-Cortical Connections of Primary Sensory Areas and Associated Symptoms in Migraine.

Migraine is a recurring, episodic neurological disorder characterized by headache, nausea, vomiting, and sensory disturbances. These events are thought to arise from the activation and sensitization of neurons along the trigemino-vascular pathway. From animal studies, it is known that thalamocortical projections play an important role in the transmission of nociceptive signals from the meninges to the cortex. However, little is currently known about the potential involvement of cortico-cortical feedback projections from higher-order multisensory areas and/or feedforward projections from principle primary sensory areas or subcortical structures. In a large cohort of human migraine patients (N = 40) and matched healthy control subjects (N = 40), we used resting-state intrinsic functional connectivity to examine the cortical networks associated with the three main sensory perceptual modalities of vision, audition, and somatosensation. Specifically, we sought to explore the complexity of the sensory networks as they converge and become functionally coupled in multimodal systems. We also compared self-reported retrospective migraine symptoms in the same patients, examining the prevalence of sensory symptoms across the different phases of the migraine cycle. Our results show widespread and persistent disturbances in the perceptions of multiple sensory modalities. Consistent with this observation, we discovered that primary sensory areas maintain local functional connectivity but express impaired long-range connections to higher-order association areas (including regions of the default mode and salience network). We speculate that cortico-cortical interactions are necessary for the integration of information within and across the sensory modalities and, thus, could play an important role in the initiation of migraine and/or the development of its associated symptoms.

Functional magnetic resonance imaging (FMRI) and expert testimony.

Medical experts frequently use imaging studies to illustrate points in their court testimony. This article reviews how these studies impact the credibility of expert testimony with judges and juries. The apparent "objective" evidence provided by such imaging studies can lend strong credence to a judge's or jury's appraisal of medical expert's testimony. However, as the court usually has no specialized scientific expertise, the use of complex images as part of courtroom testimony also has the potential to mislead or at least inappropriately bias the weight given to expert evidence. Recent advances in brain imaging may profoundly impact forensic expert testimony. Functional magnetic resonance imaging and other physiologic imaging techniques currently allow visualization of the activation pattern of brain regions associated with a wide variety of cognitive and behavioral tasks, and more recently, pain. While functional imaging technology has a valuable role in brain research and clinical investigation, it is important to emphasize that the use of imaging studies in forensic matters requires a careful scientific foundation and a rigorous legal assessment.