Recent advances in the understanding of the aetiology and therapeutic strategies in burning mouth syndrome: Focus on the actions of cannabinoids.

Burning mouth syndrome (BMS) is a neuropathic pain disorder associated with a burning sensation on oral mucosal surfaces with frequently reported xerostomia, dysgeusia and tingling or paraesthetic sensations. However, patients present no clinically evident causative lesions. The poor classification of the disorder has resulted in a diagnostic challenge, particularly for the clinician/dentist evaluating these individuals. Major research developments have been made in the BMS field in recent years to address this concern, principally in terms of the pathophysiological mechanisms underlying the disorder, in addition to therapeutic advancements. For the purpose of this review, an update on the pathophysiological mechanisms will be discussed from a neuropathic, immunological, hormonal and psychological perspective. This review will also focus on the many therapeutic strategies that have been explored for BMS, including antidepressants/antipsychotics, non-steroidal anti-inflammatories, hormone replacement therapies, phytotherapeutic compounds and non-pharmacological interventions, overall highlighting the lack of controlled clinical studies to support the effectiveness of such therapeutic avenues. Particular focus is given to the cannabinoid system and the potential of cannabis-based therapeutics in managing BMS patients.

Assessment of Thiel-Embalmed Cadavers as a Teaching Tool for Oral Anatomy and Local Anesthesia.

The aim of this study was to determine whether Thiel-embalmed cadavers would provide a useful anatomy teaching tool for topics that cannot be approached using formalin-fixed cadavers such as oral cavity examination and maxillary anesthesia. The suitability of Thiel-embalmed bodies for performing oral examinations was assessed by asking first-year dental and dental hygiene students at a dental school in Ireland to identify oral structures on a classmate and on a Thiel-embalmed body. The study was conducted in 2016. The ease of location was compared in the two settings, and their quality was assessed on the cadavers. The suitability of Thiel-embalmed cadavers to teach maxillary anesthesia was assessed by students' performing mock injections at five adjacent sites daily for five consecutive days, followed by inspection of the gingival surface by experienced anatomists and dentists. Data were obtained from 57 students, but only the 54 forms that were fully completed were analyzed, for an overall response rate of 85.7%. The results showed that most oral structures were more difficult to locate on cadavers. The texture and appearance of features in the cadavers were rated at a midpoint between realistic and unrealistic. The relative inexperience of the participants, the accumulation of fixative in the oral cavity, and discoloration were mentioned as potential confounding factors. Visual analysis of images obtained following repeated injections revealed no deterioration of the tissue. Importantly, the puncture marks appeared to reduce over time, suggesting that the gingival tissue maintains some elasticity following Thiel fixation. These findings suggest that Thiel-embalmed cadavers may be a useful tool to provide students more time to localize and study aspects of the oral cavity. Likewise, the recoiling capacity of gingival tissue suggests that Thiel-embalmed cadavers may provide an ideal tool for teaching injection technique of local anesthetics.

Toll-like receptor signalling as a cannabinoid target in Multiple Sclerosis.

Toll-like receptors (TLRs) are the sensors of pathogen-associated molecules that trigger tailored innate immune intracellular signalling responses to initiate innate immune reactions. Data from the experimental autoimmune encephalomyelitis (EAE) model indicates that TLR signalling machinery is a pivotal player in the development of murine EAE. To compound this, data from human studies indicate that complex interplay exists between TLR signalling and Multiple Sclerosis (MS) pathogenesis. Cannabis-based therapies are in clinical development for the management of a variety of medical conditions, including MS. In particular Sativex®, a combination of plant-derived cannabinoids, is an oromucosal spray with efficacy in MS patients, particularly those with neuropathic pain and spasticity. Despite this, the precise cellular and molecular mechanisms of action of Sativex® in MS patients remains unclear. This review will highlight evidence that novel interplay exists between the TLR and cannabinoid systems, both centrally and peripherally, with relevance to the pathogenesis of MS. This article is part of the Special Issue entitled 'Lipid Sensing G Protein-Coupled Receptors in the CNS'.

Cannabinoids and innate immunity: taking a toll on neuroinflammation.

The biologically active components of cannabis have therapeutic potential in neuroinflammatory disorders due to their anti-inflammatory propensity. Cannabinoids influence immune function in both the peripheral and the central nervous system (CNS), and the components of the cannabinoid system, the cannabinoid receptors and their endogenous ligands (endocannabinoids), have been detected on immune cells as well as in brain glia. Neuroinflammation is the complex innate immune response of neural tissue to control infection and eliminate pathogens, and Toll-like receptors (TLRs), a major family of pattern recognition receptors (PRRs) that mediate innate immunity, have emerged as players in the neuroinflammatory processes underpinning various CNS diseases. This review will highlight evidence that cannabinoids interact with the immune system by impacting TLR-mediated signaling events, which may provide cues for devising novel therapeutic approaches for cannabinoid ligands.