Is burning mouth syndrome a neuropathic pain condition?

Topical amitriptyline in burning mouth syndrome: A retrospective real-world evidence study

OBJECTIVE

To evaluate the effectiveness, tolerability, and safety of topical amitriptyline as a potential route of administration for the management of burning mouth syndrome.

BACKGROUND

Burning mouth syndrome is a complex, idiopathic, and debilitating orofacial pain disorder that impairs quality of life, with a prevalence of up to 18% in menopausal women. Available drugs to alleviate its burning sensation have inconsistent and limited efficacy. Given its physicochemical properties, excellent tolerability, and ability to target peripheral pathways, topical amitriptyline seems a promising mechanistically specific analgesic drug for burning mouth syndrome.

METHODS

In this retrospective cross-sectional real-world evidence study, patients with burning mouth syndrome who were prescribed topical amitriptyline for 8 weeks were identified. Eligibility criteria stemmed from ICHD-3, ICOP, and consensus definitions. The primary outcome measure was mean daily pain intensity (on a 0-10 scale); secondary outcomes included adverse events and patient global impression of improvement. Data are given as the mean ± SD.

RESULTS

A total of 15 patients fulfilling the eligibility criteria were included and analyzed. Mean daily pain was 6.7 ± 2.1 at baseline and 3.7 ± 2.3 after treatment, with a mean reduction of 3.1 ± 2.8 (p = 0.002). Half of the patients experienced a decrease in pain by at least 50% (p = 0.008). Several mild adverse events were reported, such as somnolence or dry mouth.

CONCLUSIONS

Topical amitriptyline may be a safe and potent route of administration in the treatment of burning mouth syndrome, a hypothesis to be tested in further controlled trials.

The potential of Acmella oleracea as a nutraceutical source for the symptomatic treatment of Burning Mouth Syndrome

This study analysed the phytochemical profile of Acmella oleracea extract and the molecular interactions of its main compounds with TRPV1 and CB2, target receptors in the Burning Mouth Syndrome (BMS) pathogenesis. The phytochemical profile of A. oleracea's floral buds extract treated with activated charcoal (TCEE) was analysed by High-Performance Liquid Chromatography (HPLC) coupled to Mass Spectrometry (LC-MS). The quantification of spilanthol was analysed by HPLC coupled to a Diode-Array Detector (HPLC-DAD). The phytochemical analysis revealed the presence of nine alkylamides and phenolic compounds. The TCEE showed a significant increase in spilanthol content compared to the crude extract (CEE), going from 28.33 mg/g to 117.96 mg/g. The molecular docking indicated a behaviour of the alkylamides as partial TRPV1 agonists and CB2 agonists and, for the first time, indicates the action of these compounds in the symptomatic management of BMS.

An overview of the safety and efficacy of LX-9211 in treating neuropathic pain conditions

INTRODUCTION

LX-9211 is a drug designed to treat neuropathic pain conditions. It functions by inhibiting the adaptor-associated kinase 1 (AAK1) enzyme which promotes clathrin-dependent endocytosis. Preclinical studies have shown that LX-9211 does produce a reduction in nociceptive related behaviors and produces no major adverse effects in rats. Thus, LX-9211 has advanced to clinical trials to assess its safety and efficacy in humans. So far, phase 1 and phase 2 clinical trials involving patients with postherpetic neuralgia and diabetic peripheral neuropathic pain have been conducted with phase 3 trials planned in the future.

AREAS COVERED

This paper highlights preclinical studies involving LX-9211 in rodents. Additionally, phase 1 clinical trials examining the safety of LX-9211 in healthy subjects as well as phase 2 studies looking at the safety and efficacy of LX-9211 compared to placebo in patients with diabetic peripheral neuropathic pain and postherpetic neuralgia are also discussed.

EXPERT OPINION

In phase 1 and phase 2 clinical trials conducted so far, LX-9211 has been shown to produce few adverse effects as well as cause a significantly greater reduction in pain compared to placebo. However, more clinical studies are needed to further assess its effects in humans to ensure its safety.

Long-Term Benefits of Photobiomodulation Therapy on Health-Related Quality of Life in Burning Mouth Syndrome Patients: A Prospective Study

Background/Objectives: Burning Mouth Syndrome (BMS) patients experience a reduction in health-related quality of life and an increased intake of medication. Photobiomodulation with low-level laser therapy has been demonstrated to be an efficacious treatment for BMS. However, its long-term benefits remain relatively unknown. This study aimed to evaluate the impact of prolonged Photobiomodulation with low-level laser therapy on BMS patients by examining the efficacy of an outpatient protocol in a real-world setting. Methods: A prospective study was designed to address the research question. Photobiomodulation was performed, irradiating the affected areas once every two weeks for 12 months. Health-related quality of life was assessed using the EQ-5D-5L questionnaire at the initial consultation and after 6 months and 12 months of treatment. Additionally, the patients' pharmacological profile was also monitored. Nonparametric statistical analysis was performed (p < 0.05 was considered statistically significant). Results: The study was completed by 15 individuals, comprising 14 females and 1 male. The results indicated a statistically significant improvement (p < 0.001) in four of the five dimensions of the health-related quality of life questionnaire, namely self-care, usual activities, pain/discomfort, and anxiety/depression, along with the patients' perceived health level. A total of 13 participants reported suspending or reducing their intake of medications for Burning Mouth Syndrome. Conclusions: Therefore, Photobiomodulation with low-level laser therapy has a positive effect on improving patients' quality of life and reducing BMS symptoms, contributing to a subsequent reduction or suspension of previous medications. These findings support the efficacy of the applied protocol. Given the innovative methodology and promising results, further research is warranted.

Local anesthesia nerve block for managing burning mouth syndrome: a scoping review

OBJECTIVE

To assess the clinical scenarios in which nerve blocks are employed in the context of burning mouth syndrome (BMS).

STUDY DESIGN

This scoping review followed the PRISMA-ScR. A protocol was generated on Open Science Framework. Electronic searches were performed in the following databases: PubMed, Scopus, EMBASE, Web of Science, LILACS, and Cochrane, in addition to the grey literature and citations from Grémeau-Richard et al. (2010).

RESULTS

Nerve blocks were used for treatment purposes in all cases. The mandibular nerve and the stellate ganglion were both blocked in 50% studies, while the maxillary nerve and lingual nerve were blocked in 25% study each. The anesthetics used were lidocaine (50%) and bupivacaine (50%). Relief was generally reported after immediate block, and at a mean follow-up of 4.5 weeks, there was considerable improvement compared to the initial conditions when the mandibular and/or maxillary nerve were targeted.

CONCLUSIONS

The use of nerve blocks has been employed in the treatment of patients with refractory BMS. Clinical studies with standardized methodology are necessary to validate and understand the potential role of mandibular and maxillary nerve block in this setting.

Clinical characteristics and salivary biomarkers of burning mouth syndrome

OBJECTIVES

To investigate the clinical characteristics and salivary biomarkers in each type of burning mouth syndrome (BMS) patients.

MATERIALS AND METHODS

Ninety-eight postmenopausal female patients with BMS were included. Fifty and 21 patients were assigned to the primary and secondary groups, respectively. Twenty-seven patients with both primary and secondary characteristics were assigned to the intermediate group. Comprehensive clinical characteristics and salivary biomarkers were analyzed.

RESULTS

Significant differences in age, proportion of hyposalivator patients based on unstimulated whole saliva (UWS), symptom distribution, severties of burning sensation and effect of oral complaints in daily life (Eff-life), and positive symptom distress index (PSDI) were observed among the three groups. The primary group had significant higher UWS flow rate, fewer UWS hyposalivator proportions, and lesser severity of Eff-life than the secondary group. The intermediate group had significantly greater intensities of burning sensation and Eff-life and higher PSDI score than did the primary group. The primary group had significantly higher cortisol and dehydroepiandrosterone (DHEA) levels in stimulated whole saliva than did the secondary group.

CONCLUSIONS

This study's findings show that clinical characteristics differentiate each BMS type. Cortisol and DHEA levels are potential salivary biomarkers for discriminating between the primary and secondary types of BMS.

Time-course of pain and salivary opiorphin release in response to oral capsaicin differ in burning mouth syndrome patients, temporomandibular disorders patients and control subjects

OBJECTIVES

Opiorphin is an analgesic peptide released by salivary glands and capsaicin an agonist of TRPV1 receptors eliciting burning sensations. The primary objective of this study was to assess opiorphin release after stimulation of the tongue by capsaicin (STC). The secondary objectives were to compare opiorphin release after STC in 3 groups of subjects [healthy (CTRL), Burning Mouth Syndrome (BMS), painful Temporomandibular disorders (TMDp)] and pain evoked by STC in these 3 groups.

MATERIALS AND METHODS

Salivary opiorphin was assessed with high-performance liquid chromatography at 3 different time points (baseline, after 5 min and 20 min of STC). Pain was self-reported on a (0-10) numeric rating scale.

RESULTS

Three groups (N = 16) of adults were recruited at the Clinical Hospital Centre and School of Dental Medicine in Zagreb. Opiorphin levels were higher (1) in TMDp compared to CTRL in 1st (2.23 ± 1.72 pg/ul vs. 0.67 ± 0.44 pg/ul, p = 0.002) and 3rd sampling (2.44 ± 2.01 pg/ul vs. 0.74 ± 0.52 pg/ul, p = 0.020) and (2) within BMS group at 3rd sampling vs. baseline (p < 0.025). Pain scores were higher in BMS compared to TMDp (p < 0.025) and CTRL (p < 0.025).

CONCLUSION

This study evidenced (1) a differential basal amount of opiorphin in two pain conditions and control subjects (2) a differential kinetic of release of opiorphin after STC in CTRL, BMS and TMDp (3) a differential pain perception after STC in BMS and TMDp vs. CTRL, which can provide a readout for animal models.

CLINICAL RELEVANCE

The specific regulation of opiorphin release in patients with orofacial painful conditions provides valuable insights for clinicians and researchers in physiology and pathology and encourages further research in this area.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04694274. Registered on 01/05/2021.

Efficacy of 660 nm Photobiomodulation in Burning Mouth Syndrome Management: A Single-Blind Quasi-Experimental Controlled Clinical Trial

Background: Burning mouth syndrome (BMS) is characterized by a burning sensation of the oral mucosa without any evidence of clinical signs or underlining condition. Several treatment modalities have been utilized with various results and levels of evidence. Lately, photobiomodulation (PBM) has emerged as a noninvasive effective therapy due to its anti-inflammatory and biostimulatory effects, especially the low-power laser setting of red wavelength. Objective: This single-blind quasi-experimental controlled clinical trial aimed to evaluate the PBM effectiveness at a low level of red laser light in patients with BMS compared with sham control. Materials and methods: Thirty patients diagnosed with BMS were consecutively assigned to intervention (PBM therapy) and control (sham) groups. The protocol for PBM dosimetry was as follows: laser 660 nm; spot size: 0.04 cm2; power output: 100 mW; emission mode: continuous wave; power density: 6 J/cm2; irradiation time: 10 sec per point within 1 cm2 surface area of the symptomatic area. The treatment protocol was based on once a week for a total of 10 sessions. Results: Our results showed no statistically significant difference in reduction of pain intensity between the two groups at all the evaluated timepoints during the course of treatment. However, in both groups, we observed a statistically significant reduction of maximum pain intensity of 50% compared with patient-self reporting before the treatment. Conclusions: Further randomized clinical trials to validate our positive results with a large sample size with a long-term follow-up and understanding further the sham placebo effect are warranted.

Burning mouth in oncology care: a systematic review

Burning mouth, also referred to as oral dysesthesia, is an underreported condition among cancer patients that may represent an early symptom of cancer or an adverse effect of treatment. This review sought to characterize this symptom in oncology care where burning symptoms may occur. A systematic review of the literature was performed based on the PRISMA statement, and the protocol was registered at PROSPERO database. A structured search was done using eight databases. The process of study selection was conducted in two distinct phases. The JBI Critical Appraisal Tools were utilized to evaluate the risk of bias in the studies included. Of the total number of studies assessed, sixteen met the eligibility criteria. Of these studies included, 7 were case reports, 7 cross-sectional studies, and 2 non-randomized clinical trials. Most studies presented low risk of bias (n = 9), while the remaining studies were evaluated and scored as moderate (n = 5) or high (n = 2) risk of bias. Burning mouth was reported as a first symptom of cancer in three studies, and as an adverse event of radiotherapy (n = 2), chemoradiotherapy (n = 2), and chemotherapy (n = 9). Burning mouth was a first symptom in 0.62% of oral squamous cell carcinoma (OSCC), and 3.3% of patients with pain as chief complaint. Oral dysesthesia prevalence was 13.6% in patients experiencing chemotherapy-induced oral adverse events. The symptom of burning mouth should be examined in oncology care, as it may be underreported and therefore undertreated. New therapies may be related to a higher risk of oral burning and studies assessing approach to management are needed. Current management borrows from the current management of burning mouth in the non-cancer setting.

Trigeminal neuralgia and trigeminal neuropathic pain

It is very important that the dental team are aware of the varied presentations of pain in the mouth, face and other parts of the trigeminal region which are not directly caused by teeth or oral structures. Our understanding of underlying causes in this complex area is evolving. Ultimately, patients who present with what may at first seem to be oral or dental problems will require specialist input in secondary care with potential for use of systemic medications. This article reviews the common non-dental pains encountered in the orofacial region related to dysfunction of the trigeminal nerve.

Current developments and opportunities of pluripotent stem cells-based therapies for salivary gland hypofunction

Salivary gland hypofunction (SGH) caused by systemic disease, drugs, aging, and radiotherapy for head and neck cancer can cause dry mouth, which increases the risk of disorders such as periodontitis, taste disorders, pain and burning sensations in the mouth, dental caries, and dramatically reduces the quality of life of patients. To date, the treatment of SGH is still aimed at relieving patients' clinical symptoms and improving their quality of life, and is not able to repair and regenerate the damaged salivary glands. Pluripotent stem cells (PSCs), including embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs), and extended pluripotent stem cells (EPSCs), are an emerging source of cellular therapies that are capable of unlimited proliferation and differentiation into cells of all three germ layers. In recent years, the immunomodulatory and tissue regenerative effects of PSCs, their derived cells, and paracrine products of these cells have received increasing attention and have demonstrated promising therapeutic effects in some preclinical studies targeting SGH. This review outlined the etiologies and available treatments for SGH. The existing efficacy and potential role of PSCs, their derived cells and paracrine products of these cells for SGH are summarized, with a focus on PSC-derived salivary gland stem/progenitor cells (SGS/PCs) and PSC-derived mesenchymal stem cells (MSCs). In this Review, we provide a conceptual outline of our current understanding of PSCs-based therapy and its importance in SGH treatment, which may inform and serve the design of future studies.

Is burning mouth syndrome associated with stress? A meta-analysis

BACKGROUND

Some studies have shown burning mouth syndrome (BMS) as comorbid psychosocial and psychiatric disorders, and as well, pointed at stress as a major risk factor.

OBJECTIVE

The aim of this meta-analysis was to answer the following question: 'Is there an association between BMS and stress, compared to healthy controls?'

METHODS

Two reviewers searched for the effect of stress in BMS and published on five main databases and three from the grey literature. Various questionnaires and biomarkers were analysed. Of the 2489 selected articles, 30 met the inclusion criteria. Studies englobed questionnaires, such as Perceived Stress Questionnaire, Lipp Stress Symptoms Inventory, Holmes-Rahe scale, Depression, Anxiety, and Stress Scale (DASS-21), Recent Experience Test; and various biomarkers, such as cortisol, opiorphin, IgA, α-amylase and interleukins.

RESULTS

In all studies with questionnaires, stress was significantly increased in the BMS group vs. control. Patients with BMS presented 25.73% higher cortisol levels, 28.17% higher IgA levels and 40.62% higher α-amylase levels than controls. Meta-analysis found that BMS subjects presented 3.01 nmoL/L [0.53; 5.50] higher cortisol levels, 84.35 kU/L [15.00; 153.71] higher α-amylase levels, 29.25 mg/mL [9.86; 48.64] higher IgA levels and 258.59 pg/mL [59.24; 457.94] higher IL-8 levels than control. No differences were found for opiorphin concentration in ng/mL [-0.96; 2.53]. For interleukins, no differences were founded for IL-1 β, IL-2, IL-4, IL-6, IL-8, IL-10 and TNF-α.

CONCLUSION

Based on the available evidence, this meta-analysis suggests more stress factors in questionnaire-based studies, and higher levels of cortisol, α-amylase, IgA and IL-8 biomarkers in BMS subjects than controls.

Effects of self-perceived psychological stress on clinical symptoms, cortisol, and cortisol/ACTH ratio in patients with burning mouth syndrome

BACKGROUND

Psychological stress is a crucial parameter in defining the symptoms of burning mouth syndrome (BMS). We hypothesized that the level of psychological stress in patients with BMS would correlate with severity of clinical symptoms, cortisol levels, and cortisol/ adrenocorticotropic hormone (ACTH) ratio. We aimed to comprehensively investigate the influence of clinical and hematologic parameters on the hypothalamic-pituitary-adrenal axis, particularly concerning the presence or absence of self-perceived psychological stress in patients with BMS. In addition, we aimed to identify parameters predicting psychological stress in these patients.

METHODS

One hundred and forty-one patients with BMS (117 women, 82.98%; 56.21 ± 13.92 years) were divided into psychological stress (n = 68; 55 females, 56.39 ± 12.89 years) and non-psychological stress groups (n = 73; 62 females, 56.03 ± 14.90 years), and inter- and intra-group statistical analyses were conducted. Significant predictors of psychological stress in patients with BMS were investigated through multiple logistic regression analysis.

RESULTS

The prevalence of xerostomia was significantly higher (67.6% vs. 34.2%, p < 0.001), while unstimulated salivary flow rate was lower (0.66 ± 0.59 vs. 0.91 ± 0.53 mL/min, p < 0.01) in the psychological stress group than in the non-psychological stress group. SCL-90R subscale values for somatization, hostility, anxiety, and depression, as well as cortisol and ACTH levels and the cortisol/ACTH ratio, were also higher in the psychological stress group (all p < 0.05). Above-mean values for cortisol (AUC = 0.980, 95%CI: 0.959-1.000) and cortisol/ACTH (AUC = 0.779; 95%CI, 0.701-0.856) were excellent predictors of psychological stress, with cortisol (r = 0.831, p < 0.01) and cortisol/ACTH (r = 0.482, p < 0.01) demonstrating substantial correlations. Above-average values for cortisol (OR = 446.73) and cortisol/ACTH (OR = 6.159) significantly increased incidence of psychological stress in patients with BMS (all p < 0.001).

CONCLUSIONS

Among patients with BMS, xerostomia, decreased salivary flow rate, increased cortisol levels, and cortisol/ACTH ratio were associated with psychological stress, highlighting the psycho-neuro-endocrinological features of this condition. Cortisol and cortisol/ACTH ratio were strong predictors of psychological stress in patients with BMS.

The over-expression of miRNA-206 in peripheral blood of patients with burning mouth syndrome and its relationship with anxiety and depression

BACKGROUND

Burning mouth syndrome (BMS) is characterised by persisting burning pain of the oral mucosa, and its etiopathogenesis remains poorly understood.

OBJECTIVES

Our study aimed to detect the expression of miRNA-206 in the blood and clarify the relationship among miRNA-206, pain, anxiety and depression of BMS patients.

METHODS

Thirty patients with BMS and 30 healthy individuals were enrolled in the experimental and control groups, respectively. Data on medical history and clinical oral examination for all participants were collected. Simultaneously, scores of Visual Analogous Scale (VAS), Self-rating Anxiety Scale (SAS) and Self-rating Depression Scale (SDS) were administered. The expression level of miRNA-206 in plasma were determined by RT-(q)PCR. Finally, the relationship of miRNA-206 expression with the VAS score, SAS score, and SDS score was analysed. Chi-square test and t-test were used for statistical analysis of the data, and p < .05 was considered statistically significant.

RESULTS

The majority of the patients with BMS identified the tongue as the main pain area, and showed dry mouth and poor sleep quality. The SAS and SDS scores of patients with BMS were higher than those of healthy controls (p < .05) and were positively correlated with VAS pain score. In addition, miRNA-206 expression was higher in patients with BMS than in healthy individuals (p < .05), and was positively correlated with the VAS and SDS scores (p < .05).

CONCLUSIONS

Patients with BMS suffer from pain and tend to be more anxious and depressed than healthy controls. miRNA-206 expression in the peripheral blood of patients with BMS is positively correlated with pain and depression, which may be involved in the pathogenesis of BMS.

COVID-19-Related Burning Eye Syndrome and Burning Mouth Syndrome: A Systematic Review and Meta-analysis

BACKGROUND

Previous research highlights burning eye syndrome (BES) and burning mouth syndrome (BMS) as chronic complications of COVID-19 infection. The aim of this systematic review and meta-analysis is to establish the prevalence of COVID-19-related BES and COVID-19-related BMS and describe their phenomenology.

METHODOLOGY

A literature search in the PubMed database was performed, and seven papers (five on BES and two on BMS) were eligible to be included in this systematic review and meta-analysis.

RESULTS

The pooled prevalence of COVID-19-related BES was 9.9% (95% CI 3.4-25.4%). The frequency of COVID-19-related BMS is only reported in isolated cases and ranges from 4% in mild-to-moderate cases to 15% in severe, hospitalized cases, with female patients being mostly affected. COVID-19 severity is a potential risk factor for both BES and BMS. Neither syndrome occurs in isolation. COVID-19-related BES usually appears within the first week post-infection, persisting up to 9 weeks later. COVID-19-related BMS occurs during and after initial infection, and may also persist as a chronic disease.

CONCLUSIONS

Both BES and BMS are neuropathic COVID-19 infection complications, still under-studied and under-investigated, despite the fact that both are prevalent. Both COVID-19-related BES and COVID-19-related BMS could potentially be initial long COVID syndrome manifestations, and further research should be carried out in this field.

WWOM VII: Effectiveness of systemic pharmacotherapeutic interventions in the management of BMS: A systematic review and meta-analysis

OBJECTIVES

To determine the effectiveness of systemic pharmacotherapeutic interventions compared to placebo in burning mouth syndrome (BMS) randomized controlled trials (RCTs) based on the core outcome domains recommended by the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT).

METHODS

A systematic literature review of RCTs, concerning systemic pharmacotherapeutic interventions for BMS, published from January 1994 through October 2019, and meta-analysis was performed.

RESULTS

Fourteen RCTs (n = 734 participants) were included. Of those, nine were eligible for the quantitative assessment due to the availability/homogeneity of data for at least one of the IMMPACT domains. Pain intensity was the only domain reported in all RCTs. Weighted mean changes in pain intensity, based on visual analogue scale (ΔVAS), were reported in three RCTs at 6 ± 2 weeks and only one RCT at 10+ weeks follow-ups. Quantitative assessment, based on ΔVAS, yielded very low evidence for the effectiveness of alpha-lipoic acid and clonazepam, low evidence for effectiveness of trazodone and melatonin, and moderate evidence for herbal compounds.

CONCLUSIONS

Based on the RCTs studied, variable levels of evidence exist that suggest that select pharmacological interventions are associated with improved symptoms. However, the underreporting of IMMPACT domains in BMS RCTs restricts the multidimensional assessment of systemic interventions outcomes. Standardized outcome measures need to be applied to future RCTs to improve understanding of intervention outcomes.

Sexual desire, mood disorders and sleep disturbances in female BMS patients: A controlled study

BACKGROUND

Burning mouth syndrome is a chronic orofacial pain with intraoral burning and other oral dysaesthetic symptoms that significantly affects the quality of life. The aim of this study is to evaluate the sexual desire in women with BMS and to investigate the possible related factors.

METHODS

A case-control study was performed. BMS patients were enrolled according to the International Classification of OroFacial Pain criteria. Demographic variables were collected. We evaluated pain with the Numeric Rating Scale (NRS), Visual Analogue Scale (VAS) and Total Pain Rating Index (T-PRI), anxiety and depression using the Hospital Anxiety and Depression Scale (HADS-A e HADS-D), sleep disturbances with Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS), and sexual desire using Sexual Desire Inventory (SDI).

RESULTS

A total of 50 BMS women and 50 healthy controls were enrolled. Compared with the controls, the BMS patients showed higher scores in the NRS (7,81 ± 1,71 vs. 0,14 ± 0.40; p < 0.0001), TPR-I (10,50 ± 4,86 vs. 0,36 ± 1,06; p < 0.0001), HADS-A (11,86 ± 2,85 vs. 3,90 ± 2,81; p < 0.0001), HADS-D (8,04 ± 3,18 vs. 1,42 ± 1,86; p < 0.0001) and PSQI (9,04 ± 2,62 vs. 4,64 ± 3,27; p < 0.0001). The mean SDI in the study group was significantly lower compared to healthy controls (32,36 ± 14,45 vs. 69,70 ± 19,94; p < 0.0001). No correlation was found between SDI and others items explored.

CONCLUSION

In line with previous studies, anxiety, depression and sleep disturbances are more common in BMS patients than in healthy population. This pilot study demonstrates for the first time an association between BMS and low sexual desire.

Voltage-gated sodium channels gene expression in Burning Mouth Syndrome: a case-control study

Burning mouth syndrome (BMS) is a condition characterized by painful symptoms of the oral mucosa, despite the absence of any clinical signs. Its etiology is unknown, and there is still no effective treatment to date. Current evidence has shown neuropathic impairment in BMS patients. Neuropathic pain can be related to the dysfunction of voltage-gated sodium channels, considering that these receptors regulate the induction of action potentials in nociceptive neurons. This study evaluated the gene expression of voltage-gated sodium channels Na v 1.7, Na v 1.8 and Na v 1.9 in these patients. The gene expressions of these channels were assessed by real time RT-PCR analysis of fresh-frozen tongue biopsies in a case-control study composed of 12 patients with BMS, and 5 healthy control patients, proportionally matched by sex and age, and analyzed using the 2^(-Delta Delta CT) method. There was no statistically significant difference between the analyzed groups, despite the increase in Na v 1.7 (fold-change = 3.13, p = 0.52) and decrease in Na v 1.9 (fold-change = 0.45, p = 0.36) gene expression in the BMS group. The Na v 1.8 gene was not expressed in any of the samples analyzed. Although the gene expression in the voltage-gated sodium channels in BMS under study seems to be comparable with that of the normal oral mucosa, the functionality of these channels in BMS has not yet been identified, thus suggesting that further research is needed to better understand these voltage-gated sodium channels.

Long-term prognosis of burning mouth syndrome following treatment

The purpose of this study was to evaluate the long-term prognosis of patients with burning mouth syndrome (BMS) after the termination or discontinuation of treatment and to identify the clinical characteristics that might affect that prognosis. Of 769 patients with an oral burning sensation, 202 with primary BMS who had been treated for at least 3 months were included. Among them, 28 patients who responded to the treatment and 25 patients who did not were assigned to responder and non-responder groups, respectively. Based on telephone interviews, the responders were classified into relapse and non-relapse subgroups, and the non-responder group into persistence and remission subgroups. The majority of responders reported no oral discomfort since their last visit. Compared with the non-relapse subgroup, the relapse subgroup had significantly higher levels of xerostomia at the first visit (P = 0.026) and taste disturbance at the last visit (P = 0.015). The majority of non-responders reported persistent oral discomfort since their last visit. No significant differences were found in the characteristics of oral symptoms between the persistence and remission subgroups. In conclusion, the treatment outcomes in the majority of responders and non-responders were maintained following treatment. Xerostomia and taste disturbance were associated with relapse of oral discomfort in the responders.

Efficacy of oral nystatin treatment for patients with oral mucosal dysesthesia but without objective oral mucosal manifestations and necessity of Candida culture test before oral nystatin treatment

Background/purpose

Materials and methods

Results

Conclusion

Thermography as a Non-Ionizing Quantitative Tool for Diagnosing Burning Mouth Syndrome: Case-Control Study

Objectives: Thermography is an imaging technique based on the acquisition and analysis of thermal data. The present study evaluates the use of tongue infrared thermography (IRT) as a tool for the diagnosis of burning mouth syndrome (BMS). Material and methods: An IRT study was carried out in patients diagnosed with BMS according to the criteria of the International Association for the Study of Pain (n = 32) and in healthy controls (n = 35). Burning sensations, dry mouth and taste disturbances were assessed, and three temperature values were recorded for each tongue surface (dorsal, right lateral, left lateral and tip), along with body temperature and environmental temperature. Results: A statistically significant difference was recorded in the temperature of the dorsal surface of the tongue between the BMS group and the controls (p = 0.01). The area under the curve (AUC) was 0.731 (95% CI: 0.402–0.657; p = 0.003). The sensitivity and specificity obtained was 62% and 77%, respectively. Conclusions: Infrared thermography appears to be useful as a complementary tool for the diagnosis of BMS, though further studies are needed in this field.

Orofacial pain disorders: An overview and diagnostic approach

Background:

Non-dental orofacial pain disorders are not uncommon, but idiopathic or primary facial pain syndromes are rare. Inadequate recognition of these disorders usually leads to unsatisfactory and unmet treatment needs.

Methods:

We conducted a narrative review with a literature search in PubMed until December 2021, focusing on current guidelines and the recently published International Classification of Orofacial Pain (ICOP).

Results:

In this paper, we provide an updated overview of the common orofacial pain disorders following the ICOP, covering the classification, epidemiology, pathophysiology, clinical approaches, and treatment options. Additionally, we propose a pragmatic approach focusing on the attack duration to improve distinguishing orofacial disorders.

Conclusion:

The introduction of ICOP offers the opportunity to better coordinate and concentrate scientific efforts, which lays the foundation for the identification of the disease mechanism of facial pain disorders and the optimization of the currently still insufficient therapeutic strategies.

Sensory characteristics and chronic facial pain conditions: Cross-sectional study

OBJECTIVES

This study investigated patients with neuropathic, myofascial and other orofacial pain conditions according to the differences and similarities of the sensory profile, and the association between sensory findings and neuropathic or non-neuropathic conditions.

DESIGN

132 healthy controls were compared with 174 orofacial pain patients that were classified into three groups (neuropathic, masticatory myofascial and other orofacial pain condition) and evaluated with a systematized protocol of sensory testing. Data were analyzed with chi-quare and Bonferroni correction (categorical data), Student´s t test, oneway ANOVA, Tukey (quantitative features), Pearson´s coefficient for correlations and logistic regression.

RESULTS

Cold, olfactory and superficial pain thresholds were higher in the group of neuropathic facial pain compared with the other groups, and the highest vibratory thresholds were observed in the group of other orofacial pain conditions. Deep pain thresholds were statistically lower in the group with masticatory myofascial pain.

CONCLUSIONS

Positive sensory findings (eg. hyperalgesia) were more common in the group of patients with masticatory myofascial pain, supporting inflammatory systemic mechanisms, and negative sensory findings not restricted to the trigeminal nerve (eg. hypoesthesia, hyposmia) were more frequent in patients with neuropathic conditions. Non-classical neuropathic orofacial pains also showed sensory impairment from pain chronification and from the overlap with functional disorders.

Potential differences in somatosensory function during premenopause and early and late postmenopause in patients with burning mouth syndrome: An observational case-control study

Background/purpose

Burning mouth syndrome (BMS) is a chronic condition presenting as intraoral burning or dysesthesia, with a high preponderance in menopausal women. This study aimed to examine the association between somatosensory dysfunction and BMS in premenopausal, early postmenopausal, and late postmenopausal patients, using a standardized Quantitative Sensory Testing (QST) protocol, and to determine the predictive value of thermal or mechanical perception by QST for detecting BMS.

Materials and methods

An observational case–control study was performed with 36 female participants with BMS (12 premenopausal, 10 early postmenopausal, and 14 late postmenopausal) and 42 age- and sex-matched healthy volunteers (21 premenopausal, 10 early postmenopausal, and 11 late postmenopausal). Neurophysiological tests were used to evaluate somatosensory dysfunction at the tongue.

Results

Z-score in the late postmenopausal BMS group revealed a gain of function for the cold pain threshold and heat pain threshold (Z = 2.08 and 3.38, respectively). In the multiple regression analysis with the Visual Analog Scale as the dependent variable, the vibration detection threshold predicted the severity of burning mouth sensation in the premenopausal group.

Conclusion

Late postmenopausal patients with BMS showed an increased response of the tongue to noxious thermal stimuli. This supports the theory that changes in sex hormones may affect trigeminal somatosensory function, particularly during the late postmenopausal stage in patients with BMS.

Consensus agreement to rename burning mouth syndrome and improve International Classification of Diseases-11 disease criteria: an international Delphi study

ABSTRACT

The International Classification of Diseases (ICD-11) proposes revisions in the nomenclature, disease definition, and diagnostic criteria for "burning mouth syndrome" (BMS). This process could benefit from additional systematically collected expert input. Thus, the purpose of this study was to use the Delphi method to (1) determine whether revision in nomenclature and alternative names for "BMS" are warranted and (2) identify areas of consensus among experts for changes to the disease description and proposed diagnostic criteria of "BMS," as described in the ICD-11 (World Health Organization). From 31 international invited experts, 23 who expressed interest were sent the survey. The study used 4 iterative surveys, each with a response rate of ≥82%. Consensus was predefined as 70% of participants in agreement. Data were summarized using both descriptive statistics and qualitative thematic analysis. Consensus indicated that BMS should not be classified as a syndrome and recommended instead renaming to "burning mouth disorder." Consensus included deletion of 2 diagnostic criteria: (1) emotional distress or functional disability and (2) the number of hours symptoms occur per day. Additional items that reached consensus clarified the disease definition and proposed more separate diagnostic criteria, including a list of local and systemic factors to evaluate as potential secondary causes of oral burning. Experts in this study recommended and came to consensus on select revisions to the proposed ICD-11 BMS nomenclature, diagnostic criteria, and disease definition. The revisions recommended have the potential to improve clarity, consistency, and accuracy of diagnosis for this disorder.

Dopamine agonist responsive burning mouth syndrome: Report of eight cases

BACKGROUND

Burning mouth syndrome (BMS) is characterized by burning sensation of the oral mucosa. There is a lack of effective treatment. In recent years, a special subtype of BMS has been reported, in which oral burning sensation is alleviated after chewing, speaking, or dopaminergic drug delivery. Currently, there are few reports about the subtype of BMS in China. This study was a retrospective analysis of the clinical data of BMS patients sensitive to dopamine agonist at our hospital, aiming to improve the recognition on this disease.

CASE SUMMARY

Eight patients diagnosed with dopamine agonist responsive BMS at the Liaocheng People's Hospital from January 1, 2017 to June 30, 2020 were recruited. The clinical manifestations, treatment, and prognosis were retrospectively analyzed. There were three male and five females in the eight patients. The median age was 56 years (range, 46-65 years). All the eight patients showed burning pain in the mouth. The symptoms were mild in the morning and severe in the evening, and alleviated after chewing, talking, and other oral activities. Four patients were accompanied by restless legs syndrome (RLS). Family history of RLS was positive in two patients. All patients were treated with pramipexol, and symptoms were basically relieved after 2-8 wk.

CONCLUSION

Dopamine agonist responsive BMS is a special subtype of BMS, which is alleviated after oral activities. Dopamine receptor agonist is an effective treatment.

Prediction of treatment outcome in burning mouth syndrome patients using machine learning based on clinical data

The purpose of this study is to apply a machine learning approach to predict whether patients with burning mouth syndrome (BMS) respond to the initial approach and clonazepam therapy based on clinical data. Among the patients with the primary type of BMS who visited the clinic from 2006 to 2015, those treated with the initial approach of detailed explanation regarding home care instruction and use of oral topical lubricants, or who were prescribed clonazepam for a minimum of 1 month were included in this study. The clinical data and treatment outcomes were collected from medical records. Extreme Gradient-Boosted Decision Trees was used for machine learning algorithms to construct prediction models. Accuracy of the prediction models was evaluated and feature importance calculated. The accuracy of the prediction models for the initial approach and clonazepam therapy was 67.6% and 67.4%, respectively. Aggravating factors and psychological distress were important features in the prediction model for the initial approach, and intensity of symptoms before administration was the important feature in the prediction model for clonazepam therapy. In conclusion, the analysis of treatment outcomes in patients with BMS using a machine learning approach showed meaningful results of clinical applicability.

Psychophysical evaluation of somatosensory function in oro-facial pain: achievements and challenges

AIM

This critical review describes key methodological aspects for a successful oro-facial psychophysical evaluation of the somatosensory system and highlights the diagnostic value of somatosensory assessment and management perspectives based on somatosensory profiling.

METHODS

This topical review was based on a non-systematic search for studies about somatosensory evaluation in oro-facial pain in PubMed and Embase.

RESULTS

The recent progress regarding the psychophysical evaluation of somatosensory function was largely possible due to the development and application of valid, reliable and standardised psychophysical methods. Qualitative sensory testing may be useful as a screening tool to rule out relevant somatosensory abnormalities. Nevertheless, the patient should preferably be referred to a more comprehensive assessment with the quantitative sensory testing battery if confirmation of somatosensory abnormalities is necessary. Moreover, the identification of relevant somatosensory alterations in chronic pain disorders that do not fulfil the current criteria to be regarded as neuropathic has also increased the usefulness of somatosensory evaluation as a feasible method to better characterise the patients and perhaps elucidate some underpinnings of the so-called 'nociplastic' pain disorders. Finally, an additional benefit of oro-facial pain treatment based on somatosensory profiling still needs to be demonstrated and convincing evidence of somatosensory findings as predictors of treatment efficacy in chronic oro-facial pain awaits further studies.

CONCLUSION

Psychophysical evaluation of somatosensory function in oro-facial pain is still in its infancy but with a clear potential to continue to improve the assessment, diagnosis and management of oro-facial pain patients.

Is a neuropathic mechanism involved in the perception of oral dryness?

OBJECTIVES

The aim of the present study was to review the existing phenomena which could affect subjective oral dryness and to consider the possibility that neural processing is involved in the perception of oral dryness.

DESIGN

A comprehensive review of scientific literatures relevant to contributing factors of dry mouth symptoms including salivary parameters related with oral dryness and role of neural mechanisms in perception of dry mouth symptoms was conducted.

RESULTS

Several previous reports suggested the possibility of neural processing mechanisms in perception of oral dryness. The decreased pain threshold in the oral cavity of rats with dry tongue and complaints of subjective oral dryness in patients with burning mouth syndrome, of which lacked an actual decrease in salivary output and mucosal wetness, could support this idea. Sensory changes in the oral mucosa and oral dryness may have a bi-directional influence that patients with oral dryness would be more subject to neuropathic pain in the oral mucosa, and those with neuropathic pain in the oral cavity could have complaints associated with higher levels of dry mouth symptoms.

CONCLUSION

A bi-directional influence between sensory change in the oral mucosa and subjective oral dryness could be assumed. We suggest the administration of neuropathic pain medications for controlling subjective oral dryness in patients without objective sign of hyposalivation.

Structural connectivity changes in the cerebral pain matrix in burning mouth syndrome: a multi-shell, multi-tissue-constrained spherical deconvolution model analysis

PURPOSE

Burning mouth syndrome (BMS) is a chronic intraoral pain syndrome. Previous studies have attempted to determine the brain connectivity features in BMS using functional and structural magnetic resonance imaging. However, no study has investigated the structural connectivity using multi-shell, multi-tissue-constrained spherical deconvolution (MSMT-CSD), anatomically constrained tractography (ACT), and spherical deconvolution informed filtering of tractograms (SIFT). Therefore, this study aimed to assess the differences in brain structural connectivity of patients with BMS and healthy controls using probabilistic tractography with these methods, and graph analysis.

METHODS

Fourteen patients with BMS and 11 age- and sex-matched healthy volunteers underwent 3-T magnetic resonance imaging. MSMT-CSD-based probabilistic structural connectivity was computed using the second-order integration over fiber orientation distributions algorithm based on nodes set in 84 anatomical cortical regions with ACT and SIFT. A t-test was performed for comparisons between the BMS and healthy control brain networks.

RESULTS

The betweenness centrality was significantly higher in the left insula, right amygdala, and right lateral orbitofrontal cortex and significantly lower in the right inferotemporal cortex in the BMS group than that in healthy controls. However, no significant difference was found in the clustering coefficient, node degree, and small-worldness between the two groups.

CONCLUSION

Graph analysis of brain probabilistic structural connectivity, based on diffusion imaging using an MSMT-CSD model with ACT and SIFT, revealed alterations in the regions comprising the pain matrix and medial pain ascending pathway. These results highlight the emotional-affective profile of BMS, which is a type of chronic pain syndrome.

Orofacial Manifestations Assisting the Diagnosis of Cowden Syndrome in a Middle-Aged Patient: Case Report and Literature Overview

Middle-aged and old adults (≥ 50 years) diagnosed with Cowden syndrome (CS) with orofacial manifestations are uncommon. We describe a case of CS in a 53-year-old female showing "narrow bird-like" face, macrocephaly, acral keratoses, oral candidiasis, burning in the mouth, and multiple asymptomatic papillomatous lesions with a cobblestone pattern distributed on the alveolar ridge, tongue, buccal mucosa, and commissure. The histopathological features of lesions of the oral mucosa were those of papillary fibroepithelial hyperplasia. Immunohistochemistry revealed strong positivity for PTEN and p53 in most epithelial cells, while the expression of Bcl-2, S-100, and Ki-67 was weak/negative. According to a review conducted in PubMed, Web of Science, Embase, and Scopus for the analysis of reports of CS individuals ≥ 50 years with orofacial manifestations, 56 cases have been described in literature. Predilection for women was observed, with a female:male ratio of 2.3:1. Thirty-five (62.5%) individuals developed some malignant neoplasms. Oral health providers should be aware of the orofacial aspects of CS, including multiple papillomatosis, which can be an important criterion for diagnosis. Since malignancies may occur in older adults with CS, the need for strict surveillance is necessary. The present case has been under follow-up for 7 years without evidence of other manifestations.

Acute and Chronic Pain from Facial Skin and Oral Mucosa: Unique Neurobiology and Challenging Treatment

The oral cavity is a portal into the digestive system, which exhibits unique sensory properties. Like facial skin, the oral mucosa needs to be exquisitely sensitive and selective, in order to detect harmful toxins versus edible food. Chemosensation and somatosensation by multiple receptors, including transient receptor potential channels, are well-developed to meet these needs. In contrast to facial skin, however, the oral mucosa rarely exhibits itch responses. Like the gut, the oral cavity performs mechanical and chemical digestion. Therefore, the oral mucosa needs to be insensitive, to some degree, in order to endure noxious irritation. Persistent pain from the oral mucosa is often due to ulcers, involving both tissue injury and infection. Trigeminal nerve injury and trigeminal neuralgia produce intractable pain in the orofacial skin and the oral mucosa, through mechanisms distinct from those seen in the spinal area, which is particularly difficult to predict or treat. The diagnosis and treatment of idiopathic chronic pain, such as atypical odontalgia (idiopathic painful trigeminal neuropathy or post-traumatic trigeminal neuropathy) and burning mouth syndrome, remain especially challenging. The central integration of gustatory inputs might modulate chronic oral and facial pain. A lack of pain in chronic inflammation inside the oral cavity, such as chronic periodontitis, involves the specialized functioning of oral bacteria. A more detailed understanding of the unique neurobiology of pain from the orofacial skin and the oral mucosa should help us develop novel methods for better treating persistent orofacial pain.

Orofacial pain in 1916 patients with early or moderate Parkinson disease

This article reports the largest epidemiological study of orofacial pain prevalence in patients with Parkinson disease to date.

Introduction:

Several studies have reported that some types of orofacial pain are more common in patients with Parkinson disease (PD) than the general population.

Objectives:

In this study, we aimed to investigate the prevalence of self-reported orofacial pain in a larger group of patients with PD than has been previously studied.

Methods:

We analysed data from 1916 participants with PD in a cross-sectional study recruited to the UK Parkinson's Pain Study who had detailed assessments of pain, motor, and nonmotor symptoms. The King's Parkinson's Pain scale was used to quantify different subtypes of pain.

Results:

A total of 139 (7.3%) patients reported the presence of some form of orofacial pain. Burning mouth syndrome was reported in 32 (1.7%), whereas chewing pain was found in 38 (2.0%) and grinding pain in 78 (4.0%). Orofacial pain was significantly more common in females (10.4%) than males (5.9%). Multiple logistic regression analysis showed a significant association between orofacial pain and pain severity, neuropathic pain, and oral motor and nonmotor dysfunction.

Conclusion:

In our study, population cohort of early patients with PD found prevalence of orofacial pain conditions similar to that in the general population.

The Mystery of "Metal Mouth" in Chemotherapy

Of all the oral sensations that are experienced, "metallic" is one that is rarely reported in healthy participants. So why, then, do chemotherapy patients so frequently report that "metallic" sensations overpower and interfere with their enjoyment of food and drink? This side-effect of chemotherapy-often referred to (e.g., by patients) as "metal mouth"-can adversely affect their appetite, resulting in weight loss, which potentially endangers (or at the very least slows) their recovery. The etiology of "metal mouth" is poorly understood, and current management strategies are largely unevidenced. As a result, patients continue to suffer as a result of this poorly understood phenomenon. Here, we provide our perspective on the issue, outlining the evidence for a range of possible etiologies, and highlighting key research questions. We explore the evidence for "metallic" as a putative taste, and whether "metal mouth" might therefore be a form of phantageusia, perhaps similar to already-described "release-of-inhibition" phenomena. We comment on the possibility that "metal mouth" may simply be a direct effect of chemotherapy drugs. We present the novel theory that "metal mouth" may be linked to chemotherapy-induced sensitization of TRPV1. Finally, we discuss the evidence for retronasal olfaction of lipid oxidation products in the etiology of "metal mouth." This article seeks principally to guide much-needed future research which will hopefully one day provide a basis for the development of novel supportive therapies for future generations of patients undergoing chemotherapy.

Effect of a Homemade Salivary Substitute Prepared Using Chamomile (Matricaria chamomilla L.) Flower and Flax (Linum usitatissimum L.) Seed to Relieve Primary Burning Mouth Syndrome: A Preliminary Report

Objectives: To evaluate (1) the effect of a salivary substitute prepared using chamomile (Matricaria chamomilla L.) flower and flax (Linum usitatissimum L.) seed to relieve Primary burning mouth syndrome (BMS) symptoms, (2) their effect on the inhibition of matrix metallopeptidase 2 (MMP2) and MMP9 metalloproteinases, and (3) their potential cellular cytotoxic effect. Subjects: 40 women aging >40 years with diagnosis of primary BMS. Settings/Location: Center of Diagnosis of Diseases of the Mouth, Federal University of Pelotas, Brazil. Design: This was an open clinical trial where primary BMS patients used the homemade salivary. At the first appointment, after 30 and 60 days, the authors evaluated the pattern and intensity of BMS and xerostomia symptoms, and then determined and compared the unstimulated salivary flow rate (SFR), viscosity, and salivary pH. MMP2 and MMP9 activities in saliva and cytotoxicity were assessed using different concentrations of chamomile flower and flax seed separately. Interventions: Subjects used the homemade salivary substitute for 3 months and were instructed to rinse their mouth three to four times daily for 1 min. Outcome measures: A numeric rating scale to evaluate the intensity of burning sensation and xerostomia symptoms, salivary flow rate (SFR) to determine salivary volume, dynamic rheology technique for viscosity and a digital meter for salivary pH. MMP2 and MMP9 activities in saliva and cytotoxicity were assessed by zymography and cell viability assay respectively. Results: After treatment, severity of BMS symptoms decreased, the SFR increased, salivary viscosity decreased, and severity of xerostomia sensation (in patients who reported having this symptom) improved (p < 0.05). Chamomile flower and flax seed had no effect on inhibiting MMP2 and MMP9 activities, and neither showed cellular cytotoxic effects. Conclusion: This homemade salivary substitute is an economical, viable, easily manipulated, noncytotoxic, and a practical alternative to relieve BMS symptoms.

Chemosensory Function in Burning Mouth Syndrome a Comparative Cross-Sectional Study

Taste and smell are considered to be functions that contribute to the maintenance of good nutritional status. The present study evaluates taste and smell function in patients with burning mouth syndrome (BMS) versus a control group. A cross-sectional study was made of 36 consecutive patients with BMS and 56 healthy patients. Smell was assessed using the Sniffin' Sticks test, while taste was evaluated with Taste Strips. Oral quality of life was assessed with the Oral Health Impact Profile-14 (OHIP-14), and the severity of dry mouth with the Thompson Xerostomia Inventory. The patients with BMS had a mean age of 60.4 0 ± 10.5 years, while the controls had a mean age of 61.3 ± 19 years. No significant differences in smell were recorded between the two groups. In contrast, significant differences in taste function were observed between the patients with BMS and the controls. In the patients with BMS, 44.4% suffered taste alterations compared with the 3.4% healthy controls. Further studies in such patients are needed to allow improved management of the chemosensory problems, mouth dryness, and oral health-related quality of life in BMS.

Evaluating the Suitability and Potential Efficiency of Cannabis sativa Oil for Patients with Primary Burning Mouth Syndrome: A Prospective, Open-Label, Single-Arm Pilot Study

OBJECTIVE

To evaluate the use of a Cannabis sativa oil in the management of patients diagnosed with primary burning mouth syndrome (BMS).

DESIGN

Prospective, open-label, single-arm pilot study.

SETTING

University hospital.

SUBJECTS

Seventeen patients with diagnosed BMS were included.

METHODS

Subjects were treated for 4 weeks with a full cannabis plant extract, which was prepared from standardized plant material (cannabis flos) in specialized pharmacies by means of Romano-Hazekamp extraction and was diluted in oil (1 g of cannabis in 10 g of olive oil). The primary outcome was the change in pain intensity (assessed by the visual analog scale, Present Pain Intensity scale, McGill Pain Questionnaire, and Oral Health Impact Profiles) at the end of the protocol and during the succeeding 24 weeks; the neuropathic pain was also investigated with a specific interview questionnaire (DN4-interview [Douleur Neuropathique en 4 Questions]). Levels of anxiety and depression were considered as secondary outcomes, together with reported adverse events due to the specified treatment.

RESULTS

Subjects showed a statistically significant improvement over time in terms of a clinical remission of the oral symptoms. Levels of anxiety and depression also changed statistically, displaying a favorable improvement. No serious reactions were detailed. None of the patients had to stop the treatment due to adverse events.

CONCLUSIONS

In this pilot evaluation, the C. sativa oil provided was effective and well tolerated in patients with primary BMS. Further bigger and properly defined randomized controlled trials, with different therapeutic approaches or placebo control, are needed, however.

Differences in personality, perceived stress and physical activity in women with burning mouth syndrome compared to controls

OBJECTIVES

Burning mouth syndrome (BMS) is a long-lasting pain condition which is commonly associated with anxiety symptoms and experience of adverse, stressful life events have been reported by those diagnosed with the syndrome. Stress-related biomarkers have been related to personality traits in BMS and a personality with high stress susceptibility and perceived stress may be of importance. Although biopsychosocial approaches are suggested to manage long-lasting orofacial pain, to date little is known about physical activity in women with BMS. The aim of this study was to investigate if personality, perceived stress and physical activity distinguish women with BMS from controls.

METHODS

Fifty-six women with BMS and 56 controls matched on age and gender completed Swedish universities Scales of Personality (SSP), Perceived Stress Questionnaire (PSQ) and a general questionnaire with an item on weekly physical activity frequency. In addition, health-related quality of life was explored by additional questionnaires and reported in a companion article (Jedel et al. Scand J Pain. 2020. PubMed PMID: 32853174).

RESULTS

SSP subscales Somatic Trait Anxiety, Psychic Trait Anxiety, Stress Susceptibility and Verbal Trait Aggression differed between women with BMS and controls and the personality factor scores for Neuroticism and Aggressiveness were higher. Perceived stress measured by PSQ index was higher for women with BMS compared to controls. Women with BMS reported lower physical activity frequency compared to controls and those reporting physical activity <4 days/week scored higher on PSQ compared to those with weekly physical activity ≥4 days/week.

CONCLUSIONS

Personality distinguished women with BMS from controls in this study. Perceived stress was higher and weekly physical activity was lower in women with BMS compared to controls. Our findings suggest physical activity should be more comprehensively measured in future BMS studies and, by extension, physical activity may be a treatment option for women with BMS. Pain management aiming to restore function and mobility with stress reduction should be considered in clinical decision making for women with BMS who have a personality with stress susceptibility, especially if reporting high perceived stress and insufficient physical activity.

Thermal quantitative sensory testing in burning mouth syndrome

OBJECTIVES

Subjects with burning mouth syndrome (BMS) have altered sensitivity and pain thresholds for thermal stimuli compared to a control group.

MATERIALS AND METHODS

Fourteen women and 6 men (average age = 62.60 years, median = 63.50) with BMS and a control group were tested using the method of thermal quantitative sensory testing (tQST) (tip, right, and left lateral border of the tongue, left thumb) to determine their heat/cold detection threshold (WDT/CDT) and heat/cold pain threshold (HPT/CPT).

RESULTS

Only the CPT values at the tip and both lateral border of the tongue show a statistically significant difference: tip of the tongue: sick = 12.0 ± 5.5 °C, median 14.2°C; healthy = 4.5 ± 2.9 °C; median = 6.4 °C; p = 0.000; right lateral border: sick = 8.55 ± 3.34 °C; healthy = 4.46 ± 1.90 °C; median 5.8 °C; p < 0.001; left lateral border: sick = 10.18 ± 3.94 °C¸ healthy = 4.15 ± 2.18 °C; median = 6.0 °C; p < 0.001.

CONCLUSIONS

BMS may be a combination of a dysfunction of free nociceptive nerve endings in the peripheral nervous system and impaired pain processing in the central nervous system.

CLINICAL RELEVANCE

This preliminary study provides hints to other causes of BMS. This offers the possibility of further therapeutic options.

Relationships between subjective taste sensations and electrogustometry findings in patients with taste disorders

This study aimed to examine the relationships between subjective taste sensations and electrogustometry (EGM) findings in patients with taste disturbances according to the presence of burning mouth (BM) symptoms. Forty-six patients were included and asked to complete a questionnaire that contained questions on subjective taste sensations for the four basic taste qualities and the pattern of taste disorders such as ageusia, hypogeusia and dysgeusia. EGM was performed to measure detection thresholds. To examine the influence of BM symptoms, patients were divided into two groups: patients with and without BM symptoms. The patients consisted of 11 men and 35 women. The group without BM symptoms (n=26) had significantly lower degrees of subjective taste sensations for all taste qualities and higher correlation levels between subjective taste sensations and EGM thresholds than the group with BM symptoms (n=20). The patterns of taste disorders also showed more significant associations with the levels of subjective taste sensations in the patients without BM symptoms compared with those with BM symptoms. In conclusion, patients with taste disorders without BM symptoms had more severe taste disturbances than those with BM symptoms. The pathophysiology of taste disturbances differs according to the presence or absence of BM symptoms.

Central mechanisms of pain in orofacial pain patients: Implications for management

BACKGROUND

Central sensitization (CS) is a form of neuroplasticity characterized by changes in the neural sensitivity, responsiveness, and/or output that are not contingent on peripheral input nor activity-dependent. CS is characterized by activation of unmyelinated C-fibers resulting in a cascade of events at molecular and cellular levels which eventuate into generation of synaptic currents at rest. CS, therefore, contributes to heightened generalized pain sensitivity, further complicates the process of reaching a diagnosis, and increases the possibility of treatment failure. BODY: Trigeminal nerve is the main sensory supplier of the anterior part of the head, including the intraoral structures. Primary afferent nociceptors of the trigeminal nerve and low threshold mechanoreceptors synapse with wide dynamic range (WDR) neurons in the pons. This multifaceted network of nerve interactions which is further complicated by the modulatory circuits that can suppress or heighten the activity of WDR neurons is one of the main contributors to CS. The importance of CS in orofacial pain disorders is emphasized in the context of chronic pain development. As for all chronic pain conditions, it is crucial to consider the biopsychosocial aspects of chronic orofacial pain in managing this diverse group of conditions. This review highlights current understanding of the biopsychosocial model and central mechanisms contributing to the pathogenesis of chronic orofacial pain.

Psychophysical characterisation of burning mouth syndrome-A systematic review and meta-analysis

BACKGROUND

Primary burning mouth syndrome (BMS) is an oro-facial disease with neuropathic characteristics. Psychophysics, such as quantitative sensory testing (QST), is used to sub-classify neuropathic pain syndromes, but their usefulness in characterising BMS is not yet clear.

OBJECTIVE

The aim of this study was to summarise and to quantitatively and qualitatively analyse the available information about QST findings in BMS, and to reflect on possible mechanisms of disease.

METHODS

In this systematic review and meta-analysis, different search strategies were used to screen for articles in PubMed, Embase, EBSCOhost, Cochrane Library, Web of Science, Google Scholar and two sources of conference abstracts. Primary clinical studies focused on QST assessment in patients with BMS were included. Data were synthesised qualitatively and quantitatively. Risk of bias was assessed following the AHRQ guidelines.

RESULTS

Thirteen articles with low to moderate risk of bias and one conference abstract were selected from 45 unique articles that were identified. Individually, the studies reported combinations of thermal and mechanical sensory impairments measured by QST. The meta-analysis showed significant sensory differences between patients and controls in warmth (effect size = 0.683; P < .05) and cold detection thresholds (effect size = -0.580; P < .001).

CONCLUSION

The results indicate that thermal sensitivity seems to be altered in patients with BMS compared to controls, suggesting a small-fibre neuropathy. However, study protocols were highly variable and heterogeneous. Therefore, studies with better designs and complete reporting of results should be performed to bring value to the use of psychophysics in the assessment of BMS.

Salivary Biomarkers and Their Correlation with Pain and Stress in Patients with Burning Mouth Syndrome

Objective: To evaluate a panel of salivary analytes involving biomarkers of inflammation, stress, immune system and antioxidant status in patients with burning mouth syndrome (BMS) and to study their relationship with clinical variables. Materials and Methods: A total of 51 patients with BMS and 31 controls were consecutively enrolled in the study, with the recording of oral habits, the severity of pain using a visual analogue scale (VAS), the Hospital Anxiety and Depression (HAD) score and the Oral Health Impact Profile-14 (OHIP14) score. Resting whole saliva was collected with the drainage technique, followed by the measurement of 11 biomarkers. Results: The salivary flow was higher in patients with BMS. Among all the biomarkers studied, significantly higher levels of alpha-amylase, immunoglobulin A (IgA), and macrophage inflammatory protein-4 (MIP4) and lower levels of uric acid and ferric reducing activity of plasma (FRAP) were observed in the saliva of patients with BMS as compared to the controls (p < 0.05 in all cases). Positive correlations were found between pain, oral quality of life and anxiety scores and salivary biomarkers. Conclusions: BMS is associated with changes in salivary biomarkers of inflammation, oxidative stress and stress, being related to the degree of pain and anxiety.

Facial Pain: A Comprehensive Review and Proposal for a Pragmatic Diagnostic Approach

BACKGROUND

Facial pain, alone or combined with other symptoms, is a frequent complaint. Moreover, it is a symptom situated at, more than any other pain condition, a crosspoint where several disciplines meet, for example, dentists; manual therapists; ophthalmologists; psychologists; and ear-nose-throat, pain, and internal medicine physicians besides neurologists and neurosurgeons. Recently, a new version of the most widely used classification system among neurologists for headache and facial pain, the International Classification of Headache Disorders, has been published.

OBJECTIVE

The aims of this study were to provide an overview of the most prevalent etiologies of facial pain and to provide a generic framework for the neurologist on how to manage patients presenting with facial pain.

METHODS

An overview of the different etiologies of facial pain is provided from the viewpoint of the respective clinical specialties that are confronted with facial pain. Key message: Caregivers should "think outside their own box" and refer to other disciplines when indicated. If not, a correct diagnosis can be delayed and unnecessary treatments might be given. The presented framework is aimed at excluding life- or organ-threatening diseases, providing several clinical clues and indications for technical investigations, and ultimately leading to the correct diagnosis and/or referral to other disciplines.