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.

Oxidative stress-mediated proapoptosis signaling: A novel theory on the mechanism underlying the pathogenesis of burning mouth syndrome.

BACKGROUND: Burning mouth syndrome (BMS) is a chronic oral pain disorder characterized by a generalized burning sensation in the oral mucosa without apparent medical or dental causes. Despite various hypotheses proposed to explain BMS pathogenesis, a clear understanding of the cellular-level events and associated histologic and molecular findings is lacking. Advancing our understanding of BMS pathogenesis could facilitate the development of more targeted therapeutic interventions. TYPES OF STUDIES REVIEWED: The authors conducted an extensive literature search and review of cellular mechanisms, focusing on evidence-based data that support a comprehensive hypothesis for BMS pathogenesis. The authors explored novel and detailed mechanisms that may account for the characteristic features of BMS. RESULTS: The authors proposed that BMS symptoms arise from the uncontrolled activation of proapoptotic transmembrane calcium permeable channels expressed in intraoral mucosal nerve fibers. Elevated levels of reactive oxygen species or dysfunctional antiapoptosis pathways may lead to uncontrolled oxidative stress-mediated apoptosis signaling, resulting in upregulation of transmembrane transient receptor potential vanilloid type 1 and P2X 3 calcium channels in nociceptive fibers. Activation of these channels can cause nerve terminal depolarization, leading to generation of action potentials that are centrally interpreted as pain. CONCLUSIONS AND PRACTICAL IMPLICATIONS: The authors present a novel hypothesis for BMS pathogenesis, highlighting the role of proapoptotic transmembrane calcium permeable channels and oxidative stress-mediated apoptosis signaling in the development of BMS symptoms. Understanding these underlying mechanisms could provide new insights into the development of targeted therapeutic interventions for BMS. Additional research is warranted to validate this hypothesis and explore potential avenues for effective management of BMS.

Use of oral devices in the management of oral dysesthesia: case reports and literature review.

Oral dysesthesia (OD) is a diagnosis of exclusion that manifests as an unpleasant and abnormal sensation of the oral mucosa without any noticeable oral lesions. Burning sensation is one of the manifestations of OD which may advocate for similar pharmacotherapeutic options to burning mouth syndrome (BMS), resulting in possible adverse events. The aim of these case reports was to illustrate the significance and rationale for the use of oral devices as a mechanical/physical barrier and a safe approach in the management of OD, without experiencing any antagonistic effects from pharmacotherapeutic agents. Two patients with spontaneous and evoked (following dental procedures) OD symptoms in the right posterior mandibular quadrant and anterior hard palatal areas were evaluated. Additionally, their OD symptoms were associated with hyposalivation and taste changes. A thorough history and complete head and neck examination, with the exclusion of oral lesions and systemic conditions, were performed. These patients were previously prescribed topical clonazepam rinses. An in-office trial, with application of orthodontic wax to the affected area, was performed as a preliminary test in order to justify the fabrication of an oral device for possible symptomatic relief. Conclusion: The case reports demonstrated significant improvement of OD symptoms and amelioration of pain following fabrication of oral devices in two patients with no undesirable effects from pharmacotherapy. Additionally, the oral devices aided as a mechanical/physical barrier, potentially exerting a placebo effect while facilitating an improved quality of life. Furthermore, the cost-effectiveness and ease of fabricating the oral device has been advantageous over other systemic medications. This encourages the need for a detailed prospective study.

Topical gabapentin solution for the management of burning mouth syndrome: A retrospective study.

OBJECTIVE: The aim of this retrospective study was to evaluate the effectiveness and safety of topical gabapentin solution (250 mg/mL) for the management of burning mouth syndrome (BMS). STUDY DESIGN: A retrospective chart review was conducted of all patients diagnosed with BMS and managed with gabapentin 250 mg/mL solution (swish and spit) between January 2021 and October 2022. Patient-reported outcomes included changes in burning score ranked on a 10-point numeric rating scale (NRS) and reported adverse drug reactions (ADR). Wilcoxon signed-rank test was used to assess differences in the oral burning score ranked on a NRS (0-10) between the baseline visit and the second visit. RESULTS: A total of 19 patients (68.4% females) with BMS were included and evaluated for follow-up at a median of 86 days (range: 29-195). Overall, patients reported a median 2-point burning decrease on a 0-10 NRS between the baseline visit and the second visit (p < 0.01). ADRs were reported by 3 patients (15.8%). CONCLUSION: Although this was a small retrospective study, BMS management with topical gabapentin (250 mg/mL) appears to be effective and well-tolerated. Future randomized prospective studies are needed to verify these preliminary findings.

A Case Report of Burning Mouth Syndrome with Dry Mouth Managed by Kampo Medicine.

The patient was a 56-year-old woman who complained of chronic pain involving her tongue. We diagnosed her with burning mouth syndrome (BMS) based on exclusion of any local factors or systemic conditions. The patient not only had tongue pain but also had other signs and symptoms like scalloped tongue, dry mouth, and headache. To manage these additional issues, we used Goreisan, an herbal Kampo medicine, as a complementary alternative medicine (CAM) approach along with cognitive behavioral therapy (CBT). The patient's BMS was successfully managed with the combination of CAM and CBT, which may suggest that the pathophysiology for BMS might be nociplastic pain rather than purely nociceptive or neuropathic.

Therapeutic effects of clonazepam in patients with burning mouth syndrome and various symptoms or psychological conditions.

Burning mouth syndrome (BMS) is frequently accompanied by dysgeusia and xerostomia. Clonazepam has been widely prescribed and is effective, but it is unclear whether clonazepam also affects the symptoms that accompany BMS, or whether such symptoms affect treatment outcomes. Here, we investigated the therapeutic outcomes in BMS patients with various symptoms or comorbidities. We retrospectively reviewed 41 patients diagnosed with BMS between June 2010 and June 2021 at a single institution. Patients were instructed to take clonazepam for 6 weeks. Before the first dose, burning pain intensity was measured using a visual analog scale (VAS); the unstimulated salivary flow rate (USFR), psychologic characteristics, site(s) of pain, and any taste disturbance were evaluated. Burning pain intensity was measured again after 6 weeks. Thirty-one of the 41 patents (75.7%) exhibited a depressed mood, whereas more than 67.8% of the patients exhibited anxiety. Subjective xerostomia was reported by ten patients (24.3%). The mean salivary flow rate was 0.69 mL/min and hyposalivation (an unstimulated salivary flow rate ≤ 0.5 mL/min) was apparent in ten patients (24.3%). Dysgeusia was present in 20 patients (48.7%); a bitter taste (n = 15, 75%) was reported by the largest proportion of patients. Patients who reported a bitter taste responded best in terms of burning pain reduction after 6 weeks (n = 4, 26.6%). Overall, 32 patients (78%) reported decreased oral burning pain after clonazepam (mean VAS score changed from 6.56 to 5.34) use. Patients who reported taste disturbances exhibited a significantly greater decrease in burning pain, compared with other patients (mean VAS score changed from 6.41 to 4.58) (p = 0.02). Clonazepam significantly improved burning pain in BMS patients who had taste disturbances.

Treatments for Burning Mouth Syndrome: A Network Meta-analysis.

The aim of this systematic review and network meta-analysis (NMA) of randomized controlled trials was to evaluate the effectiveness of treatments for pain relief of burning mouth syndrome (BMS). Five databases and gray literature were searched. Independent reviewers selected studies, extracted data, and assessed the risk of bias. The primary outcome was pain relief or burning sensation, and the secondary outcomes were side effects, quality of life, salivary flow, and TNF-α and interleukin 6 levels. Four comparable interventions were grouped into different network geometries to ensure the transitivity assumption for pain: photobiomodulation therapy, alpha-lipoic acid, phytotherapics, and anxiolytics/antidepressants. Mean difference (MD) and 95% CI were calculated for continuous outcomes. The minimal important difference to consider a therapy beneficial against placebo was an MD of at least -1 for relief of pain. To interpret the results, the GRADE approach for NMA was used with a minimally contextualized framework and the magnitude of the effect. Forty-four trials were included (24 in the NMA). The anxiolytic (clonazepam) probably reduces the pain of BMS when compared with placebo (MD, -1.88; 95% CI, -2.61 to -1.16; moderate certainty). Photobiomodulation therapy (MD, -1.90; 95% CI, -3.58 to -0.21) and pregabalin (MD, -2.40; 95% CI, -3.49 to -1.32) achieved the minimal important difference of a beneficial effect with low or very low certainty. Among all tested treatments, only clonazepam is likely to reduce the pain of BMS when compared with placebo. The majority of the other treatments had low and very low certainty, mainly due to imprecision, indirectness, and intransitivity. More randomized controlled trials comparing treatments against placebo are encouraged to confirm the evidence and test possible alternative treatments (PROSPERO CRD42021255039).

Low-dose naltrexone for treatment of burning mouth syndrome.

OBJECTIVE: The International Classification of Disease defines burning mouth syndrome (BMS) as a chronic intraoral burning sensation, with no identifiable local or systemic cause. Since current management is often unsatisfactory, the aim of this report is to describe a new treatment modality (i.e., low-dose naltrexone [LDN]). STUDY DESIGN: A 62-year-old woman presented with the complaint of burning on the tongue of 3 years' duration. Existing comorbidities were fibromyalgia, irritable bowel syndrome, headache, and interstitial cystitis. Her reported pain intensity ranged from 2/10 (morning) to 8/10 (evening) on a numeric rating scale. With the diagnosis of BMS and hyposalivation, and in light of her current clonazepam use and fibromyalgia, a dry mouth protocol and LDN (3 mg) were prescribed. RESULTS: After 1 month, her pain intensity decreased by 50%, with no pain upon awakening. After 2 months, the widespread pain associated with her chronic morbidities also reduced by 50%, and her headache disappeared. After adjusting LDN dose to 4.5 mg, the patient was stable at 6 months, with 50% reduction of widespread pain and 2/10 BMS pain, and no reported side effects. CONCLUSIONS: These preliminary results suggest that LDN may be a feasible and effective treatment for BMS, especially in patients' refractory to traditional treatment.

WWOM VII: Effectiveness of topical interventions in the management of burning mouth syndrome: A systematic review.

OBJECTIVES: To assess the effectiveness of topical interventions in the management of burning mouth syndrome (BMS), 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 on topical interventions for the management of BMS, published in PubMed, Web of Science, PsycInfo, Cochrane Database/Central, and Google Scholar through May 2021 was performed. RESULTS: Eight RCTs (n = 358 study participants) were included in this study. Due to underreporting of IMMPACT domains, publication bias, high degree of heterogeneity between studies, meta-analysis was not undertaken. Based on changes in visual analogue pain scores (ΔVAS), the most reported outcome, the effectiveness of the topical interventions was demonstrated; however, it is low level of evidence. CONCLUSIONS: High levels of variability (interventions, outcomes, outcome measurement tools, and intervention effects evaluated), heterogeneity, publication bias, and underreporting of IMMPACT domains were observed across the RCTs. This systematic review highlights the need for application of standardized outcome measures to future RCTs. At the present time, there is lack of moderate-strong evidence on short- and long-term outcomes to support or refute the use of any particular topical intervention in managing BMS. Future RCTs with standardized outcome measures are needed.

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.

Innovative histological and histochemical characterization of tongue biopsies from patients with burning mouth syndrome.

OBJECTIVES: The present pilot study aims to perform an innovative histological and histochemical characterization of samples from patients with burning mouth syndrome (BMS) to correlate these findings with the clinical scenario. METHODS: To carry out this objective, the study samples were stained with the hematoxylin-eosin stain and later, an histochemical study was carried out to determine the composition of the extracellular matrix (ECM) using the stains of Alcian Blue, Picrosirius, Reticulin from Gomori and Verhoeff. RESULTS: The results of this study revealed histological patterns compatible with cellular hypertrophy in different layers of the epithelium as well as a greater keratinization in BMS cases. On the other hand, a lower amount of proteoglycans and a greater amount of collagen fibers were observed compared to the control. In addition, older patients had fewer reticular fibers and younger patients had fewer elastic fibers compared to the control. CONCLUSIONS: In conclusion, the present study shows the existence of a correlation between the histological patterns, age and symptoms of patients with BMS. Therefore, it is necessary to develop synergistic studies in order to assess and implement new classification systems that could improve the therapeutic approach of patients with BMS.

Challenge in the diagnosis, evaluation, and management of burning mouth sensation: A retrospective cohort study.

BACKGROUND: Burning mouth sensation is a common symptom with varying etiologies that can affect patient quality of life. The authors aimed to investigate the clinical characteristics, differentiate the underlying causes, and evaluate the impact on quality of life of patients with burning mouth sensation. CASE DESCRIPTION: A retrospective cohort study of 583 patients with burning mouth sensation symptoms was conducted. Demographic features, clinical characteristics, and associated systemic comorbidities of patients were collected. The 14-item Oral Health Impact Profile Questionnaire score and posttreatment follow-up were evaluated and analyzed among patients. In total, 583 patients with burning mouth sensation symptoms were enrolled; perimenopausal women were most affected; mean (SD) age was 57.04 (12.03) years, and the female to male ratio was 7:1. Patients were stratified into 178 patients (30.53%) with burning mouth syndrome (BMS) and 405 patients (69.47%) without BMS. No significant differences were found for age, sex, clinical characteristics, and 14-item Oral Health Impact Profile Questionnaire scores between BMS and no BMS groups. Notably, 72 of 119 patients without BMS who participated in follow-up had received referrals and treatment for systemic diseases, of which 76.39% achieved complete (45.83%) or partial (30.56%) remission. Among these patients, treatment for gastrointestinal disorders (92.59%), oral candidiasis (78.57%), thyroid diseases (66.67%), and avoidance of local irritants (62.50%) were most effective, and they were perpetuated as the common underlying causes. PRACTICAL IMPLICATIONS: The study results implied significance of adopting multidisciplinary management of burning mouth sensation. It is imperative for dentists and physicians to strengthen their collaborative relationships and focus on both systemic and oral conditions in these patients.

Place of placebo therapy in the treatment of burning mouth syndrome: A systematic review.

Burning mouth syndrome (BMS) is defined as an idiopathic orofacial pain with intraoral burning or dysesthesia. This systematic review aimed to analyze the scientific literature with regard to the effectiveness of placebo therapy in patients with BMS. A literature search was conducted through the PubMed-indexed journals within MEDLINE®, Scopus, Cochrane Central Register of Controlled Trials (CENTRAL), and Trip databases from their inception to May 31, 2022. The search terms were defined by combining (medical subject headings (MeSH) terms OR keywords) "burning mouth syndrome" AND (MeSH terms OR keywords) "placebo". Methodological quality assessments were performed utilizing the Joanna Briggs Institute (JBI) Critical Appraisal tool to attribute scores from 1 to 11 to the selected studies. The literature search, study selection and data extraction were carried out by 2 authors. Disagreements between the authors were resolved by the 3rd author, if necessary. A total of 44 articles met the inclusion criteria. After assessing full-text articles for eligibility, 20 articles were excluded. Consequently, 24 articles were retained. A total of 21 studies included in this systematic review had a low score of bias. In 13 studies, a positive response to placebo was noted. Among them, 7 showed a placebo response indistinguishable from active treatment. These changes were more pronounced in patients receiving placebo therapy compared to active treatment in 1 study. Placebo therapy may occasionally be beneficial and ethically acceptable for patients with BMS. To get stronger evidence for the use of a placebo, future studies with standardized methodology and outcomes are required.

Topical tretinoin treatment for burning mouth syndrome: a pilot study.

OBJECTIVES: Burning mouth syndrome is an intraoral chronic pain condition characterized by a moderate to severe sensation of burning from the oral mucosa. No clinical signs are found and there is no efficient treatment. METHOD AND MATERIALS: This pilot study included 10 women that were resistant to other previous treatments or noncompliant to systemic medications. Patients were asked to apply tretinoin gel 0.05% on their tongues twice daily for 14 days. Treatment effectiveness was assessed by completing a pre-study psychologic questionnaire and recording a daily wellbeing and pain log. RESULTS: Significant pain-score decrease in 50% of the patients (delta numerical rating score -3.15 ± 3.02, P value = .005) was recorded. This finding was in concordance with the verbal statements including major quality-of-life improvement (P value = .05), without any treatment positive or negative predictive factors. CONCLUSIONS: Topical tretinoin exhibits potential efficacy in patients with treatment resistant burning mouth syndrome and may also be used as a primary treatment modality.

Comparison of Clonazepam and Tongue Protector in the Treatment of Burning Mouth Syndrome.

BACKGROUND: BMS is a chronic pain syndrome affecting the oral mucosa. It consists of experiencing a burning or dysesthetic sensation. BMS prevalence varies, with up to 15% among women. An effective treatment is still unattainable. MATERIAL AND METHODS: A total of 60 patients with BMS qualified for a randomised trial, divided in two groups: the clonazepam-treated and tongue protector group. Treatment was provided for 4 weeks in both groups. In the former, the oral dosage of clonazepam 0.5 mg; in the latter, a tongue protector was used. Clinical oral examination was performed, and the presence of taste disorder and pain intensity, on the visual analogues scale, were recorded. Psychological domains were explored with the Beck depression inventory (depression), Athens insomnia scale (insomnia), Eyesenck personality questionnaire-revised (personality traits), and WHO quality of life questionnaire (quality of life). RESULTS: Complete recovery was observed in three patients after clonazepam and one patient after tongue guard treatment. A greater improvement in the VAS scores, from baseline to the control values, was demonstrated in the clonazepam group, and it was statistically significant. In women, the level of depression significantly correlated with all domains of quality of life. CONCLUSIONS: BMS is an ongoing multi-specialist challenge. The development of new pathophysiological concepts of BMS offers hope for more effective treatment. Considering the influence of BMS on the quality of life and mental disorders in most patients, further research on the possibilities of therapy seems to be very important.

Efficacy of photobiomodulation in reducing pain and improving the quality of life in patients with idiopathic burning mouth syndrome. A systematic review and meta-analysis.

Burning mouth syndrome is a chronic condition, which is characterised by a burning sensation or pain in the mucosa of the oral cavity. Treatment options include antidepressants, antipsychotics, anticonvulsants, analgesics, hormone replacement therapies and more recently photobiomodulation. This study aims to perform a systematic review with meta-analysis in order to determine the effect of photobiomodulation on pain relief and the oral health-related quality of life associated with this condition. A bibliographical search of the Pubmed, Embase, Web of Science and Scopus databases was conducted. Only randomised clinical trials were included. Pain and quality of life were calculated as mean difference and pooled at different treatment points (baseline = T0 and final time point = Tf) and laser modality. From a total of 103 records, 7 articles were retrieved for inclusion. PBM group had a greater decrease in pain than control group at Tf with a mean difference = - 2.536 (IC 95% - 3.662 to - 1.410; I2 = 85.33%, p < 0.001). An improvement in oral health-related quality of life was observed in both groups, although this was more significant in the photobiomodulation group mean difference = - 5.148 (IC 95% - 8.576 to - 1.719; I2 = 84.91%, p = 0.003). For the red laser, a greater improvement than infrared was observed, in pain, mean difference = - 2.498 (IC 95% - 3.942 to - 1.053; I2 = 79.93%, p < 0.001), and in quality of life, mean difference = - 8.144 (IC 95% - 12.082 to - 4.206; I2 = 64.22%, p = 0.027). Photobiomodulation, in particular, red laser protocols, resulted in improvement in pain and in quality of life of burning mouth syndrome patients.