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

Oral Dysaesthetic and Perceptual Disorder, A Distinct Subset of Chronic Orofacial Pain Without Burning Symptoms: A Case-Control Study

BACKGROUND

According to the ICOP 2020, Burning Mouth Syndrome (BMS) is a chronic orofacial pain disorder characterised by an intraoral burning sensation, which represents the main diagnostic criterion. However, some patients experience other symptoms such as xerostomia, taste alterations, and globus, without the burning sensation (non-BMS).

OBJECTIVE

This study aims to explore non-BMS as a distinct subclinical entity by comparing the classical BMS with this new group of patients in a case-control study, addressing gaps in current diagnostic criteria.

METHODS

Eighty-three non-BMS patients were compared with an equal number of BMS patients matched for age and sex. Data on sociodemographic and risk factors, systemic comorbidities and drug intake, symptom patterns, psychological profiles were collected and statistically analysed.

RESULTS

No significant differences between BMS and non-BMS groups were found in sociodemographic characteristics, comorbidities, drug consumption and extraoral symptoms. Both groups reported similar symptoms patterns, with discomfort intensifying in the evening. Although oral symptoms prevalence varied, with the burning sensation exclusive to BMS patients, none of these differences reached statistical significance. Psychological assessments revealed mild depression (17 [14-19] vs. 17 [14-20], p  0.981), mild to moderate anxiety (18 [15-21] vs. 17 [15-20.5], p = 0.767), and sleep disturbance (5 [4-7] vs. 8 [5-10], p < 0.001) in both groups.

CONCLUSION

Non-BMS patients exhibit similarities to BMS patients yet remain unclassified under current diagnostic criteria. Therefore, we have suggested the term "Oral Dysaesthetic and Perceptual Disorder (ODPD)" to define these patients (non-BMS). This study emphasises the need to expand diagnostic criteria to better identify and manage ODPD patients.

Sexual hormones changes in burning mouth syndrome: A systematic review

BACKGROUND

Burning mouth syndrome (BMS) is a chronic pain condition affecting the oral cavity. This condition mostly affects peri- or postmenopausal women; for this reason, sexual hormonal changes have been implicated in BMS pathogenesis.

METHODS

A systematic review was performed in MEDLINE/PubMed, Scopus, Web of Science, Cochrane Library and EMBASE without restriction for language or year. Eligibility criteria were controlled studies addressing the PICO question: (P) patients with BMS; (I) detection of the sex hormones; (C) patients without BMS; (O) changes on sexual hormones as a risk factor for BMS severity. Risk of bias was performed with Newcastle-Ottawa Quality Assessment Scale.

RESULTS

Four studies were included. Salivary levels were evaluated in three studies and serum blood was used in one. Three studies analysed oestradiol and/or dehydroepiandrosterone (DHEA), two assessed progesterone and one evaluated follicle-stimulating hormone (FSH). Oestradiol results were contradictory, with two studies reporting lower levels in BMS patients compared to controls and one finding the opposite. DHEA was statistically lower in the BMS group in one study. Progesterone showed opposite results in two studies, although none with statistical significance. FSH was statistically higher in the BMS group compared to controls. Correlation of hormones with quality of life was performed in three studies and there was no significant correlation with self-perceived symptoms severity.

CONCLUSION

Sexual hormones can be altered in BMS, especially oestradiol. Despite these changes, we did not find correlation between hormone fluctuation and BMS symptoms intensity affecting quality of life. These findings suggested the need for further investigation on hormonal alterations, which may be a promising target on BMS management.

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.

Neurobiology of bruxism: The impact of stress (Review)

Bruxism is a non-functional involuntary muscle activity that affects more than one-third of the population at some point in their lives. A number of factors have been found to be related to the etiopathogenesis of bruxism; therefore, the condition is considered multifactorial. The most commonly accepted factor is stress. Stress has long been considered to increase muscle tone and to reduce the pain threshold. Current evidence indicates that exposure to chronic stress, distress and allostatic load ignite neurological degeneration and the attenuation of critical neuronal pathways that are highly implicated in the orofacial involuntary muscle activity. The present review discusses the negative effects that chronic stress exerts on certain parts of the central nervous system and the mechanisms through which these changes are involved in the etiopathogenesis of bruxism. The extent of these morphological and functional changes on nerves and neuronal tracts provides valuable insight into the obstacles that need to be overcome in order to achieve successful treatment. Additionally, particular emphasis is given on the effects of bruxism on the central nervous system, particularly the activation of the hypothalamic-pituitary-adrenal axis, as this subsequently induces an increase in circulating corticosterone levels, also evidenced by increased levels of salivary cortisol, thereby transforming bruxism into a self-reinforcing loop.

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.

Advancements in Understanding and Classifying Chronic Orofacial Pain: Key Insights from Biopsychosocial Models and International Classifications (ICHD-3, ICD-11, ICOP)

In exploring chronic orofacial pain (COFP), this review highlights its global impact on life quality and critiques current diagnostic systems, including the ICD-11, ICOP, and ICHD-3, for their limitations in addressing COFP's complexity. Firstly, this study outlines the global burden of chronic pain and the importance of distinguishing between different pain types for effective treatment. It then delves into the specific challenges of diagnosing COFP, emphasizing the need for a more nuanced approach that incorporates the biopsychosocial model. This review critically examines existing classification systems, highlighting their limitations in fully capturing COFP's multifaceted nature. It advocates for the integration of these systems with the DSM-5's Somatic Symptom Disorder code, proposing a unified, multidisciplinary diagnostic approach. This recommendation aims to improve chronic pain coding standardization and acknowledge the complex interplay of biological, psychological, and social factors in COFP. In conclusion, here, we highlight the need for a comprehensive, universally applicable classification system for COFP. Such a system would enable accurate diagnosis, streamline treatment strategies, and enhance communication among healthcare professionals. This advancement holds potential for significant contributions to research and patient care in this challenging field, offering a broader perspective for scientists across disciplines.

Comparative analysis of photobiomodulation therapy and transcutaneous electrical nerve stimulation for burning mouth: a randomized clinical trial

OBJECTIVE

To compare the effect of photobiomodulation (PBM) and transcutaneous electrical nerve stimulation (TENS) in the treatment of burning mouth.

MATERIALS AND METHODS

Randomized clinical trial of 25 patients with burning mouth treated by TENS (n=12) and PBM (n=13). The patients were treated weekly for 8 weeks. Two-factor ANOVA was used to determine whether the two interventions promoted significant differences in symptoms (measured with a visual analogue scale), unstimulated salivary flow, xerostomia, and dysgeusia between T0 (baseline), T1 (after the 4th treatment session), T2 (after the 8th treatment session), and T3 (30 days after the end of treatment).

RESULTS

Intragroup comparison of VAS scores for pain showed a significant difference between T0xT1, T0xT2, and T0xT3 in the TENS group and between T0xT2 and T0xT3 in the PBM group (p˂0.001). Intergroup comparison of VAS scores for pain between T2xT3 showed a better response to PBM than to TENS (p=0.003). Patients of the TENS group showed an increase in salivary flow between T1 and T2 (p=0.052). There were no expressive variations in xerostomia or dysgeusia in the two groups analyzed.

CONCLUSION

TENS and PBM were effective in reducing the symptoms of burning mouth during and after treatment. The PBM group showed a better response during follow-up.

TRIAL REGISTRATION

This clinical trial was registered at http://clinicaltrials.gov (Number: NCT05816200).

CLINICAL RELEVANCE

TENS was found to be a safe and effective therapy for burning mouth. Trial registration number (TRN) and date of registration: This clinical trial was registered at http://clinicaltrials.gov (Number: NCT05816200; date: May 08, 2023).

Neuropsychological assessment of Romanian burning mouth syndrome patients: stress, depression, sleep disturbance, and verbal fluency impairments

Burning Mouth Syndrome (BMS) is a chronic condition characterized by a burning sensation in the oral mucosa, lasting more than 2 hours daily for more than 3 months, without clinical and/or laboratory evidence. BMS is often comorbid with mood, and psychiatric disorders, and a complex pathophysiology and interaction between impairments in nociceptive processing and psychologic function is occurring. In this work, we aimed to define the neuropsychological profile specific for BMS patients for a better management of this complex disease. We conducted a case-control study comparing 120 BMS patients and 110 non-BMS individuals (CTRL). Sociodemographic data and lifestyle habits, were collected, along with data regarding quality of life (SF-36 scale), stress (PSS), depression and anxiety (MADRS and HADS scales), sleep quality (PSQI scale), and cognitive functions (MoCA, SVF and PVF tests). The statistical analysis revealed a lower general quality of life (p < 0.001), worse sleep quality (p < 0.001) in BMS patients than CTRL. The BMS patients also displayed a higher prevalence of mild depressive symptoms than CTRL applying the MADRS (p < 0.001) and HADS-Depression scales (p = 0.001), whereas no differences in anxiety symptoms were found between the two groups (p = 0.174). Moreover, reduced scores semantic and phonemic verbal fluency tests (p < 0.05) were found, but no change in cognition was observed through MoCA (p = 0.551). Our results highlight that synergy between dentistry and neuropsychiatric assessment is essential for a successful management of BMS.

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.

Role of Photobiomodulation Therapy in Neurological Primary Burning Mouth Syndrome. A Systematic Review and Meta-Analysis of Human Randomised Controlled Clinical Trials

Mitochondrial homeostasis is crucial for energy production and neuronal survival in neurological primary burning mouth syndrome (npBMS). Photobiomodulation therapy (PBMT) has been utilised in npBMS management, however, its role of intervention remains controversial. The aim of this systematic review and meta-analysis of CRD 42020198921 PROSPERO registration reference was to oversee and determine the efficacy of PBMT in patients with npBMS, identifying the gaps and bridge them by proposing recommendations for future studies purposes. PRISMA guidelines and Cochrane Collaboration recommendations followed. Various search engines employed to analyse a total of 351 studies of which 12 were included. A wide range of utilised PBM wavelengths was between 635-980 nm and the power output ranged between 30 mW and 4000 mW. A high risk of bias (RoB) was noted in 7 out of 12 included studies (58.3%), as results of qualitative analysis. Meta-analysis findings of 4 out of 12 studies showed statistically significant intergroup differences (SSID) for visual analogue scale (VAS) values (MD = -1.47; 95% CI = -2.40 to -0.53; Z = 3.07 (p = 0.002) whereas meta-analysis on 5 out of 12 studies revealed SSID for anxiety/depression and quality of life (MD = -1.47; 95% CI = -2.40 to -0.53; Z = 3.07 (p = 0.002), favouring PBMT group to the control treatment strategies. Despite the inconsistency and diversity in PBM parameters (wavelength, power, light source, spot size, emission mode, energy per point, total energy) and treatment protocols (exposure time, number of sessions, time interval between sessions, treatment duration)-majority of the included studies showed positive PBM results. The high RoB and meta-analytical heterogeneity in the eligible studies warrant the necessity to perform well-designed and robust RCTs after acknowledging the drawbacks of the available scientific literature and addressing our suggested recommendations highlighted in our review.

The association of sleep disturbances with burning mouth syndrome: An overlooked relationship-A qualitative systematic review

OBJECTIVES

To review the relevant literature to assess whether patients with burning mouth syndrome (BMS) are more prone to have sleep disturbances than general population.

METHODS

The literature search for relevant articles was from July 2020 to March 2021. A systematic search of PubMed, Embase, Google Scholar, Cochrane library, Dentistry & Oral Sciences Source, and Scopus was conducted to search for relevant studies. The quality of studies was assessed in accordance with the Joanna Briggs Institute's guidelines and using the software SUMARI-The System for the Unified Management, Assessment and Review of Information. Confidence in the findings was assessed using the GRADE-CERQual approach.

RESULTS

A total of 1064 studies were initially identified from the search; six studies, two cross-sectional and four case-control, met the inclusion criteria and were selected for this systematic review. Sleep disturbances were a required outcome measured in selected studies evaluating symptoms of BMS. For studies that were included in the final analyses, BMS was found to relate to several dimensions of sleep including sleep disturbance and duration (n = 6), sleep affecting daytime function (n = 4), sleep quality (n = 6), sleep efficiency (n = 4), and ability to fall asleep (n = 4). Consistent evidence of moderate confidence found that BMS was associated with greater sleep disturbance, reduced sleep quality, increased time taken to fall asleep, reduced sleep efficiency, and poor daytime function, whereas evidence of low confidence was found regarding the association of BMS with reduced sleep duration.

CONCLUSIONS

Although the presented studies could not establish a direct causal relationship between BMS and sleep disturbances, it supports the evidence that sleep disturbance is associated with symptoms of BMS. Management strategies to improve sleep may be considered in future research for managing BMS patients.