The role of xerostomia in burning mouth syndrome: a case-control study

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.

Salivary Complaints in Burning Mouth Syndrome: A Cross Sectional Study on 500 Patients

BACKGROUND

Xerostomia and sialorrhea often accompany Burning Mouth Syndrome (BMS) despite no change in saliva quantity. This study analyzed BMS patients with different symptom combinations: burning only (B), burning and xerostomia (BX), burning and sialorrhea (BS), and burning with xerostomia and sialorrhea (BXS), using a large sample of 500 patients from the University of Naples Federico II.

METHODS

After a medical evaluation, patients were divided into four groups based on their reported symptoms: B (140), BX (253), BS (49), and BXS (58). Patient data on education, BMI, smoking/alcohol habits, comorbidities, medication use, pain intensity, quality, and psychological profile were collected.

RESULTS

The BX group showed a higher prevalence of patients taking blood thinners. Additional symptoms varied among groups, with the BX group experiencing more dysgeusia and globus, and the BS group reporting more tingling. Multivariate analysis identified BMI, dysgeusia, globus, and blood thinner use as significant factors in the B and BX groups, while male gender, tingling, alcohol use, and pain quality were significant in the BS and BXS groups.

CONCLUSIONS

Overall, BMS patients display a complex range of symptoms, with xerostomia being the most frequent additional symptom. Sociodemographic, psychological, and medical factors cannot fully explain the variations in symptomatology among different patient subgroups. Further research is needed to understand the underlying causes and develop tailored treatment approaches.

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.

World Workshop on Oral Medicine VIII: Development of a Core Outcome Set for Dry Mouth: A Systematic Review of Outcome Domains for Xerostomia

OBJECTIVE

The purpose of this study was to identify all outcome domains used in clinical studies of xerostomia, that is, subjective sensation of dry mouth. This study is part of the extended project "World Workshop on Oral Medicine Outcomes Initiative for the Direction of Research" to develop a core outcome set for dry mouth.

STUDY DESIGN

A systematic review was performed on MEDLINE, EMBASE, CINAHL, and Cochrane Central Register of Controlled Trials databases. All clinical and observational studies that assessed xerostomia in human participants from 2001 to 2021 were included. Information on outcome domains was extracted and mapped to the Core Outcome Measures in Effectiveness Trials taxonomy. Corresponding outcome measures were summarized.

RESULTS

From a total of 34,922 records retrieved, 688 articles involving 122,151 persons with xerostomia were included. There were 16 unique outcome domains and 166 outcome measures extracted. None of these domains or measures were consistently used across all the studies. The severity of xerostomia and physical functioning were the 2 most frequently assessed domains.

CONCLUSION

There is considerable heterogeneity in outcome domains and measures reported in clinical studies of xerostomia. This highlights the need for harmonization of dry mouth assessment to enhance comparability across studies and facilitate the synthesis of robust evidence for managing patients with xerostomia.

A systematic review of treatment for patients with burning mouth syndrome

BACKGROUND

Burning mouth syndrome is a chronic idiopathic intractable intraoral dysaesthesia that remains a challenge to clinicians due to its poorly understood pathogenesis and inconsistent response to various treatments.

AIM

This review aimed to study the short- (≤3 months) and long-term (>3 months) effectiveness and sustainable benefit of different burning mouth syndrome treatment strategies and the associated side effects.

MATERIALS AND METHODS

Randomised controlled trials of burning mouth syndrome treatment compared with placebo or other interventions with a minimum follow up of 2 months were searched from the PubMed, Embase and Cochrane database (published to July 2020).

RESULTS

Twenty-two studies were selected based on the inclusion and exclusion criteria and analysed. Nine categories of burning mouth syndrome treatment were identified: Anticonvulsant and antidepressant agents, phytomedicine and alpha lipoic acid supplements, low-level laser therapy, saliva substitute, transcranial magnetic stimulation, and cognitive behaviour therapy. Cognitive behaviour therapy, topical capsaicin and clonazepam, and laser therapy demonstrated favourable outcome in both short- and long-term assessment. Phytomedicines reported a short-term benefit in pain score reduction. The pooled effect of alpha lipoic acid (ALA) pain score improvement was low, but its positive effects increased in long term assessment.

CONCLUSION

A more significant volume in terms of sample size, multi-centres, and multi-arm comparison of therapeutic agents with placebo and longitudinal follow-up studies is recommended to establish a standardised burning mouth syndrome treatment protocol. Further studies are required to assess the analgesic benefits of topical clonazepam and capsaicin, alternative medicines with neurodegenerative prevention capability and psychology support in treating burning mouth syndrome and reducing systemic adverse drug reactions.Registration International Prospective Register of Systematic Reviews (PROSPERO):Protocol ID - CRD42020160892.

Evaluation of the efficacy of treatment modalities in burning mouth syndrome-A systematic review

OBJECTIVES

Burning mouth syndrome (BMS) is a medical entity characterised by a spontaneous sensation of burning, numbness or pain of the oral mucosa in the absence of clinical symptoms. The goal of this systematic review was to assess the efficacy of various current treatments for BMS.

METHODS

The literature search used the following inclusion criteria: randomised controlled trials (RCTs) which compared one or more treatment strategies for patients with primary/idiopathic BMS with a placebo group describing all types of interventions. The primary and secondary outcome measures included: relief of pain/burning sensations, changes in psychosocial factors and feeling of sensation of dryness. A computer and manual search was performed in Pubmed, Web of Science and Cochrane Library up to 5 November 2019 and updated on 28 June 2020. The risk of bias was measured with the Cochrane Collaboration tool.

RESULTS

Thirty RCTs which included 727 study participants and 589 controls were identified. The following interventions were introduced: dietary supplements, anticonvulsants, benzodiazepines, antidepressants, analgesics, topical agents, electromagnetic radiation or induction, physical barriers and psychological therapies. The most successful therapeutic outcomes were observed for clonazepam tested in 3 RCTs, where significant pain reduction appeared after both topical and systemic application. Evident pain reduction was also reported for tongue protectors and capsaicin in 2 separate studies.

DISCUSSION

Short follow-up periods, low numbers of participants, variability of the metrics used in the evaluation of the results and heterogeneous study design were the main limitations of the reviewed studies. Based on our analysis, clonazepam appears to be the most effective treatment option for BMS.

Association between craniofacial pain complaints, somatoform symptoms and chronic diseases

OBJECTIVE

This case-control study aimed to investigate associations between craniofacial pain complaints, somatoform symptoms and chronic diseases.

DESIGN

306 subjects were included in this study (174 patients and 132 healthy subjects). The evaluation consisted of demographic data, number of functional and nonfunctional chronic diseases, medications, somatoform symptoms (xerostomia, dry mucosa, numbness, gastrointestinal complaints), and pain complaints with associated characteristics (number of pain areas, sensation of tired face, bruxism, sleep disturbances, masticatory musculoskeletal evaluation). Statistical analysis included descriptive data, tested with chi-square, Fisher's exact, nonparametric Kolmogorov-Smirnoff, Student's t-test, Pearson's coefficient, two-steps cluster classification, multivariate linear and LASSO regressions.

RESULTS

Functional disorders were prevalent in 111 (63.8 %) patients with facial pain. They were taking more medication (p < 0.001) and had more sleep disturbances (p < 0.001), higher xerostomia scores (p < 0.001) and more gastrointestinal complaints (p < 0.001) than controls. There was a positive correlation between the functional score and the number of cranial areas with headache (R² = 0.266, <0.001). The regression models for facial pain (R² = 0.632), craniofacial pain (R² = 0.623) and headache (R² = 0.252) showed significant dependency of functional disorders (p < 0.001).

CONCLUSION

craniofacial pain was associated with functional diseases and somatoform symptoms. This association needs further investigation to understand the role of those disorders in craniofacial pain, considering that pain complaints are common somatoform and functional symptoms.

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.

An updated review on pathophysiology and management of burning mouth syndrome with endocrinological, psychological and neuropathic perspectives

Burning mouth syndrome (BMS) is a chronic oro-facial pain disorder of unknown cause. It is more common in peri- and post-menopausal women, and sex hormone dysregulation is believed to be an important causative factor. Psychosocial events often trigger or exacerbate symptoms, and persons with BMS appear to be predisposed towards anxiety and depression. Atrophy of small nerve fibres in the tongue epithelium has been reported, and potential neuropathic mechanisms for BMS are now widely investigated. Historically, BMS was thought to comprise endocrinological, psychosocial and neuropathic components. Neuroprotective steroids and glial cell line-derived neurotrophic factor family ligands may have pivotal roles in the peripheral mechanisms associated with atrophy of small nerve fibres. Denervation of chorda tympani nerve fibres that innervate fungiform buds leads to alternative trigeminal innervation, which results in dysgeusia and burning pain when eating hot foods. With regard to the central mechanism of BMS, depletion of neuroprotective steroids alters the brain network-related mood and pain modulation. Peripheral mechanistic studies support the use of topical clonazepam and capsaicin for the management of BMS, and some evidence supports the use of cognitive behavioural therapy. Hormone replacement therapy may address the causes of BMS, although adverse effects prevent its use as a first-line treatment. Selective serotonin reuptake inhibitors (SSRIs) and serotonin and noradrenaline reuptake inhibitors (SNRIs) may have important benefits, and well-designed controlled studies are expected. Other treatment options to be investigated include brain stimulation and TSPO (translocator protein 18 kDa) ligands.

Mucin 5B in saliva and serum of patients with oral lichen planus

Oral lichen planus (OLP) is among the most common oral diseases. Its etiopathogenesis has yet to be clearly identified. OLP patients complain of mouth dryness. This study aimed to assess the level of Mucin 5B in OLP patients with xerostomia. This study was conducted on 30 OLP patients and 30 healthy individuals. In addition to patient complaint of mouth dryness, xerostomia was assessed by tongue blade and lipstick tests. Stimulated and unstimulated saliva were collected in plastic vials by spitting method. Level of Mucin 5B was measured by ELISA. Unstimulated saliva flow was significantly lower in OLP patients (P = 0.0001). Stimulated saliva flow was not significantly different between the two groups (P > 0.05). Level of Mucin 5B in unstimulated saliva was significantly lower in OLP group (P = 0.0001) while it was not significantly different in stimulated saliva of the two groups (P > 0.05). Level of Mucin 5B was significantly higher in serum of OLP patients (P = 0.016). Both saliva flow and level of Mucin 5B decrease in OLP patients. Since Mucin 5B is effective for wetting and lubrication of the oral cavity, this result can suggest a possible reason for mouth dryness in OLP patients.

Burning mouth syndrome: a systematic review of treatments

Burning mouth syndrome (BMS) is a chronic oral pain syndrome that primarily affects peri- and postmenopausal women. It is characterized by oral mucosal burning and may be associated with dysgeusia, paresthesia, dysesthesia, and xerostomia. The etiology of the disease process is unknown, but is thought to be neuropathic in origin. The goal of this systematic review was to assess the efficacy of the various treatments for BMS. Literature searches were conducted through PubMed, Web of Science, and Cochrane Library databases, which identified 22 randomized controlled trials. Eight studies examined alpha-lipoic acid (ALA), three clonazepam, three psychotherapy, and two capsaicin, which all showed modest evidence of potentially decreasing pain/burning. Gabapentin was seen in one study to work alone and synergistically with ALA. Other treatments included vitamins, benzydamine hydrochloride, bupivacaine, Catuama, olive oil, trazodone, urea, and Hypericum perforatum. Of these other treatments, Catuama and bupivacaine were the only ones with significant positive results in symptom improvement. ALA, topical clonazepam, gabapentin, and psychotherapy may provide modest relief of pain in BMS. Gabapentin may also boost the effect of ALA. Capsaicin is limited by its side effects. Catuama showed potential for benefit. Future studies with standardized methodology and outcomes containing more patients are needed.

Interventions for treating burning mouth syndrome

BACKGROUND

Burning mouth syndrome (BMS) is a term used for oral mucosal pain (burning pain or discomfort in the tongue, lips or entire oral cavity) without identifiable cause. General population prevalence varies from 0.1% to 3.9%. Many BMS patients indicate anxiety, depression, personality disorders and impaired quality of life (QoL). This review updates the previous versions published in 2000 and 2005.

OBJECTIVES

To determine the effectiveness and safety of any intervention versus placebo for symptom relief and changes in QoL, taste, and feeling of dryness in people with BMS.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 31 December 2015), the Cochrane Central Register of Controlled Trials (CENTRAL; 2015, Issue 11) in the Cochrane Library (searched 31 December 2015), MEDLINE Ovid (1946 to 31 December 2015), and Embase Ovid (1980 to 31 December 2015). We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform for ongoing trials. We placed no restrictions on the language or date of publication when searching the electronic databases SELECTION CRITERIA: Randomised controlled trials (RCTs) comparing any treatment against placebo in people with BMS. The primary outcomes were symptom relief (pain/burning) and change in QoL. Secondary outcomes included change in taste, feeling of dryness, and adverse effects.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Outcome data were analysed as short-term (up to three months) or long-term (three to six months).

MAIN RESULTS

We included 23 RCTs (1121 analysed participants; 83% female). Interventions were categorised as: antidepressants and antipsychotics, anticonvulsants, benzodiazepines, cholinergics, dietary supplements, electromagnetic radiation, physical barriers, psychological therapies, and topical treatments.Only one RCT was assessed at low risk of bias overall, four RCTs' risk of bias was unclear, and 18 studies were at high risk of bias. Overall quality of the evidence for effectiveness was very low for all interventions and all outcomes.Twenty-one RCTs assessed short-term symptom relief. There is very low-quality evidence of benefit from electromagnetic radiation (one RCT, 58 participants), topical benzodiazepines (two RCTs, 111 participants), physical barriers (one RCT, 50 participants), and anticonvulsants (one RCT, 100 participants). We found insufficient/contradictory evidence regarding the effectiveness of antidepressants, cholinergics, systemic benzodiazepines, dietary supplements or topical treatments. No RCT assessing psychological therapies evaluated short-term symptom relief.Four studies assessed long-term symptom relief. There is very low-quality evidence of a benefit from psychological therapies (one RCT, 30 participants), capsaicin oral rinse (topical treatment) (one RCT, 18 participants), and topical benzodiazepines (one RCT, 66 participants). We found no evidence of a difference for dietary supplements or lactoperoxidase oral rinse. No studies assessing antidepressants, anticonvulsants, cholinergics, electromagnetic radiation or physical barriers evaluated long-term symptom relief.Short-term change in QoL was assessed by seven studies (none long-term).The quality of evidence was very low. A benefit was found for electromagnetic radiation (one RCT, 58 participants), however findings were inconclusive for antidepressants, benzodiazepines, dietary supplements and physical barriers.Secondary outcomes (change in taste and feeling of dryness) were only assessed short-term, and the findings for both were also inconclusive.With regard to adverse effects, there is very low-quality evidence that antidepressants increase dizziness and drowsiness (one RCT, 37 participants), and that alpha lipoic acid increased headache (two RCTs, 118 participants) and gastrointestinal complaints (3 RCTs, 138 participants). We found insufficient/contradictory evidence regarding adverse events for anticonvulsants or benzodiazepines. Adverse events were poorly reported or unreported for cholinergics, electromagnetic radiation, and psychological therapies. No adverse events occurred from physical barriers or topical therapy use.

AUTHORS' CONCLUSIONS

Given BMS' potentially disabling nature, the need to identify effective modes of treatment for sufferers is vital. Due to the limited number of clinical trials at low risk of bias, there is insufficient evidence to support or refute the use of any interventions in managing BMS. Further clinical trials, with improved methodology and standardised outcome sets are required in order to establish which treatments are effective. Future studies are encouraged to assess the role of treatments used in other neuropathic pain conditions and psychological therapies in the treatment of BMS.