Reduction in unstimulated salivary flow rate in burning mouth syndrome

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.

Clinical and epidemiological profile of burning mouth syndrome patients following the International Headache Society classification: a systematic review and meta-analysis

OBJECTIVE

This systematic review aimed to determine the clinical and epidemiologic profile of patients with burning mouth syndrome (BMS) following the current classification of the International Headache Society (IHS)-the International Classification of Headache Disorders (ICHD-3) and the International Classification of Orofacial Pain (ICOP).

STUDY DESIGN

This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist and involved a comprehensive search on PubMed, Scopus, EMBASE, Web of Science, LILACS, and the gray literature.

RESULTS

Of the 4,252 studies identified, 41 were included. In general, there were no differences between the clinical and epidemiologic profiles of patients with BMS classified based on ICHD-3 or ICOP. Studies were pooled in meta-analyses and showed a significant prevalence of female patients between the sixth and seventh decade of life. The burning sensation and the tongue were the most prevalent descriptors and affected location. Significant associations were demonstrated between BMS and anxiety (P = .0006), depression (P = .004), and poor oral hygiene (P = .00001).

CONCLUSIONS

Under the existing contemporary classification systems, patients with BMS were found to be mostly females in the sixth and seventh decade of life with a burning sensation on the tongue. Experiencing depression and anxiety was a commonly existing comorbidity.

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.

Evaluation and management of dry mouth and its complications in rheumatology practice

INTRODUCTION

The symptom of dry mouth has multiple potential etiologies and can be a diagnostic clue to the presence of common systemic diseases encountered in rheumatology practice. The presence of decreased saliva flow (i.e. salivary hypofunction) defines a subset of dry mouth patients in whom there may be reversible drug effects, an iatrogenic insult such as head and neck irradiation, or a disease that directly involves the salivary glands (e.g. Sjögren's disease). The assessment of salivary hypofunction includes sialometry, salivary gland imaging, salivary gland biopsy, and an assessment for relevant systemic diseases. Optimal management of dry mouth requires accurate definition of its cause, followed by general measures that serve to alleviate its symptoms and prevent its complications.

AREAS COVERED

Through a literature search on xerostomia and salivary hypofunction, we provide an overview of the causes of dry mouth, highlight the potential impact of salivary hypofunction on oral and systemic health, detail routine evaluation methods and treatment strategies, and emphasize the importance of collaboration with oral health care providers.

EXPERT OPINION

Our Expert Opinion is provided on unmet needs in the management of dry mouth and relevant research progress in the field.

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.

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.

Xerogenic medications may contribute to decreased unstimulated salivary flow in patients with oral burning and/or gastro-esophageal reflux disease

Background

Patients who complain of mucosal burning sensations (i.e., glossodynia and gastro-esophageal reflux disease, GERD) often take multiple medications. However, the relationship between xerogenic medication intake and salivary flow in these patients has not been thoroughly examined.

Methods

A retrospective study of 192 consecutive patients diagnosed with glossodynia (ICD-10-CM) at a regional center over a six-year period was performed. Data from electronic health records were extracted and relationships between medication intake, unstimulated whole salivary flow rate (UWSFR), xerostomia and GERD were determined by chi-square, t-test, and correlation analysis.

Results

Of 134 records that met inclusion criteria, 87.1% of patients reported daily intake of one or more xerogenic medications. Two or more xerogenic medications were taken significantly more often by patients with glossodynia reporting GERD than those with glossodynia without GERD (p = .02). UWSFR was negatively correlated with number of medications [r(103) = −.277, p = .005] and xerogenic medications [r(103) = −.195, p = .049]. The lowest UWSFR was observed with use of trazodone and cyclobenzaprine.

Conclusions

Daily xerogenic medication intake, hyposalivation, and xerostomia were commonly present and potentially interrelated in patients who suffer from glossodynia and/or GERD.

Practical implications

Clinicians should be aware of the consequences of prescribing multiple and certain xerogenic medications in reducing UWSFR, especially in patients physiologically at risk of hyposalivation such as those suffering from GERD and/or glossodynia.

Smell and Taste Function and Their Disturbances in Sjögren's Syndrome

Chemosensory disorders are a possible disturbance in Sjögren's syndrome (SS). The aim of the study is to comprehensively present chemosensory disorders in SS and to indicate their possible causes. The possible causes of taste and smell disorders in SS are changes in the structure of exocrine glands and their dysfunction, damage to receptors and weakening of their ability to regenerate, and neurological changes in the form of peripheral neuropathy and impaired cognitive function. Other postulated causes of chemosensory disorders are autoimmune mechanisms, adverse effects of drugs used in SS, and primary potentially SS-triggering viral infections. They are multifactorial and may occur independently of each other. The time of their onset and correlation with other disease symptoms may facilitate the determination of their primary cause in each patient. Awareness of chemosensory disorders in SS may help to ease their progress and eliminate other factors responsible for their more severe manifestation. In the prevention and treatment of chemosensory disorders in SS, the most important thing is to alleviate xerostomia and dryness in the nasal cavity and their effects in the form of chronic local inflammations, counteract receptor atrophy, and an implementation of appropriate neurological diagnosis and treatment.

Clinical Utility of Quantitative Parameters of Salivary Gland Scintigraphy for Diagnosing Burning Mouth Syndrome

Burning mouth syndrome (BMS) is a chronic disorder characterized by a burning sensation in the oral cavity, often accompanied by xerostomia, with no relevant clinical or laboratory findings. This study aimed to investigate diagnostic values of quantitative parameters of salivary gland scintigraphy for BMS in patients with xerostomia. A total of 164 patients who underwent salivary gland scintigraphy for the workup of xerostomia were retrospectively reviewed. All patients were classified into patient groups with primary BMS, secondary BMS, and non-specific xerostomia. From salivary gland scintigraphy, 22 quantitative parameters were calculated and their diagnostic values were assessed based on the area under the receiver operating characteristic curve (AUC) values. Among salivary gland scintigraphy parameters, uptake speed in the left submandibular gland showed the highest AUC value (0.647) for detecting BMS and pre-stimulatory oral activity showed the highest AUC value (0.710) for detecting primary BMS. A salivary gland scintigraphy scoring system based on these two parameters further enhanced the diagnostic ability, demonstrating AUC values of 0.731 for BMS and 0.782 for primary BMS. These results suggest a potential diagnostic value of the quantitative parameters of salivary gland scintigraphy for detecting BMS in patients with xerostomia.

Candidiasis and Other Bacterial Infections among Patients Diagnosed with Burning Mouth Syndrome

Background and Objectives: Burning mouth syndrome (BMS) is a state in which a patient experiences intraoral burning or a dysesthetic sensation without clinically evident causative lesions in the oropharyngeal area. The disorder is linked to a variety of conditions, including dry mouth, Candida, and bacterial infections. The aim of this study was to determine the incidence of oral Candida and/or bacterial infections among patients with BMS and whether they have an effect on pain/burning and salivary flow levels. Objectives: (1) Gather patient data regarding the presence of oral infections, dry mouth, and pain levels in the morning, afternoon, and evening periods; (2) data analysis and assessment to determine medians, means, frequencies, correlations, and statistically significant differences between patient groups. Materials and Methods: Overall, 173 patients (23 males and 150 females) with BMS and 13 controls (five males and eight females) took part in the study. We measured pain/burning levels, unstimulated and stimulated salivary flow, the percentage of patients infected with Candida species and/or bacterial species, and the said species growth in Petri dishes. Results: Candida albicans was the most commonly found infection among patients with BMS (n = 28, 16.2%). Overall, 21.4% patients with BMS were diagnosed with either C. albicans or another Candida species. Enterobacter had the richest growth among patients with BMS (7.5% out of the infected 10.4% BMS patients). No statistical significance could be noted between the existence of either Candida species or bacterial species infections and changes in pain/burning and salivary flow levels. Negative correlations were noted between age and unstimulated and stimulated salivary flow, and positive correlations were noted between age and Candida andspecific bacteria species’ growth levels. Conclusions: Although patients with present bacterial or Candida infections showed a marginal increase in pain/burning levels, no direct statistically significant associations could be made between the presence of Candida species or other bacteria and the symptoms among patients with BMS.

Salivary characteristics in burning mouth syndrome: a systematic review

INTRODUCTION

Compare through case-control studies, the salivary characteristics of patients with and without BMS.

EVIDENCE ACQUISITION

Searches in Embase, PubMed, Web of Science, Scopus, Cochrane, and BIREME were conducted for the identification of case-controls studies reported.

EVIDENCE SYNTHESIS

Thirty-three studies were included, of which 26 articles evaluated OSB, 17 SRF, and 7 SE. Nineteen organic biomarkers showed higher levels in BMS patients, the two most indicated being α-amylase and cortisol. Ten organic biomarkers, including Tumor Necrosis Factor-alpha (TNF-α) and IL-6, showed lower levels in BMS patients. Regarding salivary flow rate (SFR), five articles indicated that BMS patients have less unstimulated SFR (uSRF)Two articles indicate that stimulated SFR (sSRF) is lower in BMS patients nevertheless, but eight did not show differences. Sialochemical analysis revealed that sodium (Na), chloride (Cl), potassium (K), sodium (Na), and calcium (Ca), showed higher levels in BMS patients according to three studies, but two studies did not establish any differences. Two study established that BMS patients have lower Mg salivary levels.

CONCLUSIONS

Qualitative salivary characteristics suggest that BMS has neuropathic, inflammatory, emotional, immune, and hormonal involvements. BMS can be associated with changes in salivary biomarkers of inflammation and oxidative stress, is related to anxiety and degree of pain.

Dysgeusia: A review in the context of COVID-19

Background

Taste disorders in general, and dysgeusia in particular, are relatively common disorders that may be a sign of a more complex acute or chronic medical condition. During the COVID-19 pandemic, taste disorders have found their way into the realm of general as well as specialty dentistry, with significance in screening for patients who potentially may have the virus.

Types of Studies Reviewed

The authors searched electronic databases (PubMed, Embase, Web of Science, Google Scholar) for studies focused on dysgeusia, ageusia, and other taste disorders and their relationship to local and systemic causes.

Results

The authors found pertinent literature explaining the normal physiology of taste sensation, proposals for suggested new tastes, presence of gustatory receptors in remote tissues of the body, and etiology and pathophysiology of taste disorders, in addition to the valuable knowledge gained about gustatory disorders in the context of COVID-19. Along with olfactory disorders, taste disorders are one of the earliest suggestive symptoms of COVID-19 infection.

Conclusions

Gustatory disorders are the result of local or systemic etiology or both. Newer taste sensations, such as calcium and fat tastes, have been discovered, as well as taste receptors that are remote from the oropharyngeal area. Literature published during the COVID-19 pandemic to date reinforces the significance of early detection of potential patients with COVID-19 by means of screening for recent-onset taste disorders.

Practical Implications

Timely screening and identification of potential gustatory disorders are paramount for the dental care practitioner to aid in the early diagnosis of COVID-19 and other serious systemic disorders.

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.

Salivary characteristics may be associated with burning mouth syndrome?

Background

Burning mouth syndrome (BMS) it is characterized by burning and uncomfortable sensations with no clinical alterations or laboratory findings. The evaluation of the salivary characteristics of people with BMS can help the understanding of the pathogenesis of this condition. This case-control study aimed to trace the salivary profile of women with burning mouth syndrome (BMS).

Material and Methods

40 women with BMS and 40 control women were recruited. Unstimulated salivary flow rate (uSFR), pH, salivary cortisol levels, salivary viscosity, and oral health impact profile (OHIP-14 questioner) were determined. P< 0.05 was considered statistically significant.

Results

For uSFR, mean values obtained for BMS and for control group respectively were 0.35 and 0.61 mL/min; for pH, 7.23 and 7.34; for cortisol levels, 0.36 and 0.15 μg/dL; for viscosity values, 31.1 and 45.01 mPas and for OHIP-14 scores, 21.7 and 5.7. To uSFR, cortisol levels, viscosity values and OHIP-14 scores, differences were statistically significant. Salivary cortisol levels and OHIP-14 scores were correlated positively (rho = 0.624; p< 0.05).

Conclusions

BMS women have lower uSFR and salivary viscosity and higher salivary cortisol levels that were associated with worse quality of life, compared with the control group.

Key words:Xerostomia, Burning mouth syndrome, Viscosity.

Saliva flow rates and clinical characteristics of patients with burning mouth syndrome: A case-control study

Burning mouth syndrome (BMS) is a chronic pain condition that most commonly affects postmenopausal women older than 50 years of age. Xerostomia is a common complaint among BMS patients. However, previous studies showed inconsistent findings regarding saliva flow rate reduction. This study examined saliva flow rates, degree of mucosal hydration, xerostomia, and clinical characteristics in BMS patients compared with healthy controls. Unstimulated whole saliva (USWS) was collected through passive drooling; residual mucosal saliva (RMS) was collected using filter paper strips. Stimulated whole saliva (SWS) was collected while chewing on gum base. Oral exam and self-report data were collected. A total of 50 women (22 BMS cases and 28 healthy controls) aged 50 years or older were included in the analysis of this study. Mean age was 62 years for cases and 56 years for controls (P=0.05). Compared with controls, cases had significantly lower USWS flow rates (P<0.001) and had a higher prevalence of xerostomia (P=0.001), gastrointestinal disease (P<0.001), and vaginal dryness (P=0.01). These data show that oral and vaginal dryness are common among BMS patients. Further studies are needed to investigate potential pathophysiological mechanisms related to the quality of saliva and mucosal barrier status among these patients.

Oral health-related quality of life and associated factors in patients with burning mouth syndrome

OBJECTIVE

The purpose of this study was to assess oral health-related quality of life (OHRQoL) in patients with burning mouth syndrome (BMS) and to identify clinical factors associated with OHRQoL.

METHODS

Fifty-seven patients with BMS (56.4 ± 10.7 years) participated in the study. Patients underwent oral examination, laboratory tests, psychological evaluation, measurement of salivary flow rates and evaluation of clinical characteristics using a BMS questionnaire. The OHRQoL of patients was assessed using the Oral Health Impact Profile-14 (OHIP-14).

RESULTS

The OHIP-14 score for patients with BMS was 38.6 ± 12.8. Patients had higher scores for the psychological discomfort and physical pain dimensions of the OHIP-14. The intensity of taste disturbance or xerostomia symptoms (β = 0.464, P < .001), worry about symptoms (β = 0.307, P = .020), and results of psychological evaluation (β = 0.311, P = .026) were significantly associated with OHIP-14 score. Multiple linear regression showed that the intensity of taste disturbance or xerostomia symptoms was significantly associated with decreased OHRQoL (β = 0.637, P = .026).

CONCLUSIONS

This study suggests that severity of taste disturbance or xerostomia is an important factor that influences OHRQoL in patients with BMS.

Burning Mouth Syndrome

Burning mouth syndrome is a chronic condition characterized by an intraoral burning sensation in the absence of a local or systemic cause.

Chemosensory dysfunction, Oral disorders and Oral health-related quality of life in patients with primary Sjögren's syndrome: comparative cross-sectional study

Background

The aim of this study was to evaluate chemosensory function and oral disorders in patients with primary Sjögren’s syndrome (pSS) and to compare these findings with those of age- and gender-matched healthy controls.

Methods

This comparative cross-sectional study included 58 patients with primary Sjögren’s syndrome (pSS) and 55 age- and gender-matched healthy controls. Olfactory and gustatory function, burning sensations in the tongue (BST) and halitosis were assessed. Oral health-related quality of life (OHRQoL) was evaluated using the short-form Oral Health Impact Profile (OHIP-14).

Results

Patients with pSS had significantly lower self-reported visual analogue scale (VAS) smell score (8.6 ± 2.2 vs. 9.6 ± 0.7, p = 0.016) and VAS taste score (8.5 ± 2.1 vs. 9.5 ± 0.7, p = 0.014) than healthy controls. A greater proportion of patients with pSS had anosmia (3.8% vs. 0.0%) or hyposmia (36.5% vs. 13.2%) and ageusia for basic tastes: sweetness (34.0% vs. 7.5%), sourness (10.6% vs. 0.0), saltiness (10.0% vs. 5.7%) or bitterness (19.1% vs. 1.9%) as evaluated using Sniffin Sticks test and taste stripts, respectively. A higher proportion of pSS patients complained of dysgeusia (52.6% vs. 9.4%, p < 0.0001) and BST (45.6% vs. 0.0%, p < 0.0001), while similar number of patients with pSS and controls reported halitosis (31.6% vs. 28.3%, p = 0.434). The mean OHIP-14 score was significantly higher in patients with pSS (6.8 ± 7.0 vs. 2.3 ± 8.5, p < 0.001) indicating patients’ poorer OHRQoL compared with controls.

Conclusions

The majority of patients with pSS had impaired chemosensory function and indicators of oral health in comparison with the age- and gender-matched healthy controls. Further studies of oral hygiene habits and dietary intake of these patients are needed to ensure better management of oral health problems in patients with pSS.

A perspective from experimental studies of burning mouth syndrome

Burning mouth syndrome (BMS) is one of the most frequently seen idiopathic pain conditions in a dental setting. Peri- and postmenopausal women are most frequently affected, and patients who experience BMS complain of persistent burning pain mainly at the tip and the bilateral border of the tongue. Recent studies have assessed whether BMS is a neuropathic pain condition, based on morphologic changes in biopsied tongue specimens, and whether there are abnormal pain responses in patients with this disease. Somatosensory studies have reported some abnormal findings in sensory and pain detection thresholds with inconsistency; however, the most distinct finding was exaggerated responses to painful stimuli. Imaging and electrophysiologic studies have suggested the possibility of dysregulation of the pain-modulating system in the central nervous system, which may explain the enhanced pain responses despite the lack of typical responses toward quantitative sensory tests. Basic studies have suggested the possible involvement of neuroprotective steroids, although the underlying mechanisms of this condition have not been elucidated. Experimental studies are looking for preferable supportive therapies for BMS patients despite the obscure pathogenesis.

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.

Is there an association between drugs and burning mouth syndrome? A case-control study

OBJECTIVE

The purpose of this case-control study was to compare the pharmacological anamnesis collected from a group of 150 burning mouth syndrome (BMS) patients with that of a control group of 150 patients matched for age and sex.

MATERIALS AND METHODS

The patients' medical histories were reviewed, and data on drug therapy were collected. Drugs were classified on the basis of pharmacological effects; the classes were antihypertensives (i.e., ACE inhibitors/ARBs, calcium antagonists, diuretics and beta-blockers), antiaggregants, anticoagulants, antidiabetics, vitamin D integrators, bisphosphonates, psychotropics (i.e., anxiolytics and antidepressants), gastroprotectors, statins, thyroid hormone substitutes, corticosteroids and immunosuppressants.

RESULTS

The BMS patients and the controls were matched for age (mean age: 69 years) and sex (128 females and 22 males). Antihypertensives, especially ACE inhibitors/ARBs (OR = 0.37, CI: 0.22-0.63, p = 0.0002) and beta-blockers (OR = 0.36, CI: 0.19-0.68 p = 002), revealed an inverse association with the presence of BMS, whereas anxiolytics (OR = 3.78, CI: 2.12-6.75 p < 0.0001), but neither antidepressants nor antipsychotics, were significantly associated with BMS. There were no correlations with other drug classes.

CONCLUSION

Our study highlighted that ACE inhibitors, ARBs and beta-blockers were in inverse relation to BMS and found that anxiolytics, but neither antidepressants nor antipsychotics, were linked to the presence of the syndrome.

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.

Distorted Taste and Impaired Oral Health in Patients with Sicca Complaints

Senses of smell and taste, saliva flow, and dental status are considered as important factors for the maintenance of a good nutritional status. Salivary secretory rates, chemosensory function, burning mouth sensation, halitosis and dental status were investigated in 58 patients with primary Sjögren’s syndrome (pSS), 22 non-Sjögren’s syndrome sicca (non-SS) patients, and 57 age-matched healthy controls. A significantly greater proportion of patients with pSS and non-SS had ageusia, dysgeusia, burning mouth sensation, and halitosis compared to controls. Patients with pSS had significantly lower olfactory and gustatory scores, and significantly higher caries experience compared to controls. Patients with pSS and non-SS patients had significantly lower unstimulated and stimulated whole saliva secretory rates compared to controls. The findings indicated that several different aspects of oral health were compromised in both, patients with pSS and non-SS, and this may affect their food intake and, hence, their nutritional status. Although non-SS patients do not fulfill Sjögren’s syndrome classification criteria, they have similar or, in some cases, even worse oral complaints than the patients with pSS. Further studies are needed to investigate food preferences, dietary intake, and nutritional status in these two patient groups in relation to their health condition.

Oral burning: local and systemic connection for a patient-centric approach

Burning symptoms in the oral cavity are caused by a range of systemic and local factors, in addition to the neuropathic pain disorder burning mouth syndrome (BMS). Patients may state oral burning as a standalone symptom or may report as a secondary symptom in association with other factors, most commonly with oral dryness, oral mucosal lesions, or certain systemic conditions. There is a level of uncertainty in the presentation of this condition which creates a diagnostic challenge from both the patient's perspective and the practitioner evaluating these individuals. The diagnoses are complicated due to the lack of a clear definition of BMS and clinical guidelines to distinguish BMS from other conditions that are responsible for oral burning symptoms. A clinician should be able to differentiate oral burning from burning mouth syndrome. This integrative review discusses on local and systemic etiologies of oral burning based on current evidence that needs to be excluded for a diagnosis of BMS. It also provides an algorithm for diagnostic workup and therapeutic management to medical providers for patients experiencing oral burning symptoms. This comprehensive system provides a systematic stepwise workup in diagnosing and managing patients presenting with a complaint of oral burning that optimally meets a predictive, preventive, and personalized medicine (PPPM) approach.

Oral Disorders in Sjögren’s Syndrome

Sjogren’s syndrome (SS) is a complex, chronic, systemic, autoimmune disease that mainly affects the exocrine glands, especially the salivary and lacrimal glands, leading to the dryness of the mouth and eyes, along with fatigue, joint and muscle pain. The prevalence of SS is estimated to be between 0.05% and 1% in European population. Diagnosis of SS is based on the revised criteria of the American-European consensus group (AECG). Sjogren’s syndrome can be subclassified into primary disease (primary Sjogren syndrome, pSS) and a secondary disease (secondary Sjogren syndrome, sSS) when present with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and systemic sclerosis. The decrease in salivary flow and qualitative alterations in saliva could explain many of the oral manifestations frequently present in patients with SS. Low salivary flow may affect chewing, swallowing, speech and sleeping in pSS patients. Oral manifestations include dental erosion, dental caries, mucosal infection, ulcers and oral candidiasis. Recent studies reveal that pSS patients experience impaired olfactory and gustatory functions and have higher occurrence of oral complications such as dysgeusia, burning sensation in the tongue (BST) and halitosis. The exocrine manifestations and systemic involvement in SS significantly impact the patient’s perception of oral healthrelated quality of life (OHRQoL).

Proteomics of the acid-soluble fraction of whole and major gland saliva in burning mouth syndrome patients

OBJECTIVE

In the present study the salivary proteome of burning mouth syndrome patients and healthy subjects was characterized by a top-down proteomic approach and compared to highlight possible qualitative and quantitative differences that may give suggestions about the causes of this pathology which are still unknown.

MATERIALS AND METHODS

Resting and stimulated whole saliva, stimulated parotid and submandibular/sublingual saliva samples were collected from burning mouth syndrome patients (n = 16) and age- and gender-matched healthy subjects (n = 14). An equal volume of 0.2% trifluoroacetic acid was added to each sample immediately after collection and the supernatants were analysed by liquid chromatography coupled to electrospray-ionisation mass spectrometry. Proteins and peptides were quantified using a label-free approach measuring the extracted ion current peak areas of the main salivary proteins and peptides.

RESULTS

The quantitation of the main salivary proteins and peptides revealed a higher concentration of cystatin SN in resting saliva of burning mouth syndrome patients with respect to healthy controls and no other conspicuous changes.

CONCLUSIONS

The reported data showed that the salivary protein profile was not affected, in composition and relative abundance, by the burning mouth syndrome, except for the cystatin SN, a protein up-regulated in several pathological conditions, that might be considered potentially indicative of the disease.

Evaluation of laser therapy and alpha-lipoic acid for the treatment of burning mouth syndrome: a randomized clinical trial

The aim of this study was to evaluate the efficacy of low-level laser therapy (LLLT) and alpha-lipoic acid (ALA) in the treatment of burning mouth syndrome (BMS) and secondary oral burning (SOB) by unstimulated sialometry, symptom assessment, and measurement of salivary TNF-α levels. Forty-four patients were randomized into four treatment groups: BMS/laser (n = 10), BMS/ALA (n = 5), SOB/laser (n = 15), and SOB/ALA (n = 14). The control group consisted of eight healthy female subjects. Unstimulated salivary flow was measured before and after treatment, and the collected saliva was stored at - 20 °C for the analysis of TNF-α. Symptoms were evaluated before and after treatment using a pain visual analog scale. Most patients were women (81.8%) during menopause (72.2%). LLLT and ALA were efficient in increasing salivary flow only in BMS but provided symptom relief in both conditions. TNF-α levels did not differ between patients with BMS and SOB or between those patients and the control group. No differences were observed in posttreatment TNF-α levels in either condition. The results of this study suggest that LLLT and ALA are efficient therapies in reducing burning mouth symptoms, with LLLT being more efficient than ALA.

Compliance with Saliva Collection Protocol in Healthy Volunteers: Strategies for Managing Risk and Errors

Salivary bioscience technologies such as electrophoresis are widely applied for diagnosing systemic health status. Diagnosis using a saliva sample has emerged as a preferred technique since the sample is easy to collect and the method is inexpensive and non-invasive. Salivary diagnostics have even been identified as potential substitutes for serum protein biomarkers. However, the optimal protocol for collecting saliva has not yet been established. In many scientific settings, such as randomized controlled trials, sampling and statistical errors often occur when handling samples from healthy volunteers. These errors can be due to the psychological behavior of the volunteers, subject nonadherence, questionnaire characteristics, collection methods, and/or sample processing. The purpose of the review presented here is to outline the strategies for managing the risk factors and to minimize the sampling errors during saliva collection in healthy volunteers.

Oral disorders, saliva secretion, and oral health-related quality of life in patients with primary Sjögren's syndrome

Chemosensory function, burning sensations in the tongue (BST), halitosis, saliva secretion, and oral health-related quality of life (OHRQoL) were investigated in patients with primary Sjögren's syndrome (pSS). In 31 patients with pSS and 33 controls, olfactory and gustatory functions were evaluated. Self-reported complaints of dysgeusia, BST, and halitosis were recorded. Saliva secretion rates were measured and OHRQoL was assessed using the short-form Oral Health Impact Profile (OHIP-14). Patients had significantly lower olfactory (8.8 ± 3.5 vs. 10.7 ± 1.2) and gustatory (18.9 ± 7.1 vs. 25.4 ± 4.3) scores than controls, and significantly more patients complained of dysgeusia (58.1% vs. 0%), BST (54.8% vs. 6.1%), and halitosis (41.9% vs. 0%). A significantly greater proportion of patients with pSS had ageusia (19% vs. 0%), hypogeusia (32% vs. 12%), anosmia (13% vs. 0%), or hyposmia (29% vs. 9%). Significantly lower saliva secretion rates (ml min^-1 ) were observed in patients with pSS for stimulated (0.62 ± 0.40 vs. 1.57 ± 0.71) and unstimulated (0.08 ± 0.07 vs. 0.29 ± 0.17) saliva. The mean OHIP-14 score was significantly higher in patients with pSS (16.2 ± 10.8 vs. 2.7 ± 3.1) and was positively correlated with dysgeusia, BST, and halitosis. In conclusion, patients with pSS reported higher occurrence of dysgeusia, BST, and halitosis, and demonstrated relatively impaired chemosensory and salivary functions. The patients' poorer OHRQoL was associated with dysgeusia, BST, and halitosis.

Burning mouth syndrome

Objective

To review the clinical entity of primary burning mouth syndrome (BMS), its pathophysiological mechanisms, accurate new diagnostic methods and evidence-based treatment options, and to describe novel lines for future research regarding aetiology, pathophysiology, and new therapeutic strategies.

Description

Primary BMS is a chronic neuropathic intraoral pain condition that despite typical symptoms lacks clear clinical signs of neuropathic involvement. With advanced diagnostic methods, such as quantitative sensory testing of small somatosensory and taste afferents, neurophysiological recordings of the trigeminal system, and peripheral nerve blocks, most BMS patients can be classified into the peripheral or central type of neuropathic pain. These two types differ regarding pathophysiological mechanisms, efficacy of available treatments, and psychiatric comorbidity. The two types may overlap in individual patients. BMS is most frequent in postmenopausal women, with general population prevalence of around 1%. Treatment of BMS is difficult; best evidence exists for efficacy of topical and systemic clonazepam. Hormonal substitution, dopaminergic medications, and therapeutic non-invasive neuromodulation may provide efficient mechanism-based treatments for BMS in the future.

Conclusion

We present a novel comprehensive hypothesis of primary BMS, gathering the hormonal, neuropathic, and genetic factors presumably required in the genesis of the condition. This will aid in future research on pathophysiology and risk factors of BMS, and boost treatment trials taking into account individual mechanism profiles and subgroup-clusters.

Is it Sjögren's syndrome or burning mouth syndrome? Distinct pathoses with similar oral symptoms

Sjögren's syndrome (SS) and burning mouth syndrome (BMS) typically occur in postmenopausal women. Although these conditions have significantly different etiopathogeneses, patients with SS or BMS often present with analogous oral complaints. The similarities between the two conditions have led to considerable confusion on the part of medical and dental practitioners, and those with BMS or SS often wait years to receive a diagnosis. Therefore, it is imperative for clinicians to understand the characteristic subjective and objective features of each disease and how these can be used to distinguish them. This review will discuss the proposed etiology, clinical manifestations, histopathology, diagnostic criteria, and patient management of SS and BMS. We also identify key differences between the two pathoses that aid in establishing the correct diagnosis. Recognition of the defining features of each condition will lead to reduced time to diagnosis and improved patient management for these poorly understood conditions.

Characteristic changes of saliva and taste in burning mouth syndrome patients

BACKGROUND

Burning mouth syndrome (BMS) is characterized by chronic pain with a burning sensation of the tongue and oral mucosa and reported to be often accompanied by subjective xerostomia and dysgeusia. Since the etiology of BMS has not been elucidated, to understand the characteristics of BMS, we measured some components of saliva and taste sensitivity and compared the measured values between BMS and healthy subjects.

METHODS

Unstimulated saliva was collected from 15 female BMS patients and 30 healthy women. The flow rate, viscosity (spinnability) and concentration of secretory IgA (SIgA) of saliva and serum antioxidant capacity were measured. The recognition thresholds for sweet, salty, sour, bitter, and umami tastes were measured by whole-mouth method. The statistical analyses were performed using Student's t-test, and P < 0.05 was considered to be significant.

RESULTS

In BMS group, the flow rate of saliva was significantly lower and the spinnability was significantly higher compared with healthy group. The secreted amount of SIgA per min and serum antioxidant capacity was significantly lower in the patients. The threshold for sourness in patients was significantly higher, while those for other tastes did not differ from healthy group.

CONCLUSIONS

BMS patients showed lower salivary flow and higher salivary spinnability. These results together with decreased SIgA amount, suggest that BMS may be relevant to the deterioration of salivary condition, which could in turn affect taste function. Furthermore, the lower antioxidant capacity in patient's serum suggests that it can serve as a diagnostic tool for BMS.

Burning mouth syndrome

Burning mouth syndrome (BMS) is a chronic condition characterized by burning of the oral mucosa, with or without dysgeusia and xerostomia, in the setting of no underlying systemic disease or identifiable abnormalities on physical examination or laboratory testing. BMS disproportionately affects postmenopausal women. The pathophysiology of the disease is unknown; no single treatment has proven universally successful. In light of these shortcomings, having a practical approach to the evaluation and management of patients with BMS can improve both patient quality of life and physician satisfaction.