Oral mucosal blood flow in patients with burning mouth syndrome

Management of Burning Mouth Syndrome

This article provides an update for the practicing dentist and/or oral and maxillofacial surgeon on the recognition, identification, and treatment of burning mouth syndrome (BMS). We discuss the most common clinical findings and most common causes of BMS. This article provides a classification flowchart that assists the practitioner in diagnosing and classifying BMS. The article then discusses the pathophysiology and treatment of BMS updated in the literature from the latest studies and reviews. Treatment can vary from topical or systemic medication to behavioral therapy.

Treatments for Burning Mouth Syndrome: A Network Meta-analysis

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

Neuropathic and Psychogenic Components of Burning Mouth Syndrome: A Systematic Review

The pathophysiology of primary burning mouth syndrome (BMS) has been extensively debated but is poorly understood despite a large number of hypotheses attempting to explain its etiopathogenic mechanisms. The aim of the present work was to systematically review papers that could provide arguments in favour of the neuropathic and psychogenic components of primary BMS for a better understanding of the disease. This systematic review (SR) was registered in PROSPERO (CRD42021224160). The search was limited to articles in English or French from 1990 to 01 December 2020. A total of 113 articles were considered for data extraction. We divided them into four subgroups: pharmacological and nonpharmacological management studies (n = 23); neurophysiological studies (n = 35); biohistopathological studies (n = 25); and questionnaire-based studies (n = 30). Several of these studies have shown neuropathic involvement at various levels of the neuraxis in BMS with the contribution of quantitative sensory testing (QST), functional brain imaging, and biohistopathological or pharmacologic studies. On the other hand, the role of psychological factors in BMS has also been the focus of several studies and has shown a link with psychiatric disorders such as anxiety and/or depression symptoms. Depending on the patient, the neuropathic and psychogenic components may exist simultaneously, with a preponderance of one or the other, or exist individually. These two components cannot be dissociated to define BMS. Consequently, BMS may be considered nociplastic pain.

Neuropathic Pain and Burning Mouth Syndrome: An Overview and Current Update

Burning mouth syndrome/glossodynia and trigeminal neuropathic conditions can have serious negative impact on a patient's overall quality of life. These conditions are often hard to diagnose and even harder to fully treat and manage, but it is important for dentists/oral and maxillofacial surgeons to be aware of these conditions and modalities of their treatment. Often the only method for arriving at the proper diagnosis is for patients to undergo traditional approaches for treatment of presenting signs and symptoms, and it is the unexpected failure of interventional therapies that leads ultimately to a proper diagnosis.

The use of laser Doppler flowmetry to evaluate oral soft tissue blood flow in humans: A review

The objective of this work is to define the conditions for improving the use of laser Doppler flowmetry (LDF) and to determine the limits for the use of this technique. This article systematically reviews the literature on the evaluation of oral soft tissue blood microcirculation by LDF. We analysed the available literature through October 2016 using the database resources Medline/PubMed, the Cochrane Oral Health Group Specialist Trials Register and the ISI Web of Knowledge. Several points emerged from this literature review The use of LDF involves specific constraints; however, the influence of different factors (temperature, tobacco, pressure etc.) must be adequately controlled when using LDF. LDF measurements of soft tissue within the oral cavity vary depending on the anatomical site. In dentistry, LDF can be used to track healing progress in periodontal surgery and to diagnose vascular flow changes in the connective tissue of mucosae covered by a removable prosthesis at an early stage prior to the onset of clinical inflammation signs.

A diagnostic and therapeutic approach to primary burning mouth syndrome

Primary burning mouth syndrome (BMS) is an oral mucosal disorder that is characterized by a chronic and often debilitating intraoral burning sensation for which no localized or systemic cause can be found. BMS most commonly affects postmenopausal women. The pathophysiology of primary BMS is not well understood. Diagnosing BMS can prove to be challenging. BMS patients can also pose a therapeutic challenge to clinicians who are consulted to evaluate these patients. Most commonly used therapies include tricyclic antidepressants, α-lipoic acid, clonazepam, and cognitive-behavioral therapy. Clinical judgment, patient counseling, and monitoring of pain are important. Further research is required to assess the effectiveness of serotonin and newer serotonin-noradrenalin reuptake inhibitors.

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.

Opiorphin in burning mouth syndrome patients: a case-control study

OBJECTIVES

Opiorphin is a pentapeptide isolated from human saliva that suppresses pain from chemically induced inflammation and acute physical pain. Burning mouth syndrome (BMS) is a chronic condition of a burning sensation in the mouth, where no underlying dental or medical cause can be identified. We aimed to measure the level of opiorphin in whole unstimulated (UWS) and stimulated (SWS) saliva of patients with BMS.

MATERIALS AND METHODS

Originally developed and validated LC-MS/MS method was used for opiorphin quantification. Samples were obtained from 29 BMS patients and 29 age- and sex-matched controls.

RESULTS

The average concentration of opiorphin in UWS and SWS in the BMS group was 8.13 ± 6.45 and 5.82 ± 3.59 ng/ml, respectively. Opiorphin in BMS patients' UWS was significantly higher, compared to the control group (t = 2.5898; p = 0.0122). SWS opiorphin levels were higher, but not significantly, in BMS patients than in controls.

CONCLUSIONS

Our results indicate that higher quantities of salivary opiorphin in BMS may be a consequence of chronic pain, but we cannot exclude that they occur as a result of emotional and behavioral imbalances possibly associated with BMS. To our knowledge, this is the first original article measuring opiorphin in a pain disorder.

CLINICAL RELEVANCE

Opiorphin may be a measurable biomarker for chronic pain, which could help in objectifying otherwise exclusively a subjective experience. Increased opiorphin could serve as a universal objective indicator of painful conditions. Since opiorphin may also reflect emotional and socio-relational imbalances occurring with BMS, it could as well represent a biomarker for BMS. Knowledge on opiorphin's involvement in pain pathways could contribute to developing new clinical diagnostic methods for BMS.

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.

Burning mouth syndrome: Current concepts

Burning mouth syndrome (BMS) is a chronic pain condition. It has been described by the International Headache Society as "an intra-oral burning or dysesthetic sensation, recurring daily for more than 2 h/day for more than 3 months, without clinically evident causative lesions." BMS is frequently seen in women in the peri-menopausal and menopausal age group in an average female/male ratio of 7:1. The site most commonly affected is the anterior two-thirds of the tongue. The patient may also report taste alterations and oral dryness along with the burning. The etiopathogenesis is complex and is not well-comprehended. The more accepted theories point toward a neuropathic etiology, but the gustatory system has also been implicated in this condition. BMS is frequently mismanaged, partly because it is not well-known among healthcare providers. Diagnosis of BMS is made after other local and systemic causes of burning have been ruled out as then; the oral burning is the disease itself. The management of BMS still remains a challenge. Benzodiazepines have been used in clinical practice as the first-line medication in the pharmacological management of BMS. Nonpharmacological management includes cognitive behavioral therapy and complementary and alternative medicine (CAM). The aim of this review is to familiarize healthcare providers with the diagnosis, pathogenesis, and general characteristics of primary BMS while updating them with the current treatment options to better manage this group of patients.

Burning Mouth Syndrome

Burning mouth syndrome (BMS) is multifactorial in origin which is typically characterized by burning and painful sensation in an oral cavity demonstrating clinically normal mucosa. Although the cause of BMS is not known, a complex association of biological and psychological factors has been identified, suggesting the existence of a multifactorial etiology. As the symptom of oral burning is seen in various pathological conditions, it is essential for a clinician to be aware of how to differentiate between symptom of oral burning and BMS. An interdisciplinary and systematic approach is required for better patient management. The purpose of this study was to provide the practitioner with an understanding of the local, systemic, and psychosocial factors which may be responsible for oral burning associated with BMS, and review of treatment modalities, therefore providing a foundation for diagnosis and treatment of BMS.

Thermal and mechanical quantitative sensory testing in Chinese patients with burning mouth syndrome--a probable neuropathic pain condition?

Background

To explore the hypothesis that burning mouth syndrome (BMS) probably is a neuropathic pain condition, thermal and mechanical sensory and pain thresholds were tested and compared with age- and gender-matched control participants using a standardized battery of psychophysical techniques.

Methods

Twenty-five BMS patients (men: 8, women: 17, age: 49.5 ± 11.4 years) and 19 age- and gender-matched healthy control participants were included. The cold detection threshold (CDT), warm detection threshold (WDT), cold pain threshold (CPT), heat pain threshold (HPT), mechanical detection threshold (MDT) and mechanical pain threshold (MPT), in accordance with the German Network of Neuropathic Pain guidelines, were measured at the following four sites: the dorsum of the left hand (hand), the skin at the mental foramen (chin), on the tip of the tongue (tongue), and the mucosa of the lower lip (lip). Statistical analysis was performed using ANOVA with repeated measures to compare the means within and between groups. Furthermore, Z-score profiles were generated, and exploratory correlation analyses between QST and clinical variables were performed. Two-tailed tests with a significance level of 5 % were used throughout.

Results

CDTs (P < 0.02) were significantly lower (less sensitivity) and HPTs (P < 0.001) were significantly higher (less sensitivity) at the tongue and lip in BMS patients compared to control participants. WDT (P = 0.007) was also significantly higher at the tongue in BMS patients compared to control subjects . There were no significant differences in MDT and MPT between the BMS patients and healthy subjects at any of the four test sites. Z-scores showed that significant loss of function can be identified for CDT (Z-scores = −0.9±1.1) and HPT (Z-scores = 1.5±0.4). There were no significant correlations between QST and clinical variables (pain intensity, duration, depressions scores).

Conclusion

BMS patients had a significant loss of thermal function but not mechanical function, supporting the hypothesis that BMS may be a probable neuropathic pain condition. Further studies including e.g. electrophysiological or imaging techniques are needed to clarify the underlying mechanisms of BMS.

Tongue color changes within a menstrual cycle in eumenorrheic women

Tongue color (舌色 shé sè) has been used to diagnose abnormal body conditions for thousands of years in traditional Chinese Medicine (中醫 zhōng yī). However, it is not clear whether tongue color alters with physiological changes within a normal menstrual cycle (月經周期 yuè jīng zhōu qī). This study investigated difference in tongue color between the follicular phase and luteal phase in eumenorrheic women. Tongue surface photographs were taken in the follicular phase and the luteal phase of thirty-two volunteers with biphasic basal body temperature. Color values on five areas of the tongue surface were examined and comparisons of color values were made between the two phases according to the red–green–blue (RGB), hue–saturation–brightness (HSB), luminance-a-b (Lab), and cyan–magenta–yellow–black (CMYK) models. Based on the RGB model, the values of green and blue in the tip area were larger in the follicular phase than both in the luteal phase. The values of magenta and yellow based in the CMYK model were smaller in the tip area in the follicular phase than that in the luteal phase. The saturation in the tip area was smaller in the follicular phase than that in the luteal phase. Based on the Lab model, b value in the middle area was smaller in the follicular phase than that in the luteal phase. The data revealed that tongue color varied within a eumenorrheic menstrual cycle, suggesting that tongue color differences between the follicular and luteal phases need to be considered while practicing tongue diagnosis (舌診 shé zhěn) or performing clinical studies among childbearing women.

Phototherapy on the Treatment of Burning Mouth Syndrome: A Prospective Analysis of 20 Cases

The aim of this study was to report the effect of laser phototherapy (LPT) on the treatment of burning mouth syndrome (BMS). This prospective clinical study reports on preliminary outcomes of twenty volunteers diagnosed with BMS who have undergone the conventional treatment prior to laser phototherapy. LPT consisted of weekly sessions of LPT (660 nm), for a period of 10 weeks. The laser protocol consisted of the following parameters: 40 mW, 10 J cm(2) and 0.4 J per point, irradiation time of 10 s. In all sessions, the burning intensity was evaluated with a 10 cm Visual Analogue Scale (VAS). The burning intensity evaluation by VAS was performed immediately before and after each LPT session. Nonparametric test of Wilcoxon was used for statistical analysis, considering a significance level of 5%. All volunteers reported reduced burning intensity in all sessions when compared to the previous one and reduction in VAS scores by up to 49% in the last clinical session when compared to the first session. When only the VAS baseline of the first session was compared with the consecutive sessions, there was a statistically significant reduction in VAS scores in almost all sessions. The LPT may be an alternative treatment for the relief of oral burning symptoms in patients with BMS.

Development of a Novel Oral Cavity Compartmental Absorption and Transit Model for Sublingual Administration: Illustration with Zolpidem

Intraoral (IO) delivery is an alternative administration route to deliver a drug substance via the mouth that provides several advantages over conventional oral dosage forms. The purpose of this work was to develop and evaluate a novel, physiologically based oral cavity model for projection and mechanistic analysis of the clinical pharmacokinetics of intraoral formulations. The GastroPlus™ Oral Cavity Compartmental Absorption and Transit (OCCAT™) model was used to simulate the plasma concentration versus time profiles and the fraction and rate of intraoral drug transit/absorption for Intermezzo® sublingual tablets (zolpidem tartrate). The model was evaluated by the goodness-of-fit between simulated and observed concentrations and the deviation of key PK parameters (e.g., C max, T max, and AUC). In addition, a sensitivity analysis was conducted to demonstrate the interplay and impact of key modeling parameters on the fraction absorbed via oral mucosa (F a_IO). The OCCAT™ model captured the observed pharmacokinetics for Intermezzo® sublingual tablets (R (2) > 0.9). The predicted deviations (%) for C max, AUC0-inf, AUC0-20 min, and T max were 5.7, 28.0, 11.8, and 28.6%, respectively, indicating good prediction accuracy. The model also estimated ~18% of total drug was absorbed via the IO route. Furthermore, the sensitivity analysis indicated that the F a_IO was not only associated with drug diffusivity and unbound fraction in epithelium tissue (f ut) but also depended on the physicochemical properties of compounds for IO delivery (e.g., solubility and logD pH = 7.4). The novel physiologically based IO absorption OCCAT™ model showed satisfactory performance and will be helpful to guide development of future intraoral formulations.

A population-based study of the incidence of burning mouth syndrome

OBJECTIVE

To calculate the incidence of burning mouth syndrome (BMS) in Olmsted County, Minnesota, from 2000 through 2010.

PATIENTS AND METHODS

By using the medical record linkage system of the Rochester Epidemiology Project, we identified newly diagnosed cases of BMS from January 1, 2000, through December 31, 2010. Diagnoses were confirmed through the presence of burning pain symptoms of the oral mucosa with normal oral examination findings and no associated clinical signs. Incidence was estimated using decennial census data for Olmsted County.

RESULTS

In total, 169 incident cases were identified, representing an annual age- and sex-adjusted incidence of BMS of 11.4 per 100,000 person-years. Age-adjusted incidence was significantly higher in women than in men (18.8 [95% CI, 16.4-22.9] per 100,000 person-years vs 3.7 [95% CI, 2.6-5.7] per 100,000 person-years; P<.001). Postmenopausal women aged 50 to 89 years had the highest incidence of the disease, with the maximal rate observed in women aged 70 to 79 years (70.3 per 100,000 person-years). After the age of 50 years, the incidence of BMS in men and women significantly increased across age groups (P=.02). Study participants residing in Olmsted County, Minnesota, were predominantly white, which is a study limitation. In addition, diagnostic criteria for identifying BMS in the present study may not apply for all situations because no diagnostic criteria are universally recognized for identifying BMS.

CONCLUSION

To our knowledge, this is the first population-based incidence study of BMS reported to date. The data reveal that BMS is an uncommon disease highly associated with female sex and advancing age.

Burning mouth syndrome: A review on its diagnostic and therapeutic approach

Burning mouth syndrome (BMS), a chronic and intractable orofacial pain syndrome is characterized by the presence of burning sensation of the oral mucosa in the absence of specific oral lesion. This condition affects chiefly of middle aged and elderly woman with hormonal changes or psychological disorders. In addition to burning sensation, patient with BMS also complains of oral mucosal pain, altered taste sensation, and dry mouth. This condition is probably of multifactorial origin, often idiopathic and its exact etiopathogenesis remains unclear. So far, there is no definitive cure for this condition and most of the treatment approaches, medications remains unsatisfactory. An interdisciplinary and systematic approach is required for better patient management. The purpose of this article is to present a review of epidemiology, clinical presentation, classification, etiopathogenesis, diagnosis and management of BMS.

Group cognitive-behavioral intervention for patients with burning mouth syndrome

This study was conducted to assess the psychological characteristics of, and determine the effectiveness of group cognitive-behavioral (CB) treatment for, patients with burning mouth syndrome (BMS). The baseline characteristics of 24 female patients (age 69.7 ± 5.9 years) and an identical number of healthy female control subjects (age 69.2 ± 5.5 years) were compared. The patient group had significantly higher anxiety scores (P < 0.05) at baseline. A brief group CB intervention was delivered in a small-group format. Two sessions were planned 6 months apart. A numeric rating scale (NRS) was used to assess pain intensity. Anxiety was evaluated using a state and trait anxiety inventories. Present pain intensity decreased after both the first and second sessions. The session effect was significant (P = 0.02), but no repeat effect was found (P = 0.19). The state anxiety inventory score also decreased after the second session. The session effect was significant (P < 0.01), as was the repeat effect (P < 0.01). The trait anxiety inventory score decreased after the second session, and the session effect was significant (P = 0.013), but the repeat effect was not (P = 0.93). The results suggest that a brief group CB intervention reduces pain intensity and anxiety in patients with BMS.

Increased prevalence of geographic tongue in burning mouth complaints: a retrospective study

OBJECTIVES

The objective of this study was to assess the frequency of geographic tongue and fissured tongue (GFT) in patients with burning mouth syndrome (BMS). Our hypothesis was that benign soft tissue changes to the tongue, such as GFT, are associated with BMS.

STUDY DESIGN

Retrospective review of 161 patients with BMS and 87 TMJ dysfunction cases as control. Frequency of GFT and demographics for both groups was assessed.

RESULTS

In the BMS group, 26.7% of the subjects were diagnosed with GFT, whereas in the control group, 11.5% had GFT (P < .05). In the subgroup of BMS with GFT, the male-to-female ratio was approximately 1:2, whereas the male-to-female ratio of those with BMS and no GFT was approximately 1:5 (P < .05).

CONCLUSIONS

Our results demonstrate a higher than expected prevalence of GFT among patients with BMS compared with a control group of patients with TMJ. In males, GFT may be a significant predictor for BMS.

Burning Mouth Syndrome

The aetiology of BMS remains an enigma, however novel evidence suggests a neuropathic basis, which may explain concomitant vulvodynia in some patients.The constant high level spontaneous chronic pain in BMS has significant functional and psychological repercussions for these patients.Cognitive behavioural therapy remains the sole evidence based management of this condition, whilst some patients respond to treatment with Tricyclic antidepressants, SSRIs or SNRIs, compliance with medication remains an issue due to pharma side effects.Increasing evidence suggests that there may be 3 subgroups that should be managed differently.

Pathophysiology of primary burning mouth syndrome

Primary burning mouth syndrome (BMS) is severe, disabling and chronic intraoral pain condition for which no local or systemic cause can be found and clinical examination is normal. It mostly affects elderly citizens, especially postmenopausal women with prevalence up to 12-18%. In addition to spontaneous burning pain, patients may complain of taste alterations. Recent neurophysiologic, psychophysical, neuropathological, and functional imaging studies have elucidated that several neuropathic mechanisms, mostly subclinical, act at different levels of the neuraxis and contribute to the pathophysiology of primary BMS. Demonstration of loss of small diameter nerve fibres in the tongue epithelium explains thermal hypoesthesia and increase in taste detection thresholds found in quantitative sensory testing. As in neuropathic pain, decreased brain activation to heat stimuli has been demonstrated with fMRI in BMS patients. However, it seems that the clinical diagnosis of primary BMS encompasses at least three distinct, subclinical neuropathic pain states that may overlap in individual patients. The first subgroup (50-65%) is characterized by peripheral small diameter fibre neuropathy of intraoral mucosa. The second subgroup (20-25%) consists of patients with subclinical lingual, mandibular, or trigeminal system pathology that can be dissected with careful neurophysiologic examination but is clinically indistinguishable from the other two subgroups. The third subgroup (20-40%) fits the concept of central pain that may be related to hypofunction of dopaminergic neurons in the basal ganglia. The neurogenic factors acting in these subgroups differ, and will require different treatment strategies. In the future, with proper use of diagnostic tests, BMS patients may benefit from interventions specifically targeted at the underlying pathophysiological mechanisms.

Trehalose inhibits oral dryness by protecting the cell membrane

This study assessed the clinical efficacy and acceptability of trehalose solution for oral dryness caused by dental treatment. The efficacy of trehalose on oral dryness under drying conditions was assessed by measuring the surface area of the fungiform papillae and the moisture content of the tongue in seven healthy volunteers. Based on the data from this pilot study, a clinical study was performed, in which the efficacy of oral trehalose spray was evaluated on oral dryness in 10 patients undergoing root canal treatment. The effects of trehalose on cell viability were also assessed under drying conditions in vitro. Trehalose suppressed oral dryness and associated pain caused by dental treatment and protected cells from dryness-related damage. These results indicate that pretreatment application of trehalose solution on the oral mucosa is effective in preventing oral dryness caused by dental treatment.

Smell and taste disorders in polyneuropathy: a prospective study of chemosensory disorders

OBJECTIVE

The aim of the study was to assess the occurrence and the frequency of chemosensory dysfunction in patients with polyneuropathy (PNP).

METHODS

We performed a prospective observational study. Olfactory function was assessed using the standardized 'Sniffin' Sticks' test to measure odor threshold for phenyl ethyl alcohol, odor discrimination, and odor identification. Gustatory function was assessed using the standardized 'taste strips' test. In addition, we assessed etiology, neurophysiology, and severity of the PNP, and the patients' comorbidities and medication.

RESULTS

A total of 53 consecutive patients were enrolled (15 women, 38 men; mean age 61 years); 27 of them (51%) exhibited olfactory dysfunction and 23 of them (43%) gustatory dysfunction. Patients with diabetic PNP had significantly lower taste scores than patients with inflammatory, genetic, or idiopathic PNP. In addition, odor identification was negatively correlated with PNP severity.

CONCLUSION

The applied bedside tests are useful to detect chemosensory dysfunction in patients with PNP. Chemosensory dysfunction is quite frequent in these patients.

Response of human oral mucosa and skin to histamine provocation: laser Doppler perfusion imaging discloses differences in the nociceptive nervous system

OBJECTIVE

To investigate the existence of histamine-excitable nerve fibers in the oral mucosa and to compare the response to histamine provocation in healthy volunteers with that in a small group of patients with chronic oral pain.

MATERIAL AND METHODS

Thirteen healthy volunteers and six patients suffering from chronic oral pain took part in the study. Blood perfusion was monitored in the hard palate, the tongue, and the skin of the cheek using laser Doppler perfusion imaging (Perimed; Sweden). Baseline scannings were performed, followed by 15 scannings after iontophoresis of histamine (1%). A free description of the sensations was then obtained from the participants after finishing the measurements.

RESULTS

Compared to pre-histamine scanning, histamine application resulted in a considerable increase in blood perfusion in all regions (p<0.001) that was significantly higher in skin than in oral mucosa (p<0.001). There were no significant differences between the healthy volunteers and the patients regarding baseline blood flow, increased blood perfusion, or flare size after histamine provocation. The sensory impression was reported to be more persistent and intense in the skin than in the oral mucosa. No effect on mucosa could be detected by visual inspection.

CONCLUSIONS

Intra-oral flare could be induced by activating histamine-excitable nerve fibers. Both duration and intensity of the flare were considerably less pronounced than in the control skin site. Histamine application was not clearly associated with itch.

Serum interleukin-6 in patients with burning mouth syndrome and relationship with depression and perceived pain

Objective. To examine alteration of serum interleukin-6 and its clinical significance in burning mouth syndrome (BMS) patients. Methods. 48 BMS patients and 31 healthy controls participated in the study. Serum interleukin-6 was measured by means of ELISA. Hamilton rating scale of depression (HRSD) and visual analogue scale (VAS) were used to quantitiate depressive status and pain levels of subjects, respectively. Results. 15 (31%) patients displayed substantial depressive symptoms (HRSD ≧ 16). HRSD scores of patients were significantly higher than controls and positively correlated to their VAS values (P = .002). Serum interleukin-6 in patients was much lower than controls and negatively correlated to their VAS values (P = .011). However, no significant relations were found between interleukin-6 and HRSD scores (P = .317). Conclusions. Serum interleukin-6 in patients with burning mouth syndrome is decreased and negatively correlated to chronic pain. Both psychological and neuropathic disorders might act as precipitating factors in BMS etiopathogenesis.

Measurement of sublingual blood velocity as a tool for monitoring sepsis

Measurements of sublingual blood velocity and blood flow were performed at normal body temperature and after both hot and cold stimulation. Laser speckle measurements of blood velocity were compared with measurements of blood flow obtained with a commercial laser Doppler flowmeter. Sublingual blood velocity increased in all subjects in response to both hot and cold stimulation as compared with that at normal temperature.

Burning mouth syndrome as a trigeminal small fibre neuropathy: Increased heat and capsaicin receptor TRPV1 in nerve fibres correlates with pain score

Burning mouth syndrome (BMS) is often an idiopathic chronic and intractable pain condition, affecting 1.5-5.5% of middle-aged and elderly women. We have studied the heat and capsaicin receptor TRPV1, and its regulator nerve growth factor (NGF), in BMS. Patients with BMS (n=10) and controls (n=10) were assessed for baseline and post-topical capsaicin pain scores, and their tongue biopsies immunostained for TRPV1, NGF, and structural nerve markers neurofilament and peripherin. Nerve fibres penetrating the epithelium were less abundant in BMS (p<0.0001), indicating a small fibre neuropathy. TRPV1-positive fibres were overall significantly increased in BMS (p=0.0011), as were NGF fibres (p<0.0001) and basal epithelial cell NGF staining (p<0.0147). There was a significant correlation between the baseline pain score and TRPV1 (p=0.0143) and NGF fibres (p=0.0252). A significant correlation was observed between baseline and post-capsaicin pain (p=0.0006). Selective TRPV1 and NGF blockers may provide a new therapy for BMS.

Burning Mouth Syndrome: Will Better Understanding Yield Better Management?

"Burning mouth syndrome" (BMS) refers to a chronic orofacial pain disorder usually unaccompanied by mucosal lesions or other clinical signs of organic disease. BMS is typically characterized by a continuous, spontaneous, and often intense burning sensation as if the mouth or tongue were scalded or on fire. Burning mouth syndrome is a relatively common condition. The estimated prevalence of BMS reported in recent studies ranges between 0.7 and 4.6% of the general population. About 1.3 million American adults, mostly women in the postmenopausal period, are afflicted with BMS. The etiology of this disorder is poorly understood even though new evidence for a possible neuropathic pathogenesis of idiopathic BMS is emerging. Burning mouth syndrome may present as an idiopathic condition (primary BMS type) distinct from the symptom of oral burning that can potentially arise from various local or systemic abnormalities (secondary BMS type), including nutritional deficiencies, hormonal changes associated with menopause, local oral infections, denture-related lesions, xerostomia, hypersensitivity reactions, medications, and systemic diseases including diabetes mellitus. In more than a third of patients, multiple, concurrent causes of BMS may be identified. It is important to note that the diagnosis of BMS should be established only after all other possible causes have been ruled out. Professional delay in diagnosing, referring, and appropriately managing of BMS patients occurs frequently. Treatment should be tailored to each patient and it is recommended to practice the treatment in a multidisciplinary facility. This article discusses our current understanding of the etiology and pathogenesis of BMS. The authors have tried to emphasize new pharmacological approaches to manage this challenging disorder.

Management of burning mouth syndrome: systematic review and management recommendations

Primary burning mouth syndrome (BMS) is a chronic, idiopathic intraoral mucosal pain condition that is not accompanied by clinical lesions or systemic disease. There is some uncertainty whether this condition should be referred to as a disease, a disorder, or a syndrome but there are insufficient data to justify any change in taxonomy at present. BMS occurs most often among women and is often accompanied by xerostomia and taste disturbances. More recently a neuropathological basis has been proposed so that BMS may be regarded as an oral dysesthesia or painful neuropathy. However, our incomplete understanding of the epidemiology, etiology, pathophysiology, and lack of diagnostic criteria are barriers to critical investigation and selection of effective treatments. There is only limited evidence to guide clinicians in the management of patients with BMS. Treatable secondary causes should be investigated before diagnosing primary BMS. Topical clonazepam and cognitive therapy have been proven efficacious in some patients. Emerging evidence supports the effectiveness of the antioxidant, alpha lipoic acid, with further studies of this agent being warranted. Additional research into mechanisms, diagnostic criteria, and randomized controlled interventional studies are needed.

Causative or precipitating aspects of burning mouth syndrome: a case–control study

BACKGROUND

On causative or precipitating causes of burning mouth syndrome (BMS), there is a lack of consensus. In this prospective case-control study, we compared clinical features and laboratory aspects to evaluate the association of the proposed causative/precipitating factors of BMS.

METHODS

A total of 61 BMS patients and 54 control subjects underwent several evaluations: rest and stimulated salivary flow rates measurements, laboratory tests, isolation of Candida species, assessment of parafunctional activities, detection of anxiety and depression by means of the Hospital Anxiety and Depression Scale. Odds ratio and 95% confidence interval were calculated to compare the variables.

RESULTS

No statistically significant differences were found with regard to the tested variables except for anxiety and depression.

CONCLUSIONS

The results of this study seem not to support a role for the usually reported causative or precipitating factors of BMS and efforts should be addressed towards different aetiologies including possible neuropathic mechanisms of BMS.

The distribution of oral mucosal pH values in healthy saliva secretors

OBJECTIVES

To establish the normal range of oral mucosal pH and to correlate these measurements to salivary flow rate in healthy individuals according to age and gender.

SUBJECTS AND METHODS

Measurements of pH levels using a flat pH meter and salivary secretion rates were established in eight mucosal sites from a total of 50 healthy individuals.

RESULTS

The mean pH (+/-s.d.) of all sites was 6.78 +/- 0.04 with significant differences between mean pH values in the palate (7.34 +/- 0.38), the floor of the mouth (6.5 +/- 0.3), the buccal mucosa (6.28 +/- 0.36) and the tongue (6.8 +/- 0.26). A significant correlation was found between age and pH at palatal and tongue sites but no gender effects were noted.

CONCLUSIONS

This method is easy and relatively quick to manipulate, and may offer many diagnostic possibilities for oral related diseases and disorders such as oral malodour, mouth breathing, dysgeusia, acidic diet consumption and gastrointestinal disorders affecting the mouth.

Cerebral activation during thermal stimulation of patients who have burning mouth disorder: An fMRI study

The pathophysiology of burning mouth disorder (BMD) is not clearly understood, but central neuropathic mechanisms are thought to be involved. The aim of this study was to gain insight into the pathophysiology associated with BMD by using functional magnetic resonance imaging (fMRI). Areas of brain activation following thermal stimulation of the trigeminal nerve of eight female patients with BMD (mean age 49.1+/-10.1) were mapped using fMRI and compared with those of eight matched pain-free volunteers (mean age 50.3+/-12.3). Qualitative and quantitative differences in brain activation patterns between the two study groups were demonstrated. BMD patients displayed greater fractional signal changes in the right anterior cingulate cortex (BA 32/24) and bilateral precuneus than did controls (p<0.005). The control group showed larger fractional signal changes in the bilateral thalamus, right middle frontal gyrus, right pre-central gyrus, left lingual gyrus, and cerebellum than did the BMD patients (p<0.005). In addition, BMD patients had less volumetric activation throughout the entire brain compared to the control group. Overall, BMD patients displayed brain activation patterns similar to those of patients with other neuropathic pain conditions and appear to process thermal painful stimulation to the trigeminal nerve qualitatively and quantitatively different than pain-free individuals. These findings suggest that brain hypoactivity may be an important feature in the pathophysiology of BMD.

Zinc gluconate in the treatment of dysgeusia--a randomized clinical trial

In the treatment of dysgeusia, the use of zinc has been frequently tried, with equivocal results. The aim of the present randomized clinical trial, which involved a sufficiently large sample, was therefore to determine the efficacy of zinc treatment. Fifty patients with idiopathic dysgeusia were carefully selected. Zinc gluconate (140 mg/day; n=26) or placebo (lactose; n=24) was randomly assigned to the patients. The patients on zinc improved in terms of gustatory function (p <0.001) and rated the dysgeusia as being less severe (p <0.05). Similarly, signs of depression in the zinc group were less severe (Beck Depression Inventory, p <0.05; mood scale, p <0.05). With the exception of the salivary calcium level, which was higher in the zinc patients (p <0.05), no other significant group differences were found. In conclusion, zinc appears to improve general gustatory function and, consequently, general mood scores in dysgeusia patients.

Quantifying labial blood flow using optical Doppler tomography

OBJECTIVES

Changes in the oral microvasculature occur in a variety of diseases. Optical Doppler tomography (ODT) combines laser Doppler flowmetry with optical coherence tomography (OCT) to produce high-resolution tomographic images of biological tissues that also detect the velocity and direction of blood flow. The objective of this study was to determine the feasibility of ODT to image labial blood flow. A prototype ODT imaging system was constructed that characterized and measured labial blood flow in healthy subjects.

MATERIALS AND METHODS

A prototype ODT instrument was constructed using a diode light source with a central wavelength of 1300 nanometers, a 40-nanometer spectral width and 2.4 microwatts output power. To verify the accuracy of the system, the flow rates of a phantom material (Intralipid) pumped through a capillary tube at various speeds was measured. To evaluate the clinical feasibility of the ODT prototye, the mucosal aspect of the upper and lower lips at the midline was imaged in 9 healthy volunteers. The sample arm of the instrument consisted of a fiberoptic probe with a 2-mm in diameter polished glass lens attached to the end. The probe was placed approximately 3 mm from the mucosal surface of the lip and oriented perpendicular to the surface. A motorized translation stage moved the fiber in a superior to inferior direction while the subject's head was stabilized by placing the chin into a chin rest. Imaging time for a 12-mm x 2.5-mm scan was approximately 64 seconds.

RESULTS

The phantom experiments revealed that accuracy of this novel ODT prototype to measure flow was within 5%. In vivo labial blood flow velocity ranged from 11.8 to 43.1 mm/second in the upper lip and 8.2 to 53.2 mm/second in the lower lip. There were no statistically significant differences between flow rates in the upper and lower lips. OCT images and Doppler velocity signals were successfully integrated producing in vivo images of labial blood in all of the subjects (15 images). The resulting cross-sectional images revealed microscopic details of labial structures and, to the best of our knowledge, are the first ODT images of the labial microvasculature.

CONCLUSIONS

The results of this in vivo study prove the feasibility of ODT to quantify labial blood flow and produce high spatial resolution images specifically localizing vessels anatomically. ODT provides both flow speed and flow direction information. ODT is noninvasive and offers the advantages of high volumetric flow sensitivity.