Salivary metabolomics of burning mouth syndrome: A cross-sectional study.

OBJECTIVE: There is a lack of systematic studies on salivary metabolomic profiles in burning mouth syndrome (BMS); metabolomics could help explore BMS pathogenesis. We aimed to explore the salivary metabolomic profile of patients with BMS using untargeted metabolomics techniques. DESIGN: A cross-sectional study was designed to analyze the characteristics of unstimulated whole salivary metabolomics of patients with BMS (n = 34) and healthy participants (n = 30). Ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry, principal component, orthogonal partial least-squares-discriminant, hierarchical clustering, and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were performed to identify differentially expressed metabolites and metabolic pathways in which they were enriched. RESULTS: We identified 12,982 metabolite ions. Among them, 394 differentially expressed metabolites were identified with variable importance in projection scores of > 1 (P < 0.05) compared with those in the controls. Based on the Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis, 30 metabolites were identified, and 16 of them were enriched in 25 metabolic pathways. The levels of caffeine (log2-fold change = -2.91) and its metabolites, paraxanthine (-2.01) and theophylline (-2.03), were low, and the caffeine metabolism pathway was downregulated in the BMS group compared with those in the controls (P < 0.05). CONCLUSIONS: The salivary metabolomic profile of patients with BMS presented characteristics distinct from those of the controls. A low caffeine level may be associated with BMS. This study provides a novel insight for further exploration of the pathogenesis of and potential therapeutic approaches for BMS.

Reduced sialyl-Lewisx on salivary MUC7 from patients with burning mouth syndrome.

We analysed and compared MUC7 O-glycosylation and inflammatory biomarkers in saliva from female patients with burning mouth syndrome (BMS) and gender/age-matched controls. Oligosaccharides from salivary MUC7 from BMS and controls were released. Inflammatory mediators were measured by multiplex proximity extension assay. Presence of sialyl-Lewisx (Si-Lex) epitope on MUC7 was confirmed using Western blot. MUC7 O-glycans and measured inflammatory biomarkers were found to be similar between BMS and controls. However, oligosaccharides sialyl-Lewisx (Si-Lex) was found to be reduced in samples from BMS patients. Positive correlation (combined patients and controls) was found between levels of C-C motif chemokine 19 (CCL-19) and the amount of core-2 oligosaccharides on MUC7 as well as fractalkine (CX3CL1) and level of sialylation. Patients with BMS were shown to represent a heterogeneous group in terms of inflammatory biomarkers. This indicates that BMS patients could be further stratified on the basis of low-level inflammation. The results furthermore indicate that reduced sialylation of MUC7, particularly Si-Lex, may be an important feature in patients with BMS. However, the functional aspects and potential involvement in immune regulation of Si-Lex remains unclear. Our data suggests a chemokine driven alteration of MUC7 glycosylation.

Proteomic profiling of whole-saliva reveals correlation between Burning Mouth Syndrome and the neurotrophin signaling pathway.

Burning mouth syndrome (BMS) is characterized by a spontaneous and chronic sensation of burning in the oral mucosa, with no apparent signs. The underlying pathophysiological and neuropathic mechanisms remain unclear. Here, we attempt to elucidate some of these mechanisms using proteomic profiling and bioinformatic analyses of whole-saliva (WS) from BMS patients compared to WS from healthy individuals. Qualitative and quantitative proteomic profiling was performed using two dimensional gel electrophoresis (2-DE) and quantitative mass spectrometry (q-MS). In order to improve protein visibility, 21 high abundance proteins were depleted before proteomic profiling. Quantitative proteomic analysis revealed 100 BMS specific proteins and an additional 158 proteins up-regulated by more than threefold in those with BMS. Bioinformatic analyses of the altered protein expression profile of BMS group indicated high correlations to three cellular mechanisms including the neurotrophin signaling pathway. Based on this finding, we suggest that neurotrophin signaling pathway is involved in the pathophysiology of BMS by amplifying P75NTR activity, which in turn increases neural apoptosis thereby reducing sub-papillary nerve fiber density in the oral mucosa.

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.

Saliva on the oral mucosa and whole saliva in women diagnosed with burning mouth syndrome.

OBJECTIVE: The aim of the study was to examine mucosal saliva and unstimulated (UWS) and stimulated (SWS) whole saliva secretion rates and associated factors, in 56 female patients diagnosed with BMS and age-matched control women. MATERIAL AND METHODS: Mucosal saliva was assessed using the Periotron® method and blood flow using laser Doppler flowmetry. Diseases, drug usage and xerostomia were registered using questionnaires. RESULTS: The patients with BMS displayed less lingual and whole saliva, and more hyposalivation, xerostomia diseases/disorders and drug usage, compared to the controls. Only a low SWS and xerostomia differed after adjusting for drugs and systemic diseases. Regression analyses suggested an importance of saliva affecting drugs for saliva on the tongue and for SWS, and the total number of drugs used for UWS. Lingual saliva and UWS were also associated with systemic diseases in the patients. Xerostomia was significantly associated with drug use and whole saliva for all subjects but not in separate analyses of the groups. CONCLUSION: Less saliva in patients with BMS could be related to more systemic diseases and medication and not to the syndrome per se. Xerostomia in the patients was not related to any of these factors.

Therapeutic Applications of Capsaicin in Upper Airways.

BACKGROUND: Capsaicin (8-methyl-N-vanillyl-6-nonenamide) is the substance responsible of the irritation caused by the contact of chili peppers with the skin or mucous membranes. This protoalkaloid acts by stimulating the transient receptor potential cation channel subfamily V member 1 (TRPV1), which is mainly expressed by nociceptive fibers of peripheral sensory neurons, but is also present in the central nervous system, and in some non-neuronal cells. Following the initial, intense neuronal excitation, a brief refractory period occurs. However, repeated and massive exposures to capsaicin can impair nociceptive fiber function for weeks or months. During this lapse of time, disorders related to the hyperreactivity of peripheral nociceptors are abolished or greatly reduced. Capsaicin has been utilized to treat several diseases of upper airways. OBJECTIVE: The objective of this review was to report the latest findings on the use of Capsaicin in the treatment of upper airway diseases. RESULTS: Capsaicin effectiveness has been proved in non allergic rhinitis. Some studies suggest that this substance may be also effective in nasal polyposis and in the burning mouth syndrome. No clear evidence has been obtained about its use in allergic rhinitis. CONCLUSION: To date, the use of capsaicin to treat upper airway diseases is still limited in clinical practice. This may originate by the lack of strong, conclusive evidences of its effectiveness, by the variety of therapeutic schemes used in literature, and finally by the unpleasant effects of the exposure to capsaicin, which are only partly relieved by the pretreatment with local anesthetics.

A “burning” therapy for burning mouth syndrome: preliminary results with the administration of topical capsaicin.

Burning mouth syndrome is defined as an intraoral burning sensation for which no medical or dental cause can be found. Recently, researchers have demonstrated an altered trophism of the small nerve fibres and alterations in the numbers of TRPV-1 vanilloid receptors. Capsaicin is a molecule that is contained in hot peppers and is specifically detected by TRPV-1 vanilloid receptors that are distributed in the oral mucosae. We aimed at verifying if topical capsaicin could prove to be an effective treatment of Burning Mouth Syndrome. A group of 99 BMS patients were recruited. We subdivided the BMS patients into two groups: the collaborative patients, who expressed a predominantly neuropathic pattern of symptoms, and the non-collaborative patients, who were characterised by stronger psychogenic patterns of the syndrome. Both groups underwent topical therapy with capsaicin in the form of a mouth rinse 3 times a day for a long period. After 1 year of treatment, the final overall success rate was approximately 78%, but with a significant difference in the success rates of the two groups of patients (87% and 20% among the collaborative and non-collaborative patients, respectively; p=0.000). The use of topical capsaicin can improve the oral discomfort of BMS patients, especially during the first month of therapy, but it is more effective for those patients in which the neuropathic component of the syndrome is predominant. Our hypothesis is that chronic stimulation with capsaicin leads to decreases in burning symptoms. This phenomenon is called desensitisation and is accompanied by substantial improvements in oral symptoms.

Potential protein biomarkers for burning mouth syndrome discovered by quantitative proteomics.

Burning mouth syndrome (BMS) is a chronic pain disorder characterized by severe burning sensation in normal looking oral mucosa. Diagnosis of BMS remains to be a challenge to oral healthcare professionals because the method for definite diagnosis is still uncertain. In this study, a quantitative saliva proteomic analysis was performed in order to identify target proteins in BMS patients' saliva that may be used as biomarkers for simple, non-invasive detection of the disease. By using isobaric tags for relative and absolute quantitation labeling and liquid chromatography-tandem mass spectrometry to quantify 1130 saliva proteins between BMS patients and healthy control subjects, we found that 50 proteins were significantly changed in the BMS patients when compared to the healthy control subjects ( p ≤ 0.05, 39 up-regulated and 11 down-regulated). Four candidates, alpha-enolase, interleukin-18 (IL-18), kallikrein-13 (KLK13), and cathepsin G, were selected for further validation. Based on enzyme-linked immunosorbent assay measurements, three potential biomarkers, alpha-enolase, IL-18, and KLK13, were successfully validated. The fold changes for alpha-enolase, IL-18, and KLK13 were determined as 3.6, 2.9, and 2.2 (burning mouth syndrome vs. control), and corresponding receiver operating characteristic values were determined as 0.78, 0.83, and 0.68, respectively. Our findings indicate that testing of the identified protein biomarkers in saliva might be a valuable clinical tool for BMS detection. Further validation studies of the identified biomarkers or additional candidate biomarkers are needed to achieve a multi-marker prediction model for improved detection of BMS with high sensitivity and specificity.

Relationships between oral MUC1 expression and salivary hormones in burning mouth syndrome.

OBJECTIVES: To investigate possible relationships among oral mucosal epithelial MUC1 expression, salivary female gonadal hormones and stress markers, and clinical characteristics in patients with burning mouth syndrome (BMS). DESIGN: Thirty post-menopausal female patients with BMS (60.0±5.0 years) were included. Clinical and psychological evaluations were performed and the expression level of oral mucosal epithelial MUC1 was analyzed. The levels of cortisol, dehydroepiandrosterone (DHEA), 17ß-estradiol, progesterone, chromogranin A, and blood contamination were determined from unstimulated whole saliva (UWS) and stimulated whole saliva (SWS) samples. RESULTS: Salivary progesterone level had significant positive correlations with oral mucosal epithelial MUC1 expression level and with salivary cortisol and DHEA levels. The salivary level of 17ß-estradiol showed significant positive correlations with period of symptom duration, severity of effects of oral complaints on daily life, and results from psychological evaluations. Cortisol level in UWS and cortisol/DHEA ratio in UWS and SWS had negative correlations with severity of oral burning sensation significantly. The severity of taste disturbance had positive correlations with results from psychometry significantly. CONCLUSION: Dysregulated psychoendocrinological interactions might affect oral mucosal MUC1 expression and severity of oral burning sensation in post-menopausal BMS patients.

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.

Opiorphin levels in fluids of burning mouth syndrome patients: a case-control study.

OBJECTIVES: Idiopathic Burning mouth syndrome (iBMS) is a poorly understood affection characterized by persistent pain in the oral cavity without any clinical or biological abnormality. Opiorphin is a natural inhibitor of enkephalin-inactivating ectopeptidases, mainly produced by salivary glands, that has demonstrated analgesic properties. The objective of the present case-control study was to test the hypothesis of a decrease in opiorphin levels in iBMS patients. MATERIALS AND METHODS: Twenty-one iBMS patients and 21 matched controls subjects were included between 2011 and 2013. Submandibular and sublingual salivary, blood, and urinary opiorphin levels of iBMS patients were compared to controls. RESULTS: Results are expressed as mean values ± SD and compared using the Wilcoxon Signed Rank test. Correlations were analyzed with Spearman coefficient. The level of significance was fixed at p < 0.05. Opiorphin levels in iBMS and controls were respectively (in ng/ml) in basal saliva: 37.8 ± 42.5 and 67.6 ± 188.9 (p = NS); stimulated saliva: 28.8 ± 25.3 and 31.1 ± 29.1 (p = NS); blood: 4.6 ± 5.4 and 1.9 ± 1.4 (p < 0.05); and urines: 68.5 ± 259.8 and 8.9 ± 6.2 (p = NS). CLINICAL RELEVANCE: In conclusion, the lack of significative difference in salivary opiorphin levels between iBMS and controls does not favor a direct local role for opiorphin in the etiopathogeny of iBMS. However, higher blood opiorphin levels may reflect a systemic dysregulation in iBMS. Trial registration NCT02686359 https://clinicaltrials.gov/ct2/show/NCT02686359.

Evaluation of salivary oxidate stress biomarkers, nitric oxide and C-reactive protein in patients with oral lichen planus and burning mouth syndrome.

OBJECTIVES: The aim of this study was to evaluate oxidative stress factors and C-reactive protein in the saliva of patients with oral lichen planus (OLP) and burning mouth syndrome (BMS). METHODS: This consecutive, cross-sectional study included 20 patients with OLP, 19 with burning mouth syndrome (BMS), and 31 control subjects. The oral cavity of each patient was examined and patients responded to a quality of life questionnaire (OHIP-14) and the xerostomia inventory. The following parameters were measured in whole non-stimulated saliva: trolox equivalent antioxidant capacity (TEAC); total antioxidant capacity (TAC); cupric reducing antioxidant capacity (CUPRAC); ferric reducing ability of plasma (FRAP); C-reactive protein (CRP); nitric oxide; nitrates; and nitrites. RESULTS: The OLP group presented statistically significant differences in reactive oxygen species (ROS) (29 600 cps) in comparison with the control group (39 679 cps) (P < 0.05). In the BMS group, ROS was 29 707 cps with significant difference in comparison with the control group (P < 0.05). Significantly higher salivary nitric oxide (145.7 µmol) and nitrite (141.0 µmol) levels were found in OLP patients in comparison with control group (P < 0.05). CONCLUSION: Increases in nitric oxide and C-reactive protein were found in the saliva of OLP patients in comparison with BMS and control patients. Further studies are required to confirm these findings.

Comparative Analysis of Psychological, Hormonal, and Genetic Factors Between Burning Mouth Syndrome and Secondary Oral Burning.

OBJECTIVE: The objective of this study was to evaluate the association between psychological, hormonal, and genetic factors with the development of burning mouth syndrome (BMS) and secondary oral burning (SOB) in order to provide a better characterization and classification of these conditions. DESIGN: Cross sectional study. SETTING: Patients with complaints of mouth burning registered at the Oral Diagnostic Service of the Federal University of Rio Grande do Norte between 2000 and 2013. SUBJECTS: The sample consisted of 163 subjects divided into a group of patients with BMS (n = 64) and a group of subjects with SOB (n = 99). METHODS: The following variables were analyzed: passive and stimulated saliva flow, stress levels and phase, depression, anxiety, serum cortisol and dehydroepiandrosterone (DHEA) levels, and the presence of polymorphisms in the interleukin 6 (IL-6) gene. RESULTS: The results showed significant differences in the presence of xerostomia (p = 0.01), hyposalivation at rest (p < 0.001) and symptoms of depression (p = 0.033) between the two groups, which were more prevalent in the BMS group. DHEA levels were lower in the BMS group (p = 0.003) and were sensitive and specific for the diagnosis of this condition. Genetic analysis revealed no significant association between the polymorphisms analyzed and the development of BMS. CONCLUSION: These results suggest a possible role of depression, as well as of reduced DHEA levels, as associated factors for development of BMS.

Involvement of peripheral artemin signaling in tongue pain: possible mechanism in burning mouth syndrome.

Burning mouth syndrome is characterized by altered sensory qualities, namely tongue pain hypersensitivity. We found that the mRNA expression of Artemin (Artn) in the tongue mucosa of patients with burning mouth syndrome was significantly higher than that of control subjects, and we developed a mouse model of burning mouth syndrome by application of 2,4,6-trinitrobenzene sulfonic acid (TNBS) diluted with 50% ethanol to the dorsum of the tongue. TNBS treatment to the tongue induced persistent, week-long, noninflammatory tongue pain and a significant increase in Artn expression in the tongue mucosa and marked tongue heat hyperalgesia. Following TNBS treatment, the successive administration of the transient receptor potential vanilloid 1 (TRPV1) antagonist SB366791 or neutralizing anti-Artn antibody completely inhibited the heat hyperalgesia. The number of glial cell line-derived neurotrophic factor family receptor α3 (GFRα3)-positive and TRPV1-positive trigeminal ganglion (TG) neurons innervating the tongue significantly increased following TNBS treatment and was significantly reduced by successive administration of neutralizing anti-Artn antibody. The capsaicin-induced current in TG neurons innervating the tongue was enhanced following TNBS treatment and was inhibited by local administration of neutralizing anti-Artn antibody to the tongue. These results suggest that the overexpression of Artn in the TNBS-treated tongue increases the membrane excitability of TG neurons innervating the tongue by increasing TRPV1 sensitivity, which causes heat hyperalgesia. This model may be useful for the study of tongue pain hypersensitivity associated with burning mouth syndrome.

The association of openness personality trait with stress-related salivary biomarkers in burning mouth syndrome.

BACKGROUND: Burning mouth syndrome (BMS) is a chronic disorder defined as a burning sensation in the oral mucosa without evidence of pathological findings. Its pathophysiology is largely unknown, but psychiatric disorders and personality traits have been implicated. OBJECTIVE: This study investigated whether there is any association between salivary biomarkers and personality traits in BMS patients. METHODS: It was a cross-sectional, controlled study that evaluated 30 individuals with BMS and 32 controls. All subjects were assessed with a structured psychiatric interview (Mini International Neuropsychiatric Interview) and the Big Five inventory. Salivary levels of brain-derived neurotrophic factor (BDNF), neural growth factor, tumor necrosis factor-α, interleukin (IL)-6, IL-10 and cortisol were determined. RESULTS: We found that BMS patients exhibited more traits of neuroticism and lower openness than controls. Openness showed a moderate and negative correlation with cortisol, BDNF and IL-6. CONCLUSION: Personality traits are associated with salivary biomarkers in BMS.

Epithelial expression of vanilloid and cannabinoid receptors: a potential role in burning mouth syndrome pathogenesis.

Burning mouth syndrome (BMS) is an intra-oral burning sensation for which presently no medical or dental causes have been found, and in which the oral mucosa appears normal. It remains an unknown disease for which there is still no long-term treatment. The aim of this study was to assess the epithelial alteration of transient receptor potential vanilloid channel type 1 (TRPV1) and cannabinoid receptors type 1 (CB1) and type 2 (CB2) in the human tongue. The study was performed on eight healthy controls and eight BMS patients. All patients underwent a 3-mm punch biopsy at the anterolateral aspect of the tongue close to the tip. TRPV1, CB1 and CB2 immuno-histochemistry was carried out showing an altered expression of all receptors. In BMS patients there was increased TRPV1, decreased CB1 and increased CB2 expression in tongue epithelial cells also associated with a change in their distribution. It would appear that these receptors are related to BMS. These data could be useful for future characterization of BMS epithelial markers and therapy.

Mineral and trace element analysis of saliva from patients with BMS: a cross-sectional prospective controlled clinical study.

OBJECTIVE: The aim of this study was to investigate salivary markers related to burning mouth syndrome (BMS). STUDY DESIGN: A cross-sectional prospective controlled clinical study of 58 patients (28 BMS and 30 control). The presence of mineral and trace metals in unstimulated whole saliva was analyzed in BMS patients and in control subjects by means of ICP-OES. The parameters analyzed were as follows: oral health-related quality of life (OHIP-14) and the Hospital Anxiety Depression (HAD) scale. A visual analogue scale (VAS) was used to measure the intensity of burning sensation (pain). RESULTS: The mean pain value for patients with BMS was 7.8 ± 2.4. OHIP-14 oral health-related quality of life among BMS patients was found to be affected: total BMS OHIP-14 (16.98 ± 12.29) vs. control (8.53 ± 10.5) with significant difference (P = 0.015). Concentrations of the different elements were slightly higher among BMS patients but without statistically significant differences for any of the elements analyzed (Na, K, Ca, Mg, Fe, Cu, Mn, Zn, B, P, S, Al, Pb, Cd, Cr, Ni, As, Be, Bi, Co, Li, Mo, Sb, Se, Sr, Ti, Tl, V). CONCLUSIONS: This study failed to identify abnormal levels of minerals or trace elements in saliva of patients with BMS.

MUC1 and Toll-like receptor-2 expression in burning mouth syndrome and oral lichen planus.

OBJECTIVE: Expression levels of MUC1 and TLR-2 were evaluated in burning mouth syndrome (BMS) patients and compared with those of controls and oral lichen planus (OLP) patients. The relationships between the expression levels of MUC1 and TLR-2 and levels of salivary pro-inflammatory cytokines were also investigated. DESIGN: Ten female BMS and ten female OLP patients were included. Ten female age-matched volunteers served as controls. RNA was isolated from stimulated whole saliva samples. Real-time PCR was used to quantify MUC1 and TLR-2 mRNA levels relative to ß-actin and GAPDH mRNA levels. The clarified supernatants of saliva samples were used to measure IL-1ß, IL-6, IL-8, and TNF-α levels. The level of blood contamination in saliva samples was also determined. RESULTS: There were significant increases in MUC1 transcripts in BMS patients compared with OLP patients (1.766-fold) as well as controls (1.840-fold). There was no significant difference in TLR-2 expression among the groups. The OLP patients showed significantly higher levels of IL-6 and blood contamination in saliva than other groups. The levels of MUC1 or TLR-2 expression did not correlate significantly with the levels of cytokines or blood contamination in saliva. CONCLUSIONS: MUC1 may play a role in the development and/or progression of BMS.

Proinflammatory cytokine levels in saliva in patients with burning mouth syndrome before and after treatment with low-level laser therapy.

The aim of this study was to determine the levels of proinflammatory tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) cytokines in whole unstimulated saliva in subjects with burning mouth syndrome (BMS) before and after treatment with low-level laser therapy (LLLT). BMS is characterized by a continuous, painful burning sensation in a clinically normal-appearing oral mucosa. A sample consisting of 40 consecutive subjects was selected on a voluntary basis from the pool of patients who presented for diagnosis and treatment of BMS at the Oral Medicine Unit of the Faculty of Medicine of the University of Rijeka. For determination of salivary levels of TNF-α and IL-6, ELISA (Sigma Immunochemicals, St. Louis, MO, USA) was performed to determine the salivary levels of TNF-α and IL-6. After 4 weeks of LLLT, the salivary levels of TNF-α and IL-6 in the experimental group decreased significantly (p < 0.001). There was no significant difference in the experimental group regarding visual analogue scale.