Salivary biomarkers in burning mouth syndrome: A systematic review and meta-analysis

Salivary and serum biomarkers to evaluate psychological disorders in burning mouth syndrome: A systematic review and meta-analysis

BACKGROUND

Burning mouth syndrome is a chronic pain syndrome mainly characterized by an intensive burning sensation of tongue. Previous studies have suggested that saliva/serum biomarkers in burning mouth syndrome might be associated with psychological disorders. The aim of systematic review was to observe whether the biomarkers in serum/saliva could be an alternative method to evaluate the psychological disorders in patients with burning mouth syndrome.

MATERIALS AND METHODS

The PubMed, Embase, and Cochrane Library databases were searched for papers published up to March 15, 2023. Risk of bias was measured by using the Newcastle-Ottawa Scale. RevMan was used for meta-analysis.

RESULTS

A total of 467 articles were screened, which of 12 studies were included. These studies collected 43 different biomarkers in saliva and 35 in serum. Of these biomarkers, only three (cortisol, α-amylase, and IL-6) were analyzed in two or more studies. Only salivary cortisol levels were significantly higher in the patient group compared to the controls (Mean Difference = 1.39; 95% CI [0.80-1.97]; p < 0.001). Moreover, cortisol might be relevant to psychological scores, especially anxiety.

CONCLUSION

Different papers have investigated salivary and serum biomarkers in burning mouth syndrome patients with controversial results. This meta-analysis showed that cortisol levels in saliva may be a potential biomarker to assess the psychological disorders in burning mouth syndrome patients.

Oral mucosal diseases and psychosocial factors: progress in related neurobiological mechanisms

The aetiology of oral mucosal diseases, such as recurrent aphthous ulcer (RAU), oral lichen planus (OLP) and burning mouth syndrome (BMS), involves many factors, and it remains difficult for clinicians to effectively relieve disease symptoms and formulate coping strategies. With the rapid development of psychology, the role of mental and psychological factors in RAU, OLP and BMS has gradually attracted researchers attention, but the specific mechanism has not been completely determined. This narrative review describes the potential neurobiological mechanism of oral mucosal diseases and detailed psychological factors after introducing relevant research into psychological factors and oral mucosal diseases. Future research strategies and innovations needed to understand and treat oral mucosal diseases and psychological factors, as well as how to prevent oral mucosal diseases by regulation of the neuroendocrine system, are also discussed.

Effects of low-level laser therapy on burning pain and quality of life in patients with burning mouth syndrome: a systematic review and meta-analysis

BACKGROUND

Burning mouth syndrome (BMS) is a complex chronic pain disorder that significantly impairs patients' quality of life. Low-level laser therapy (LLLT) uses infrared or near-infrared light to produce analgesic, anti-inflammatory, and biological stimulation effects. The aim of this systematic review is to evaluate the effect of LLLT on burning pain, quality of life, and negative emotions in patients with BMS.

METHODS

The PubMed, Embase, Cumulative Index of Nursing and Allied Health Literature (CINAHL), Cochrane Library, Web of Science, and Scopus databases were searched up January 2023 to identify relevant articles. All randomized controlled trials that were published in English and examined the use of LLLT treatment for BMS were included. The methodological quality of the included trials was assessed using the Cochrane risk of bias tool for randomized controlled trials (RCTs). A meta-analysis was performed to evaluate burning pain, quality of life, and negative emotions. Sensitivity, subgroup, and funnel plot analyses were also carried out.

RESULTS

Fourteen RCTs involving a total of 550 patients with BMS met the inclusion criteria. The results showed that LLLT (measured by the Visual Analog Scale; SMD: -0.87, 95% CI: -1.29 to -0.45, P < 0.001) was more effective for reducing burning pain than placebo LLLT or clonazepam. LLLT improved quality of life (evaluated by the Oral Health Impact Profile-14; SMD: 0.01, 95% CI: -0.58 to 0.60, P = 0.97) and negative emotions (evaluated by the Hospital Anxiety and Depression Scale; SMD: -0.12, 95% CI: -0.54 to 0.30, P = 0.59), but these effects were not statistically significant.

CONCLUSIONS

The meta-analysis revealed that LLLT may be an effective therapy for improving burning pain in patients with BMS, and producing a positive influence on quality of life and negative emotions. A long-term course of intervention, a larger sample size, and a multidisciplinary intervention design are urgently needed in future research.

TRIAL REGISTRATION

PROSPERO registration number: CRD42022308770.

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.

Association between Salivary Cortisol and α-Amylase with the Psychological Profile of Patients with Oral Lichen Planus and Burning Mouth Syndrome: A Case-Control Study

The aim of our study was to assess the relationship between the concentration/activity of salivary stress biomarkers (cortisol, α-amylase) and the psychological profile of patients with oral lichen planus (OLP) and primary burning mouth syndrome (BMS). A total of 160 subjects participated in this case-control study: 60 patients with OLP; 60 patients with primary BMS; and 40 control subjects. Unstimulated whole saliva (UWS) was collected between 9 and 10 a.m. Salivary biomarkers were analyzed by enzyme-linked immunosorbent assays (ELISAs). Psychological assessment was evaluated with the Depression, Anxiety, and Stress Scale (DASS-21). The patients with primary BMS had higher salivary cortisol concentrations and α-amylase activity (0.52 vs. 0.44 µg/dL; 160,531 vs. 145,804 U/L; one-way analysis of variance (ANOVA) with post hoc Scheffe test) compared with patients with OLP. The patients with primary BMS had statistically significant higher scores for depression, anxiety, and stress compared with patients with OLP and control subjects (p < 0.001, Kruskal-Wallis test). There was a strong positive correlation between anxiety and depression, stress and depression, and stress and anxiety in patients with OLP and BMS (p < 0.001 and p < 0.001, respectively; Spearman's correlation). There was a good positive correlation between symptom intensity (pain/burning) and psychological profile (depression, anxiety, stress) in patients with primary BMS (r = 0.373, p = 0.003; r = 0.515, p < 0.001; r = 0.365, p = 0.004, respectively; Spearman's correlation). This case-control study is the first to compare the psychoendocrinological profile of patients with two different oral diseases. The patients with BMS showed a higher concentration/activity of salivary stress biomarkers (cortisol, α-amylase) and a stronger association with mental disorders compared with patients with OLP. However, an interdisciplinary psychoneuroimmunological approach is equally important in both patient groups (OLP and BMS), regardless of whether mental disorders are the cause or the consequence.

Saliva biomarkers in oral disease

Saliva is a versatile biofluid that contains a wide variety of biomarkers reflecting both physiologic and pathophysiologic states. Saliva collection is noninvasive and highly applicable for tests requiring serial sampling. Furthermore, advances in test accuracy, sensitivity and precision for saliva has improved diagnostic performance as well as the identification of novel markers especially in oral disease processes. These include dental caries, periodontitis, oral squamous cell carcinoma (OSCC) and Sjögren's syndrome (SS). Numerous growth factors, enzymes, interleukins and cytokines have been identified and are the subject of much research investigation. This review highlights current procedures for successful determination of saliva biomarkers including preanalytical factors associated with sampling, storage and pretreatment as well as subsequent analysis. Moreover, it provides an overview of the diagnostic applications of these salivary biomarkers in common oral diseases.

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.