Efficacy of photobiomodulation in reducing pain and improving the quality of life in patients with idiopathic burning mouth syndrome. A systematic review and meta-analysis

Long-Term Benefits of Photobiomodulation Therapy on Health-Related Quality of Life in Burning Mouth Syndrome Patients: A Prospective Study

Background/Objectives: Burning Mouth Syndrome (BMS) patients experience a reduction in health-related quality of life and an increased intake of medication. Photobiomodulation with low-level laser therapy has been demonstrated to be an efficacious treatment for BMS. However, its long-term benefits remain relatively unknown. This study aimed to evaluate the impact of prolonged Photobiomodulation with low-level laser therapy on BMS patients by examining the efficacy of an outpatient protocol in a real-world setting. Methods: A prospective study was designed to address the research question. Photobiomodulation was performed, irradiating the affected areas once every two weeks for 12 months. Health-related quality of life was assessed using the EQ-5D-5L questionnaire at the initial consultation and after 6 months and 12 months of treatment. Additionally, the patients' pharmacological profile was also monitored. Nonparametric statistical analysis was performed (p < 0.05 was considered statistically significant). Results: The study was completed by 15 individuals, comprising 14 females and 1 male. The results indicated a statistically significant improvement (p < 0.001) in four of the five dimensions of the health-related quality of life questionnaire, namely self-care, usual activities, pain/discomfort, and anxiety/depression, along with the patients' perceived health level. A total of 13 participants reported suspending or reducing their intake of medications for Burning Mouth Syndrome. Conclusions: Therefore, Photobiomodulation with low-level laser therapy has a positive effect on improving patients' quality of life and reducing BMS symptoms, contributing to a subsequent reduction or suspension of previous medications. These findings support the efficacy of the applied protocol. Given the innovative methodology and promising results, further research is warranted.

Burning Mouth Syndrome Treated with Low-Level Laser and Clonazepam: A Randomized, Single-Blind Clinical Trial

OBJECTIVE

Burning mouth syndrome (BMS) is a chronic pain disorder characterized by intraoral burning or dysaesthetic sensation, with the absence of any identifiable lesions. Numerous treatments for BMS have been investigated, though without conclusive results. An analysis was conducted of the efficacy of treatment with a low-level diode laser and clonazepam in patients with BMS, and a study was carried out on the levels of different salivary biomarkers before and after treatment.

MATERIAL AND METHODS

A randomized, single-blind clinical trial was carried out involving 89 patients divided into the following groups: group 1 (laser, The Helbo® Theralite Laser 3D Pocket Probe + clonazepam) (n = 20), group 2 (sham laser placebo) (n = 19), group 3 (laser) (n = 21) and group 4 (clonazepam) (n = 18). Symptom intensity was scored based on a visual analogue scale (VAS). Sialometry was performed before and after treatment, and the Xerostomia Inventory, Oral Health Impact Profile-14 (OHIP-14) and Mini-Nutritional Assessment (MNA) questionnaires were administered. The following markers were measured in saliva samples: interleukins (IL2, IL4, IL5, IL6, IL7, IL8, IL1β, IL10, IL12, IL13, IL17, IL21 and IL23), proteins (MIP-3α, MIP-1α and MIP-1β), GM-CSF, interferon gamma (IFNγ), interferon-inducible T-cell alpha chemoattractant (ITAC), fractalkine and tumor necrosis factor α (TNFα).

RESULTS

A significant decrease in the VAS scores was observed after treatment in group 1 (laser + clonazepam) (p = 0.029) and group 3 (laser) (p = 0.005). In turn, group 3 (laser) showed a decrease in the salivary concentration of fractalkine (p = 0.025); interleukins IL12 (p = 0.048), IL17 (p = 0.020), IL21 (p = 0.008), IL7 (p = 0.001) and IL8 (p = 0.007); proteins MIP1α (p = 0.048) and MIP1β (p = 0.047); and TNFα (p = 0.047) versus baseline. Following treatment, group 1 (laser + clonazepam) showed significant differences in IL21 (p = 0.045) and IL7 (p = 0.009) versus baseline, while group 4 (clonazepam) showed significant differences in IL13 (p = 0.036), IL2 (p = 0.020) and IL4 (p = 0.001). No significant differences were recorded in group 2 (sham laser placebo).

CONCLUSIONS

The low-level diode laser is a good treatment option in BMS, resulting in a decrease in patient symptoms and in salivary biomarkers. However, standardization of the intervention protocols and laser intensity parameters is needed in order to draw more firm conclusions.

Burning mouth in oncology care: a systematic review

Burning mouth, also referred to as oral dysesthesia, is an underreported condition among cancer patients that may represent an early symptom of cancer or an adverse effect of treatment. This review sought to characterize this symptom in oncology care where burning symptoms may occur. A systematic review of the literature was performed based on the PRISMA statement, and the protocol was registered at PROSPERO database. A structured search was done using eight databases. The process of study selection was conducted in two distinct phases. The JBI Critical Appraisal Tools were utilized to evaluate the risk of bias in the studies included. Of the total number of studies assessed, sixteen met the eligibility criteria. Of these studies included, 7 were case reports, 7 cross-sectional studies, and 2 non-randomized clinical trials. Most studies presented low risk of bias (n = 9), while the remaining studies were evaluated and scored as moderate (n = 5) or high (n = 2) risk of bias. Burning mouth was reported as a first symptom of cancer in three studies, and as an adverse event of radiotherapy (n = 2), chemoradiotherapy (n = 2), and chemotherapy (n = 9). Burning mouth was a first symptom in 0.62% of oral squamous cell carcinoma (OSCC), and 3.3% of patients with pain as chief complaint. Oral dysesthesia prevalence was 13.6% in patients experiencing chemotherapy-induced oral adverse events. The symptom of burning mouth should be examined in oncology care, as it may be underreported and therefore undertreated. New therapies may be related to a higher risk of oral burning and studies assessing approach to management are needed. Current management borrows from the current management of burning mouth in the non-cancer setting.

Relationship between Laser Intensity at the Peripheral Nerve and Inhibitory Effect of Percutaneous Photobiomodulation on Neuronal Firing in a Rat Spinal Dorsal Horn

Photobiomodulation is an effective treatment for pain. We previously reported that the direct laser irradiation of the exposed sciatic nerve inhibited firing in the rat spinal dorsal horn evoked by mechanical stimulation, corresponding to the noxious stimulus. However, percutaneous laser irradiation is used in clinical practice, and it is unclear whether it can inhibit the firing of the dorsal horn. In this study, we investigated whether the percutaneous laser irradiation of the sciatic nerve inhibits firing. Electrodes were inserted into the lamina II of the dorsal horn, and mechanical stimulation was applied using von Frey filaments (vFFs) with both pre and post laser irradiation. Our findings show that percutaneous laser irradiation inhibited 26.0 g vFF-evoked firing, which corresponded to the noxious stimulus, but did not inhibit 0.6 g and 8.0 g vFF-evoked firing. The post- (15 min after) and pre-irradiation firing ratios were almost the same as those for direct and percutaneous irradiation. A photodiode sensor implanted in the sciatic nerve showed that the power density reaching the sciatic nerve percutaneously was attenuated to approximately 10% of that on the skin. The relationship between the laser intensity reaching the nerve and its effect could be potentially useful for a more appropriate setting of laser conditions in clinical practice.

A Holistic Perspective on How Photobiomodulation May Influence Fatigue, Pain, and Depression in Inflammatory Bowel Disease: Beyond Molecular Mechanisms

BACKGROUND

Numerous mechanisms, mostly molecular, have been tested and proposed for photobiomodulation. Photobiomodulation is finding a niche in the treatment of conditions that have no gold-standard treatment or only partially effective pharmacological treatment. Many chronic conditions are characterised by symptoms for which there is no cure or control and for which pharmaceuticals may add to the disease burden through side effects. To add quality to life, alternate methods of symptom management need to be identified.

OBJECTIVE

To demonstrate how photobiomodulation, through its numerous mechanisms, may offer an adjunctive therapy in inflammatory bowel disease. Rather than considering only molecular mechanisms, we take an overarching biopsychosocial approach to propose how existing evidence gleaned from other studies may underpin a treatment strategy of potential benefit to people with Crohn's disease and ulcerative colitis.

MAIN FINDINGS

In this paper, the authors have proposed the perspective that photobiomodulation, through an integrated effect on the neuroimmune and microbiome-gut-brain axis, has the potential to be effective in managing the fatigue, pain, and depressive symptoms of people with inflammatory bowel disease.

Short-Term Effects of Whole-Body Photobiomodulation on Pain, Quality of Life and Psychological Factors in a Population Suffering from Fibromyalgia: A Triple-Blinded Randomised Clinical Trial

BACKGROUND

Fibromyalgia (FM) is a multifunctional chronic musculoskeletal pain condition characterised by sensory hypersensitivity. Photobiomodulation (PBM) has shown a positive impact on relieving pain; however, no studies to our knowledge have analysed a whole-body PBM intervention in subjects with FM. The aims of the study were to compare the effects of whole-body PBM with placebo PBM on pain, functionality and psychological symptoms in patients suffering from FM.

METHODS

Forty-two subjects were recruited from a private care practice. The design of the study is a randomised, triple-blinded, placebo-controlled clinical trial. Participants received 12 treatment sessions. Pain, quality of life, level of physical activity and psychological factors were assessed at baseline (T0), after session 6 (T1), after treatment (T2) and at 2-week (T3) follow-up.

RESULTS

There were statistically significant differences in pain at 4 weeks (p ≤ 0.001) (T2) and the 2-week follow-up (T3) (p ≤ 0.001). In relation to the quality of life, there were statistically significant improvements after session 6 (p ≤ 0.001) (T1), immediately after treatment (p ≤ 0.001) (T2) and at the 2-week (T3) follow-up (p ≤ 0.001). Kinesiophobia presented significant differences between groups immediately after treatment (p ≤ 0.001) (T2) and at the 2-week (T3) follow-up (p ≤ 0.001), with self-efficacy only showing significant differences between groups 2 weeks after the treatment (p = 0.01) (T2). There were no differences between groups when comparing pain catastrophising at any time.

CONCLUSION

Whole-body PBM resulted in a significant reduction in pain and an improvement in quality of life in those participants suffering from FM after receiving 4 weeks of treatment. Furthermore, psychological factors such as kinesiophobia and self-efficacy were also improved. Thus, a whole-body PBM treatment is presented as a possible new multifactorial treatment with potential benefits for those with FM and more studies are needed to corroborate our findings.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT0424897).