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

Burning mouth syndrome is a chronic condition, which is characterised by a burning sensation or pain in the mucosa of the oral cavity. Treatment options include antidepressants, antipsychotics, anticonvulsants, analgesics, hormone replacement therapies and more recently photobiomodulation. This study aims to perform a systematic review with meta-analysis in order to determine the effect of photobiomodulation on pain relief and the oral health-related quality of life associated with this condition. A bibliographical search of the Pubmed, Embase, Web of Science and Scopus databases was conducted. Only randomised clinical trials were included. Pain and quality of life were calculated as mean difference and pooled at different treatment points (baseline = T0 and final time point = Tf) and laser modality. From a total of 103 records, 7 articles were retrieved for inclusion. PBM group had a greater decrease in pain than control group at Tf with a mean difference =  − 2.536 (IC 95% − 3.662 to − 1.410; I² = 85.33%, p < 0.001). An improvement in oral health-related quality of life was observed in both groups, although this was more significant in the photobiomodulation group mean difference =  − 5.148 (IC 95% − 8.576 to − 1.719; I² = 84.91%, p = 0.003). For the red laser, a greater improvement than infrared was observed, in pain, mean difference =  − 2.498 (IC 95% − 3.942 to − 1.053; I² = 79.93%, p < 0.001), and in quality of life, mean difference =  − 8.144 (IC 95% − 12.082 to − 4.206; I² = 64.22%, p = 0.027). Photobiomodulation, in particular, red laser protocols, resulted in improvement in pain and in quality of life of burning mouth syndrome patients.

Comparative effectiveness of low-level laser therapy with different wavelengths and transcutaneous electric nerve stimulation in the treatment of pain caused by temporomandibular disorders: A systematic review and network meta-analysis

OBJECTIVE

To assess the efficacy of low-level laser therapy (LLLT) with different wavelengths and transcutaneous electric nerve stimulation (TENS) and explore the optimal wavelength range of laser application in the treatment of pain caused by temporomandibular disorders (TMD).

METHODS

An electronic search on PubMed, Cochrane Library, Embase, Scopus and Web of Science was undertaken to identify the randomised clinical trials (RCTs) published from database inception to 16 April 2021, aiming to compare the effects of LLLT with different wavelengths (632.8-672 nm, 780-904 nm, and 910-1100 nm) or TENS or placebo group on TMD patients pain reduction. In addition, manual search of the studies was performed. The reviewers assessed the risk of bias of individual studies with the Cochrane risk of bias tool and excluded the RCTs with a high risk of bias in any field. Meanwhile, the reviewers, after performing the network meta-analysis, assessed the quality of evidence, which contributed to network estimate via the GRADE framework.

RESULTS

Twenty-seven RCTs with 969 patients with TMD were included. In the meta-analysis, all treatment groups showed an overall improvement in pain scores, when compared with the placebo group. LLLT with wavelength ranging from 910 nm to 1100 nm produced more pain relief in the visual analogue scale (VAS) immediately after treatment [mean difference (MD) = 4.68, 95% confidence interval (CI):(3.08,6.28)]. After one-month follow-up, LLLT with wavelength ranging from 910 nm to 1100 nm also showed superior pain-relieving effects [MD = 3.61, 95% CI: (-1.77, 8.99)]. However, no significant difference was observed. Based on the SUCRA ranking, L3 ranked first immediately after treatment and 1 month later.

CONCLUSION

The results of the meta-analysis showed the LLLT had better short-term efficacy than TENS in the treatment of pain caused by TMD. Better results can be achieved with higher wavelengths. Therefore, we recommended to treat TMD using LLLT with wavelength ranging from 910 nm to 1100 nm.