Long-term efficacy of photobiomodulation in burning mouth syndrome: A secondary analysis of a randomized controlled...

This secondary analysis investigated the long-term efficacy of photobiomodulation (PBM) in managing pain symptoms associated with burning mouth syndrome (BMS) and explored proposed factors contributing to pain recurrence at 12-month follow-up.

A secondary analysis of a randomized clinical trial categorized BMS patients into responders (≥ 23 % VAS reduction) and non-responders (< 23 % reduction). Patients were divided into four groups: PBM + oral cryotherapy (OCT, n = 24), PBM (n = 25), OCT (n = 24), and drug therapy (DT, n = 20). Pain intensity was assessed using the visual analog scale (VAS). Binary logistic regression identified clinically significant recurrence risk factors, controlling for potential confounders. Statistical significance was defined as p < 0.05.

Among 93 BMS patients, 68 (73.1 %) were responders, of whom 37 (54.4 %) experienced pain recurrence within 2.55-5.33 months post-treatment. The recurrence group had relatively higher pain intensity, poorer oral health-related quality of life, and more severe anxiety and depressive symptoms compared to non-recurrence patients (p < 0.05). PBM + OCT combination therapy showed a lower recurrence rate (45.0 %, 9/20) and longer recurrence-free duration (5.33 ± 2.96 months), while PBM alone demonstrated comparable efficacy (22.2 % complete remission; 33.3 % recurrence in PBM responders). Xerostomia (OR = 5.49, p = 0.020) and mental stress (OR = 12.62, p = 0.024) were potentially associated with increased recurrence risk.

PBM, either alone or in combination with OCT, demonstrates lower recurrence rates and more sustained pain relief compared to OCT or DT alone. However, 54.4 % of responders still experienced pain recurrence within 2.55-5.33 months, highlighting the critical need to address proposed risk factors such as mental stress and xerostomia.

PBM, either alone or in combination with OCT, shows promise as a long-term management strategy for BMS, while OCT may be better suited as a short-term adjuvant intervention, though these preliminary findings require confirmation in larger trials. Regular follow-up is essential for patients with mental stress and xerostomia.