Effects of Photobiomodulation Therapy Irradiation Intensity, Frequency, and Duration on Pain, and Functional Improvements in Patients with Temporomandibular Disorder.

PURPOSE: To systematically review and meta-analyze the efficacy of photobiomodulation therapy (PBMT) for temporomandibular disorders (TMDs), focusing on the influence of intensity, frequency, and duration on pain reduction and functional improvement.

METHODS

Through a systematic search of PubMed, Cochrane, and EMBASE, we identified randomized controlled trials (RCTs) involving adults with TMD who were treated with PBMT. Ultimately, 40 RCTs were included, and a meta-analysis was conducted using Review Manager 5.4. The primary outcomes included pain, pain-free opening (PFO), maximum-unassisted opening, and maximum-assisted opening (MAO).

RESULTS

PBMT significantly reduced pain at the third assessment (T2). The optimal parameters included wavelengths (951-1070 nm) and output power (below 100 mW). Additionally, PFO and MAO significantly improved at T2. Treatment durations exceeding 10 weeks were most effective for articular-muscular TMDs, whereas shorter durations were more beneficial for purely articular or muscular TMDs. Three to four sessions per week yielded the best outcomes.

CONCLUSION

Effective pain reduction was achieved with high wavelengths (951-1070 nm), low power (<100 mW), and frequent, long-term treatment (3-4 times per week over 10 weeks). Avoiding high energy consumption over a short period was crucial. This approach is more effective for articular-muscular TMDs than for purely articular or muscular conditions.