Blue LED-Induced Photobiomodulation Enhances Growth in Organ-Cultured Rat Mandibular Condyles

This study evaluated the effects of blue light-emitting diode (LED)-induced photobiomodulation (PBM) on growth and chondrocyte differentiation in organ-cultured rat mandibular condyles under conditions free from systemic influences. Mandibular condyles were harvested from embryonic day 21 Sprague-Dawley rat fetuses and cultured for 8 days. Samples were assigned to four groups: baseline (day 0), control (no irradiation), 100 mW LED, and 1,000 mW LED. Blue LED light (455 nm) was applied for 30 seconds daily for five consecutive days. Histological and morphometric analyses were performed to assess changes in tissue architecture and condylar dimensions. The 1,000 mW group showed significant increases in the thickness of the mature chondrocyte layer and vertical condylar length compared to the control and baseline groups (p < 0.05). Both LED-irradiated groups demonstrated enhanced chondrocyte differentiation, with the 1,000 mW group showing the most pronounced effects. The superficial and proliferative layers were thinner in the 1,000 mW group, suggesting accelerated cellular progression toward maturity. Blue LED-induced PBM promoted growth and chondrocyte differentiation in the mandibular condyle under organ culture conditions. These findings suggest that PBM may serve as a promising, non-invasive modality to support cartilage development and regeneration, particularly in the context of temporomandibular joint disorders.