Intraoperative PBM Modulates Osteogenic Activity in Human Jawbone Explants: A Comparative Ex Vivo Translational Study

Background: Surgical removal of jaw cysts may result in bone defects that compromise local structural integrity and delay spontaneous regeneration. Photobiomodulation (PBM) has been proposed as a minimally invasive intraoperative adjunct capable of modulating osteogenic activity; however, translational evidence derived from freshly harvested human jawbone tissue remains limited. Objective: This study evaluated the effects of an intraoperative 980 nm PBM protocol on early osteogenic activity, osteoblast-like cell abundance, morphometric outcomes, and cell viability in primary human jawbone explants obtained during cystectomy. Materials and Methods: A comparative translational ex vivo study was conducted using cortical bone explants harvested from 40 patients undergoing surgical treatment of medium- to large-sized maxillary or mandibular cystic lesions. For each patient, one explant was exposed immediately after harvesting to pulsed 980 nm laser irradiation (20 J total energy; 40 J/cm2 fluence), whereas the paired explant served as an untreated control. Explants were cultured using a primary outgrowth technique and subjected to osteogenic induction for 14 days. Osteogenic activity was evaluated by immunofluorescence staining for alkaline phosphatase (ALPL) and osteocalcin (OCN), followed by confocal microscopy and quantitative morphometric analysis. Cell viability was assessed using a live/dead fluorescence assay. Results: Viable cultures were successfully established from 34 patients (85% experimental yield). PBM-treated explants exhibited significantly greater osteoblast-like cell counts than paired controls (median: 2820 vs. 1525 cells; p < 0.001), together with greater cumulative osteoblastic area (median: 537,028 vs. 325,166 relative units; p < 0.001) and higher osteoblastic area occupancy (median: 19.00% vs. 11.75%; p < 0.001). Immunofluorescence analysis demonstrated qualitatively stronger ALPL and OCN expression in PBM-treated cultures. Cell viability did not differ significantly between paired PBM-treated and control cultures (Wilcoxon signed-rank test, p = 0.18). Conclusions: In this comparative ex vivo model, intraoperative 980 nm PBM significantly enhanced early osteogenic activity and increased osteoblast-like cellular abundance in human jawbone explants while maintaining cellular viability. These findings provide translational support for further investigation of PBM as a biostimulatory adjunct to enhance bone regeneration following cyst surgery.