Abstract
Background: High-energy laser systems may offer oncologic control with fewer complications in OSCC. Methods: Following PRISMA 2020, 30 studies were synthesized. Effect sizes were pooled as HR, OR, or SMD, with 95% CIs using inverse variance methods. Fixed effects were used when I(2) ≤ 50, random effects otherwise. Risk of bias was assessed with RoB 2 and ROBINS-I. Results: Compared with conventional surgery, laser resection was associated with lower local recurrence (OR 0.58, 95% CI 0.43 to 0.77, I(2) 47, random effects), higher 3-year overall survival (HR 0.72, 95% CI 0.55 to 0.94, I(2) 22, fixed effects), and fewer intraoperative complications (OR 0.29, 95% CI 0.18 to 0.47, I(2) 39, random effects). Quality of life favored lasers at 3 months (SMD 0.61, 95% CI 0.38 to 0.84, I(2) 66, random effects). Upon subgroup analysis, CO(2) and Er,Cr:YSGG showed the most consistent benefits. Risk of bias was commonly low for sequence generation and reporting, but high for blinding due to the surgical context. Several cohorts were observational with potential confounding. Funnel plots and Egger tests did not indicate major small-study effects for the primary outcomes. Conclusions: High-energy lasers, particularly CO(2) and Er,Cr:YSGG, are associated with improved oncologic and functional outcomes versus conventional surgery. Given the study heterogeneity, limited RCTs, and risks of bias, these findings should be interpreted with caution and confirmed in standardized, multicenter randomized trials. The protocol is registered with PROSPERO (CRD420251119822).