Epidemiology of Craniomaxillofacial Trauma in Chile: A Systematic Review and 24-Year Nationwide Interrupted Time-Series Analysis.

Craniomaxillofacial trauma (CMFt) poses a significant burden, yet in many countries the evidence base is fragmented across single-center hospital series without specialized registry. Using Chile as a case study, we demonstrate a dual-synthesis approach to construct a national CMFt profile. Six databases were searched through February 2026 (PROSPERO: CRD420261290860). Two reviewers independently screened studies. Risk of bias was assessed with the JBI critical appraisal tool. Fracture-site proportions were pooled via random-effects meta-analysis and synthesized using GRADE. DEIS trauma discharges (2001-2024) were analyzed with negative binomial interrupted time-series. Nineteen studies were included. CMFt represented 2.6-6.1% of emergency consultations. CMFt admissions were 54.2/1000 trauma discharges; this rate dropped during 2020-2021 and rebounded post-2022. Pooled fracture-site distributions were highest for mandibular (45.3%) and zygomatic (24.2%) fractures. CMFt disproportionately affected males across both hospital series and national discharge data. According to DEIS, low-energy accidental injuries were the predominant etiology, followed by transport-related high-energy injuries and interpersonal violence, contrasting with hospital series where interpersonal violence predominated among adult surgical cohorts. Fracture admissions had longer length of stay (LOS) than soft-tissue CMFt (+0.94 days), with mean LOS ranging from 2.08 (nasal) to 8.35 days (multiple skull/facial fractures). These findings support prioritizing surgical preparedness and training in common fracture patterns, while strengthening trauma surveillance, referral pathways, and service planning in health systems without dedicated CMFt registries.