Evaluating infra-orbital nerve injury in zygomaticomaxillary complex fractures: a systematic review and meta-analysis.

Aim: This systematic review aimed to assess infraorbital nerve (ION) injury in zygomatico-maxillary complex (ZMC) fractures, specifically examining the incidence, diagnostic approaches, and comparative efficacy of surgical vs. conservative management. Methods: This review was completed in accordance with PRISMA 2020 principles and was recorded in PROSPERO (CRD42024545221). The Cochrane CENTRAL, Embase, MEDLINE, and PubMed databases were thoroughly examined between January 2015 and April 2025. Adult patients (≥18 years) with radiologically confirmed ZMC fractures who specifically reported infraorbital nerve outcomes, such as sensory abnormalities, diagnostic evaluations, and recovery after therapy, were eligible for inclusion in the studies. Cochrane RoB 2.0 for randomized trials and the modified Newcastle-Ottawa Scale for observational studies were used to assess the quality of the studies. RevMan 5.4 was used to carry out statistical pooling using a random-effects model. Results: Initially, 457 articles were found in the literature search; duplicates were eliminated, titles and abstracts were screened, and 48 complete texts were examined; 13 studies (1,308 patients) met the inclusion criteria. The meta-analysis includes 11 trials with 802 patients. After ZMC fractures, the combined incidence of ION damage was 51.9% (95% CI: 48%-55%). When compared to conservative therapies, early surgical decompression (within two weeks after the damage) consistently produced superior sensory recovery. With little use of objective testing (blink reflex, current perception thresholds), diagnostic evaluations were mostly based on subjective measurements (two-point discrimination, pain thresholds). Conclusion: Infraorbital nerve injury remains a prevalent complication in ZMC fractures, affecting approximately half of the patients. Surgical decompression performed early after injury significantly improves sensory recovery outcomes over conservative management. There remains substantial variability in diagnostic methods and outcome measurements, highlighting the need for standardized approaches. Future randomized controlled trials with robust methodologies and consistent outcome assessments are necessary to enhance clinical guidance and patient outcomes. Systematic Review Registration: : ROSPERO CRD42024545221.