Anatomical danger zones related to motor nerves in dermatologic facial and neck surgery and strategies to prevent and treat injury: a systematic review

Motor nerve injury is a significant complication of facial and neck dermatologic surgery, leading to functional deficits, cosmetic deformities, and patient distress. Anatomical knowledge and effective management are key to reducing harm. This work was developed with the following objectives: to systematically review the literature on (1) anatomical danger zones for motor nerves during dermatologic surgery of the face and neck, (2) clinical consequences of nerve injury, (3) prevention and treatment strategies, and (4) quality of existing evidence. A systematic review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Eligible studies included randomized trials, cohort studies, case series (≥ 3 patients), and reviews in English or Portuguese. Searches in PubMed, Embase, Cochrane Library, and Web of Science identified 11 studies. Data were synthesized narratively due to heterogeneity. The temporal and marginal mandibular branches were the most frequently injured. Prevention strategies included anatomical mapping and meticulous dissection. Most minor injuries resolved with observation and physiotherapy, while surgical repair was reserved for transections. Dynamic or static reconstruction addressed persistent deficits. The evidence was mostly low-level, with few randomized controlled trials and limited outcome reporting. Prevention of motor nerve injury relies on anatomical precision and early management. Stronger evidence is needed to guide practice and improve outcomes.