Facial Overfilled Syndrome: A Narrative Clinical Review

Background: Facial Overfilled Syndrome (FOS) is an increasingly prevalent iatrogenic complication resulting from the excessive or inappropriate use of dermal fillers. Clinically significant for causing facial distortion and unnatural dynamics, it is frequently compounded by profound psychological distress and aesthetic perception biases. Aim: This narrative clinical review aims to summarize the etiology, clinical features, diagnostic approaches, and management strategies of FOS, establishing a structured framework to emphasize the importance of prevention through anatomical knowledge and individualized treatment planning. Methods: A comprehensive literature search was conducted in PubMed, Google Scholar, and CNKI using keywords such as "facial overfilled syndrome", "facial overfilling", "overfilled face" and "dermal filler complications". Relevant original studies, clinical trials, meta-analyses, and reviews published until October 2025 were included and synthesized into a narrative framework. Results: The pathogenesis of FOS extends beyond mere volumetric excess, driven by a complex triad of anatomical mismatch, biomechanical dysregulation, and the cumulative payload of repeated treatments. Clinical hallmarks include resting distortion and unnatural facial animation. Management must be highly individualized; while targeted, ultrasound-guided hyaluronidase injection remains the established gold standard for hyaluronic acid fillers, evolving adjunctive therapies (eg, recombinant enzymes, energy-based devices, and micro-liposuction) demand strict clinical caution. Conclusion: Addressing FOS requires a clinical paradigm shift from simple volume restoration to precision-driven, layer-specific augmentation. Prevention through patient education and anatomical mastery is paramount. Future research should prioritize elucidating filler degradation kinetics, developing objective 3D assessment tools, and engineering fully reversible biomaterials.