Management of Severe Pediatric Lower Lip Defect After Canine Bite with Polyhexamethylene Biguanide (PHMB), Full-Thickness Skin Graft (FTSG) and Compression Foam: A Case Report

Introduction: Pediatric lower-lip dog bite injuries are challenging due to contamination, tissue loss, and the need to maintain function, appearance, and psychological well-being. This single case describes immediate definitive closure using sharp debridement with adjunct polyhexanide (PHMB), a full-thickness skin graft (FTSG), and a polyurethane (PU) compression foam bolster. Methods: A 10-year-old boy with a severe contaminated lower-lip defect underwent debridement and 0.04% PHMB irrigation. An upper-arm FTSG was inset and compressed with a suture-anchored PU dressing. Topical PHMB gel was used perioperatively and for seven days after bolster removal. Oral antibiotics were given for five days. The patient was discharged eight days after the injury with detailed wound care instructions. Results: Immediate definitive closure was achieved with complete graft survival and no infection, necrosis, unplanned early dressing changes, or reoperations. At 12 months, oral competence, speech, lip mobility, and contour were preserved. However, mild residual esthetic differences remained (dyschromia, shallow border indentation, vellus hairs on the graft). Conclusion: In this single descriptive case, primary closure of a lower-lip injury with the combined intervention was associated with an uncomplicated functional course and manageable esthetic trade-offs at 12 months. These observations are descriptive; comparative studies with standardized functional, esthetic, and psychosocial measures are needed.