Polyacrylamide hydrogel (PAAG) is widely regarded as a safe soft tissue filler and has been extensively utilized for cosmetic enhancements, such as breast and facial augmentation in China from 1997 until its ban in 2006. Common complications associated with its use include inflammation, infection, granulomas, fibrosis, gel migration, and facial and soft tissue deformities. This case report describes a 45-year-old Chinese woman who experienced PAAG migration into her mandible 24 years after facial augmentation, causing irritation of the mandibular alveolar nerve - apparently the first documented instance of this occurrence. Surgical intervention was necessary to remove the migrated gel and associated calcifications. A literature review explored adverse events and management strategies for PAAG complications in cosmetic procedures. While generally considered safe, this report underscores the importance of meticulous injection techniques and careful anatomical site selection to prevent such severe complications.