Inflammatory Fibrous Hyperplasia (IFH) is a benign lesion induced by chronic denture trauma that reduces vestibular depth and complicates prosthetic rehabilitation. This case report describes the comprehensive management of a 64-year-old edentulous man presenting with severe ridge resorption and extensive mandibular fibrous hyperplasia caused by overextended denture flanges. Treatment involved initial tissue conditioning using adjusted existing dentures to reestablish vertical dimension of occlusion and maxillomandibular relationship in centric relation, followed by surgical excision of the lesion combined with vestibuloplasty. The corrected prostheses were immediately reinserted to guide mucosal healing and maintain vestibular depth. Secondary epithelialization provided favourable tissue conditions and supported long-term prosthetic success. While conservative tissue conditioning effectively reduces initial inflammation, extensive fibrous lesions require surgical intervention. Because excision alone compromises vestibular depth, adjunctive vestibuloplasty is essential to restore the prosthetic bed. The combined use of tissue conditioning, surgical excision and vestibuloplasty offers a predictable management strategy for extensive IFH, ensuring optimal mucosal healing and stable prosthetic rehabilitation while minimizing recurrence.