Rehabilitation of a Severely Atrophic Maxilla Using Sinus Augmentation and Palatal Rotational Flap for Implant-retained Overdenture: A Case Report with Literature Review

Rehabilitation of a severely absorbed maxilla poses significant surgical and prosthetic challenges owing to limited bone availability, sinus pneumatization, and insufficient keratinized mucosa.Implant-retained overdentures (IROD) offer a less invasive and cost-effective alternative to fixed prostheses; however, compromised bone and soft tissue conditions often necessitate complex reconstructive procedures.This case report describes the staged management of a 70-year-old woman who presented with spontaneous exfoliation of the maxillary implants for overdenture support.Following the removal of the residual fixtures, bilateral sinus augmentation via the lateral window technique was performed with a freeze-dried cortical bone allograft, enabling the placement of four wide-diameter implants in the posterior maxilla.In second-stage surgery, the extremely shallow vestibular depth precluded the use of conventional free gingival grafts.Instead, bilateral palatal rotational flaps based on the greater palatine artery were used to augment the keratinized mucosa around the abutments.This approach resulted in stable peri-implant soft tissue, satisfactory prosthetic retention, and the absence of mucosal irritation.Although posterior-only implant placement is inherently accompanied by biomechanical limitations, such as anterior cantilevering, this report highlights the feasibility of combining sinus augmentation and palatal rotational flap techniques for clinically favorable IROD rehabilitation in patients with extreme maxillary atrophy.