Project Sage Oldco, Inc., a medical aesthetics company, develops and sells medical aesthetics products in the United States and internationally. It offers silicone gel breast implants for use in breast augmentation and breast reconstruction procedures; breast tissue expanders; and scar management products under the Sientra Round, Sientra Teardrop, AlloX2, Dermaspan, Softspan, and BIOCORNEUM brand names. The company also provides fat transfer systems; body contouring products; facial and nasal implants; saline filled sizers. It serves to hospitals, surgery centers, plastic surgeons, dermatologists, and other specialties. The company was formerly known as Sientra, Inc. Project Sage Oldco, Inc., was incorporated in 2003 and is headquartered in Irvine, California. On February 12, 2024, Project Sage Oldco, Inc., along with its affiliates, filed a voluntary petition for reorganization under Chapter 11 in the U.S. Bankruptcy Court for the District of Delaware.