Maxillofacial prosthetics is defined as the branch of Prosthodontics concerned with restoration, replacement or both of stomatognathic and associated facial structures by artificial substitutes that may or may not be removed. The face is the most noticeable part of the body. The rehabilitation of maxillofacial defect patients is a complex process of restoration of a previous state following a major change. The defect may be functional, cosmetic or emotional as it causes psychological trauma to the patient. Long term success of facial prostheses mainly depends on retention. Anatomic undercuts, skin adhesives and implants are important factors to provide sufficient retention. Extraoral implant retained prosthesis have been proved to be a predictable treatment option for maxillofacial rehabilitation. Recent developments in computerized three-dimensional (3D) data processing and computer-aided systems have made it possible to obtain facial morphology measurements with more comfort and great ease. This book is intended to cover a complete detailed description and review of the retentive measures used for maxillofacial prosthesis.