A maxillofacial prosthesis needs to fulfil two essential requirements, aesthetics and function. Prosthesis would serve its purpose only when it is retentive. In the field of maxillofacial rehabilitation there is no definite configuration of the defect anatomy. So without using any retentive aids achieving retention is quite oblique and its understanding obscure. Many a times the prosthesis would require an auxiliary retentive feature. This book covers various modalities for achieving retention for a maxillofacial prosthesis.