This paper reviews the use of an intracavitary mold in the radiotherapeutic management of recurrent sub-orbital carcinoma of the maxillary sinus. An overview of the clinical features of antral carcinomas and the concept of brachytherapy in the management of these lesions is presented. Brachytherapy is usually reserved for relatively accessible lesions. Post-surgical and radiation-induced trismus can be a complicating factor, as in the case presented, where the inter-incisal distance was less than three millimeters. To circumvent the problem, a multi-layer antral plug was utilized as a carrier for the radioactive sources, and its construction is described.