Loss of continuity of the mandible leads to deviation of the residual segment towards the surgical site and alteration in muscle function. This results in facial asymmetry and malocclusion. A corrective device known as 'guide flange prosthesis' is indicated to limit this clinical manifestation. Guide flange prosthesis serves as a training device. It can successfully guide the patient to close the mandible into the correct intercuspal position. This clinical report reveals the rehabilitation of patient who underwent hemisection of the mandible, subsequent to treatment for an ameloblastoma. He was successfully rehabilitated with mandibular guide flange prosthesis.