The authors have treated two patients (Case I : 68-year-old woman and Case II:48-year-old man), having defects part of the mandibule by partial ectomy because of ameloblastoma and malignant tumor of tongue respectively. The facial form and oral function of the patients were restored by dentures for their mandibular defect, using a Swing Lock Attachment in Case I , a part of hinge joint in Case II. But, a little unsatisfactory result was remained, such as the regio-submandibularis form in Case I and the swallowing desturbance in Case II. Then, the authors considered that there were necessities to improve prosthetic treatment methods and the quality of the material.