One of the most consistently frustrating areas of maxillofacial rehabilitation is the treatment of patients who have had radical cancer surgery of the tongue, floor of the mouth, and mandible. The patient described in this report, was a 66-year-old man who had squamous cell carcinoma of the right jaw. The right body of the mandible distal to the right cuspid was resected, and this part of the mandible was not reconstructed. For this mandibulectomy patient, we have treated with the removable partial denture using 30 degree teeth and TS telescope crown as retainer, registrating maxillomandibular relation with Gothic arch tracer and MKG. In addition, masticatory function in this patient was evaluated on tooth contact, tapping pattern, masticatory efficiency and rhythm of mastication. Consequently, 4 to 8 weeks later, tapping pattern and centric occlusion was stabilized, and masticatory function was improved. We will continue to observe this case in long term.