It is well known that the massage therapy is useful for the rehabilitation of various diseases (i.e. oral health problems, etc.). Although various apparatus have been developed for the massage of the torso and limbs, a machine to perform precise massage therapy to maxillofacial region is not developed yet. The ability of a robotic system to exert itself without fatigue aims in providing more hours of therapy per day, resulting in an increased number of patients that can be treated. This increased potential for treatment would benefit the elderly persons as well allowing more frequent treatments and more convenience in scheduling. For this purpose, the authors have developed the Oral-Rehabilitation Robot which provides massage of the maxillofacial region as a therapy to patients with temporomandibular joint disorders, etc. Then, we developed the Waseda-Asahi Oral-Rehabilitation Robot No.1 Refined (WAO-1R) by redesigning the arms of WAO-1 to increase variety of massage. By this improvement, the angular limitation of end-effector is increased from 60° to 360°. In order to assess the effectives of the massage provided by the robotics system, different performances indexes were proposed based on the medical literature and from our discussion with experts. A set of experiments were carried out to confirm if the mechanical improvements enhanced or not the effect of the massage provided by the WAO-1R. From the experimental results, we could detect increasing the thickness of masseter muscle on volunteers and the amount of mouth-opening after providing the massage with WAO-1R compared with the previous robot.