It is well known that the massage therapy is useful for the rehabilitation of various diseases. 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. Therefore, we developed a robot system that provides massage therapy to maxillofacial region. The name of our newly developed robot was WAO-1. WAO-1 has been designed to perform appropriate massage to the patients with dry mouth, etc. WAO-1 is composed by two 6-degree of freedom arms with plungers attached at the end-effectors. The massage is applied to the patient by controlling the force and position of the plunger (virtual compliance). As a preliminary step of the clinical application, a simulation therapy of robotic massage to stimulate salivary flow from parotid gland was performed. The dynamic force on patient's head during the massage using WAO-1 was evaluated. The results suggested that WAO-1 could perform equivalent massage to human hand. We expect that WAO-1 will be useful to provide massage therapy to several patients with oral health problems. This will aim in reducing the therapy costs due to the need of human efforts when long-time therapies are needed.