Development and experimental evaluation of oral rehabilitation robot that provides maxillofacial massage to patients with oral disorders

Hiroyuki Ishii, Hiroki Koga, Yuichi Obokawa, Jorge Solis, Atsuo Takanishi, Akitoshi Katsumata

Research output: Contribution to journalArticle

12 Citations (Scopus)


We have developed an oral-rehabilitation robot WAO-1 (Waseda Asahi Oral-rehabilitation robot No. 1) for use in cases of oral disorders such as temperomandibular joint (TMJ) disorder and dry mouth. WAO-1 is the first robot designed to provide massage to the facial tissues of a patient with oral disorders. This robot provides massage to the masseter and temporal muscles and to the parotid gland and duct with simple operation. It consists of two six-degree-of-freedom arms with plungers, a body with headrest, a control box, a PC, and an automatic massage trajectory generation system with virtual compliance control. Two evaluation experiments were performed to verify the effectiveness of the oral massages of WAO-1 compared with the massages given by doctors. In the experiments, the massage to the parotid gland and duct by WAO-1 increased the amount of saliva in the subjects, and the massage to the masseter muscle by WAO-1 increased facial skin temperature and width of the masseter muscle in the subjects. We consider that these results indicate that massage by WAO-1 can be effective for patients with oral disorders.

Original languageEnglish
Pages (from-to)1228-1239
Number of pages12
JournalInternational Journal of Robotics Research
Issue number9
Publication statusPublished - 2009 Sep 1



  • Dry mouth
  • Impedance control
  • Maxillofacial massage.
  • Medical robot
  • Rehabilitation robot
  • Temperomandibular joint disorder

ASJC Scopus subject areas

  • Software
  • Modelling and Simulation
  • Mechanical Engineering
  • Artificial Intelligence
  • Electrical and Electronic Engineering
  • Applied Mathematics

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