1. Department of Oral and Maxillofacial Functional Rehabilitation, Graduate School of Medicine, University of the Ryukyus, Nishihara, Okinawa 903‑0215, Japan
2. Department of Child Health and Welfare (Pediatrics), Graduate School of Medicine, University of the Ryukyus, Nishihara, Okinawa 903‑0215, Japan
3. Department of Plastic and Reconstructive Surgery, Graduate School of Medicine, University of the Ryukyus, Nishihara, Okinawa 903‑0215, Japan