1. Department of Otolaryngology-Head and Neck Surgery, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan.
2. Hayashima Clinic, Dermatology & Otolaryngology, Hayashima, Tsukubo-gun, Okayama, Japan.
3. KIDS*FIRST, Child Development Support office, Okayama, Japan.