About the Authors

Toru Yamazaki

Affiliation Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan

Masashi Yamori

yamori@kuhp.kyoto-u.ac.jp

Affiliation Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan

Keita Asai

Affiliation Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan

Ikuko Nakano-Araki

Affiliation Department of Oral and Maxillofacial Surgery, Nagahama City Hospital, Nagahama, Japan

Akihiko Yamaguchi

Affiliation Department of Oral and Maxillofacial Surgery, Nagahama City Hospital, Nagahama, Japan

Katsu Takahashi

Affiliation Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan

Akihiro Sekine

Affiliation EBM Research Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan

Fumihiko Matsuda

Affiliation Unit of Human Disease Genomics, Center for Genomic Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan

Shinji Kosugi

Affiliation Department of Medical Ethics, School of Public Health, Graduate School of Medicine, Kyoto University, Kyoto, Japan

Takeo Nakayama

Affiliation Department of Health Informatics, School of Public Health, Graduate School of Medicine, Kyoto University, Kyoto, Japan

Nobuya Inagaki

Affiliation Department of Diabetes and Clinical Nutrition, Graduate School of Medicine, Kyoto University, Kyoto, Japan

Kazuhisa Bessho

Affiliation Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan

for the Nagahama Study Collaboration Group

Membership of the Nagahama Study Group is provided in the Acknowledgments.

Competing Interests

This study is partly supported by the grants-in-aid from the following organizations: Kyoto University (2006), Takeda Science Foundation (2008), Mitsui Sumitomo Insurance Welfare Foundation (2010), Ministry of Health, Labour and Welfare, Japan (2009-2013). The authors also declare the following interests: some of the chewing gum for this study was provided by Lotte Co., Ltd. There are no further patents, products in development or marketed products to declare. These do not alter the authors' adherence to the PLOS ONE requirements on sharing data and materials, as detailed online in the guide for authors.

Author Contributions

Conceived and designed the experiments: TY MY KA INA AY KT AS FM SK TN NI KB. Performed the experiments: TY MY KA INA KT FM TN. Analyzed the data: TY KA. Contributed reagents/materials/analysis tools: AS. Wrote the paper: TY MY. Contributed to the initial revision of the manuscript: FM TN. Contributed to the critical revision of the manuscript: INA AY KT AS SK NI KB. Agree with manuscript results and conclusions: TY MY KA INA AY KT AS FM SK TN NI KB.