Submitted for Publication: September 23, 2012; accepted December 19, 2012.
Author Contributions: All authors had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. Study concept and design: Hakuba and Hato. Acquisition of data: Nota and Takahashi. Analysis and interpretation of data: Nota and Gyo. Drafting of the manuscript: Nota, Takahashi, Hakuba, and Hato. Critical revision of the manuscript for important intellectual content: Gyo. Statistical analysis: Nota. Obtained funding: Takahashi. Study supervision: Hakuba, Hato, and Gyo.
Conflict of Interest Disclosures: None reported.
Funding/Support: This research was supported in part by grants-in-aid for scientific research from the Ministry of Education, Culture, Sports, Science, and Technology of Japan (Program for Enhancing Systematic Education in Graduate School).
Additional Contributions: We thank Yasuhiko Tabata, PhD, Department of Biomaterials, Institute for Frontier Medical Sciences, Kyoto University, for technical support of this project; Takaki Miwa, MD, PhD, Department of Otorhinolaryngology–Head and Neck Surgery, Kanazawa Medical University, for technical advice; and Takeshi Kiyoi, Integrated Center for Science, Ehime University, for assistance with histological staining.