*Department of Otorhinolaryngology, The Jikei University School of Medicine, Minato-Ku, Tokyo, Japan

†Department of Otorhinolaryngology-Head and Neck Surgery, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan

Address correspondence and reprint requests to Masaomi Motegi, MD, PhD, Department of Otorhinolaryngology-Head and Neck Surgery, Gunma University Graduate School of Medicine, 3‐39‐22, Showa‐machi, Maebashi, Gunma 371‐8511, Japan; E-mail: [email protected]

The data that support the findings of this study are available upon request from the corresponding author. The data are not publicly available because of privacy or ethical restrictions.

This study involved human participants and was approved by the institutional review board (approval number: 33-469[11096]), and the need for informed consent was waived owing to the retrospective nature.

M.N.: Concept, literature search, and data collection; M.M.: Supervision and critical reviews; M.N. and M.M.: Writing. M.N. and M.M. contributed equally to this work.

The authors report no conflicts of interest.