Yu Li1, An Juan2. 1. Department of Plastic and Reconstructive Surgery, Shanghai 9th People's Hospital, Shanghai Jiaotong University, School of Medicine, 21 Floor, No. 1 Building, No. 639, Zhi Zao Ju Road, Shanghai, China. yuoli@163.com. 2. Department of Plastic and Reconstructive Surgery, Shanghai 9th People's Hospital, Shanghai Jiaotong University, School of Medicine, 21 Floor, No. 1 Building, No. 639, Zhi Zao Ju Road, Shanghai, China.