Danying Wang1, Bo Chen2. 1. Department of Plastic and Reconstructive Surgery, Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 33 Ba-Da-Chu Road, Beijing, 100144, People's Republic of China. 2. Department of Plastic and Reconstructive Surgery, Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 33 Ba-Da-Chu Road, Beijing, 100144, People's Republic of China. chenboys@hotmail.com.