title: Answer to the authors.
authors.affiliation: Department of Orthodontics, Tianjin Medical University, Tianjin, China. zzhao6@yahoo.com.
authors.forename: Z H
authors.initials: ZH
authors.lastname: Zheng
mesh_terms: D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D008310:Malocclusion / Q000473:pathology*; D010614:Pharynx / Q000473:pathology*