title: Studies of the chronological course of third molars eruption in a northern Chinese population.
abstract: Dental age estimation is of great importance for individual identification in forensic medicine and many other fields of study. Among them, tooth eruption is a parameter developmental morphology that can be determined by clinical examinations or by dental X-rays. The purpose of present research is to study the chronological course of third molars eruption in a Chinese population and compare that with other ethnic population for age estimation. A total of 1135 conventional orthopantomograms from 506 male and 629 female northern Chinese subjects aged between 11 and 26 years were analyzed. The eruption status of the third molars was assessed using the developmental stages described by Olze et al. Results showed that the third molars 18, 28, 38 and 48 in the stage A showed significant younger average age in males than in females. The Olze's stage A could be used as a reference stage to determine whether a male or female northern Chinese is likely to be equal or above age 16, with 99.6-100% and 97.4-98.1% of correct predictions, respectively. The stage D was found to be a useful marker for diagnosing age under 16 years, with 98.9-100% and 100% of correct predictions in males and females, respectively. There were some significant differences of the chronological course of the third molars eruption in different ethnic groups, which indicated that population-specific standards could enhance the accuracy of forensic age estimation based on third molar eruption.
authors.affiliation: College of Medicine and Forensics, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an 710061, Shaanxi, PR China; Key Laboratory of the Health Ministry for Forensic Sciences, Xi'an Jiaotong University, 76 West Yanta Road, Xi'an 710061, Shaanxi, PR China; Key Laboratory of the Education Ministry for Environment and Genes Related to Diseases, 76 West Yanta Road, Xi'an 710061, Shaanxi, PR China.
authors.forename: Yu-cheng
authors.initials: YC
authors.lastname: Guo
authors.affiliation: College of Medicine and Forensics, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an 710061, Shaanxi, PR China; Key Laboratory of the Health Ministry for Forensic Sciences, Xi'an Jiaotong University, 76 West Yanta Road, Xi'an 710061, Shaanxi, PR China; Key Laboratory of the Education Ministry for Environment and Genes Related to Diseases, 76 West Yanta Road, Xi'an 710061, Shaanxi, PR China. Electronic address: yanchunxia@mail.xjtu.edu.cn.
authors.forename: Chun-xia
authors.initials: CX
authors.lastname: Yan
authors.affiliation: Department of Implantodontics, the Affiliated Stomatological Hospital of Xi'an Jiaotong University Health Science Center, 98 West Five Road, Xi'an 710004, Shaanxi, PR China.
authors.forename: Xing-wei
authors.initials: XW
authors.lastname: Lin
authors.affiliation: Department of Orthodontics, the Affiliated Stomatological Hospital of Xi'an Jiaotong University Health Science Center, 98 West Five Road, Xi'an 710004, Shaanxi, PR China.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Department of Orthodontics, the Affiliated Stomatological Hospital of Xi'an Jiaotong University Health Science Center, 98 West Five Road, Xi'an 710004, Shaanxi, PR China.
authors.forename: Feng
authors.initials: F
authors.lastname: Pan
authors.affiliation: College of Medicine and Forensics, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an 710061, Shaanxi, PR China; Key Laboratory of the Health Ministry for Forensic Sciences, Xi'an Jiaotong University, 76 West Yanta Road, Xi'an 710061, Shaanxi, PR China; Key Laboratory of the Education Ministry for Environment and Genes Related to Diseases, 76 West Yanta Road, Xi'an 710061, Shaanxi, PR China.
authors.forename: Lai
authors.initials: L
authors.lastname: Wei
authors.affiliation: College of Medicine and Forensics, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an 710061, Shaanxi, PR China; Key Laboratory of the Health Ministry for Forensic Sciences, Xi'an Jiaotong University, 76 West Yanta Road, Xi'an 710061, Shaanxi, PR China; Key Laboratory of the Education Ministry for Environment and Genes Related to Diseases, 76 West Yanta Road, Xi'an 710061, Shaanxi, PR China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Tang
authors.affiliation: College of Medicine and Forensics, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an 710061, Shaanxi, PR China; Key Laboratory of the Health Ministry for Forensic Sciences, Xi'an Jiaotong University, 76 West Yanta Road, Xi'an 710061, Shaanxi, PR China; Key Laboratory of the Education Ministry for Environment and Genes Related to Diseases, 76 West Yanta Road, Xi'an 710061, Shaanxi, PR China.
authors.forename: Feng
authors.initials: F
authors.lastname: Liang
authors.affiliation: College of Medicine and Forensics, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an 710061, Shaanxi, PR China; Key Laboratory of the Health Ministry for Forensic Sciences, Xi'an Jiaotong University, 76 West Yanta Road, Xi'an 710061, Shaanxi, PR China; Key Laboratory of the Education Ministry for Environment and Genes Related to Diseases, 76 West Yanta Road, Xi'an 710061, Shaanxi, PR China. Electronic address: chenteng@mail.xjtu.edu.cn.
authors.forename: Teng
authors.initials: T
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D000328:Adult; D000366:Age Determination by Teeth / Q000379:methods*; D044466:Asian People; D002648:Child; D002681:China; D005260:Female; D005553:Forensic Dentistry / Q000379:methods*; D006801:Humans; D008297:Male; D008964:Molar, Third / Q000000981:diagnostic imaging / Q000254:growth & development*; D011862:Radiography, Panoramic; D012727:Sex Characteristics; D013997:Time Factors; D014078:Tooth Eruption
keywords: Age estimation; Forensic odontology; Northern Chinese population; Third molar; Tooth eruption