title: Twins and the paradox of dental-age estimations: a caution for researchers and clinicians.
abstract: The biological age difference among twins is frequently an issue in studies of genetic influence on various dental features, particularly dental development. The timing of dental development is a crucial issue also for many clinicians and researchers. The aim of this study was therefore to verify within groups of twins how dental development differs, by applying Demirjian's method, Mincer's charts of development of third molars and two of Cameriere's methods for dental age estimation, which are among the most popular methods both in the clinical and the forensic scenario. The sample consisted of 64 twin pairs: 21 monozygotic, 30 dizygotic same-sex and 13 dizygotic opposite-sex with an age range between 5.8 and 22.6 years. Dental age was determined from radiographs using the mentioned methods. Results showed that dental age of monozygotic twins is not identical even if they share all their genes. The mean intra-pair difference of monozygotic pairs was low and similar to the difference in dizygotic same-sex twins; the maximum difference between monozygotic twins, however, was surprisingly large (nearly two years). This should lead to some circumspection in the interpretation of systematic estimations of dental age both in the clinical and forensic scenario.
authors.affiliation: LABANOF - Laboratorio di Antropologia ed Odontologia Forense, Sezione di Medicina Legale, Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, Via Mangiagalli 37, 20133 Milano, Italy; Institute of Anatomy, Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Ostrava, 70103 Ostrava, Czech Republic.
authors.forename: M
authors.initials: M
authors.lastname: Pechníková
authors.affiliation: LABANOF - Laboratorio di Antropologia ed Odontologia Forense, Sezione di Medicina Legale, Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, Via Mangiagalli 37, 20133 Milano, Italy.
authors.forename: D
authors.initials: D
authors.lastname: De Angelis
authors.affiliation: LABANOF - Laboratorio di Antropologia ed Odontologia Forense, Sezione di Medicina Legale, Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, Via Mangiagalli 37, 20133 Milano, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Gibelli
authors.affiliation: LABANOF - Laboratorio di Antropologia ed Odontologia Forense, Sezione di Medicina Legale, Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, Via Mangiagalli 37, 20133 Milano, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Vecchio
authors.affiliation: Institute of Legal Medicine, University of Macerata, 62100 Macerata, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Cameriere
authors.affiliation: University Dental Clinical Center of Kosovo, Kosovo.
authors.forename: B
authors.initials: B
authors.lastname: Zeqiri
authors.affiliation: LABANOF - Laboratorio di Antropologia ed Odontologia Forense, Sezione di Medicina Legale, Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, Via Mangiagalli 37, 20133 Milano, Italy. Electronic address: cristina.cattaneo@unimi.it.
authors.forename: C
authors.initials: C
authors.lastname: Cattaneo
mesh_terms: D000293:Adolescent; D000366:Age Determination by Teeth / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D008964:Molar, Third / Q000033:anatomy & histology / Q000254:growth & development; D009805:Odontogenesis / Q000235:genetics; D014070:Tooth / Q000033:anatomy & histology / Q000254:growth & development; D014078:Tooth Eruption / Q000235:genetics; D014429:Twins, Dizygotic / Q000235:genetics; D014430:Twins, Monozygotic / Q000235:genetics; D055815:Young Adult
keywords: Dental age; Forensic anthropology; Teeth development; Twins