title: Age assessment based on third molar mineralisation : An epidemiological-radiological study on a Central-European population.
abstract: OBJECTIVE
  The method published in 1973 by Demirjian et al. to assess age based on the mineralisation stage of permanent teeth is standard practice in forensic and orthodontic diagnostics. From age 14 onwards, however, this method is only applicable to third molars. No current epidemiological data on third molar mineralisation are available for Caucasian Central-Europeans. Thus, a method for assessing age in this population based on third molar mineralisation is presented, taking into account possible topographic and gender-specific differences.
  
  
  METHODS
  The study included 486 Caucasian Central-European orthodontic patients (9-24 years) with unaffected dental development. In an anonymized, randomized, and blinded manner, one orthopantomogram of each patient at either start, mid or end of treatment was visually analysed regarding the mineralisation stage of the third molars according to the method by Demirjian et al. Corresponding topographic and gender-specific point scores were determined and added to form a dental maturity score. Prediction equations for age assessment were derived by linear regression analysis with chronological age and checked for reliability within the study population.
  
  
  RESULTS
  Mineralisation of the lower third molars was slower than mineralisation of the upper third molars, whereas no jaw-side-specific differences were detected. Gender-specific differences were relatively small, but girls reached mineralisation stage C earlier than boys, whereas boys showed an accelerated mineralisation between the ages of 15 and 16.
  
  
  CONCLUSIONS
  The global equation generated by regression analysis (age = -1.103 + 0.268 × dental maturity score 18 + 28 + 38 + 48) is sufficiently accurate and reliable for clinical use. Age assessment only based on either maxilla or mandible also shows good prognostic reliability.
authors.affiliation: Department of Orthodontics, University Hospital Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Hofmann
authors.affiliation: Department of Orthodontics, University Hospital Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Robold
authors.affiliation: Department of Orthodontics, University Hospital Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Proff
authors.affiliation: Department of Orthodontics, University Hospital Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany. christian.kirschneck@ukr.de.
authors.forename: Christian
authors.initials: C
authors.lastname: Kirschneck
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods / Q000639:trends; D000293:Adolescent; D000366:Age Determination by Teeth; D017677:Age Distribution; D002113:Calcification, Physiologic; D002648:Child; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D008297:Male; D008964:Molar, Third / Q000000981:diagnostic imaging* / Q000502:physiology*; D011862:Radiography, Panoramic / Q000379:methods* / Q000706:statistics & numerical data; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017678:Sex Distribution; D016037:Single-Blind Method; D044465:White People / Q000706:statistics & numerical data*; D055815:Young Adult
keywords: Age determination by teeth/methods; European continental ancestry group; Molar; Panoramic; Radiography; Reference standards; Third/growth and development/radiography; Tooth root/growth and development/radiography