title: Secular trend of earlier onset and decelerated development of third molars: evidence from Croatia.
abstract: The purpose of this study was to evaluate the influence of the secular trend on development of third molars in 30 years period in Littoral region of Croatia. A total of 1103 panoramic radiographs of subjects aged from 6 to 18 years were analysed. First group comprised 531 panoramic radiographs (258 girls) taken from year period 1977 till 1979 and second group 572 radiographs (325 girls) taken from year period 2007 till 2009. Demirjian's method was used to determine the developmental stage of third molars. A secular trend in 30 years period was observed as earlier onset of third molars development in boys (6 months on average maxillary and 11 months mandibular) and girls (6 months for maxillary and 4 months for mandibular). Now-a-days, an increase in mineralisation for one Demirjian stage occurs at a slower pace of 5.2 months in boys and 3.4 in girls in maxilla and 2.3 or 2 months in mandible for boys and girls, respectively. The study showed a secular trend present as earlier onset but decelerated development of third molars in both genders and both jaws.
authors.affiliation: Public Health Centre, Glavani 89a, 51221 Kostrena, Croatia.
authors.forename: Anja
authors.initials: A
authors.lastname: Sasso
authors.affiliation: Private Dental Practice, I.G. Kovacica 3, 52440 Porec, Croatia.
authors.forename: Mario
authors.initials: M
authors.lastname: Legovic
authors.affiliation: Private Dental Practice, Batijanova 19, 51000 Rijeka, Croatia.
authors.forename: Barbara
authors.initials: B
authors.lastname: Mady Maricic
authors.affiliation: Department of Orthodontics, School of Medicine, University of Rijeka, Kresimirova 40, 51000 Rijeka, Croatia. Electronic address: andrej.pavlic2@medri.uniri.hr.
authors.forename: Andrej
authors.initials: A
authors.lastname: Pavlic
authors.affiliation: Department of Orthodontics, School of Medicine, University of Rijeka, Kresimirova 40, 51000 Rijeka, Croatia.
authors.forename: Stjepan
authors.initials: S
authors.lastname: Spalj
mesh_terms: D000293:Adolescent; D000366:Age Determination by Teeth / Q000379:methods; D002648:Child; D017523:Croatia; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008964:Molar, Third / Q000000981:diagnostic imaging* / Q000254:growth & development*; D011862:Radiography, Panoramic; D012044:Regression Analysis; D012727:Sex Characteristics; D014074:Tooth Calcification
keywords: Croatia; Mineralisation of teeth; Panoramic radiography; Secular trend; Third molar