title: Agenesis of second premolars and delayed dental maturation.
abstract: OBJECTIVE
  The purpose of this work was to examine the relationship between second-premolar agenesis and how rapidly permanent dentition develops.
  
  
  METHODS
  Panoramic radiographs of 678 girls and boys aged 6-14 years were evaluated. Subjects with syndromes or history of tooth extraction were excluded. The permanent dentition's stages of mineralization (scale 1-10) and eruption (1-7), and the resorption (1-5) of deciduous teeth were assessed.
  
  
  RESULTS
  Adjusted for age and sex, subjects with one or more missing second premolars revealed earlier developmental stages (mineralization: average -0.37 stages per tooth, 95% CI -0.23 to -0.50; eruption: -0.42, 95% CI -0.60 to -0.24; resorption: -0.36, 95% CI -0.49 to -0.24; all p < 0. 001). Canines, premolars, and second molars were particularly affected, regardless of their location in the same or opposing jaw, and independent of the number of missing teeth. Overall dental development was delayed by 8.6 months (95% CI 5.4-11.8) in subjects with missing second premolars.
  
  
  CONCLUSIONS
  These results have implications for several areas of medicine. Joint biological etiology for the agenesis and late maturation of permanent teeth should be considered in developmental research. Orthodontists should be aware of the delay associated with missing second premolars when timing interventions. Forensic age assessment based on tooth development should adjust for missing teeth to avoid underestimating the subject's age.
authors.affiliation: Department of Orthodontics, University Hospital Leipzig, Liebigstr. 10/14, 04103, Leipzig, Germany, bianca.gelbrich@medizin.uni-leipzig.de.
authors.forename: Bianca
authors.initials: B
authors.lastname: Gelbrich
authors.forename: Alexander
authors.initials: A
authors.lastname: Hirsch
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Dannhauer
authors.forename: Götz
authors.initials: G
authors.lastname: Gelbrich
mesh_terms: D000293:Adolescent; D000375:Aging; D000848:Anodontia / Q000503:physiopathology*; D001641:Bicuspid / Q000002:abnormalities* / Q000503:physiopathology*; D002113:Calcification, Physiologic; D002648:Child; D005260:Female; D005858:Germany; D006801:Humans; D008297:Male; D014078:Tooth Eruption