title: Permanent first molar extraction in adolescents and young adults and its effect on the development of third molar.
abstract: OBJECTIVE
  The aim of the present study was to determine the prevalence of permanent first molar (P1M) extraction among Turkish adolescents and young adult subpopulation, and to investigate the effects of P1M extraction on development of the third molars (3Ms) in the same quadrant.
  
  
  METHODS
  A retrospective study including 2,925 panoramic radiographs (PRs) taken from patients (aged 13-20 years) who were examined to identify cases of had at least one maxillary or mandibular P1Ms extracted was performed. Additionally, 294 PRs with the maxillary or mandibular unilateral loss of a P1M were used to assess the developmental grades of the 3Ms. Statistical analyses were performed by means of parametric tests after performing a Shapiro-Wilks normality test to the data.
  
  
  RESULTS
  A total of 945 patients (32.3 %) presented with at least one P1M extraction with no gender difference (P = 0.297). There were more cases of mandibular P1Ms extracted (784 patients, 1,066 teeth) than maxillary P1Ms extracted (441 patients, 549 teeth) (P < 0.001). The development of the 3Ms on the extraction side, in the both maxilla and mandible, was significantly accelerated when compared with the contralateral teeth (P = 0.000, P = 0.000, respectively). No statistically significant differences were found in the differences in the developmental of the 3Ms between the maxilla and mandible (P = 0.718).
  
  
  CONCLUSIONS
  High prevalence of P1Ms extraction among Turkish adolescents and young adults shows a need for targeted dental actions, including prevention and treatment. The development of the 3Ms on the extraction side, in the both maxilla and mandible, was significantly accelerated.
  
  
  CONCLUSIONS
  To date, no information about prevalence of P1Ms extraction among Turkish adolescents and young adults is documented. In addition, the present study has a larger population and complementary information about 3Ms development than previous studies.
authors.affiliation: Department of Orthodontics, Faculty of Dentistry, Abant İzzet Baysal University, 14300, Bolu, Turkey, koray.halicioglu@ibu.edu.tr.
authors.forename: Koray
authors.initials: K
authors.lastname: Halicioglu
authors.forename: Orcun
authors.initials: O
authors.lastname: Toptas
authors.forename: Ismail
authors.initials: I
authors.lastname: Akkas
authors.forename: Mevlut
authors.initials: M
authors.lastname: Celikoglu
mesh_terms: D000293:Adolescent; D000328:Adult; D006801:Humans; D008963:Molar / Q000601:surgery*; D008964:Molar, Third / Q000254:growth & development*; D015203:Reproducibility of Results; D014081:Tooth Extraction; D055815:Young Adult