title: Does smoking affect the Ki67 and p53 expressions in asymptomatic fully impacted lower third molar follicles?
abstract: OBJECTIVE
  Ki67 and p53 protein expressions are the most widely used markers to show the pathologic proliferation and early-stage tumoral alterations in vital tissues. The aim of this study was to compare Ki67 and p53 protein expressions in smokers' and nonsmokers' pericoronal follicles of asymptomatic impacted lower third molars (ILTMs).
  
  
  METHODS
  A cross-sectional study was planned. The study sample was derived from a population of patients who presented for evaluation and operative treatment of asymptomatic ILTMs. The predictor variable was smoking status, defined as smoker or nonsmoker. Outcome variables were Ki67 and p53 protein expressions in ILTM follicles. Other study variables were age, gender, tooth position, cigarette pack-year, epithelial layer staining, and inflammation. Independent-samples t test analyses were conducted with SPSS 10.0 (SPSS, Inc, Chicago, IL), with statistical significance set at a P value equal to .05.
  
  
  RESULTS
  The study sample was composed of 70 patients (35 in the smoker group) who contributed 60 follicles. There were statistical differences between the 2 groups for variables Ki67 and p53. Mean expression levels of Ki67 were 3.93 ± 2.17 and 2.48 ± 2.09, respectively, for smokers and nonsmokers (P = .011). Mean expression levels of p53 were 5.32 ± 1.98 and 3.06 ± 2.34, respectively, for smokers and nonsmokers (P = .000).
  
  
  CONCLUSIONS
  The present study showed that dental follicles of smokers have higher Ki67 and p53 protein expressions than nonsmokers' follicles.
authors.affiliation: Assistant Professor, Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Abant Izzet Baysal University, Bolu, Turkey. Electronic address: toptasorcun@yahoo.com.
authors.forename: Orçun
authors.initials: O
authors.lastname: Toptaş
authors.affiliation: Professor, Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Süleyman Demirel University, Isparta, Turkey.
authors.forename: Timuçin
authors.initials: T
authors.lastname: Baykul
authors.affiliation: Pathologist, Department of Pathology, Lütfi Kırdar Kartal Training and Research Hospital, İstanbul, Turkey.
authors.forename: Kayhan
authors.initials: K
authors.lastname: Başak
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism*; D008297:Male; D008964:Molar, Third / Q000378:metabolism* / Q000473:pathology; D012907:Smoking / Q000378:metabolism*; D014095:Tooth, Impacted / Q000378:metabolism*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D055815:Young Adult
chemical_list: D019394:Ki-67 Antigen; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53