title: Maternal periodontal disease and preterm or extreme preterm birth: an ordinal logistic regression analysis.
abstract: BACKGROUND
  Despite previous studies addressing the link between preterm or low birth weight infants and maternal periodontitis, extreme preterm births have received far less attention. This study is designed to address the possible association between maternal periodontal disease and preterm or extreme preterm birth.
  
  
  METHODS
  Immediately after childbirth, 1,207 women underwent an examination in which periodontal disease was assessed according to two alternative definitions: 1) four or more teeth with at least one site showing probing depth (PD) >or=4 mm and clinical attachment loss (AL) >or=3 mm, and 2) at least one site showing PD and clinical AL >or=4 mm. For each of these definitions, two types of multivariate analysis were conducted: a linear regression analysis for the number of gestation weeks, and a more specific ordinal logistic regression analysis for the ordinal variable gestation time categorized as normal (term) (n = 1,046 women) or mild-moderate (n = 146 women) or extreme preterm (n = 15 women).
  
  
  RESULTS
  Periodontal disease was associated with fewer weeks of gestation by linear regression (definition 1: P = 0.012; definition 2: P <0.001) and with preterm (n = 161; mild-moderate and extreme) or extreme preterm births (n = 15) by ordinal logistic regression (definition 1: odds ratio [OR] = 1.83, 95% confidence interval [CI]: 1.28 to 2.62; definition 2: OR = 2.37, 95% CI: 1.62 to 3.46).
  
  
  CONCLUSIONS
  Our findings suggest that periodontal disease is associated with a premature or extremely premature birth.
authors.affiliation: Department of Health and Sociomedical Sciences, Biostatistics Unit, Faculty of Medicine, Alcalá University, Madrid, Spain. le_ng@hotmail.com
authors.forename: Alessandra Neves
authors.initials: AN
authors.lastname: Guimarães
authors.forename: Agustín
authors.initials: A
authors.lastname: Silva-Mato
authors.forename: Luis Otavio
authors.initials: LO
authors.lastname: Miranda Cota
authors.forename: Fernanda Mafra
authors.initials: FM
authors.lastname: Siqueira
authors.forename: Fernando Oliveira
authors.initials: FO
authors.lastname: Costa
mesh_terms: D000293:Adolescent; D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D008875:Middle Aged; D015233:Models, Statistical; D010518:Periodontitis / Q000150:complications* / Q000473:pathology; D011247:Pregnancy; D047928:Premature Birth / Q000209:etiology*; D012959:Socioeconomic Factors; D055815:Young Adult