title: A comparative analysis of periapical health based on historic and current data.
abstract: OBJECTIVE
  To compare periapical health using samples from prehistoric and historic periods until the present day, and to emphasize the major risk indicators for apical periodontitis (AP).
  
  
  METHODS
  A comparative survey to assess periapical health was performed on five samples (525 individuals) drawn from different periods of history within the time frame 2000 BC to 2000 AD. Twenty-one binary risk indicators for AP were retained for a logistic regression model. The probability of a diseased tooth was defined from a two-level response variable based on the periapical index (PAI). An individual regression model was computed with partial least squares (PLS) regression model, based on the individual mean values of the nine retained risk indicators.
  
  
  RESULTS
  Condensing osteitis, tooth wear, caries, root fillings and the presence of inadequate root fillings were associated with the PAI levels. The maxillary molars and recent time periods (contemporaneous and seventeenth century) were also risk indicators for the pathological condition. The PLS regression for individuals demonstrated correlations between risk factors. This multidimensional analysis indicated that the mean PAI was correlated mainly with caries and condensing osteitis. Condensing osteitis was more frequent in the mandibular than in the maxillary bone (P=0.001), and correlated with tooth wear in ancient periods.
  
  
  CONCLUSIONS
  This comparative analysis demonstrated a significantly higher prevalence of AP in the contemporary period. The most important risk indicators for that period were the presence of inadequate root fillings, carious lesions and condensing osteitis.
authors.affiliation: UFR d'Odontologie de Montpellier, Montpellier, France. j-c.chazel@wanadoo.fr
authors.forename: J C
authors.initials: JC
authors.lastname: Chazel
authors.forename: P
authors.initials: P
authors.lastname: Tramini
authors.forename: J
authors.initials: J
authors.lastname: Valcarcel
authors.forename: B
authors.initials: B
authors.lastname: Pélissier
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003731:Dental Caries / Q000453:epidemiology / Q000266:history; D003793:Dental Restoration, Permanent / Q000266:history / Q000706:statistics & numerical data; D005260:Female; D049669:History, 16th Century; D049670:History, 17th Century; D049674:History, 21st Century; D049690:History, Ancient; D049691:History, Medieval; D006801:Humans; D016015:Logistic Models; D008297:Male; D008336:Mandibular Diseases / Q000453:epidemiology / Q000266:history; D008439:Maxillary Diseases / Q000453:epidemiology / Q000266:history; D008963:Molar / Q000473:pathology; D010000:Osteitis / Q000453:epidemiology / Q000266:history; D010164:Paleopathology; D010485:Periapical Periodontitis / Q000453:epidemiology* / Q000266:history; D012307:Risk Factors; D014072:Tooth Abrasion / Q000453:epidemiology / Q000266:history; D014092:Tooth Root / Q000473:pathology