title: Is tooth wear in the primary dentition predictive of tooth wear in the permanent dentition? Report from a longitudinal study.
abstract: OBJECTIVE
  To determine the prevalence of tooth wear in the permanent dentition of a sample of 12-year-old school children and establish whether an association exists between tooth wear recorded now and tooth wear recorded in their primary dentition at age five.
  
  
  METHODS
  A prospective cohort study.
  
  
  METHODS
  At follow-up to a previous study complete data were available for 123 children; fieldwork was conducted in the child's primary school. Measurement of tooth wear used a scoring system modified from the Smith and Knight Tooth Wear Index (TWI). Tooth wear which had progressed to dentine was assessed on the occlusal surfaces of the four first permanent molars, the labial, lingual/palatal and incisal surfaces of the six upper and six lower anterior teeth; a total of 40 scoreable surfaces. Demographic data were collected from the parents, and a questionnaire on oral hygiene habits, diet and behaviours was completed by each child.
  
  
  RESULTS
  In total 38% (n = 47) of subjects had tooth wear, if incisor teeth only were included, 33% (n = 40) had tooth wear and similarly if the occlusal surfaces of molar teeth only were included 10% (n = 12) had signs of tooth wear. Gender was significantly associated with tooth wear: males had more tooth wear. The presence of tooth wear with dentine exposed in the primary dentition was significantly associated with tooth wear on the occlusal surfaces of the first permanent molars.
  
  
  CONCLUSIONS
  Males had more tooth wear than females. An association existed between tooth wear recorded at age 5 and molar tooth wear recorded at age 12. Tooth wear is a lifelong cumulative process and should be recorded in both the primary and permanent dentitions.
authors.affiliation: Oral Health Services Research Centre, University College Cork, Ireland. m.harding@ucc.ie
authors.forename: M A
authors.initials: MA
authors.lastname: Harding
authors.forename: H P
authors.initials: HP
authors.lastname: Whelton
authors.forename: S C
authors.initials: SC
authors.lastname: Shirodaria
authors.forename: D M
authors.initials: DM
authors.lastname: O'Mullane
authors.forename: M S
authors.initials: MS
authors.lastname: Cronin
mesh_terms: D001903:Bottle Feeding / Q000009:adverse effects; D002648:Child; D002652:Child Behavior; D002675:Child, Preschool; D015331:Cohort Studies; D019229:Dentition, Permanent; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D007494:Ireland / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D016017:Odds Ratio; D015995:Prevalence; D011379:Prognosis; D011446:Prospective Studies; D012737:Sex Factors; D011795:Surveys and Questionnaires; D057085:Tooth Wear / Q000453:epidemiology* / Q000209:etiology; D014094:Tooth, Deciduous