title: A longitudinal controlled study of factors associated with mutans streptococci infection and caries lesion initiation in children 21 to 72 months old.
abstract: OBJECTIVE
  The purpose of this longitudinal study was to determine factors associated with mutans streptococci (MS) infection and development of caries lesions in a group of children 21 to 72 months old.
  
  
  METHODS
  The 63 caries-free children, recruited since birth, were divided into: (1) a study group of 24 children who were colonized with MS; and (2) a control group of 39 children without MS. The children were recalled every 3 months for approximately 24 months, and their social, medical, and dental histories were updated. At each recall, the teeth were checked for presence or absence of plaque, enamel hypoplasia, and caries lesions, and their MS status was assessed using a commercial test kit.
  
  
  RESULTS
  MS infection was associated with: (1) visible plaque (P < .01); (2) enamel hypoplasia (P < .05); (3) commencement of tooth-brushing after 12 months of age (P < .05); (4) lack of parental assistance with tooth-brushing (P < .025); and (5) increased hours of child care/school (P < .05). Four children (20%) were colonized at an age range of 21 to 36 months, 9 (45%) at 37 to 48 months, and 7 (35%) at 49 to 72 months (P < .001). Eight children who developed caries lesions: (1) had more hypoplastic teeth (P < .001); (2) ate sugar-containing snacks (P < .05); and (3) did not brush regularly with chlorhexidine gel (P < .01) compared to those who remained free of caries lesions.
  
  
  CONCLUSIONS
  Lack of oral hygiene, consumption of sugar-containing snacks, and enamel hypoplasia are significant factors for both MS infection and caries lesion initiation.
authors.affiliation: Pediatric Dentistry, School of Dentistry, University of Queensland, Brisbane, Australia.
authors.forename: Vicky
authors.initials: V
authors.lastname: Law
authors.forename: W Kim
authors.initials: WK
authors.lastname: Seow
mesh_terms: D000704:Analysis of Variance; D001903:Bottle Feeding / Q000009:adverse effects; D016022:Case-Control Studies; D002675:Child, Preschool; D003731:Dental Caries / Q000209:etiology / Q000382:microbiology*; D003732:Dental Caries Activity Tests; D003744:Dental Enamel Hypoplasia / Q000150:complications; D003773:Dental Plaque / Q000150:complications / Q000382:microbiology; D019422:Dietary Sucrose / Q000009:adverse effects; D005260:Female; D006801:Humans; D007223:Infant; D008137:Longitudinal Studies; D008297:Male; D009910:Oral Hygiene / Q000706:statistics & numerical data; D013290:Streptococcal Infections / Q000150:complications; D013295:Streptococcus mutans / Q000302:isolation & purification / Q000472:pathogenicity*; D014094:Tooth, Deciduous
chemical_list: D019422:Dietary Sucrose