title: Open bite in prematurely born children.
abstract: OBJECTIVE
  The aims of this study were to: examine the expression of open bite in prematurely born children and discuss the etiological factors that may lead to bite it.
  
  
  METHODS
  The subjects were 328 prematurely born (<37 gestational weeks) Caucasoid and African American children and 1,804 full-term control children, who participated in the cross-sectional study of the Collaborative Perinatal Project in the 1960s and 1970s. Dental documents, including casts and photographs, were taken once at the age of 6-12 years in the mixed dentition. The occlusion was recorded by examining and measuring the hard stone casts. Vertical open bite was recorded only for full erupted teeth. The statistical method used was chi-square analysis.
  
  
  RESULTS
  Significant differences in the incidence of anterior open bite (from left to right canine) was found between the preterm and control groups and between gender and ethnic groups. The prevalence of anterior open bite was nearly 9% in the preterm group and almost 7% in the control group. African Americans (9%) had a significantly greater incidence of open bite than Caucasians (3%; P<.0001). Generally, girls had a greater incidence of open bite than boys (8% vs 6%; P<.11). When the study groups were divided by prematurity, gender, and ethnic group, the prevalence of open bite was increased--especially in preterm African American boys compared to controls (11% vs 8%).
  
  
  CONCLUSIONS
  The results show differences in the development of anterior open bite between ethnic and gender groups. Premature birth may also influence dental occlusal development. Of importance are the patient's: general health condition; respiratory infections; inadequate nasal- and mouth-breathing; oral habits; and other medical problems. Preterm children may be relatively more predisposed to etiological factors for the development of anterior open bite.
authors.affiliation: Department of Oral Development and Orthodontics, Institute of Dentistry, University of Oulu, Oulu, Finland. Virpi.Harila@oulu.fi
authors.forename: V
authors.initials: V
authors.lastname: Harila
authors.forename: T
authors.initials: T
authors.lastname: Heikkinen
authors.forename: M
authors.initials: M
authors.lastname: Grön
authors.forename: L
authors.initials: L
authors.lastname: Alvesalo
mesh_terms: D001741:Black or African American / Q000706:statistics & numerical data; D016022:Case-Control Studies; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D005386:Fingersucking / Q000009:adverse effects; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D009058:Mouth Breathing / Q000150:complications; D024343:Open Bite / Q000209:etiology*; D044465:White People / Q000706:statistics & numerical data