title: Survey of incisor trauma in second grade students of central Taiwan.
abstract: BACKGROUND
  The purpose of this study was to investigate the prevalence and related factors of incisor trauma among 1200 second grade students in Taichung City, Taiwan.
  
  
  METHODS
  The study population consisted of 1200 second grade students, 645 boys (53.8%) and 555 girls (46.3%), at four elementary schools in Taichung City, Taiwan. This survey was composed of two parts: (1) a questionnaire of dental traumatic history, and (2) a clinical examination of each subject to record any clinical evidence of traumatic dental injury on permanent incisors.
  
  
  RESULTS
  The questionnaires indicated that 16.5% of the children had a positive history of dental trauma. The male to female ratio of a prior dental trauma was 1.4:1. The maxilla (78.2%) was affected more frequently than the mandible. Most of the injuries had occurred at home (63.7%). Clinical examinations disclosed that 3% of the subjects, 43 teeth in 37 children, had clinical signs and symptoms of dental trauma. Maxillary central incisors (77%) were the teeth most often affected. The most common type of crown injury was enamel fracture (67%).
  
  
  CONCLUSIONS
  The prevalence of a history of dental trauma and clinical findings of incisor injury in this study was lower than that in previous reports. Home and school were the settings where dental injury was most likely to occur. Clinical signs and symptoms of dental trauma were found in 3% of the subjects. Maxillary incisors were the most commonly affected teeth, and 67% of these cases involved enamel fracture.
authors.affiliation: Division of Craniofacial Dentistry, Chang Gung Memorial Hospital, Taipei, Taiwan, R.O.C.
authors.forename: Y L
authors.initials: YL
authors.lastname: Chen
authors.forename: T P
authors.initials: TP
authors.lastname: Tsai
authors.forename: L C
authors.initials: LC
authors.lastname: See
mesh_terms: D000367:Age Factors; D002648:Child; D005260:Female; D006801:Humans; D007180:Incisor / Q000293:injuries*; D008297:Male; D015995:Prevalence; D012737:Sex Factors; D014947:Wounds and Injuries / Q000453:epidemiology / Q000209:etiology / Q000628:therapy