title: Dental injuries in 12-year old Nigerian students.
abstract: OBJECTIVE
  To determine the prevalence and causes of Traumatic Dental Injuries (TDIs) in 12-year-old Nigerian students. The study also sought to ascertain the relationship(s) among gender, location (urban and rural areas) and overjet in the presentation of TDIs.
  
  
  METHODS
  The sample size included 719 school children aged 12years from 36 public schools. They were proportionately selected through a multistage sampling technique. TDIs to the teeth were evaluated clinically by one examiner (intra-examiner reliability test was 0.771 by Cronbach's Alpha test). The TDIs were classified according to the WHO classification. Overjet was considered a risk when its values were >6mm. The children answered a structured questionnaire on sociodemographics and oral health behaviours. Analysis was performed using spss V16.0 (SPSS Inc, Chicago, IL, USA). Pearson's Chi-squared test was used to test for association between variables and Odds ratio (OR). P values <0.05 were considered statistically significant.
  
  
  RESULTS
  There were 411 (57.2%) boys. More than half (54.2%) were from the urban areas. Prevalence of TDI was 15.2% (prevalence in the urban and rural locations were 15.1% and 15.2% respectively). The maxillary central incisors (66.7%) were the most affected teeth followed by the laterals (17.4%). Enamel fracture (73.5%) was the most common type of TDI noticed followed by enamel and dentine fracture (15.9%). Falls (64.2%) were the most frequent cause of trauma. Collisions account for 9.2%. Eighteen (2.5%) students had overjet >6mm. TDIs were more prevalent among males (P=0.025, OR=1.520, 95% CI =1.049, 2.202) and those with overjet >6mm (P=0.029, OR=0.344, 95% CI=0.141, 1.088). The occurrence of TDIs was not related to location (P>0.05).
  
  
  CONCLUSIONS
  The prevalence of traumatized teeth among 12-year-olds in Nigeria was comparable to other studies. Being male and having an overjet >6mm were associated with a higher probability of having a traumatized tooth.
authors.affiliation: Regional Centre for Oral Health Research and Training Initiatives for Africa, Jos, Plateau State, Nigeria. taiwo25@yahoo.co.uk
authors.forename: Olaniyi O
authors.initials: OO
authors.lastname: Taiwo
authors.forename: Hassan P
authors.initials: HP
authors.lastname: Jalo
mesh_terms: D000058:Accidental Falls / Q000706:statistics & numerical data; D002648:Child; D003743:Dental Enamel / Q000293:injuries; D003804:Dentin / Q000293:injuries; D005260:Female; D006801:Humans; D007180:Incisor / Q000293:injuries; D008297:Male; D008310:Malocclusion / Q000453:epidemiology; D009549:Nigeria / Q000453:epidemiology; D015995:Prevalence; D012307:Risk Factors; D012423:Rural Health / Q000706:statistics & numerical data; D012737:Sex Factors; D014084:Tooth Avulsion / Q000453:epidemiology; D019228:Tooth Crown / Q000293:injuries; D014082:Tooth Fractures / Q000453:epidemiology; D018677:Tooth Injuries / Q000453:epidemiology*; D014504:Urban Health / Q000706:statistics & numerical data