Prevalence of malocclusion in primary dentition in a population-based sample of Brazilian preschool children.

AIM: The purpose of the present study was to assess the prevalence of malocclusion in the primary dentition in a randomised representative sample of Brazilian preschool children. MATERIALS AND METHODS: A cross-sectional survey was carried out in Belo Horizonte, Brazil, involving 1069 male and female preschool children from 60 to 71 months of age, randomly selected from public and private preschools and daycare centers. A questionnaire addressing demographic data was sent to parents/guardians in order to characterise the sample. The oral examination of the children was performed by a single, previously calibrated dentist (kappa inter-examiner agreement value = 0.82). The criterion for the categorisation of malocclusion was at least one of the following conditions: posterior crossbite, overjet (> 2 mm), anterior crossbite, anterior open bite and deep overbite. Univariate analysis was performed using the SPSS software RESULTS: The prevalence of malocclusion was 46.2%. Deep overbite was the most prevalent alteration (19.7% of the sample). Posterior crossbite was diagnosed in 13.1% of the children; 10.5% had accentuated overjet; 7.9% had anterior open bite; and 6.7% had anterior crossbite. CONCLUSION: Malocclusion in primary dentition is becoming a significant problem. The prevalence in the present study was high, especially vertical and transversal malocclusions.

Predisposing factors for traumatic dental injuries in Brazilian preschool children.

AIM: The aim of the present study was to assess the prevalence of traumatic dental injury (TDI) in primary teeth and determine predisposing factors. MATERIALS AND METHODS: A cross-sectional study was carried out on 388 male and female Brazilian preschool children between 60 and 71 months of age. A questionnaire addressing demographic data and history of TDI was sent to parents/caregivers. Socioeconomic status was determined using the Social Vulnerability Index (SVI), family income, number of people in the household and parents/caregivers' schooling. The chi-square test was used for the statistical analysis. RESULTS: The prevalence of TDI was 62.1%; 61.7% of the teeth were affected by enamel fracture. Statistically significant associations were found between TDI and increased overjet [OR = 2.24, 95% CI = 1.11- 4.55] and anterior crossbite [OR = 0.38, 95% CI=0.17-0.87]. No statistically significant associations were found between TDI and number of people in the household, family income, social vulnerability, parents/caregivers' schooling, lip competence, overbite, anterior open bite and dental caries (p>0.05). CONCLUSION: The prevalence of TDI was high and enamel fracture was the most common sign of TDI. Children with an increased overjet suffer more TDIs. Socioeconomic factors had no influence over the prevalence of TDI.