OBJECTIVEThe prevalence rate, distribution, and reasons of immature permanent-tooth trauma in Xi'an were investigated and described, and a scientific basis was provided for the decision-making of health-administration departments.

METHODSThrough cluster and simple random sampling survey, 4 013 pupils in schools from nine districts and four counties in Xi'an were sampled. All pupils and their parents were requested to complete a questionnaire. Oral examinations were conducted for children who had immature permanent teeth trauma. The number of trauma teeth and teeth were recorded. Survey data were analyzed statistically.

RESULTSThe prevalence rate of immature permanent dental trauma was 10.5% in Xi'an. No significant differences were observed between districts and counties (P>0.05). The peak age of permanent dental trauma was at 7-9 years old, and the most was at 8 years old (31.5%). The first reason of trauma was falling down (50.9%), and the second reason was crash (36.0%). The most common trauma teeth were maxillary incisors (75.4%).

CONCLUSIONSThe prevalence rate of immature permanent teeth trauma in Xi'an was in the middle of all international levels. Children, who are vulnerable to dental trauma at their age, should be provided with appropriate prevention measures to reduce the incidence of dental trauma.