This prospective study examined the yearly incidence of traumatic injuries to primary teeth. The aim of the study was to find out more about dental injuries to primary teeth in Norwegian children. The study was performed in one county of Norway involving approximately 20,000 children in the age group 1-8 years. Twenty-seven public dental clinics and 42 dentists participated. The dentists attended information and calibration meetings and received illustrations of the classification of dental trauma as well as examples of how to fill in the forms correctly. Two hundred and sixty-six children were involved, including 447 primary teeth, recorded during a 1-year registration period (2003). The dental trauma incidence was 1.3% with 3.5-year old being the most accident-prone. Boys were significantly more often injured than girls, 164 versus 102 (P < 0.001). The upper central incisors were most involved (92%), with a non-significant difference between the right and left side. The minor periodontal injuries dominated (59%). Hard tissue injuries were far less frequent (13%). Avulsions were observed in 6.5% and intrusions in 7.5% of the injured children, being 5.5% and 5% of the injured teeth. Most of the injuries occurred either at home (38%) or at kindergarten (32%). Sixty-two percentage were falling accidents often sustained during children's play, and 25% were pure playing accidents.
Conclusion: In Norwegian children aged 1-8 years, with a predominance of boys, the most common primary tooth injuries were minor luxations of the maxillary central incisors, sustained at an age of 3.5 years. As the traumas often occurred during children's play and/or were the consequence of falls, these are difficult to prevent. However, follow ups should be carried out to disclose pulpal or periodontal complications and/or developmental disturbances of the permanent successors.