Trauma in primary teeth and its effect on the development of permanent successors: a controlled study.

Objective: This controlled study investigated the occurrence of sequelae to permanent successors (SPS) following traumatic dental injury in primary teeth (TDIp). Additionally, this study evaluated whether TDIp is a risk factor for SPS, with a focus on an association between SPS and the child's age and type of trauma. Materials and methods: The trauma group (TG) consisted of permanent teeth, whose antecessors had suffered TDIp, in a population of children with complete eruption of permanent teeth. The control group (CG) consisted of permanent teeth from the same individuals, whose antecessors had not suffered TDIp. There were 214 cases of TDIp with their respective permanent teeth. In the CG 247 permanent teeth, whose antecessor had not suffered TDIp, were included. Data concerning such teeth and when TDIp occurred (in terms of the child's age) and types of SPS were collected. The chi-square test, regression logistic with generalized estimating equations (GEE) test, and risk analyses were applied to investigate the associations. Results: Overall, 29% of the permanent teeth in the TG presented SPS. This was compared to the development disturbances in the CG, which was 7%. The TG demonstrated the highest risk for SPS (OR, 5.388; p = .0001). The discolouration of enamel (37%) was the most common type of SPS found. SPS was more prone to occur in permanent teeth whose antecessors had been intruded (39%; p < .001). TDIp when the child was 1-year old was associated with SPS (p < .001). Moreover, children who had TDIp had a 4.1 times higher risk of presenting SPS. Conclusions: TDIp is a risk factor for the development of SPS. All types of TDIp caused SPS in this research. Additionally, the younger ages at the time of the injury and intrusions were related to SPS.