Risk factors associated with atypical root resorption of the maxillary primary central incisors.

Maxillary occlusal radiographs of 233 children between 42 and 60 months old were examined for the presence or absence of atypical root resorption (ARR). In addition, the dental records of these children were examined to determine if an association existed between ARR, oral habits, documented trauma and overjet. Thirty-three (14.2%) of the patients had radiographic evidence of ARR of either maxillary primary incisor. Children with a positive history of both trauma to the incisors and oral habits had a statistically higher prevalence of ARR than those without either finding (P = .03). ARR was more prevalent as overjet increased, independent of trauma, and oral habits (P = .03). Furthermore, as the number of risk factors (large overjet, documented trauma, and oral habits) increased, the likelihood of developing ARR also increased.