The association between traumatic dental injuries and atypical external root resorption in maxillary primary incisors.

Atypical root resorption (ARR), which is observed on radiographs of primary incisors, has been reported in the dental literature to result from digit sucking; thus ignoring any association between ARR and traumatic dental injuries (TDI). The purpose of this study was to evaluate and compare the contributions of sucking habits and TDI to external ARR in primary incisors. A history of dental trauma was assessed based on clinical and radiographic findings. Periapical radiographs of the premaxilla were evaluated for the presence of ARR. The presence or history of sucking habits was based on parents' report. Data were collected from files of 727 patients with a mean age of 52 months. Sixty-four children (8.8%) presented ARR in one or both central incisors. All 64 had experienced some type of TDI. Five hundred and forty-nine (76%) of the children had sucking habits; of them, 501 were pacifier-suckers and 48 digit suckers. Digit sucking was found in only 4 (6%) of the 64 children presenting ARR. These findings support the association of traumatic dental injury, and not of digit sucking, with ARR in primary incisors.