The aim of this study was to examine the potential relationship between the occurrence of orthodontic
root resorption and presence of dental anomalies such as tooth agenesis and pipette-shaped roots. Dental anomalies and
root resorption were assessed on dental panoramic tomographs (DPT) of 88 subjects, 27 males and 61 females, mean age 28.4 (SD = 11.3 years), selected from orthodontic patients on the basis of the following exclusion criteria: previous
fixed appliance treatment, bad quality of the
DPTs and no visibility of the periodontal ligament of every tooth, and younger than 15 years of age at the onset of treatment with fixed edgewise appliance lasting at least 18 months. A pipette-shaped root was identified as defined by a drawing. Tooth agenesis was assessed on
DPTs and from subjects' dental history.
Root resorption was calculated as the difference between the root length before and
after treatment, with and without a correction factor (crown length post-treatment/crown length pre-treatment). If one of the four upper incisors showed
root resorption of ≥2.3 mm with both formulas, the patient was scored as having
root resorption. Chi-square tests indicated that there was no relationship between orthodontic
root resorption and agenesis (P = 0.885) nor between orthodontic
root resorption and pipette-shaped roots (P = 0.800). There was no relationship between having one of the anomalies and
root resorption either (P = 0.750). In the present study, it was not possible to confirm on
DPTs a relationship between orthodontic
root resorption and dental anomalies, such as agenesis and pipette-shaped roots.