Root resorption before and after orthodontic treatment: a clinical study of contributory factors

No statistically significant differences in root resorption were found in relation to gender. Significant differences in root resorption (P = 0.000, P < 0.01) and also in treatment duration (P = 0.036, P < 0.05) were noted between the extraction and non-extraction groups; extraction and treatment duration correlated with T2 mean root resorption. Patient age correlated with root resorption of the upper incisors at T1 and T2. Using multiple regression analysis, age and duration of treatment were found to be more associated with root resorption than with extractions; the presence of root resorption at T1 was associated with T2 root resorption, especially of the anterior teeth.