PREVALENCE AND SEVERITY OF APICAL ROOT RESORPTION OF MAXILLARY ANTERIOR TEETH IN ADULT ORTHODONTIC PATIENTS

The purpose of this study was to evaluate prevalence and severity of a pical root resorption of maxillary anterior teeth in a large sample of adult orthodontic patients, to analyse any difference between subgrou ps of patients with and without a history of earlier orthodontic treat ment, and to test the hypothesis that endodontically treated teeth are less likely to experience apical root resorption. Differences in toot h length measurements of standardized periapical radiographs made befo re and after treatment of 343 adults, representing groups of consecuti vely treated patients from four orthodontic practices, were calculated . Sample means of averaged root resorption of all six anterior teeth a nd of the most severely resorbed tooth per patient were 0.94 mm (SD 0. 88) and 2.39 mm (SD 1.43), respectively. Forty per cent of the adults had one or more teeth with 2.5 mm resorption or greater. The subsample of 31 patients with a history of earlier orthodontic treatment had le ss root resorption than the remaining patients (P<0.001). Evaluation o f the 39 contralateral pairs of teeth with and without endodontic trea tment in 36 of the patients revealed less resorption of the endodontic ally treated teeth (P<0.05).