Dentistry

Abstract

External Apical Root Resorption after Six and 12 months of Non-Extraction Orthodontic Treatment

Paula Cabrini Scheibel, Kelly Regina Micheletti and Adilson Luiz Ramos

Objectives: The aim of the present study was to test the hypothesis that external apical root resorption (EARR) after six months of orthodontic treatment could be an incidence indicator of EARR after 12 months of treatment in non extraction orthodontic cases. A comparison of EARR between different types of root morphology was also performed.
Material and Methods: Periapical radiographs of the upper incisors were obtained prior to treatment (T1) as well as at six months (T2) and 12 months (T3) of non-extraction orthodontic treatment among 47 patients aged 11 years or older. The roots were classified based on anatomic shape. Triangular, pipette-shaped, bent and/or short roots were classified as having a tendency toward EARR, whereas those with a rhomboidal and rectangular shape were classified as having no tendency toward EARR.
Results: At 12 months of orthodontic treatment EARR ranged from 0 to 12.1% of total tooth length (mean: 3.5%; SD: 3.03), which meant 0 to 2.7 mm of EARR. There was significant correlation between EARR at six months and EARR at 12 months (r=0.7606; p<0.0001). There was no correlation between root shape and EARR.
Conclusions: EARR after the first six months of orthodontic treatment was a good incidence indicator of EARR after 12 months of treatment (r=0.8). Root shape did not show significant influence in root resorption level in non extraction orthodontic cases.