McNab S, Battistutta D, Taverne A, Symons A L
Faculty of Health, Queensland University of Technology, Brisbane, Australia.
Angle Orthod. 2000 Jun;70(3):227-32. doi: 10.1043/0003-3219(2000)070<0227:EARRFO>2.0.CO;2.
This study investigated the association of appliance type and tooth extraction with the incidence of external apical root resorption (EARR) of posterior teeth following orthodontic treatment. Pre- and posttreatment orthopantomograms were compared for 97 patients and a 4-grade ordinal scale used to measure EARR. The incidence of EARR was positively associated with tooth position (P < .001), appliance type (P = .038), and extractions (P = .001). This was observed in an overall analysis mutually adjusted for the effects of age at start of treatment, pretreatment overbite and overjet, use of headgear, tooth extraction, and type of appliance. The incidence of EARR was 2.30 times higher for Begg appliances compared with edgewise, and it was 3.72 times higher where extractions were performed.
