Root resorption, treatment time and extraction rate during orthodontic treatment with self-ligating and conventional brackets.
BACKGROUND
This study determined the amount and severity of EARR (external apical root resorption) after orthodontic treatment with self-ligating (SL) and conventional (Non-SL) brackets. Differences regarding rate of extraction cases, appointments and treatment time were evaluated.


METHODS
213 patients with a mean age of 12.4 ± 2.2 years were evaluated retrospectively. The treatments were performed with SL brackets (n = 139, Smartclip, 3 M Unitek, USA) or Non-SL brackets (n = 74, Victory Series, 3 M Unitek, USA). Measurements of the crown and root length of the incisors were taken using panoramic radiographs. Three-factor analysis of variance (ANOVA) was performed for an appliance effect.


RESULTS
There was no difference between patients treated with Non-SL or SL brackets regarding the amount (in percentage) of EARR (Non-SL: 4.5 ± 6.6 vs. SL: 3.0 ± 5.6). Occurrence of severe EARR (sEARR) did also not differ between the two groups (Non-SL 0.5 vs. SL: 0.3). The percentage of patients with need of tooth extraction for treatment (Non SL: 8.1 vs. SL: 6.9) and the number of appointments (Non-SL: 12.4 ± 3.4 vs. SL: 13.9 ± 3.3) did not show any differences. The treatment time was shorter with Non-SL brackets (Non-SL: 18.1 ± 5.3 vs. SL: 20.7 ± 4.9 months).


CONCLUSIONS
This is the largest study showing that there is no difference in the amount of EARR, number of appointments and extraction rate between conventional and self-ligating brackets. For the first time we could demonstrate that occurrence of sEARR does not differ between the two types of brackets.
Department of Orthodontics, University of Mainz, Mainz, Germany. Collin.jacobs@unimedizin-mainz.de.
Collin
C
Jacobs
Philipp F
PF
Gebhardt
Viviana
V
Jacobs
Marlene
M
Hechtner
Dan
D
Meila
Heinrich
H
Wehrbein
D000293:Adolescent; D002648:Child; D004867:Equipment Design; D005260:Female; D006801:Humans; D008026:Ligation; D008297:Male; D008310:Malocclusion / Q000628:therapy; D016910:Orthodontic Brackets; D009971:Orthodontics, Corrective / Q000295:instrumentation*; D011862:Radiography, Panoramic; D012189:Retrospective Studies; D012391:Root Resorption / Q000000981:diagnostic imaging; D013314:Stress, Mechanical; D019227:Tooth Apex / Q000000981:diagnostic imaging / Q000473:pathology*; D014081:Tooth Extraction; D014087:Tooth Movement Techniques / Q000295:instrumentation