External apical root resorption 6 months after initiation of orthodontic treatment: A randomized clinical trial comparing fixed appliances and orthodontic aligners
10.4041/kjod.2021.51.5.329
- Author:
Katia Cristina TOYOKAWA-SPERANDIO
1
;
Ana Cláudia de Castro FERREIRA CONTI
;
Thais Maria Freire FERNANDES
;
Renata Rodrigues de ALMEIDA-PEDRIN
;
Marcio Rodrigues FREIRDE ALMEIDA
;
Paula Vanessa PEDRON OLTRAMARI
Author Information
1. Department of Orthodontics, University of North Parana (UNOPAR), Londrina, Brazil
- Publication Type:Original Article
- From:The Korean Journal of Orthodontics
2021;51(5):329-336
- CountryRepublic of Korea
- Language:English
-
Abstract:
Objective:To compare the magnitude of external apical root resorption (EARR) 6 months after starting orthodontic treatment using orthodontic aligners (OAs) and fixed appliances (FAs).
Methods:This parallel randomized clinical trial included 40 patients randomized into two groups: OA group (n = 20, 160 incisors) and FA group (n = 20, 160 incisors). For evaluation of the tooth length, periapical radiographs and standardized linear measurements of the maxillary and mandibular incisors were acquired before (T0) and 6 months after treatment initiation (T1). EARR was calculated through the difference in length between the two time points (T1-T0). Statistical comparisons were performed by means of using t-tests, chi-squared test and covariance analysis (a = 5%).
Results:Rounding of the root apex was observed in both groups; the resorption involved 2.88% of the root length, so 97.12% of the tooth length remained intact. Intragroup comparisons between the two time points revealed a significant difference, with (T1-T0) ranging from -0.52 to -0.88 mm in the FA group and from -0.52 to -0.85 mm in the OA group. In the intergroup comparisons, only tooth #21 presented a statistically significant difference (OA: -0.52 ± 0.57 mm, FA: -0.86 ± 0.60 mm); however, the overall differences between groups were not clinically relevant, ranging from 0.03 to 0.35 mm.
Conclusions:OA and FA treatment resulted in a similar degree of EARR in the maxillary and mandibular incisors at 6 months after treatment initiation. However, the amount of resorption was small and does not impair tooth longevity.
