Download Reply Association between root resorption incident to orthodontic

273
Letters to the Editor
European Journal of Orthodontics 35 (2013) 273
doi:10.1093/ejo/cjs064
Advance Access publication 8 November 2012
Association between root resorption incident to orthodontic treatment and treatment
factors
Sir,
We read with interest the article about the association
between root resorption and orthodontics by Motokawa et al.
(2012). The prevalence and degree of root resorption induced
by orthodontic treatment in association with treatment factors was well described by the authors. The results of their
study indicated that orthodontic treatments with extractions,
long-term use of a multiloop edgewise arch-wire appliance
and elastics, treatment time, and distance of tooth movement
are risk factors for severe root resorption. However, there are
some limitations in the material and method section that we
want to draw attention. In addition, the factors that might
affect the root resorption have not been completely discussed.
As stated in the literature (Weltman et al., 2010), patientrelated and external factors are believed to be associated with
increased root resorption. Patient-related factors (Weltman
et al., 2010) such as genetic predisposition, root shape, endodontic treatment, alveolar bone density, oral habits, trauma,
age, gender, and the severity and type of the malocclusion
should be considered when planning study about root resorption. The subjects included in their study were orthodontically
treated patients aged 9–51 prior to the treatment (mean age:
18.9 ± 6.7 years). According to Mirabella and Artun (1995),
the resorption pattern might be more extreme in adults, and
a higher proportion may be severely affected. Since age is an
important factor that might affect the amount of root resorption (Mirabella and Artun, 1995; Jiang et al., 2010), this wide
age range present in their study should be checked for the
efficiency on root resorption by means of multiple logistic
regression analysis as previously done by several authors
(Artun et al., 2005). It might be better to see age and sex
distribution of the patients in the subgroups they investigated.
In the discussion section of the article, many factors have
been described to have possible affects on root resorption.
However, information about the presence of endodontic
treatment and developmental anomalies was not present in
the article. In addition, patient-related factors such as sex
and age should also be discussed in the text. Thus, we think
that readers of European Journal of Orthodontics might
consider these factors while reading this article.
Mevlüt Çelikoğlu*, Koray Halıcıoğlu** and
Murat Çağlaroğlu***
*Department of Orthodontics, Faculty of Dentistry,
Karadeniz Technical University, Trabzon, **Department of
Orthodontics, Faculty of Dentistry, Izzet Baysal University,
Bolu and ***Department of Orthodontics, Faculty of
Dentistry, Kirikkale, Trabzon, Turkey
References
Artun J, Smale I, Behbehani F, Doppel D, Van't Hof M, Kuijpers-Jagtman A M
2005 Apical root resorption six and 12 months after initiation of fixed
orthodontic appliance therapy. The Angle Orthodontics 75: 919–926
Jiang R P, McDonald J P, Fu M K 2010 Root resorption before and after
orthodontic treatment: a clinical study of contributory factors. Europen
Journal of Orthodontics 32: 693–697
Mirabella A D, Artun J 1995 Prevalence and severity of apical root resorption of maxillary anterior teeth in adult orthodontic patients. European
Journal of Orthodontics 17: 93–99
Motokawa M, Sasamoto T, Kaku M, Kawata T, Matsuda Y, Terao A, Tanne
K 2012 Association between root resorption incident to orthodontic
treatment and treatment factors. European Journal of Orthodontics 34:
350–356
Weltman B, Vig K W, Fields H W, Shanker S, Kaizar E E 2010 Root resorption
associated with orthodontic tooth movement: a systematic review. American
Journal of Orthodontics and Dentofacial Orthopedics 137: 462–476
European Journal of Orthodontics 35 (2013) 273–274
doi:10.1093/ejo/cjs077
Advance Access publication 11 August 2012
Reply
Sir,
We thank Dr Çelikoğlu et al. for their interest in our study.
I would like to answer the comment about the age of patients
in this study.
As you mentioned in your letter, patient-related factors
such as genetic predisposition, root shape, endodontic treatment, alveolar bone density, oral habits, trauma, age, gender,
and the severity and type of the malocclusion are important
risk factors of root resorption. Particularly that the initial
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age of orthodontically treated patients in our report has a
wide range and should be checked against root resorption.
In view of this comment, statistical analysis for the association between initial age of patients and root resorption
was performed by chi-square test and simple regression
analyses.
The subjects were classified into three groups based on
their age when active treatment was initiated: T1, <15 years
(n = 70 patients, 1885 teeth); T2, ≥15 years, <20 years
(n = 89 patients, 2341 teeth); and T3, ≥20 years (n = 84
patients, 2195 teeth).
Statistical differences in the prevalence of root resorption
evaluated by the number of patients and teeth were examined by use of a chi-square test, and the association between
initial age of patients and the number of teeth with overall or
severe root resorption was evaluated by a simple regression
analysis (Statview, Abacus Concepts, Inc., Berkeley, CA,
USA). The level of significance was set at 0.05.
The simple regression analysis revealed no association of the age of patients with overall or severe root
resorption (P = 0.18 or 0.053, respectively). On the other
hand, chi-square test revealed no significant differences
in the prevalence of overall root resorption. Meanwhile,
Letters to the Editor
the prevalence of severe root resorption evaluated by the
number of teeth was significantly higher in T3 group
than in T1 and T2 groups (teeth; T1 versus T2: P = 0.59,
T2 versus T3: P = 0.0001, and T1 versus T3: P = 0.001,
respectively).
These results have demonstrated no significant differences in the prevalence of overall root resorption among
these different age groups, although the prevalence of
severe root resorption is higher in the older group.
Sincerely yours,
Masahide Motokawa
Tomoko Sasamoto
Masato Kaku
Toshitsugu Kawata
Yayoi Matsuda
Akiko Terao
Kazuo Tanne
Department of Orthodontics
Applied Life Sciences
Institute of Biomedical & Health Sciences
Hiroshima University
Japan