Herbst appliance anchored to miniscrews with 2 types of ligation

Herbst appliance anchored to miniscrews with 2 types of ligation

557 Readers' forum Authors’ response Y es, canine retraction is happening! We thank the Editor for giving us the chance to respond to the comments...

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557

Readers' forum

Authors’ response

Y

es, canine retraction is happening! We thank the Editor for giving us the chance to respond to the comments on our article, “Evaluation of corticotomy-facilitated orthodontics and piezocision in rapid canine retraction” (Abbas NH, Sabet NE, Hassan IT. Am J Orthod Dentofacial Orthop 2016;149:473-80), published in April 2016. We want to acknowledge the readers for addressing the way the results have been measured, reported, and interpreted, and to give us this valuable chance to clarify to the readers that they had misinterpreted the results in Table I. Nothing in the text or the table caption stated that the numbers in the table are “cumulative” values of canine movement. The table shows the mean amount of canine movement at each successive 2-week time interval. The text was clear in stating that the rates of movement were measured. Thus, the claim that there is more molar acceleration than canine acceleration in our study results has no basis. This proves that our data support our own conclusions and completely synchronizes with the orthodontic literature. We find this topic so important, interesting, and popular that careless reading should be avoided. As for Figure 6, we understand that it should have been obvious to the readers that this is an illustrative figure that should have been magnified to guarantee that readers can easily construe it. Verifying that, this is not a careless mistake. But still the authors declared that it would have been clearer to put another figure with the actual measurement. Canine root length was measured from the cusp tip to the root apex on the precomputed and postcomputed tomographic radiographs. If there was a volumetric evaluation, more numbers would have been given, but this is not the case here. We would like to update the readers that another study is being undertaken to address the root resorption issue and use the volumetric measurement tools to investigate root conditions. Noha Hussein Abbas Noha Ezzat Sabet Islam Tarek Hassan Cairo, Egypt

Am J Orthod Dentofacial Orthop 2016;150:557 0889-5406/$36.00 Ó 2016 by the American Association of Orthodontists. All rights reserved.

http://dx.doi.org/10.1016/j.ajodo.2016.07.006

Herbst appliance anchored to miniscrews with 2 types of ligation read with interest the recent article entitled “Herbst appliance anchored to miniscrews with 2 types of ligation: Effectiveness in skeletal Class II treatment” (Manni A, Mutinelli S, Pasini M, Mazzotta L, Cozzani M. Am J Orthod Dentofacial Orthop 2016;149:871-80). Although the study was retrospective, it is understood that the authors showed great efforts to eliminate the disadvantages of a retrospectively designed clinical study. The sample size was determined using a sample calculation method before the study began, and the groups were well matched according to age and sex distributions. However, I have some questions and suggestions.

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The method used to determine the sample size should have been described completely. Whose sample calculation method was used? (I can suggest the method of Dr Pandis, who is an associate editor of the AJO-DO.) In addition, the mean difference for pogonion advancement among the groups stated in the text (2.0 6 2.0 mm) seems not to be based on the study findings they cited, because I also read the other study. It might have been better to use findings from a previous study. It is known that the occlusal plane is affected by functional fixed appliances, and thus this change might have affected their findings if the clinicians had used this plane as a vertical reference line. I suggest that the authors should use a vertical reference line that is not affected by both treatment and growth to understand the pure effects of the appliances. Finally, how did the authors orient the degree of the force as 100 g in the metallic ligature Herbst group? Mevlut Celikoglu Antalya, Turkey

Am J Orthod Dentofacial Orthop 2016;150:557 0889-5406/$36.00 Ó 2016.

http://dx.doi.org/10.1016/j.ajodo.2016.07.008

Authors' response

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hank you for giving us the opportunity to clarify some points of our article. The sample calculation was described in the article with enough data to replicate the estimation. As reported in “Material and methods,” we performed all statistical analyses with the software package STATA (version 12; StataCorp, College Station, Tex). For sample size estimation, we used the data of the study by Manni et al,1 as declared in the article.

American Journal of Orthodontics and Dentofacial Orthopedics

October 2016  Vol 150  Issue 4