Functional appliance treatment in children with morphologic deviations in the upper spine

Abstract

We read with great interest the article by Oh et al (Oh E, Ahn S-J, Sonnesen L. Treatment effects of functional appliances in children with Class II malocclusion with and without morphologic deviations in the upper spine. Am J Orthod Dentofacial Orthop. Epub 2021 Apr 19). We appreciate and thank the authors for this interesting study on functional appliance therapy. However, we would like further clarification regarding some aspects of the study. We an earlier report by the authors1Oh E. Ahn S.J. Sonnesen L. Evaluation of growth changes induced by functional appliances in children with Class II malocclusion: superimposition of lateral cephalograms on stable structures.Korean J Orthod. 2020; 50: 170-180Crossref PubMed Scopus (6) Google Scholar and noted that the 2 studies, which reported different aims, methodologies, statistical analyses, and conclusions, had the same ethical approval identification number at both the Danish Data Protection Agency (number 2015-57-0121) and Seoul National University Dental Hospital, Korea (institutional review board number 207/08-16). Please elaborate on the rationale of using 2 different designs of activator because finding the similarity or difference in their outcome was not an objective of the present study. In addition, why was high-pull headgear given to some patients despite all patients having high NSL/ML angle and traditional wisdom and evidence2Marşan G. Effects of activator and high-pull headgear combination therapy: skeletal, dentoalveolar, and soft tissue profile changes.Eur J Orthod. 2007; 29: 140-148Crossref PubMed Scopus (16) Google Scholar,3Papageorgiou S.N. Kutschera E. Memmert S. Gölz L. Jäger A. Bourauel C. et al.Effectiveness of early orthopaedic treatment with headgear: a systematic review and meta-analysis.Eur J Orthod. 2017; 39: 176-187Crossref PubMed Scopus (20) Google Scholar supporting the effectiveness of the headgear? As referenced in the article, Teuscher4Teuscher U. A growth-related concept for skeletal class II treatment.Am J Orthod. 1978; 74: 258-275Abstract Full Text PDF PubMed Scopus (102) Google Scholar recommends that the vertical displacement of the mandible be restricted to a minimum, and the anterior displacement should not exceed 6 mm for bite registration of the chosen appliance. However, with a mean overjet of 8.5 mm and 9.1 mm in the 2 groups, respectively, bite registration standardized in an edge-to-edge relationship is questionable. Was blinding done to avoid bias? Considering that the mean time duration between T1-T2 and T1-T3 mentioned was 1.6 and 3.5 years, respectively, many patients would have still been in their pubertal growth spurt at T3, particularly the patients who were in stages CS1 and CS2 (n = 23) at the commencement of the study. Therefore, please elucidate as to how these patients (approximately one-third of the study sample) could have satisfied the second inclusion criteria point (ie, lateral cephalogram available with >1-year retention after therapy at postpuberty). Treatment effects of functional appliances in children with Class II malocclusion with and without morphologic deviations in the upper spineAmerican Journal of Orthodontics and Dentofacial OrthopedicsVol. 160Issue 1PreviewThis research aimed to compare treatment effects of functional appliances between children with and without morphologic deviations in the upper spine and analyze associations between Atlas dimensions and the short- and long-term treatment effects. Full-Text PDF Authors’ responseAmerican Journal of Orthodontics and Dentofacial OrthopedicsVol. 160Issue 3PreviewWe thank the readers for their interest in the study and their letter. Full-Text PDF