Regarding comparative cone-beam computed tomographic evaluation of maxillary incisor intrusion and associated root resorption

Abstract

We read and discussed with great interest the article by Alam et al (Alam F, Chauhan AK, Sharma A, Verma S, Raj Y. Comparative cone-beam computed tomographic evaluation of maxillary incisor intrusion and associated root resorption: intrusion arch vs mini-implants. Am J Orthod Dentofacial Orthop 2023;163:e84-e92). We want to congratulate the authors on their interesting study but seek a resolution to some queries. 1.In patients, vitamin D deficiency and associated gene polymorphism may predispose them to root resorption during orthodontic treatment. 1 Fontana M.L. de Souza C.M. Bernardino J.F. Hoette F. Hoette M.L. Thum L. et al. Association analysis of clinical aspects and vitamin D receptor gene polymorphism with external apical root resorption in orthodontic patients. Am J Orthod Dentofacial Orthop. 2012; 142: 339-347 Google Scholar Was this considered during sample selection? 2.Can the authors share any scientific basis for choosing 4 months for posttreatment analysis? 3.The 2 parameters of overbite and overjet were not considered in evaluating the amount of intrusion, although the anteroposterior inclination of the incisors was assessed. 4.In the biomechanics of intrusion arch and temporary skeletal anchorage devices (TSADs), the length of the vertical arm is different, but its effect on the amount of intrusion has not been discussed. 2 Namburi M. Nagothu S. Kumar C.S. Chakrapani N. Hanumantharao C.H. Kumar S.K. Evaluating the effects of consolidation on intrusion and retraction using temporary anchorage devices-a FEM study. Prog Orthod. 2017; 18: 2 Google Scholar 5.Because the gingival and periodontal status can profoundly affect the stability of TSADs, 3 Vanarsdall R.L. Secchi A.G. Periodontal/orthodontic interrelationships. Orthodontics: current principle and techniques. 2nd ed. Mosby, St Louis1994: 712-749 Google Scholar ,4 Papageorgiou S.N. Zogakis I.P. Papadopoulos M.A. Failure rates and associated risk factors of orthodontic miniscrew implants: a meta-analysis. Am J Orthod Dentofacial Orthop. 2012; 142: 577-595.e7 Google Scholar was any specific gingival and periodontal index used in the study? 6.In the TSADs group, there was differential intrusion force on the 4 incisors because the coil spring is attached closer to the lateral incisors, whereas, in the utility arch group, the force is equally distributed over all 4 incisors. Hence, it will be interesting to note any amount of resorption variation 5 Brezniak N. Wasserstein A. Root resorption after orthodontic treatment: part 2. Literature review. Am J Orthod Dentofacial Orthop. 1993; 103: 138-146 Google Scholar ,6 Fox N. Longer orthodontic treatment may result in greater external apical root resorption. Evid Based Dent. 2005; 6: 21 Google Scholar among all 4 incisors in both groups, as individual data must be available with the authors and may be shared. If the authors can kindly share the table with individual incisor values for these parameters, the effect of the point of force application may be better understood. 7.A similar study by Jain et al 7 Jain R.K. Kumar S.P. Manjula W.S. Comparison of intrusion effects on maxillary incisors among mini implant anchorage, j-hook headgear and utility arch. J Clin Diagn Res. 2014; 8: ZC21-ZC24 Google Scholar concluded that although mini implants and utility arches can be used to attain significant amounts of incisor intrusion, using mini implants will produce true intrusion. This parameter of true intrusion has not been highlighted anywhere in this study. Moreover, the adverse effect of proclination of anterior teeth is associated with intrusion arch mechanics 8 El Namrawy M.M. Sharaby F.E. Bushnak M. Intrusive arch versus miniscrew-supported intrusion for deep bite correction. Open Access Maced J Med Sci. 2019; 7: 1841-1846 Google Scholar and not with the TSADs group. This can create a bias in the study and thus needs to be discussed. Comparative cone-beam computed tomographic evaluation of maxillary incisor intrusion and associated root resorption: Intrusion arch vs mini-implantsAmerican Journal of Orthodontics and Dentofacial OrthopedicsVol. 163Issue 3PreviewVarious literature has verified that apical root resorption is a common adverse effect of orthodontic treatment, particularly intrusion. Conventional radiographic techniques underestimated root lengths and overestimated tooth lengths. Cone-beam computed tomography (CBCT) is a useful diagnostic tool to detect orthodontically induced external apical root resorption. This prospective study aimed to compare maxillary incisor intrusion and associated root resorption via CBCT. Full-Text PDF Authors’ responseAmerican Journal of Orthodontics and Dentofacial OrthopedicsVol. 163Issue 6PreviewWe thank the authors for their questions. Our responses are below. Full-Text PDF