Volume 31 Issue 3 Article 1 2019 A Comparison of Two TAD Techniques (Miniscrews Versus Miniplates) for Treating Class III Malocclusion and The Associated Skeletal and Dental Effects James Chen Children´s Hospital, Oakland, USA., [email protected] Jesus I. Patino Private Practice, USA. Jenny Zwei-Chieng Chang Department of Dentistry, National Taiwan University Hospital, Taipei, Taiwan; School of Dentistry, National Taiwan University, Taipei, Taiwan. Chung-ChenJane Jane Yao Department of Dentistry, National Taiwan University Hospital, Taipei, Taiwan; Graduate Institute of Clinical Dentistry, School of Dentistry, National Taiwan University, Taipei, Taiwan. Ib Leth Nielsen FOrollowofacial this Sciences, and additional University works of California,at: https://www San F.tjo.orrancisco,g.tw/tjo USA. Part of the Orthodontics and Orthodontology Commons Recommended Citation Chen, James; Patino, Jesus I.; Chang, Jenny Zwei-Chieng; Yao, Chung-ChenJane Jane; and Nielsen, Ib Leth (2019) "A Comparison of Two TAD Techniques (Miniscrews Versus Miniplates) for Treating Class III Malocclusion and The Associated Skeletal and Dental Effects," Taiwanese Journal of Orthodontics: Vol. 31 : Iss. 3 , Article 1. DOI: 10.30036/TJO.201909_31(3).0001 Available at: https://www.tjo.org.tw/tjo/vol31/iss3/1 This Original Article is brought to you for free and open access by Taiwanese Journal of Orthodontics. It has been accepted for inclusion in Taiwanese Journal of Orthodontics by an authorized editor of Taiwanese Journal of Orthodontics. A Comparison of Two TAD Techniques (Miniscrews Versus Miniplates) for Treating Class III Malocclusion and The Associated Skeletal and Dental Effects Cover Page Footnote The authors wish to thank Dr. Jens Bjørn-Jørgensen, Denmark for his help with the Tiops4 program. This original article is available in Taiwanese Journal of Orthodontics: https://www.tjo.org.tw/tjo/vol31/iss3/1 Chen Original J, Patino JI, Chang Article JZC, Yao CCJ, Nielsen IL A COMPARISON OF TWO TAD TECHNIQUES (MINISCREWS VERSUS MINIPLatES) FOR TREatING CLASS III MALOCCLUSION AND THE ASSOCIatED SKELEtaL AND DENtaL EFFECTS 1 2 3,4 3,5 6 James Chen, Jesus I. Patino, Jenny Zwei-Chieng Chang, Chung-Chen Jane Yao, Ib Leth Nielsen 1 Children’s Hospital, Oakland, USA. 2 Private Practice, USA. 3 Department of Dentistry, National Taiwan University Hospital, Taipei, Taiwan. 4 School of Dentistry, National Taiwan University, Taipei, Taiwan. 5 Graduate Institute of Clinical Dentistry, School of Dentistry, National Taiwan University, Taipei, Taiwan. 6 Orofacial Sciences, University of California, San Francisco, USA. The aim of this study was to compare two different techniques for distalizing the mandibular dentition in patients with Class III malocclusion using either miniscrews or miniplates. We evaluated the skeletal and dento-alveolar changes associated with each method. The study also aimed at identifying cephalometric characteristics in the subjects associated with the most predictable, successful outcome of treatment. Patients and Methods: Our sample consisted of 20 adult subjects (10 females and 10 males) that met the inclusion criteria. We examined pre and post treatment headfilms and analyzed the dental and skeletal changes using a computer program that provided the data for statistical analysis (TIOPS4). Results: On average, both types of mechanics were successful in distalizing the lower dentition as seen by both the horizontal movement of incisors, premolars and molars and the changes in inclination of these teeth. A modest amount of vertical movement of incisors, premolars, and molars was observed in both groups, with the miniplates exhibiting slightly more vertical movement. When comparing the two types of anchorage, only the vertical level of the premolars and molars was statistically significant between the two groups with miniplates leading to more vertical change. Conclusion: Mild to moderate Class III malocclusions can successfully be treated with distalization of the lower dentition using either one of two mechanics (miniscrews or miniplates) as skeletal anchorage in the lower jaw. (Taiwanese Journal of Orthodontics. 31(3): 132-141, 2019) Keywords: Class III Malocclusion; miniscrews anchorage; miniplate anchorage; cephalometrics. Received: July 30, 2019 Revised: September 27, 2019 Accepted: September 28, 2019 Reprints and correspondence to: Dr. James Chen DDS, PhD, MPH 110, Chien Kuo N Road, Taichung city, Taiwan Tel: 510-364-5009 Fax: 650-755-3158 E-mail: [email protected] 132 Taiwanese Journal of Orthodontics. 2019, Vol. 31. No. 3 10.30036/TJO.201909_31(3).0001 Comparison TAD or Miniplate Treating Class III INTRODUCTION while at the same time limiting the amount of side effects, they found the best level was at the cementoenamel The correction of a Class III malocclusion in a non- 6 junction. Another important factor was the amount growing patient is commonly treated by either camouflage of retromolar space available for mandibular dental extractions, surgery, or with pronounced compensatory distalization. Choi et al used CBCT images to determine proclination of the maxillary incisors and retroclination the amount of retromolar space typically present in Class I of the mandibular incisors. An alternative method of 7 and Class III patients. In favor of molar distalization, the treatment that is rarely attempted is distalization of the authors found that in patients with Class III malocclusion mandibular dentition. Distalization of the mandibular and mandibular prognathism there was increased molars has been recognized as one of the more difficult retromolar space, making this procedure easier. Dang et treatment objectives in clinical orthodontics especially al. evaluated molar distalization in 11 patients treated with 1 when compared to distalization of the maxillary molars. different types of anchorage preparation and found that 8 Due to the difficulty and unpredictability of this treatment only 2 of the 11 cases showed significant distalization. modality, it is rarely attempted, and the malocclusion In contrast, Yu et al. reported a much higher success rate is corrected surgically. There have been a variety of of distalization in their population of 22 patients that 9 methods attempted to distally move the mandibular were treated with ramal plates only. On average patients 2 molars including lip bumper, a distal extension lingual experienced 2.1 mm of coronal retraction and 0.81 mm of 3 4 arch, and even multiloop Edgewise archwires. With apical retraction. The authors emphasized the importance most of these techniques, there is typically distal tipping of using bone plates for distalization because of the of the mandibular molars rather than bodily translation, increased force needed to distalize the lower arch. and treatment results rely heavily on patient compliance. Mandibular molar distalization potentially offers However, presently, with the use of temporary skeletal a viable alternative to Class III correction rather than anchorage devices (TSAD), distalization of the mandibular premolar extractions or orthognathic surgery. However, dentition can be achieved with less reciprocal side effects treatment outcome of this type of biomechanics still as compared to more traditional methods of mandibular needs to be evaluated in more detail. Our study sought 2-4 dental distalization using simple Class III mechanics. to investigate the treatment success of mandibular molar Currently, by using miniscrews the clinician can often distalization for Class III patients using two specific types correct anterior crossbite, mandibular asymmetry, distalize of anchorage preparation, miniscrews and miniplates. In the mandibular dentition and relieve mandibular crowding this context it is important to thoroughly evaluate this 5 and thereby avoid extractions. modality of treatment and determine if mandibular dental Success of mandibular molar distalization is a distalization can be a predictable treatment alternative, multifactorial challenge where the type of anchorage, and if the outcome is orthodontically acceptable. We direction of force, retromolar space, and dentofacial focused our evaluation on the dental movements of the patterns all are important components. The direction of the mandibular first molars, second premolars, and incisors retraction force is essential in order to reduce unwanted between subjects. Our hypothesis is that distalization tooth movements such as tipping and extrusion. Park et of the mandibular dentition, using one of two types of al. evaluated at which vertical level the mechanics would skeletal anchorage in a Class III non-growing patients will offer the ideal amount of mandibular dental retraction result in an acceptable orthodontic result. Taiwanese Journal of Orthodontics. 2019, Vol. 31. No. 3 133 10.30036/TJO.201909_31(3).0001 Chen J, Patino JI, Chang JZC, Yao CCJ, Nielsen IL PATIENTS AND METHODS University Hospital (NTUH) in Taiwan. Subject selection was based on completion of orthodontic treatment In this retrospective clinical study, we evaluated the within the past five years that included the use of TSAD outcomes of orthodontic treatment of patients treated for a anchorage (miniscrews or miniplates) for mandibular Class III malocclusion by mandibular dental distalization dental distalization. Patients treated at NTUH signed using either miniplates or miniscrews for anchorage. consent forms for the protection of their clinical data that The miniplate seen in Figure 1A was connected to the