Conservative treatment (without orthognathic surgery or extractions) of severe malocclusions limits cost, morbidity and surgical complications. A 32-year-old female was diagnosed as a Class Ⅲ malocclusion, combined with anterior open bite malocclusion. The Discrepancy Index (DI) was 69. A passive self-ligation appliance, with infrazygomatic crest (IZC) bone screw anchorage, and Class Ⅲ intermaxillary elastics were used to correct this severe malocclusion in only 28 months. The IZC bone screws were installed buccal to the alveolar process between the upper 1st and 2nd molars. They provided reliable anchorage for intermaxillary elastics to retract the lower incisors and increase the vertical dimension of occlusion. A marked improvement in anterior open bite correction and occlusal function was achieved. The malocclusion was corrected with a relatively short treatment time. Long term follow up is required to monitor the potential for late mandibular growth to produce a skeletal Class Ⅲ relationship.
Key words:
Class Ⅲ, anterior open bite, Damon self-ligating brackets, early light short elastics, mandibular buccal shelf (MBS) miniscrews, infrazygomatic crest (IZC) miniscrews, extra-alveolar bone screw anchorage.
* Xiao Yuan 교수(중국 Qingdao University)
Xiao yuan is Professor of Orthodontics and Head of the Department of Orthodontics Division II at the Affiliated Hospital of Qingdao University. He obtained his BS degree in dentistry from West China School of Stomatology, Sichuan University(Chengdu) in 1995; received his MS (2001) from School of Stomatology, Shanghai Jiaotong University；then he completed a PhD in Orthodontic Sciences at School of Dentistry, Sichuan Universityin in 2004; and fulfilled his postdoctoral training at School of Stomatology, the Fourth Military Medical University during 2006-2008. He is a member of the Standing Committee of the Chinese Orthodontic Society (COS). And he is also a member of several international professional organizations, including American Association of Orthodontists (AAO) and World Federation of Orthodontists (WFO).
He is an active clinical practitioner and researcher with a keen interest in several dimensional and translational research. The research of his group focuses on numerical simulation and experimental evaluation of orthodontic treatment mechanics including fixed appliances and aligners, the (patho-)physiology of the facial and masticatory motor systems, and the development and evaluation of digital methods for orthodontic diagnosis and treatment. He has been leading multiple “National Natural Science Foundation of China” to use multidisciplinary approaches to study the mechanotransduction in bone, myoblasts and mineralized tissues. He has published over 60 original articles in peer-reviewed international journals, and serves as reviewer for various international journals. His clinical focus includes the clinical application of functional orthopedic treatment, segmented arch techniques, the clinical application of microimplant and their treatment mechanics; Specially, his interests focused on the interdisciplinary treatment for adults and elderly patients based on skeletal anchorage which are particularly valuable for therapy of patients with missing teeth、openbite、crossbite and retruded mandible.
