Rapid Maxillary Anterior Teeth Retraction En Masse by Bone Compression: A Canine Model

PLOS ONE, Oct 2011

Objective The present study sought to establish an animal model to study the feasibility and safety of rapid retraction of maxillary anterior teeth en masse aided by alveolar surgery in order to reduce orthodontic treatment time. Method Extraction of the maxillary canine and alveolar surgery were performed on twelve adult beagle dogs. After that, the custom-made tooth-borne distraction devices were placed on beagles' teeth. Nine of the dogs were applied compression at 0.5 mm/d for 12 days continuously. The other three received no force as the control group. The animals were killed in 1, 14, and 28 days after the end of the application of compression. Results The tissue responses were assessed by craniometric measurement as well as histological examination. Gross alterations were evident in the experimental group, characterized by anterior teeth crossbite. The average total movements of incisors within 12 days were 4.63±0.10 mm and the average anchorage losses were 1.25±0.12 mm. Considerable root resorption extending into the dentine could be observed 1 and 14 days after the compression. But after consolidation of 28 days, there were regenerated cementum on the dentine. There was no apparent change in the control group. No obvious tooth loosening, gingival necrosis, pulp degeneration, or other adverse complications appeared in any of the dogs. Conclusions This is the first experimental study for testing the technique of rapid anterior teeth retraction en masse aided by modified alveolar surgery. Despite a preliminary animal model study, the current findings pave the way for the potential clinical application that can accelerate orthodontic tooth movement without many adverse complications. Clinical Relevance It may become a novel method to shorten the clinical orthodontic treatment time in the future.

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Rapid Maxillary Anterior Teeth Retraction En Masse by Bone Compression: A Canine Model

Citation: Liu C, Cao Y, Liu C, Zhang J, Xu P ( Rapid Maxillary Anterior Teeth Retraction En Masse by Bone Compression: A Canine Model Chufeng Liu 0 Yang Cao 0 Conghua Liu 0 Jincai Zhang 0 Pingping Xu 0 Samuel J. Lin, Harvard Medical School, United States of America 0 1 Department of Orthodontics, Guangdong Provincial Stomatological Hospital, Southern Medical University , Guangzhou , China , 2 Department of Orthodontics, Guanghua College of Stomatology, Sun Yat-sen University , Guangzhou , China , 3 Department of Periodontology, Guangdong Provincial Stomatological Hospital, Southern Medical University , Guangzhou , China , 4 Department of Oral and Maxillofacial Surgery, Guangdong Provincial Stomatological Hospital, Southern Medical University , Guangzhou , China Objective: The present study sought to establish an animal model to study the feasibility and safety of rapid retraction of maxillary anterior teeth en masse aided by alveolar surgery in order to reduce orthodontic treatment time. Method: Extraction of the maxillary canine and alveolar surgery were performed on twelve adult beagle dogs. After that, the custom-made tooth-borne distraction devices were placed on beagles' teeth. Nine of the dogs were applied compression at 0.5 mm/d for 12 days continuously. The other three received no force as the control group. The animals were killed in 1, 14, and 28 days after the end of the application of compression. Results: The tissue responses were assessed by craniometric measurement as well as histological examination. Gross alterations were evident in the experimental group, characterized by anterior teeth crossbite. The average total movements of incisors within 12 days were 4.6360.10 mm and the average anchorage losses were 1.2560.12 mm. Considerable root resorption extending into the dentine could be observed 1 and 14 days after the compression. But after consolidation of 28 days, there were regenerated cementum on the dentine. There was no apparent change in the control group. No obvious tooth loosening, gingival necrosis, pulp degeneration, or other adverse complications appeared in any of the dogs. Conclusions: This is the first experimental study for testing the technique of rapid anterior teeth retraction en masse aided by modified alveolar surgery. Despite a preliminary animal model study, the current findings pave the way for the potential clinical application that can accelerate orthodontic tooth movement without many adverse complications. Clinical Relevance: It may become a novel method to shorten the clinical orthodontic treatment time in the future. - Funding: The study was supported by the Guangdong Provincial Natural Science Fund (http://gdsf.gdstc.gov.cn/) (No. 8151026003000008) and Guangdong Provincial Science & Technology Projects (http://www.gdstc.gov.cn/) (No. 2009B080701032, No. 2009B030801182). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The authors have declared that no competing interests exist. . These authors contributed equally to this work. Distraction osteogenesis (DO) is manifested as rapid new bone growing by the mechanical stretching of the pre-existing bone tissue which takes advantage of osseous remodeling capabilities of the callus at the osteotomy and/or corticotomy sites. This innovative concept of bone biology opens a new vista for minimally invasive treatment of jaw deformities. So far, DO technique has achieved great success in the treatment of severe bone deficiencies, including micrognathia, sequelae of cleft lip and palate, and maxillofacial bone defects. In stark comparison, very few advances have been in using DO technique to treat excessive bone disorders such as prognathism. Based on the mechanical principle of DO, it will be fascinating to know the biological response when the bone is imposed on the compression force by reverse activating of the distractor, usually applied in DO for supplying the distraction force. Maxillary protrusion is a common dentognathic deformity. Orthodontics and orthodontics combined with anterior segmental osteotomy are the common treatment strategies. The combined orthodontic and anterior segmental osteotomy therapy can markedly reduce the length of treatment over the conventional orthodontic treatment and result in immediate improvement of the facial profile. But its various postoperative complications including ischemic necrosis of the anterior segment, wound dehiscence at the osteotomy site, and devitalization of the teeth adjacent to the osteotomy site deter many patients from seeking the treatment [1]. The more conventional and commonly-used orthodontic treatment for maxillary protrusion heavily relies on the biological tooth movement [2], which happens at a limited rate and thus prolongs the treatment to 2 years for most patients [3]. Even more time is required for adult patients, who often wish their treatment could (...truncated)


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Chufeng Liu, Yang Cao, Conghua Liu, Jincai Zhang, Pingping Xu. Rapid Maxillary Anterior Teeth Retraction En Masse by Bone Compression: A Canine Model, PLOS ONE, 2011, 10, DOI: 10.1371/journal.pone.0026398