Yoon-Ah Kook1, Mohamed Bayome2, Vu Thi Thu Trang3, Hye-Jin Kim4, Jae Hyun Park5, Ki Beom Kim6, Rolf G Behrents7. 1. Professor, Department of Orthodontics, Seoul St. Mary's Hospital, Catholic University of Korea, Seoul, Korea. Electronic address: kook190036@yahoo.com. 2. Research assistant professor, Graduate School, Catholic University of Korea, Seoul, Korea; visiting professor, Department of Postgraduate Studies, Universidad Autonóma del Paraguay, Asunción, Paraguay. 3. Lecturer, Department of Orthodontics, Hanoi Medical University, Hanoi, Vietnam. 4. Private practitioner, Yonseijin Dental Clinic, Seoul, Korea. 5. Associate professor and chair, Postgraduate Orthodontic Program, Arizona School of Dentistry & Oral Health, A. T. Still University, Mesa, Ariz; adjunct professor, Graduate School of Dentistry, Kyung Hee University, Seoul, Korea. 6. Associate professor, Department of Orthodontics, Center for Advanced Dental Education, Saint Louis University, St Louis, Mo. 7. Professor, Department of Orthodontics, Center for Advanced Dental Education, Saint Louis University, St Louis, Mo.
Abstract
INTRODUCTION: The purpose of this study was to evaluate the treatment effects of maxillary posterior tooth distalization performed by a modified palatal anchorage plate appliance with cephalograms derived from cone-beam computed tomography. METHODS: The sample consisted of 40 lateral cephalograms obtained from the cone-beam computed tomography images of 20 Class II patients (7 men, 13 women; average age, 22.9 years) who underwent bilateral distalization of their maxillary dentition. The lateral cephalograms were derived from the cone-beam computed tomography images taken immediately before placement of a modified palatal anchorage plate appliance and at the end of distalization. Paired t tests were used for comparisons of the changes. RESULTS: The distal movement of the maxillary first molar was 3.3 ± 1.8 mm, with distal tipping of 3.4° ± 5.8° and intrusion of 1.8 ± 1.4 mm. Moreover, the maxillary incisors moved 3.0 ± 2.7 mm lingually, with lingual tipping of 6.2° ± 7.6° and insignificant extrusion (1.1 mm; P = 0.06). The occlusal plane angle was increased significantly (P = 0.0001). CONCLUSIONS: The maxillary first molar was distalized by 3.3 mm at the crown and 2.2 mm at root levels, with distal tipping of 3.4°. It is recommended that clinicians should consider using the modified palatal anchorage plate appliance in treatment planning for patients who require maxillary total arch distalization.
INTRODUCTION: The purpose of this study was to evaluate the treatment effects of maxillary posterior tooth distalization performed by a modified palatal anchorage plate appliance with cephalograms derived from cone-beam computed tomography. METHODS: The sample consisted of 40 lateral cephalograms obtained from the cone-beam computed tomography images of 20 Class II patients (7 men, 13 women; average age, 22.9 years) who underwent bilateral distalization of their maxillary dentition. The lateral cephalograms were derived from the cone-beam computed tomography images taken immediately before placement of a modified palatal anchorage plate appliance and at the end of distalization. Paired t tests were used for comparisons of the changes. RESULTS: The distal movement of the maxillary first molar was 3.3 ± 1.8 mm, with distal tipping of 3.4° ± 5.8° and intrusion of 1.8 ± 1.4 mm. Moreover, the maxillary incisors moved 3.0 ± 2.7 mm lingually, with lingual tipping of 6.2° ± 7.6° and insignificant extrusion (1.1 mm; P = 0.06). The occlusal plane angle was increased significantly (P = 0.0001). CONCLUSIONS: The maxillary first molar was distalized by 3.3 mm at the crown and 2.2 mm at root levels, with distal tipping of 3.4°. It is recommended that clinicians should consider using the modified palatal anchorage plate appliance in treatment planning for patients who require maxillary total arch distalization.