Department of Orthodontics, University of Brazil, Rio de Janeiro, Rio de Janeiro, Brazil.
Am J Orthod Dentofacial Orthop. 2010 May;137(5):658-64. doi: 10.1016/j.ajodo.2008.06.034.
The purpose of this study was to evaluate palatal contours in nonextraction orthodontic treatment and long-term stability in patients with Class II Division 1 malocclusions.
Data were obtained from maxillary study models before treatment, after treatment, and at least 5 years postretention. Data were collected with a digital pantograph in the canine, second premolar, and first molar regions. Palatal width, base width, palatal height, and alveolar angle were evaluated.
During treatment, the canine region was stable; in the premolar and molar regions, there were statistically significant increases in transverse (palatal and base widths) and palatal height measurements, whereas the alveolar angle decreased. In the postretention evaluation, the canine region showed the greatest modifications, except for alveolar angulation, which was stable. The premolar region showed stability, but, in the molar region, palatal width and alveolar angulation decreased.
In analyzing alterations in the geometry of palatal configuration, we concluded that a favorable transverse gain of the palatal base, from growth or orthodontics, was important for stability. The transverse gain of palatal base width during Class II treatment is important to compensate for the expected transverse loss in the cervical region and the decrease of alveolar angle in the long term.
本研究的目的是评估安氏Ⅱ类 1 分类错颌畸形非拔牙矫治中腭部轮廓的变化及长期稳定性。
从治疗前、治疗后和保持至少 5 年后的上颌模型中获取数据。采用数字描记器在尖牙、第二前磨牙和第一磨牙区采集数据。评估腭宽度、基宽度、腭高度和牙槽角度。
在治疗过程中，尖牙区稳定；在磨牙和前磨牙区，横向（腭部和基宽度）和腭高度测量值有统计学意义的增加，而牙槽角减小。在保持期评估中，除了牙槽角稳定外，尖牙区的变化最大。前磨牙区稳定，但在磨牙区，腭宽度和牙槽角减小。
在分析腭部形态变化时，我们得出结论，腭基横向增加（生长或正畸）有利于稳定性。安氏Ⅱ类错颌治疗中腭基宽度的横向增加对于补偿预期的颈区横向丢失和长期牙槽角减小非常重要。
