Kravitz Neal D, Kusnoto Budi
Department of Orthodontics, University of Illinois at Chicago, Chicago, Illinois, USA.
World J Orthod. 2007 Summer;8(2):157-66.
Skeletal anterior open bite is often caused by posterior dentoalveolar excess and downward and backward mandibular rotation. Orthodontic miniscrews can successfully impact the posterior dentition, allowing for open-bite correction through upward and forward mandibular autorotation. An Asian male, 27 years of age, with a Class II skeletal relationship, dolichocephalic facial type, high mandibular plane angle, 4.0-mm anterior open bite, and convex soft-tissue profile was treated with 4 dentoalveolar orthodontic miniscrews. The maxillary first and second molars were impacted 1.4 mm, resulting in open-bite closure, 2. 1 degrees of upward and forward mandibular autorotation, 2.0-mm advancement of pogonion, 3.5-degree reduction in soft-tissue facial convexity, and 2.6-mm increase in anteroposterior pharyngeal dimension on the lateral cephalogram. This case report demonstrates successful treatment with orthodontic miniscrews in open-bite closure with Class II correction, without extraction or surgically positioned miniplates. Miniscrew-supported posterior impaction and mandibular autorotation may become a viable treatment alternative to surgery in patients desiring improvement in their excessive dentofacial vertical dimension and facial esthetics.
骨性前牙开（牙合）通常由后牙牙槽过度生长及下颌向下向后旋转引起。正畸微螺钉能够成功压低后牙列，通过下颌向上向前的自动旋转实现开（牙合）的矫治。一名27岁亚洲男性患者，安氏II类骨性错（牙合），长头型面部，高下颌平面角，4.0mm前牙开（牙合），软组织侧貌凸面型，采用4枚牙槽骨正畸微螺钉进行治疗。上颌第一、二磨牙压低1.4mm，实现了开（牙合）关闭，下颌向上向前自动旋转2.1度，颏点前移2.0mm，软组织面部凸度减小3.5度，头颅侧位片显示咽腔前后径增加2.6mm。本病例报告表明，正畸微螺钉在伴有II类错（牙合）矫治的开（牙合）关闭治疗中取得了成功，无需拔牙或使用外科植入微型钛板。对于希望改善牙颌面垂直距离过大及面部美观的患者，微螺钉支持的后牙压低及下颌自动旋转可能成为一种可行的替代手术的治疗方法。
