Tehranchi A, Behnia H
Department of Orthodontics, Shahid Beheshti University of Medical Sciences Research Center, Tehran, Iran.
Am J Orthod Dentofacial Orthop. 2001 Aug;120(2):149-53. doi: 10.1067/mod.2001.115305.
The purpose of this study was to document changes in the facial symmetry of patients with severe hypoplastic mandibles treated with distraction osteogenesis and orthodontic therapy. Ten patients (5 males and 5 females), ages 7 to 22 years, underwent unilateral mandibular distraction osteogenesis with extraoral distracting devices. Orthodontic therapy was initiated after the completion of mandibular lengthening. The mean follow-up period was 25.5 months. Posteroanterior cephalograms were traced before distraction, 6 months after distraction, and at a later follow-up appointment. Displacement of the chin point (in millimeters) and the midpoint of the mandibular incisors, the piriform angle, the intergonial angle, the occlusal cant to the horizontal line (in degrees), the ratio of linear measurements (in millimeters) Co-Gn, Co-Go, and Go-Gn of the affected to the nonaffected side, CoA'-Mid to CoA-Mid, and GoA'-Mid to GoA-Mid were compared. At the latest follow-up appointment, patients defined as having a successful result had a mean occlusal cant of 1.25 degrees, an intergonial angle of 2.13 degrees, and a piriform angle of 2.63 degrees. The mean displacement of the chin point to the midline was 1.5 mm and that of the mandibular central incisors to the midvertical line was 1.38 mm. The results indicated improvement in all patients.
本研究的目的是记录采用牵引成骨术和正畸治疗的严重下颌骨发育不全患者面部对称性的变化。10名年龄在7至22岁之间的患者（5名男性和5名女性）接受了使用口外牵引装置的单侧下颌骨牵引成骨术。下颌骨延长完成后开始正畸治疗。平均随访期为25.5个月。在牵引前、牵引后6个月以及之后的随访时拍摄正位头颅侧位片。比较颏点（以毫米为单位）和下颌切牙中点的移位、梨状孔角、下颌角间角、与水平线的咬合斜度（以度为单位）、患侧与健侧线性测量值（以毫米为单位）Co-Gn、Co-Go和Go-Gn的比值、CoA'-Mid与CoA-Mid的比值以及GoA'-Mid与GoA-Mid的比值。在最近一次随访时，被定义为治疗成功的患者平均咬合斜度为1.25度，下颌角间角为2.13度，梨状孔角为2.63度。颏点向中线的平均移位为1.5毫米，下颌中切牙向正中垂线的平均移位为1.38毫米。结果表明所有患者均有改善。
