Del Santo M, Guerrero C A, Buschang P H, English J D, Samchukov M L, Bell W H
Department of Orthodontics, Baylor College of Dentistry, TAMUS, Dallas, Texas 75256, USA.
Am J Orthod Dentofacial Orthop. 2000 Nov;118(5):485-93. doi: 10.1067/mod.2000.109887.
The purpose of this study was to evaluate the effects of mandibular symphyseal distraction osteogenesis using a tooth-borne expansion device. The sample included 20 Hispanic nonsyndromic patients (11 males and 9 females) between 13.5 years and 37.3 years of age. Predistraction (1.5 months before surgery), postdistraction (1 month after surgery), and long-term follow-up (1.3 year after surgery) records included posteroanterior, lateral, and panoramic radiographs and models. Postdistraction radiographic evaluation showed that symphyseal distraction osteogenesis produced insignificant increases in the bicondylar, bigonion, and biantegonion widths; intermolar and, especially, intercanine widths increased significantly and a distraction gap was observed in the symphyseal region. Follow-up model analysis showed the largest width increases between the first molars and second premolars and the smallest width increases between canines and first premolars. The difference between the postdistraction and long-term follow-up width changes was explained by the postdistraction orthodontic effect, which modified the shape of the dental arch. A disproportionate pattern of distraction, characterized by significantly greater dental than skeletal widening, was observed in the second molar and antegonion region. Distraction osteogenesis without presurgical orthodontic treatment produced significant proclination of the mandibular incisors; no proclination was observed in cases with predistraction orthodontic treatment. Dental crowding was resolved by the movement of teeth into the distraction regenerate and concomitant orthodontic treatment. Follow-up radiographs showed transverse skeletal stability of the distraction procedure. We conclude that mandibular symphyseal distraction osteogenesis increased mandibular arch width and partially corrected dental crowding, with a potential for disproportionate distraction patterns and proclination of the mandibular incisors.
本研究的目的是评估使用牙支持式扩弓装置进行下颌骨联合部牵张成骨的效果。样本包括20名年龄在13.5岁至37.3岁之间的西班牙裔非综合征患者（11名男性和9名女性）。术前牵引（手术前1.5个月）、牵引后（手术后1个月）和长期随访（手术后1.3年）记录包括正位、侧位和全景X线片及模型。牵引后X线片评估显示，联合部牵张成骨使双侧髁突、双侧下颌角点和双侧下颌前角点宽度增加不显著；磨牙间尤其是尖牙间宽度显著增加，联合部区域可见牵引间隙。随访模型分析显示，第一磨牙与第二前磨牙之间宽度增加最大，尖牙与第一前磨牙之间宽度增加最小。牵引后与长期随访宽度变化的差异可通过牵引后正畸效应来解释，该效应改变了牙弓形状。在第二磨牙和下颌前角区域观察到一种不成比例的牵张模式，其特征为牙齿增宽明显大于骨骼增宽。未进行术前正畸治疗的牵张成骨导致下颌切牙明显前倾；在术前进行正畸治疗的病例中未观察到前倾。牙齿拥挤通过牙齿向牵张再生区移动及同期正畸治疗得以解决。随访X线片显示牵张过程的横向骨骼稳定性。我们得出结论，下颌骨联合部牵张成骨增加了下颌弓宽度并部分纠正了牙齿拥挤，存在牵张模式不成比例和下颌切牙前倾的可能性。
