Gürsoy Seda, Hukki Jyri, Hurmerinta Kirsti
Cleft Palate and Craniofacial Centre, Department of Plastic Surgery, Helsinki University Central Hospital, Helsinki, Finland.
J Oral Maxillofac Surg. 2010 Apr;68(4):744-50. doi: 10.1016/j.joms.2009.07.036. Epub 2010 Jan 15.
To determine the long-term outcomes of maxillary distraction osteogenesis (DO) on skeletal and dental structures of growing children with cleft lip and palate.
Severe maxillary deficiencies were treated with a rigid external distractor device followed by a consolidation period. Preoperative and postoperative orthodontic treatment lasted a mean of 14 months and 16 months, respectively. The landmarks on standard lateral cephalometric x-rays were digitized and angular and linear measurements were compared by Student's t test to assess the changes before distraction, after distraction, after consolidation, at 1-year follow-up, and at 2-year follow-up. Long-term follow-up (5 years) was interpreted according to mean values because of the small sample size.
During DO, the maxilla was horizontally advanced and moved downward as indicated by the significant changes at the SNA and ANB angles (13 degrees) and at maxillary points A, ANS, and PNS. The increase at the divergence between the maxilla and mandible (ANS-PNS/Me-Go) was found to be significant. The mandible (B, Pg, Me) also moved downward (2-4 mm) and backward (Gn) significantly because of mandibular autorotation. The overjet increased (mean increase, 13.7 mm) and the overbite decreased significantly. The advancement of the upper incisors (13.3 mm) and upper molars (12.3 mm) was slightly more than the skeletal points. In a long-term follow-up (5 years), the ANB angle and horizontal overjet continued to decrease but both values remained positive, indicating a Class I relationship.
This cephalometric study of young adolescents with cleft lips and palates found great improvement in dentofacial structure after maxillary DO and stability in maxillary skeletal advancement. During a 5-year follow-up, the achieved dentoskeletal treatment outcome was partly diminished. The extreme need for maxillary advancement or facial correction because of psychosocial stress and providing an easier approach for finalizing osteotomy are the major 2 indications for DO treatment.
确定上颌骨牵张成骨术（DO）对唇腭裂患儿骨骼和牙齿结构的长期影响。
采用坚固的外部牵张器装置治疗严重上颌骨发育不全，随后进行巩固期。术前和术后正畸治疗平均分别持续14个月和16个月。对标准头颅侧位X线片上的标志点进行数字化处理，并通过学生t检验比较角度和线性测量值，以评估牵张前、牵张后、巩固后、1年随访和2年随访时的变化。由于样本量小，长期随访（5年）根据平均值进行解读。
在牵张成骨过程中，上颌骨水平前移并向下移动，SNA和ANB角（13度）以及上颌骨的A点、前鼻棘（ANS）和后鼻棘（PNS）处有显著变化。上颌骨与下颌骨之间的差异（ANS-PNS/Me-Go）增加显著。由于下颌骨自身旋转，下颌骨（B点、颏前点、下颌角）也显著向下（2-4毫米）和向后（Gn点）移动。覆盖增加（平均增加13.7毫米），覆合显著减小。上切牙（13.3毫米）和上磨牙（12.3毫米）的前移略大于骨骼标志点。在长期随访（5年）中，ANB角和水平覆盖继续减小，但两个值仍为正值，表明为I类关系。
这项对唇腭裂青少年的头影测量研究发现，上颌骨牵张成骨术后牙颌面结构有显著改善，上颌骨骨骼前移稳定。在5年随访期间，所取得的牙骨骼治疗效果部分减弱。因心理社会压力而极度需要上颌骨前移或面部矫正，以及为完成截骨术提供更简便的方法是牵张成骨术治疗的两大主要适应证。
