Kretschmer Winfried Bernhard, Baciut Grigore, Baciut Mihaela, Zoder Werner, Wangerin Konrad
Department of Oral and Maxillofacial Surgery, Marienhospital, Stuttgart, Germany.
J Oral Maxillofac Surg. 2010 Feb;68(2):372-80. doi: 10.1016/j.joms.2009.09.053. Epub 2010 Jan 15.
The aim of the present study was to investigate the effect of segmentation on the stability of Le Fort I osteotomies in bimaxillary procedures.
One hundred twenty patients undergoing bimaxillary osteotomies (60 single-piece maxilla, 60 3-piece maxilla) were included in the study. Cephalometric analysis was performed before surgery (T1), immediately after surgery (T2), and after a follow-up of 12 to 15 months (T3). The positional changes of 6 angles (angle of nasion-sella line to A point-nasion line, angle of nasion-sella line to B point-nasion line, angle of nasal line [plane] to nasion-sella line, angle of mandibular line [plane] to nasion-sella line, angle of upper incisor to nasion-sella line, angle of lower incisor to mandibular line [plane]) and 4 maxillary landmarks (upper incisor edge, mesial cusp upper first molar, anterior nasal spine, posterior nasal spine) were measured by superimposition of radiographs. Paired t test was run to evaluate surgical changes (T2-T1) and postsurgical stability (T3-T2). Differences between the 1-piece maxilla group and the 3-piece maxilla group were analyzed with 2-tailed t test. Pearson correlation coefficient was calculated to determine relations among the magnitude of maxillary advancement, superior and inferior repositioning and postsurgical changes of angle of nasion-sella line to A point-nasion line, and the respective landmarks.
The study variables (T1), surgical changes (T2-T1), and postsurgical changes (T3-T2) showed no significant differences between groups with single-piece and 3-piece maxilla. However, a tendency for more relapse was observed in the 3-piece maxilla group in the vertical direction. A significant inferior movement of the upper molar (mesial cusp upper first molar) was seen in the single-piece maxilla group (0.5 mm) and the 3-piece maxilla group (0.4 mm). In both groups and all directions, the T2-to-T3 changes had no significant correlation with the T1-to-T2 changes. No differences were observed between superior and inferior repositioning.
Segmentation of the maxilla does not provoke major skeletal or dental instability and should be considered whenever indicated. Adequate bone grafting provides good stability in anterior and inferior repositioning of the maxilla.
本研究旨在探讨分段截骨对双颌手术中Le Fort I型截骨稳定性的影响。
本研究纳入了120例行双颌截骨术的患者（60例采用整块上颌骨截骨，60例采用三段式上颌骨截骨）。在手术前（T1）、手术后即刻（T2）以及随访12至15个月后（T3）进行头影测量分析。通过X线片叠加测量6个角度（鼻根-蝶鞍线与A点-鼻根线的夹角、鼻根-蝶鞍线与B点-鼻根线的夹角、鼻线[平面]与鼻根-蝶鞍线的夹角、下颌线[平面]与鼻根-蝶鞍线的夹角、上颌切牙与鼻根-蝶鞍线的夹角、下颌切牙与下颌线[平面]的夹角）和4个上颌骨标志点（上颌切牙边缘、上颌第一磨牙近中尖、前鼻棘、后鼻棘）的位置变化。采用配对t检验评估手术变化（T2 - T1）和术后稳定性（T3 - T2）。采用双侧t检验分析整块上颌骨组和三段式上颌骨组之间的差异。计算Pearson相关系数以确定上颌前徙量、上下复位以及鼻根-蝶鞍线与A点-鼻根线夹角的术后变化与各个标志点之间的关系。
研究变量（T1）、手术变化（T2 - T1）和术后变化（T3 - T2）在整块上颌骨组和三段式上颌骨组之间无显著差异。然而，三段式上颌骨组在垂直方向上有更多复发的趋势。在整块上颌骨组（0.5 mm）和三段式上颌骨组（0.4 mm）中均观察到上颌磨牙（上颌第一磨牙近中尖）明显向下移动。在两组的所有方向上，T2至T3的变化与T1至T2的变化均无显著相关性。上下复位之间未观察到差异。
上颌骨分段截骨不会引起明显的骨骼或牙齿不稳定，在有指征时应予以考虑。充分的植骨可为上颌骨的前位和下位复位提供良好的稳定性。
