Nkenke Emeka, Vairaktaris Eleftherios, Kramer Manuel, Schlegel Andreas, Holst Alexandra, Hirschfelder Ursula, Wiltfang Jörg, Neukam Friedrich Wilhelm, Stamminger Marc
Department of Oral and Maxillofacial Surgery, University of Erlangen-Nuremberg, Glueckstr. 11, 91054 Erlangen, Germany.
Oral Maxillofac Surg. 2008 May;12(1):5-12. doi: 10.1007/s10006-008-0094-8.
It has been the objective of the present prospective study to assess visible volume changes of the facial soft tissue after LeFort I osteotomy with advancement and to determine the soft-tissue-to-hard-tissue ratios of advancement.
Twenty adult patients (ten female, ten male, mean age 33.9 +/- 14.9 years) received a LeFort I osteotomy with advancement because of a maxillary protrusion. Lateral skull radiographs and optical three-dimensional (3D) scans of the facial surface were assessed preoperatively and 12 months after surgery. The lateral skull radiographs were used to carry out standard linear and angular cephalometric measurements. The pre- and postoperative optical 3D surface scans were registered. A well-defined area in the malar region was used to determine the visible volume changes for each side separately. The mean accommodation vector that transforms the preoperative into the postoperative surface was assessed for each facial half separately. The soft-tissue-to-hard-tissue ratios between the incision superius and the labrale superius, the maximal parasagittal advancement of soft tissue, and the accommodation vectors were calculated.
A mean advancement of the incision superius of 5.3 +/- 2.1 mm was accompanied by a volume increase of 5.2 +/- 4.1 cm(3) in the right malar-midfacial region and 4.6 +/- 4.7 cm(3) on the left side, respectively, revealing a symmetrical volume change (p = 0.370). The soft-tissue-to-hard-tissue ratios were 80 +/- 94% for labrale superius and incision superius, 56 +/- 79% (right) and 51 +/- 56% (left) for accommodation vector and incision superius and 97 +/- 79% (right) and 98 +/- 89% (left) for maximal parasagittal advancement of soft tissue and incision superius.
The determination of volume changes and accompanying accommodation vectors complete the cephalometric analysis during the follow-up of patients undergoing LeFort I osteotomy. The data show that maxillary advancement leads to a more pronounced shifting of the soft tissues in the malar-midfacial area than of the upper lip. The new parameters will help to assess normative soft tissue data based on 3D imaging with a view to an improved three-dimensional prediction of the operative outcome of orthognathic surgery away from the midline.
本前瞻性研究的目的是评估LeFort I型截骨术并推进术后面部软组织的可见体积变化，并确定推进的软组织与硬组织比例。
20例成年患者（10名女性，10名男性，平均年龄33.9±14.9岁）因上颌前突接受了LeFort I型截骨术并推进。术前及术后12个月对头颅侧位片和面部表面的光学三维（3D）扫描进行评估。头颅侧位片用于进行标准的线性和角度头影测量。对术前和术后的光学3D表面扫描进行配准。使用颧区一个明确界定的区域分别确定每侧的可见体积变化。分别评估将术前表面转换为术后表面的平均适应向量。计算切口上缘与上唇唇缘之间的软组织与硬组织比例、软组织的最大矢状向推进以及适应向量。
切口上缘平均推进5.3±2.1 mm，右侧颧-面中部区域体积分别增加5.2±4.1 cm³，左侧增加4.6±4.7 cm³，显示出对称的体积变化（p = 0.370）。上唇唇缘与切口上缘的软组织与硬组织比例为80±94%，适应向量与切口上缘的比例右侧为56±79%，左侧为51±56%，软组织最大矢状向推进与切口上缘的比例右侧为97±79%，左侧为98±89%。
在接受LeFort I型截骨术患者的随访期间，体积变化和伴随的适应向量的确定完善了头影测量分析。数据表明，上颌推进导致颧-面中部区域软组织的移位比上唇更明显。这些新参数将有助于基于3D成像评估标准软组织数据，以期在远离中线的正颌手术中改进手术结果的三维预测。
