Department of Orthodontics, Riga Stradins University, Riga, Latvia.
Angle Orthod. 2012 May;82(3):441-7. doi: 10.2319/072911-475.1. Epub 2011 Nov 30.
To quantify the relative soft tissue profile response to the skeletal changes resulting from bimaxillary surgery to correct Class III malocclusion in patients with different vertical incisor relationships presurgery.
The sample comprised lateral cephalograms of 80 consecutive patients before and 2 months after surgery. All patients had one-piece Le Fort I and bilateral sagittal split osteotomies. Patients were divided in three subgroups according to their preoperative characteristics, as follows: (1) open-bite patients, (2) patients with positive overbite and the upper lip resting on upper incisors, and (3) patients with positive overbite and the upper lip resting on lower incisors (lip-block). Trimmed means of soft to hard tissue ratios were calculated for the subgroups. Regression analyses were performed to examine factors influencing the soft tissue changes.
There were strong correlations between the horizontal movement of upper incisors and upper lip in patients with open bite (r = 0.77) and in patients with positive overbite and upper lip resting on upper incisors (r = 0.85). The upper lip followed the maxilla with a ratio of 0.5∶1. In patients with lip-block, the association between maxillary repositioning and upper lip changes was weak. In all groups a strong association between horizontal soft and hard tissue changes was observed for the lower lip and chin, but the pattern differed depending on the vertical movement of the mandible.
In the prediction of soft tissue response it is important to take into account the vertical incisor relationship, particularly in patients with lip-block.
定量分析术前不同垂直切牙关系的 III 类错（牙合）患者双颌手术矫正后骨骼变化引起的软组织侧貌变化。
本研究纳入了 80 例连续患者的术前和术后 2 个月的侧位头颅侧位片。所有患者均接受了 Le Fort I 单块截骨和双侧矢状劈开截骨。根据术前特征将患者分为三组，如下：（1）开（牙合）患者；（2）上切牙覆（牙合）阳性且上唇位于上切牙上的患者；（3）上切牙覆（牙合）阳性且上唇位于下切牙上的患者（唇挡）。计算各组软组织与硬组织比值的修剪平均值。进行回归分析以检查影响软组织变化的因素。
开（牙合）患者（r=0.77）和上切牙覆（牙合）阳性且上唇位于上切牙上的患者（r=0.85）的上切牙与上唇的水平运动之间存在很强的相关性。上唇随上颌以 0.5∶1 的比例运动。在唇挡患者中，上颌重新定位与上唇变化之间的相关性较弱。在所有组中，下唇和颏部的软、硬组织水平变化之间均存在很强的相关性，但下颌骨的垂直运动模式不同。
在预测软组织反应时，重要的是要考虑垂直切牙关系，尤其是唇挡患者。
