Song H C, Throckmorton G S, Ellis E, Sinn D P
University of Texas Southwestern Medical Center, Dallas 75235-9109, USA.
J Oral Maxillofac Surg. 1997 Jan;55(1):41-9; discussion 49-50. doi: 10.1016/s0278-2391(97)90444-4.
The purpose of this investigation was 1) to compare functional and morphologic measurements between controls and patients scheduled for anterior or inferior repositioning of the maxilla, and 2) to examine how these patients' oral function adapted after surgery.
Nine male patients undergoing anterior and/or inferior repositioning of the maxilla were compared with 26 male controls preoperatively and up to 3 years after surgery. Measures of skeletal morphology, mandibular range of motion, maximum voluntary bite force, and levels of electromyographic (EMG) activity in the anterior and posterior temporalis and masseter muscles during isometric bites were made on all subjects over time. One-way ANOVA was used to compare the controls, the patients before surgery, and the patients after surgery.
Before surgery, most of the patients had morphologic characteristics of mandibular prognathism and maxillary retrognathism. Surgery made the patients' skeletal morphology similar to controls except for mandibular length, upper facial height, and palatal plane angle, which were significantly greater than those of controls. There were no significant differences in jaw muscle mechanical advantage between controls and patients either before or after surgery. Hypomobility of the jaw was apparent at 6 weeks and 6 months after surgery, but returned to normal values within 1 to 2 years. Before surgery, the patients had maximum voluntary bite forces significantly less than those of controls. Bite forces in patients steadily increased after surgery, approaching significantly higher values than those of controls. Before surgery, patients' muscle activity levels per unit of bite force were not significantly different from those of controls. Most of the patients' muscle activity levels per unit of bite forces at all bite positions showed no significant change after surgery.
The results of this study suggest that anterior or inferior repositioning of maxilla produces some significant functional benefits in patients.
本研究的目的是1）比较对照组与计划进行上颌骨前部或下部复位的患者之间的功能和形态学测量结果，以及2）研究这些患者术后口腔功能如何适应。
将9名接受上颌骨前部和/或下部复位的男性患者与26名男性对照组在术前及术后长达3年的时间里进行比较。随着时间的推移，对所有受试者进行骨骼形态、下颌运动范围、最大自主咬合力以及等长咬合时颞肌前、后部和咬肌的肌电图（EMG）活动水平的测量。采用单因素方差分析来比较对照组、术前患者和术后患者。
术前，大多数患者具有下颌前突和上颌后缩的形态学特征。手术使患者的骨骼形态与对照组相似，但下颌长度、面中高度和腭平面角除外，这些指标显著大于对照组。术前和术后，对照组与患者之间的颌肌力学优势均无显著差异。术后6周和6个月时可见下颌活动度降低，但在1至2年内恢复至正常水平。术前，患者的最大自主咬合力显著低于对照组。术后患者的咬合力稳步增加，显著高于对照组。术前，患者每单位咬合力的肌肉活动水平与对照组无显著差异。术后，大多数患者在所有咬合位置每单位咬合力的肌肉活动水平均无显著变化。
本研究结果表明，上颌骨前部或下部复位给患者带来了一些显著的功能益处。
