Ellis E, Throckmorton G S
Division of Oral and Maxillofacial Surgery, University of Texas Southwestern Medical Center, Dallas 75390-9109, USA.
J Oral Maxillofac Surg. 2001 Apr;59(4):389-95. doi: 10.1053/joms.2001.21873.
This study compared maximum voluntary bite forces in patients who received either open or closed treatment for fractures of the mandibular condylar process.
One hundred fifty-five patients (127 male, 28 female) with unilateral fractures of the mandibular condylar process (91 treated closed and 64 treated open) were included in this study. Maximum voluntary bite forces were measured at 6 weeks, 6 months, and 1, 2, and 3 years after fracture. At each trial, unilateral maximum voluntary bite force was measured at 4 different tooth positions bilaterally using a standard transducer. Electromyography (EMG) of the masseter muscles was also recorded during the bite force measurements, and ratios of the working/balancing side EMG were calculated. Analysis of the data was performed using standard statistical methods.
The only significant difference between the 2 samples was in the level of fractures on the condylar process. No patients treated open had fractures of the "head" of the condylar process, whereas there were 11 in the group treated closed. No differences were observed in maximum voluntary bite forces between the 2 treatment groups at any time period, or were there correlations between bite force magnitude and location of the fracture, displacement of the fracture, or any other variable studied. Both groups showed a significant recovery of maximum bite force from the 6-week to the 6-month testing session. For both groups, working/balancing EMG ratios were significantly greater when subjects were biting on the side opposite the fracture. When biting on that side, the working/balancing EMG ratios were higher in the closed treatment group, but the difference did not reach significance.
Maximum voluntary bite forces in patients treated for mandibular condylar process fractures do not differ significantly when treatment is open or closed. Neuromuscular adaptations to the fractured mandibular condylar process occur in both groups.
本研究比较了接受下颌髁突骨折开放治疗或闭合治疗的患者的最大自主咬合力。
本研究纳入了155例单侧下颌髁突骨折患者（127例男性，28例女性）（91例接受闭合治疗，64例接受开放治疗）。在骨折后6周、6个月以及1年、2年和3年测量最大自主咬合力。每次试验时，使用标准传感器在双侧4个不同牙位测量单侧最大自主咬合力。在测量咬合力时还记录咬肌的肌电图（EMG），并计算工作侧/平衡侧EMG的比值。使用标准统计方法进行数据分析。
两组之间唯一显著的差异在于髁突骨折的水平。接受开放治疗的患者中没有髁突“头部”骨折的情况，而在接受闭合治疗的组中有11例。在任何时间段，两个治疗组之间的最大自主咬合力均未观察到差异，咬合力大小与骨折位置、骨折移位或任何其他研究变量之间也没有相关性。两组在从6周测试期到6个月测试期时最大咬合力均有显著恢复。对于两组，当受试者在骨折对侧咬合时，工作侧/平衡侧EMG比值显著更高。当在该侧咬合时，闭合治疗组的工作侧/平衡侧EMG比值更高，但差异未达到显著水平。
下颌髁突骨折患者接受开放或闭合治疗时，最大自主咬合力没有显著差异。两组均出现了对骨折下颌髁突的神经肌肉适应性变化。
