Giannakopoulos Nikolaos N, Wirth Alexander, Braun Sebastian, Eberhard Lydia, Schindler Hans J, Hellmann Daniel
Int J Prosthodont. 2014 Jul-Aug;27(4):383-9. doi: 10.11607/ijp.3793.
The purpose of this study was to examine, on the basis of masticatory performance (MP), total muscle work (TMW), and range of movement (RoM), whether reduction of the profile of the cusps results in loss of the biomechanical effectiveness of chewing by healthy dentate patients.
Twenty healthy patients (10 female, mean age: 24.1 ± 1.2 years) chewed standardized silicone particles, performing 15 masticatory cycles. Three experimental conditions were investigated: chewing on (1) the natural dentition (ND), (2) splints with structured occlusal profiles simulating the patient's natural dentition (SS), and (3) splints with a plane surface (PS). The expectorated particles were analyzed by a validated scanning procedure. The size distribution of the particles was calculated with the Rosin-Rammler function and the mean particle sizes (X50) were determined for each experimental condition. The target variables of the experimental conditions were compared by repeated measures analysis of variance.
X50 values calculated for MP differed significantly (P < .002) between PS and SS, and between ND and SS. Conversely, no significant differences (P > .05) were observed between SS and ND. Regarding muscle work the EMG activity of the masseter differed significantly (P < .001) between the left and right sides, with higher values for the right (chewing) side. No significant differences (P > .05) were observed for TMW and RoM under the three test conditions.
The results confirm the biomechanical significance of structured occlusal surfaces during chewing of brittle test food by young dentate subjects.
本研究旨在基于咀嚼性能（MP）、肌肉总功（TMW）和运动范围（RoM），探讨健康牙列患者牙尖外形减小是否会导致咀嚼生物力学效能丧失。
20名健康患者（10名女性，平均年龄：24.1±1.2岁）咀嚼标准化硅胶颗粒，进行15个咀嚼周期。研究了三种实验条件：（1）天然牙列（ND）咀嚼，（2）佩戴模拟患者天然牙列结构咬合面的夹板（SS）咀嚼，（3）佩戴平面夹板（PS）咀嚼。通过经过验证的扫描程序分析咳出的颗粒。用罗辛-拉姆勒函数计算颗粒的尺寸分布，并确定每种实验条件下的平均粒径（X50）。通过重复测量方差分析比较实验条件的目标变量。
PS与SS之间以及ND与SS之间，MP计算得到的X50值存在显著差异（P<.002）。相反，SS与ND之间未观察到显著差异（P>.05）。关于肌肉功，咬肌的肌电图活动在左右两侧存在显著差异（P<.001），右侧（咀嚼侧）的值更高。在三种测试条件下，TMW和RoM未观察到显著差异（P>.05）。
结果证实了年轻牙列受试者咀嚼脆性测试食物时结构咬合面的生物力学意义。
