Kim Y J, Kuboki T, Tsukiyama Y, Koyano K, Clark G T
UCLA School of Dentistry, Diagnostic Sciences and Orofacial Pain, Center For The Health Sciences, Los Angeles, CA 90095-1668, USA.
Arch Oral Biol. 1999 Aug;44(8):641-50. doi: 10.1016/s0003-9969(99)00059-x.
This study evaluated the influence of low contraction forces on intramuscular haemodynamics in human masseter and temporalis using near-infrared tissue spectroscopy. This method allowed the intramuscular haemoglobin (Hb) to be assessed dynamically before, during and after a 5, 15, 25 and 100% maximum voluntary contraction (MVC). Twenty volunteers, 10 males and 10 females, without pain or dysfunction in the masticatory system were included in this study. Data were recorded for 30 s before, 30 s during and 5 min after the four sustained contraction tasks. The results showed that all four levels of voluntary contraction produced a clear haemodynamic response (during and after contraction) in both muscles. For analytical purposes, the maximum Hb achieved after 100% MVC was set equal to 1.00. In the masseter the mean peak Hb during the 5, 15, 25 and 100% MVC was 0.49, 0.92, 1.30 and 1.73 while after the contractions it was 0.50, 0.65, 0.78 and 1.00, respectively. In the temporalis the peak Hb during the contractions was 0.23, 0.36, 0.48 and 0.66 and after the contractions 0.32, 0.45, 0.56 and 1.00, respectively. Repeated-measures analysis of variance revealed a significant main effect for the different contraction levels both in the masseter (during contraction, p = 0.001; after contraction, p<0.001) and the temporalis (during contraction, p = 0.002; after contraction, p<0.001). These data suggest that low levels of contraction induce a clear haemodynamic response, even at 5% effort. When compared, the masseter and anterior temporalis showed clearly different patterns for the Hb signal during the contraction (p<0.001) as well as after it (p = 0.007). Specifically, the Hb during the contractions in the masseter appeared more stable than in the temporalis, which showed a strong return to baseline. Obviously the contracting masseter had a stronger and more sustained venous occlusion than the contracting temporalis. It is speculated that variation in architecture between the two muscles contributes to these differences in blood flow.
本研究采用近红外组织光谱技术评估了低收缩力对人类咬肌和颞肌肌内血流动力学的影响。该方法能够在5%、15%、25%和100%最大自主收缩（MVC）之前、期间和之后动态评估肌内血红蛋白（Hb）。本研究纳入了20名志愿者，其中10名男性和10名女性，咀嚼系统无疼痛或功能障碍。在四项持续收缩任务之前30秒、期间30秒和之后5分钟记录数据。结果表明，所有四个自主收缩水平均在两块肌肉中产生了明显的血流动力学反应（收缩期间和之后）。为便于分析，将100%MVC后达到的最大Hb设定为等于1.00。在咬肌中，5%、15%、25%和100%MVC期间的平均Hb峰值分别为0.49、0.92、1.30和1.73，而收缩后分别为0.50、0.65、0.78和1.00。在颞肌中，收缩期间的Hb峰值分别为0.23、0.36、0.48和0.66，收缩后分别为0.32、0.45、0.56和1.00。重复测量方差分析显示，咬肌（收缩期间，p = 0.001；收缩后，p<0.001）和颞肌（收缩期间，p = 0.002；收缩后，p<0.001）不同收缩水平均有显著的主效应。这些数据表明，即使在5%的用力程度下，低水平收缩也会引起明显的血流动力学反应。相比之下，咬肌和颞肌前部在收缩期间（p<0.001）以及收缩后（p = 0.007）的Hb信号模式明显不同。具体而言，咬肌收缩期间的Hb比颞肌更稳定，颞肌显示出强烈的恢复到基线水平的趋势。显然，收缩的咬肌比收缩的颞肌有更强且更持久的静脉阻塞。据推测，两块肌肉结构的差异导致了这些血流差异。
