Hemodynamic activities of motor cortex related to jaw and arm muscles determined by near infrared spectroscopy

Abstract

It has been reported that imbalance in the jaw can cause loss in arm strength. In order to investigate this phenomenon based on the relationship between bite and neuron activities, Near-infrared spectroscopy (NIRS) was used. The purpose of this study was to determine the influence of biting on the concentrations of oxygenated hemoglobin on the motor area. NIRS was administered for three healthy subjects. Subjects were asked to perform 3 different tasks: biting on a spacer using the right jaw, lifting up a weight with the right arm, and combining the two. The NIRS probes were positioned contralaterally, in the left region. The results suggested that using jaw muscles and arm muscles influenced the neuron activities in the motor area. Moreover, the neuron activities increased significantly when the arm muscles were used instead of the jaw muscles, as shown by levels of OxyHemoglobin in the motor area. © 2011 Springer-Verlag.