口腔領域における交感，感覚および運動神経支配に関する研究 ： Ⅰ. 顎関節，阻噂筋における神経支配

Abstract

Sympathetic，sensory and motor innervation of the temporomandibular joint (TMJ) and the masticatory muscles was investigated in the rat by use of horseradish peroxidase (HRP) method. In the case of HRP application into TMJ，labeled cells were distributed uniformly in the superior cervical ganglion (SCG). In the trigeminal ganglion (TRG) they were found in the submandibular division. In TRG the mean diameter of labeled cells of TMJ (23.7±5.9μm) was significantly smaller than that of tooth pulp (27.4±5.0μm). Almost no labeling was obtained in SCG after sectioning of the cervical sympathetic plexus. By sectioning of the auriculotemporal nerve，labeling of TMJ was eliminated in SCG and reduced by 1/10 in TRG. The above observation indicated that the sympathetic components which originate from SCG innervate TMJ through intervention of the auricurotemporal nerve after ascending along the external carotic plexus ; also，that approximately 90％ of the sensory fibers innervating TMJ are carried by the auricurotemporal nerve，which seems to contain smaller Aδ and C fibers. HRP injection into the masseteric，temporal，medial pterygoid and lateral pterygoid muscles brought ipsilateral numerous labeled cells which localized at the central 1/2 of SCG，but only few cells in the anterior digastric and mylohyoid muscles. Labeled cells were found ipsilaterally in the submandibular division in TRG. The mean diameter of TRG labeled cells in the above muscles (24.3±4.9μm) was significantly smaller than that in tooth pulp. In the trigeminal motor nucleus，labeled cells after HRP injection into the masticatory muscles were localized in each rostro-caudal level. The distribution pattern of neuron size of the masseteric muscles was bimodal，and that of the others unimodal. The mean diameter of labeled cells of the masseteric (26.0±4.3μm) and temporal muscles (26.1±4.3μm) was significantly larger than that of the others.