A Histological Study of the Distribution of the III Cervical Sensory Nerve and Its Relationship to the Craniofacial Pain

1. Peripheral distribution of the third cervical nerve was studied histologically after the neurotomy of this never on dogs. The degenerated nerve fibers were detected in the face, head, oral cavity and pharynx. 2. Sensory nerve with simple ramitying termination or free-ending were found in the skin and these appendage of dog's face. 3. Sensory nerve fibers demonstrated in the present study were consisted of myelinated nerve fibers, losing the myelin sheath in the extreme peripheral part. 4. Degenerated sensory nerve fibers were measured as 2-5μ. In diameter. This size of sensory nerve fibers is equivalent to A-δ or C fiber which is thought to be the kind of nerve fibers conducting painful impulse. 5. Although communications between the facial nerve and the third cervical nerve existed macroscopically, there was no microscopical intermingling of their fibers. 6. The third cervical nerve fibers were distributed in the third division and a part of the second division of the trigeminal area as well as in the retroauricular, temporal and occipital region. These sensory nerve endings were usually found in the epithelial layer of the skin. 7. The degenerated nerve fibers were found in a part of the nasopharyngeal region