Course and Resection of the Inferior Alveolar Nerve in the Albino Rat

¹ University of Illinois, Chicago, Illinois

The course of the inferior alveolar nerve was traced from its origins at the Gasserion ganglion to the mandible and to the teeth of the albino rat. Gross dissections under x 16 magnification were used to trace all but the incisal branch of the nerve. This latter branch was traced histologically by means of frozen-dry technique, and the serial sections were studied under polarized light. The nerve was easily traced by this method, as it appeared a green-blue color in contrast to the yellow-red of the other tissues. The incisor branch of the nerve was found to travel recurrently to the basal end of the incisor from a level inferior to the second molar.

Experimental resection of the inferior alveolar nerve was undertaken to observe the effects upon dentinogenesis and eruption. The nerve was resected from a lateral aspect through the masseteric muscle. Following resection of the nerve, animals were allowed to recover and then were sacrificed at intervals of 1, 2, 3, and 4 weeks. Eruption measurements taken showed that the lower right incisor (operated side) erupted at a faster rate than the lower left incisor. The upper right incisor decreased in eruption rate in comparison with the upper left incisor. The histologic sections showed a response of globular dentin with a widened predentin to a bizarre dentin with trapped odontoblasts, irregular calcification patterns, and widened predentin. This latter response appeared in the animals with the greatest differences in eruption rates.