1986 Volume 32 Issue 11 Pages 2025-2034
It has been accepted that parasympathetic innervation of submandibular gland is chorda tympani. This experiment is to study the influence of secretion and histopathologic change after section and suture of the chorda tympani.
A total of 33 adult mongrel dogs were used in the study. The animals were divided into the nerve section group and the nerve suture group. The chorda tympani of 12 dogs were cutted at 1cm from the submandibular gland. It was the nerve section group. Then after sectioning of the chorda tympani, the nerves of 21 dogs were sutured immediately with 10-0 mono-filament nylon sutures. This was the nerve suture group. The functional and morphological studies were carried out at various time intervals after the surgery.
The following results were obtained:
1. In the nerve section group, the gland weight was decreased to about 50% of the control group at the 8th week after the surgery. In the nerve suture group, the gland weight was decreased to about 40% of the control group at the 8th week. But at the 12th week, the gland increased its weight, and recovered to almost normal gland weight at 24th week.
2. The secretion of the submandibular gland, in the nerve section group, decreased gradually after the operation, and at the 8th week, no secretion was observed. On the other hand, the nerve suture group, the secretion started to recover at 12th week, and at the 24th week, about 80% of secretion of the control group was observed.
3. Histopathological finding showed that cells of the submandibular gland started to atrophy after the surgery, and at the 24th week after the sectioning, most of the cells were atrophied. However in the nerve suture group, the recovery of the cells were observed in all cases, and these recovered to the normal morphology at the 24th week.