Experimental studies were conducted in rabbits to investigate the applicability of a highpressure water stream or water jet in oral surgery.
We examined histologically the effects of a saline-substituted water jet system at pressures ranging from 17-20 kg/cm2 on the submandibular gland, parotid gland, tongue, palatal mucosa, facial nerve and liver.
In the salivary glands, the interlobular space showed edematous changes resulting from invasion of water and bubbles, and the blood vessels were separated from the surrounding loose connective tissues. In the tongue, the spaces between muscle bundles were torn. In contrast, the vessels were not severely damaged and bleeding was slight. The palatal mucosa was easily ablated from the palatal bone with almost no damage in the periosteum. In the liver, the vessels and ducts were separated and minimal bleeding was detected. The healing process in the parotid gland injured by conventional instruments or the water jet was investigated. At 17 kg/cm2 pressure, there was resultant damage to the parotid glands. On electrophysiological examination of the ablated facial nerve, the threshold value with the water jet, did not rise as high as that with conventional instruments.
Some problems also exist with the water jet. For example, the optimal pressure suitable for application to the different organs while causing minimal damage has not yet been determined. There is also the problem of water splashing about. We believe, however, that this instrument is very useful for the preservation of blood vessels and nerves.
