Clinical Analysis of Liquid Nitrogen Effects on Lip and Palate

Objectives: This work proposes a descriptive clinical analysis of the effects caused by liquid nitrogen applied with cotton swabs on the lip and palate of rabbits. Methods: The liquid nitrogen application was made in two cycles of one minute each. 20 New Zeland male rabbits were divided in lip and palate groups. The lesions caused by the application of liquid nitrogen were followed until their final repair being observed on the 1, 2, 3, 5, 7, 10 and 14th days. In each of these periods digital pictures were taken to determine what kind of clinical manifestations ocurred during the repair. The pictures have been analysed by the examinators and by one pathologist. The following variables have been classified as present or absent: edema, necrosis, crust, hyperemia, ecchymosis, process of tissue repair and complete tissue repair. Results: The results have showed that the edema on the lip remained from the 1st to the 5th day with its peak on the 2nd day. It was on palate just on the first day. Ecchymosis and hyperemia occurred on the first days in both groups. Necrosis showed up on the first day. There were crust formation only on the lip. The process of repair started within 5 days on the lip and 3 days on the palate. On the 14th day, all the lesions had been repaired. Conclusion: We concluded that the utilized protocol has produced necrosis on the tissue and that cicatrization has ocurred within 14 days with different periods for manifestation of tissue changes in each group.