This study attempted to determine the reduction rate of jaw cysts after marsupialization. The patients ranged from 10 to 60 years of age; the volume of the cyst cavity ranged from 2.5 to 17 ml. The cyst volume was measured by filling the cavity with water from a graduated syringe every one or two months up to 19 months after marsupialization. Twelve cases of cysts were divided into two groups according to volume: larger than 10 ml or smaller than 10ml. Two other groups were classified according to the patient's age: over 20 years of age and under 20 years of age. The results were as follows. Even larger cysts over 10 ml in volume showed a rapid reduction in size similar to the smaller cysts. Cysts in patients who were over 20 years old showed a lower reduction rate than those in patients under 20 years of age. The mean volume of the 12 cyst cavities fell to 25.8±10.1% 3 months after treatment and to 11.4±8.4% in the next 5 months.
Based on the reduction curve of the cyst cavity, the process of cyst diminution was classified into 3 stages. Stage 1, in which the cyst rapidly decreased in volume, was an initial three-month period after marsupialization. After that, the cysts showed gradual diminution and finally disappeared during the second stage, from 3 to 8 months after marsupialization. In the third stage, from 8 months onward, there was long-term persistence of any remaining cysts. Therefore, it is most important to keep the fenestration open for at least 8 months after marsupialization.
