Effects of the patient's age and the size of the primary lesion on the speed of shrinkage after marsupialisation of keratocystic odontogenic tumours, dentigerous cysts, and radicular cysts.

Marsupialisation, by which a surgical window is created in the cavity of a cystic lesion, has been recommended to avoid the formation of a bony defect in the jaw and a reduction in a patient's quality of life. However, information about the factors that affect the reduction in the size of a cyst after marsupialisation is limited. We have studied the effects of the patient's age and the size of the primary lesion on the speed of shrinkage after marsupialisation of keratocystic odontogenic tumours (KCOTs), dentigerous cysts, and radicular cysts. The speed of shrinkage (mm(2)/month) was evaluated by measuring the radiolucent area on panoramic radiographs taken before and after marsupialisation for KCOT (n=28), dentigerous cysts (n=26), and radicular cysts (n=18) in the mandibular molar regions. The mean duration of marsupialisation for each type of cyst was 11 (5), 8 (5), and 5 (2) months, respectively. The radiolucent area decreased linearly in the 3 types depending on the time after marsupialisation: r=-0.86 (p<0.01), r=-0.73 (p<0.01), and r=-0.72 (p<0.01), respectively. The relative speed of shrinkage did not correlate with the age of the patients, though it did correlate with the size of the radiolucent area before marsupialisation in KCOT (r=0.69, p<0.01) and radicular cysts (r=0.73, p<0.01). These results suggest that the size of a cyst before marsupialisation may affect the speed of shrinkage in KCOT and radicular cysts, while the age of the patient does not.