Intracystic fluid pressure in non-keratinizing jaw cysts

The technique for registration of fluid pressure in jaw cysts by means of pressure transducer and cannulation of the cyst cavity or cementation of a two-way valve into a tooth communicating with the cyst is described. Twenty-six closed cysts were subjected to registration of intracystic pressure. Subsequent histologic examination showed that all cysts were non-keratinized. Initial pressure values in apical periodontal cysts averaged +47 mmHg, in follicular cysts +44 mmHg, and in residual cysts +38 mmHg. A median palatine cyst exhibited a pressure of +81 mmHg. Most cysts showed intracystic pulsation corresponding to the number of heart beats on electrocardiograms obtained simultaneously. The intracystic pulsation disappeared when the intracystic pressure was experimentally increased and reappeared when it was lowered. In three cases in which registration of pressure was performed 7-14 days after the aspiration of the cyst fluid, an intracystic pressure in the same range as the initial one was found. The findings indicate deficient lymphatic drainage of non-keratinizing jaw cysts.