Jaw cysts, especially giant jaw cysts, keratotic cysts, and enucleated cell tumors, have been treated mainly by scraping or osteotomy in the past, and these surgical methods have disadvantages such as huge trauma, easy recurrence of residual cyst epithelium, cosmetic damage, loss of oral physiological function, and difficulty in restoration (e.g., veneers), which are no longer suitable as the preferred treatment for large jaw cysts, and are gradually being replaced by new and function-preserving surgical procedures —– open window decompression. Open window decompression of jaw cyst is to open a window on the surface of cystic lesion, open the bone and cyst wall locally, drain out the cystic fluid, and make a stopper to keep the drainage port open, so that the pressure inside and outside the cystic cavity can be kept in balance, and in the functional activity state of jaw bone, the cystic cavity is gradually reduced and the shape can be restored by the new bone around the cyst. Usually, the decompression time after open window surgery is about 1 year, and the cyst can disappear completely without 2-stage surgery, and those who have not disappeared completely can feasibly scrape the already shrunken cyst with 2-stage surgery. The purpose of window decompression is to make the cyst cavity shrink, restore the shape of the jaw bone, and protect the morphology and function of the jaw bone to the greatest extent. It is like a balloon with a hole, and the ball is crumpled and shrunk.