Described here are devices and methods for dilating tissues. In other variations, the dilatation device comprises a slotted or expandable tube that may expand to dilate tissue. In still other variations, the dilatation device comprises two or more hinged or movable plate members that separate to dilate tissue. In yet other variations, the dilation device may comprise one or more flexible members. One or more portions of the dilatation device may be detachable from the device in the body, and dilatation device may release one or more implants into the body. In some of these variations, the dilatation device may additionally be used to expand one or more implants or other devices within the body. In some variations the dilatation device may release one or more substances that may hold dilated tissue in a dilated configuration.