In certain situations where a tooth has been missing for some time, or there are no teeth present, and we wish to have a precise measurement of the bone area underneath, we ask patients that they have something called a CT scan of the area. A traditional dental X-ray is two dimensional and has limitations as it only shows available bone height. A CT scan takes a 3-D image of the area we are interested in. This tells us how wide and tall the bone area is and reveals other vital areas near the planned surgery area, such as your sinuses and nerves.