Many patients ask me why I shake their cheek when giving anesthetic, commenting that they’ve never had that done before. They often assume it is just a distraction, but there’s more to it than that. Your body has about twenty different types of nerve endings that all send messages to your brain. However, the most common receptors are heat, cold, pain, and pressure or touch receptors.
All nerve endings send potentially important information to your brain, but not all messages from nerve endings are given equal priority. Because the many different types of nerve endings all have to send their messages to the brain through shared nerve bundles it is sometimes possible for the amount of information being transmitted to exceed capacity—and some information gets left out. The nerve endings that transfer information about pressure and movement tend to get top priority, while the nerve endings that transfer information about pain have a lower priority. By “jamming the lines” with lots of information about pressure and movement (by squeezing and shaking the cheek) it is possible to reduce or eliminate the pain signals (from an injection) that the brain receives. That’s why I squeeze and shake your cheek when giving an injection—so that your brain will receive reduced input about pain. You probably have unwittingly used this pain reduction method on your self in the past. If you hit your thumb with a hammer, you tend to vigorously shake it—because it seems to hurt less when you do that. If you stub your toe, you tend to grab the toe and tightly squeeze it—because it seems to hurt less when you do that. The neuroscience that you naturally use without realizing it, we consciously apply to improve your dental experience. Of course, there are many other things we do that also work to reduce your discomfort during the administering of anesthesia. We offer nitrous oxide (relaxing) gas, place a potent topical anesthetic gel beforehand to numb the tissues, and use pre-warmed carpules of anesthetic.