Why Do Our Teeth Shift?

As we age, many changes occur to our bodies and our teeth. Our teeth shift and move slightly over time due to many factors, some that we can control and others that we can't. These factors include tongue movements, lips pushing against our teeth, and how our teeth fit together. Below, we will review some of these reasons in greater detail.

What Can Move Our Teeth

- Tongue Movements. The most common is having an abnormal tongue thrust. Our tongue places pressure on our teeth when we are eating, swallowing, and talking. We do not even realize how often our tongue presses against our teeth. If you swallow, you will realize that your tongue presses against your upper teeth. For most of us, this does not cause an issue, but for others with a powerful tongue thrust, this can cause tooth movement over time.

- Lip Habits. The pressure that your lips apply to your teeth can actually cause your teeth to move. A good example is tucking your lower lip behind your upper teeth. This is a common habit in younger children and people who bite their lips when they get nervous. The force of this over time can cause those teeth to shift outward.

- Frenum Issues. The frena is the attachment between your lips and tongue to the gum tissues on the teeth. The attachment on the inside by your tongue is called a lingual frenum. The other two are on the inside of your lips and called a labial frenum. The lingual frenum usually does not affect the teeth but can affect eating, speech, and swallowing as it can constrict tongue movement. The labial frenum can play a part in moving the front two teeth apart. To alleviate this, your dentist or oral surgeon can remove the labial frenum surgically.

- Forces From Our Teeth. Our teeth are in a constant state of pressure from each other. Normally when you bite down, your teeth touch and rest in a certain position. This position is known as centric occlusion. The top teeth oppose the bottom teeth and keep them in line. However, if you lose a tooth or a tooth becomes badly damaged from trauma or tooth decay, then a space opens up. The teeth on either side of the lost tooth move, as will the tooth that opposes it. For example, if you lost a lower tooth, the tooth on the upper jaw that normally hits it would start to grow down slightly to fill in the space. Then the adjacent teeth to the lost tooth would start to lean in towards the empty gap.

- Genetics. Our body is hardwired with a specific set of instructions and our genetics determine if our teeth will be straight or not.

- Tooth Decay. If tooth decay is left untreated, your tooth will eventually break down, changing its shape and size. This will open up space causing our teeth to shift into that space. Also, a tooth restored improperly can change the tooth’s relationship to the other teeth, causing changes as well.

- Age. As we age, the area between the teeth starts to wear away. When this happens, the enamel begins to thin out. Since the lower teeth are inherently thinner, they wear out faster. The more wear and tear on the lower teeth, the less able they are to withstand the force of the top teeth when biting down, resulting in shifting.

- Teeth Grinding (Bruxism). Teeth grinding forces the lower jaw forward and puts tension on the upper teeth. The continual thrusting affects the position of the upper arch, pushing it out of alignment.

Teeth Shifting

As you can see, there are many different factors that are constantly acting on your teeth, that can cause them to move. It is important to treat the reasons that you can control. See your dentist if you feel your teeth are shifting to avoid any future issues.