Sixteen years ago, I met a new patient, Rosemary. Rosemary was referred to me to evaluate one of her teeth that had become very uncomfortable after her first dentist had cemented a crown or cap onto it. She was afraid that she would need root canal treatment. After a brief examination, Rosemary and I figured out that she was biting too heavily on the new crown. Upon making the crown a tiny bit shorter, the pain was completely relieved. I have not seen Rosemary in a long time, but the record shows that that tooth remained fine for at least several years after our last appointment.
Uneven biting or misaligned teeth cause many problems. Dentists call this malocclusion. Occlusion is the way teeth come together. Malocclusion means that the teeth come together badly. Dental treatment, growth, habits and accidents are all causes of uneven bites. All types of malocclusion are treatable.
Most dental treatment that involves changing teeth in some way such as tooth replacement, filling cavities, and crowning teeth may change the way a patient bites. Sometimes dentists change a patient's bite on purpose. When dentists replace old worn dentures, the new dentures are usually thicker. Patience is necessary to become used to the feel of the new dentures and the new bite. If the dentures are too thick, some of the muscles of the face and temples may become sore. The patient may complain of a muscle tension headache. Given time, and ibuprofen, the muscles may stretch and the headaches will stop. If the pain does not stop in a reasonable amount of time, the dentist can thin the denture.
Another common iatrogenic (treatment induced) problem is a restoration (a filling or crown) that is too high or thick. When the treatment is finished, the dentist always checks it by looking at marks made by biting on carbon paper (articulating paper) and by asking the patient how the new restoration feels when they bite. Most patients are numb when the dentist fills their tooth. That makes it difficult to tell if the new filling feels high. In addition, the to one teaspoon of liquid injected into a muscle to make the tooth numb can change the bite so that the patient cannot feel that something is not right. After a few days of biting on a high restoration, teeth often hurt. They are sensitive to cold and to biting pressure. That is what happened to Rosemary. The pain will go away in less than a week if the dentist can find the high spot and smooth it down. After a couple of weeks, the patient may get used to the high spot and adjust their jaw movements and eating habits to it. That may cause other problems.
Malocclusion can cause teeth to wear unevenly or break. For example, when the canine or eyetooth is missing or does not line up the way it should, young patients do not feel that there is a problem. Without the canine, his back teeth would probably wear down faster than normal. He might even develop problems with his jaw joint (Temporo-Mandibular Joint). The dentist could recommend treating this problem a couple of ways. An orthodontist could move the teeth to create space for a dentist to add a using a fixed bridge or dental implant. Another technique would be to change the shape of the back tooth that had moved into the place where the canine would normally reside. A crown could be used to shape the back tooth to look and function like a canine.
Sometimes teeth will erupt (come in) in the wrong position. When the edges of the upper front teeth erupt behind the edges of the lower front teeth, the malocclusion that results is called an under bite. An under bite often pushes the lower jaw forward. The resulting tension causes the lower jaw to grow faster than the maxilla, the bone that supports the upper teeth. The appearance of a large, anvil jaw, or a smaller, pushed in, mid face is usually quite noticeable and unaesthetic. Dentists can diagnose this problem in children. Treatment of under bite is simple in early stages. Usually, a removable device can tilt the upper teeth forward in months. Older children and adults may require surgery to correct a severe under bite.
Temporo-Mandibular joint dysfunction and myofacial pain syndrome are conditions in which the jaw joint and/or the muscles that move it are in pain or do not work correctly. Symptoms range from mild pain when chewing or clicking and popping noise in the joint to debilitating jaw pain, headaches and the jaw locking open or closed. Disease, such as arthritis, or chewing habits may cause this type of problem. Frequently, malocclusion may cause jaw joint and muscle pain.
Treatment for jaw joint and muscle pain begins by taking anti-inflammatory medications like aspirin and ibuprofen, muscle relaxant medication like Soma and Flexeril, and by reducing stress to the muscles and joint. Being on a soft diet and not opening wide reduces stress. Usually, the symptoms will subside in a week or less. When the symptoms continue, the dentist will examine the patient’s bite and change it. The dentist may be able to adjust the bite by smoothing parts of the teeth to make them more even. If the teeth are too short already, the dentist may build the bite up. First, the dentist makes a mouthpiece called a bite splint or bite plane. The patient wears the bite splint on their upper or lower teeth several hours a day or more. When the dentist adjusts the splint and the patient feels comfortable with their new bite, the dentist can build the patient a new bite permanently with crowns or other similar devices. This treatment is very expensive. However, it is very valuable to the many people who feel better after years of debilitating pain.
These are only a few common examples of bite problems. The way teeth fit together may cause other problems and symptoms. If you suspect that there is something wrong with the way that you bite, speak with your dentist about it.
Dr. David Leader is the Chairman of the Health Advisory Committee of the Lynnfield Schools, a member of the Professional Advisory Committee of Tri-CAP Head Start, and is a member of the Mass Dental Society Council on Dental Care and Benefits Programs.