One of the most difficult diagnoses in dentistry is Cracked tooth syndrome. The patient generally presents to us with sharp pain on chewing in a certain area of his mouth, but he frequently cannot tell us which particular tooth hurts. It is generally a back tooth, and it becomes plain which tooth it is when the dentist has the patient bite on piece of wood placed on top of the correct tooth.
As a rule, dentists cannot see any problem with the tooth, either clinically (in the mouth or radiographicly (on an x-ray). Dr. James Courey uses CBCT 3-D radiography to diagnose cracked teeth.
The tooth may have no fillings or decay, or it may have an intact filling with no visible associated problems. Nothing looks wrong, but the patient feels sharp pain when he applies biting pressure to the top of the tooth. Symptoms of sharp pain to pressure accompanied by no visible signs of problem with the tooth are the hallmarks of cracked tooth syndrome.
The diagnosis can be further confirmed when the dentist uses an instrument that rests on one part of the tooth at a time. There is frequently sharp pain when the pressure is applied to only one
particular cusp (the pointed parts of a back tooth and not to others. If the tooth has a crack in it, the pain is caused by movement of the affected cusp. The other cusps generally prove to be non painful when the same pressure is applied. The "movement" of the fragment is usually microscopic, and not visible to the naked eye.
How can a tooth have a crack, but show no outward signs of a crack?
When a real crack occurs in a vital tooth (one with a living nerve the crack frequently does not propagate all the way through the tooth. This type of crack is called a greenstick fracture because, like a green branch from a tree, the fracture may be mechanically present, but the unbroken segments of the branch hold it together.
The crack usually propagates through sensitive parts of the tooth (the dentin many times involving the living nerve. When pressure is applied to the cracked piece of the tooth, a tiny bit of movement of that piece places pressure on the nerve, or other sensitive tooth structure and even though the movement is tiny, it hurts a lot! Since the tooth cannot heal itself, the pain is always present whenever pressure is applied to the biting surface of that tooth.
The pain will not go away until one of two things happen.
- The cracked piece of tooth may break off relieving the pain when pressure is applied to it. When this happens, the tooth can usually be repaired with a crown or a simple filling and the patient (and tooth) lives happily ever after.
- The nerve may die as a result of the repeated assaults placed on it by the moving fragment of tooth. When this happens, the pain to pressure may stop, but the dead nerve leaves the patient vulnerable to a dental abscess unless root canal, and subsequent crown are done.