Cracked tooth: types of tooth fractures

Dentists often find cracks in teeth. Determining their size and direction plays a major role to determine what type of treatment, if any, is needed. Cracks are all a type of fracture in the tooth and the terms are often used interchangeably in dentistry. The American Academy of Endodontists classifies cracks into five categories of fracture that may extend partially or down the entire length of the tooth. Whether a crack is caused by general wear and tear or a sudden injury, your dentist will be able to properly classify the type of fracture and prescribe the correct treatment.

Do you think you may already have a cracked tooth? Symptoms include sharp, brief pain upon contact with cold substances; pain upon biting; and, sometimes, spontaneous tooth pain. You may be able to see a crack or tooth damage when you look in the mirror or feel damage with your tongue. If you have any of these signs or symptoms, make an appointment with your dentist as soon as possible. The sooner a cracked tooth is properly diagnosed and treated, the better the outcome.

Types of tooth fractures

Cracked teeth are typically categorized into one of the following types: craze lines, fractured cusps, cracks that run through the crown of the tooth and reach to the gum line, split teeth, and vertical root fractures.

These five categories represent the most common types of cracked teeth that dentists encounter.

  1. Craze lines: These are the most benign of tooth cracks and can be common in adults. While not technically considered fractures, craze lines are tiny, hairline cracks that form in the tooth's enamel, typically appearing as faint vertical lines. Craze lines do not extend to the gums and, in most cases, are only a superficial concern requiring no treatment. They rarely cause any pain, and only pose a threat to oral health if they worsen and extend into the tooth dentin. An uneven bite, teeth grinding, nail biting, ice chewing and a variety of other issues can all cause stress to the enamel and lead to craze lines. It can be difficult to determine if the crack is limited to the enamel, but your dentist can review any signs and symptoms and perform various tests to determine a diagnosis.
  2. Fractured cusps: A fractured cusp occurs when a piece of the chewing surface of the tooth breaks off. It often happens in teeth with large dental fillings. The break may extend to the gumline or below, but often doesn’t harm the pulp of the tooth (where the nerves, blood vessels, and connective tissue are located). You may not feel any pain, but there could be temperature sensitivity. A fractured cusp may require a root canal if the pulp is exposed, but often can be fixed with just a new filling or a crown. In most cases, the tooth can be saved.
  3. Cracked teeth: A tooth that cracks vertically (extending from the chewing surface downwards toward the root) can occasionally crack down to or beneath the gum line. This type of crack is incomplete, however, so the tooth does not split in two, and is often able to be saved. Damage to the sensitive pulp is common with these types of cracks, and root canal therapy is often necessary. Sometimes tooth extraction is also warranted. There are a lot of variables to be considered with cracked teeth depending on the location and extent of the crack, so determining the proper treatment can be very difficult, which can also make long-term success of treatment challenging to predict. Cracked teeth tend to be more painful and require early attention in order to prevent loss of the tooth.
  4. Split teeth: A split tooth is categorized as such when a crack travels all the way from the surface to the root – to the extent that the tooth is actually split in half. This type of crack is usually too extensive to salvage the tooth and extraction is typically necessary. In some cases, on molar teeth that have multiple roots, a portion of the tooth can be saved by extracting the damaged side of the tooth and doing a root canal and crown on the remaining tooth.
  5. Vertical root fractures: A vertical root fracture begins at the root of the tooth and travels upwards toward the chewing surface. Pain or other symptoms are usually minimal, and in some cases may go undetected for a long period of time. A vertical root fracture requires extraction unless a dentist is able to successfully salvage a portion of the tooth by removing the fractured root. Vertical root fractures almost always occur in teeth that have had previous root canal treatment.

Treatment for a cracked tooth depends on the type, location, and severity of the crack. Craze lines, for instance, usually require no treatment at all, while a crack that extends down the middle of the tooth to the gum line will require immediate attention and a potential extraction.

If you are experiencing sharp pain upon exposure to cold temperature or pain upon biting or chewing, you may have a cracked tooth. Do not ignore it. Make an appointment with your dentist.

Additional resources

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