Coronectomy for a Wisdom Tooth

Liverpool University Dental Hospital

Your dentist may have advised you during your consultation that a coronectomy is the best treatment for your problems with your wisdom tooth. A coronectomy is the removal of the crown of a tooth.

This leaflet has been designed to improve your understanding of any future treatment and contains answers to many of the commonly asked questions. If you have any other questions, or would like further explanation, please ask a member of the clinical staff.

The problem

The roots of the wisdom tooth (or third molar) can be closely associated with a nerve that runs through your lower jaw. This means that the nerve may be vulnerable to damage when the roots are removed resulting in numbness of the lip and chin area. It is possible to reduce this risk by removing the crown of the tooth only and leaving the roots behind.

When is a coronectomy not an option?

If there is a significant risk of infection after this procedure, then this treatment is not advisable.

A coronectomy would be contra-indicated if there is:

• Significant or extensive decay or root abscess on the wisdom tooth.
• Any medical condition which may result in a decreased immune response e.g. diabetes.
• Any mobility of the roots at the time of surgery.

What are the risks?

Usually the roots that are left behind cause no problems, however the following problems may occur and this may result in a further surgical procedure to remove the roots:

• Infection develops around the roots.
• The roots begin to move towards the surface of the jaw - in this case their removal will be less of a risk to the nerve as they are no longer in close proximity.

It will be necessary to make a cut in the gum over the tooth and remove some bone surrounding the crown of the wisdom tooth. The crown of the tooth is then divided from the roots using a drill and lifted out of the jaw.

Once the crown of the wisdom tooth has been removed, the gum is put back into place with stitches. In the majority of cases these stitches are dissolvable and take around two weeks to disappear.

Are there any alternative treatments available?

The only alternative is to remove the wisdom teeth including the roots and accept there will be a risk of permanent nerve damage.

What type of anaesthetic is used?

A number of options are available and depend on how difficult the wisdom tooth is to remove:

• Local anaesthetic - this is an injection at the back of the mouth into the gum surrounding the wisdom tooth, similar to that you may have had at your dentist for a filling.
• The injection takes a couple of minutes to numb the area and means that you will feel no pain while the wisdom tooth is removed. This is the best option for most wisdom teeth particularly those that are less difficult to remove.
• Like all medicines, local anaesthetics may sometimes cause side effects, as well as the effects that are needed. You may experience dizziness, blurred vision, drowsiness and occasionally loss of consciousness.
• Serious side effects are rare and include fits, low blood pressure, slowed breathing and changes in heartbeat, which may be life-threatening. If you have concerns about any of these effects, you should discuss them with your dentist.
• Local anaesthetic and intravenous sedation – in addition to a local anaesthetic injection you can be given an injection into your arm. This makes you feel relaxed and less aware of the procedure. Further information is available in PIF leaflet number 641 “Conscious Sedation For Adults”.
• General anaesthetic – it is usually possible to remove wisdom teeth under a “day case” general anaesthetic, i.e. although you have had a general anaesthetic you will be able to go home on the same day as surgery. For more information, please ask for a copy of the Royal College of Anaesthetists Patient Information “You and Your Anaesthetic”.

If you have a general anaesthetic and/or sedation, you must have a friend or relative to take you home and have a responsible adult to stay with you for 24 hours.

For next 24 hours you must not

• Travel alone.
• Drive any vehicle e.g. car, scooter or ride a motorcycle or bicycle.
• Operate machinery (including domestic appliances such as a kettle).
• Climb ladders.
• Make important decisions, sign any business or legal documents.
• Drink alcohol.
• Return to work within 12 hours of treatment. Your general health and any medicines you are taking may increase the time you need off work.

You should

• Take it easy for the rest of the day, avoid strenuous activity.
• Take your medications as usual.
• Let someone else care for anyone you usually look after, such as children or elderly or sick relatives.

Is there much pain or swelling after a coronectomy?

It is likely you will have some discomfort and swelling both on the inside and outside of your mouth after surgery. This is usually worse for the first three days but it may take up to two weeks before all the soreness goes.

You may also find your jaw is stiff and you may need to eat a soft diet for a week or so. Your surgeon will give advice about this; it may also be necessary for you to have a course of antibiotics. There may be some bruising of your face, which can take a few weeks to fade away.

Is there anything else I need to do after the coronectomy?

It is important to keep the surgical site as clean as possible for the first few weeks after surgery. It may be difficult to clean teeth around the sites, because it is sore.

If this is the case, it is best to keep the area free from food debris by gently rinsing with a mouthwash or warm salt water (dissolve a flat teaspoon of kitchen salt in a cup of warm water) starting the day after surgery.

Do I need to take any time off work?

Usually it is necessary to take time off work, this varies from three to seven days depending on the difficulty of the operation and the nature of your employment.

What are the possible problems?

• Although there may be a little bleeding at the time of the extraction, this usually stops very quickly and is unlikely to be a problem if the wound is stitched.