The full complement of teeth in the mouth should be 32, of which 4 of these are the wisdom teeth, two on top and two at the bottom at the far back of the mouth. They normally erupt into the mouth between the ages of 17 and 25, sometimes even later in life, although one should know that not everybody has wisdom teeth, and if we do, they do not necessarily have to be 4 in number, so that one can have 1, or 2, or 3 or 4 erupted into the mouth, or none. Sometimes they are present, but remain under the gum and never come out. They are also known as third molars or the 8’s.
What is so particular about the wisdom teeth is that since they are the last to erupt they usually do not have enough space to fit in with the rest of the teeth. So in the process of trying hard to find a place, they come out into an abnormal position, what is usually referred to as ‘impacted’. This is due to a lack of space and the tooth wedges against the tooth in front of it. It could be fully and deeply impacted, in which case it is totally embedded in the bone and gum; or partly erupted and part of the crown of the tooth is covered with bone and gum and the remaining is exposed in the mouth and visible. The tooth may be inclined forward, backwards, or totally horizontal. The roots of the wisdom teeth may be conical in shape, or divergent, and possibly deep and close to the nerves of the face.
Impacted wisdom teeth do not always cause problems. If there is enough room for them they usually erupt into a good and useful position. And the practice is that if they are not causing any problems they should be left in place, even though often they are not positioned correctly. Sometimes they cause discomfort as they come through the gum, although this might be temporary until the tooth reaches a final position. On other occasions part of the wisdom tooth comes out while the rest remains under the gum. This gum may become infected and swell up because plaque and food particles collect under this gum flap. It may be possible to keep this gum flap clean using mouthwashes and brushes. However if it swells up often the dentist might advise to have it removed.
So when should wisdom teeth be remove?
- When there are repeated infections in the gum around the wisdom tooth ( an infection referred to as pericoronitis) causing swelling, pain, limited opening of the mouth and possibly even fever. If this happens often and antibiotics are needed each time, then the tooth should be removed.
- If the tooth itself is decaying( caries) or is causing decay of the tooth in front of it because of food particles getting stuck between the two teeth. This is more likely with wisdom teeth since they are at the far back of the mouth and hence more difficult to keep clean.
- If the tooth is developing a cyst around it.
- Sometimes they are removed because of orthodontic treatment.
- Over eruption of the lower or the upper wisdom tooth such that it starts to hit the opposing gum causing ulcers.
Some people believe that impacted wisdom teeth cause the anterior teeth in the mouth to crowd or overlap each other by pushing forward on the teeth in front of them. We know today that this is not the case and that anterior teeth will in some patients crowd over each other whether or not wisdom teeth are present.
Prior to removing a wisdom tooth, an appropriate x ray ( OPT) should be taken to check the size and shape of the roots, the depth and type of impaction and the proximity of the roots to the nerves of the face and the tongue. The tooth will usually require a surgical removal approach, whereby the gum around the wisdom tooth is reflected away, some bone around the site is also removed with or without splitting of the wisdom tooth, and once removed the site is closed again using some sutures/ stitches.
Common effects after the procedure would be pain ( controlled with appropriate pain killers), swelling for a few days ( controlled by ice packs immediately after the procedure), discomfort on eating ( eat soft foods), limited opening and closing of the mouth, and brusing. These effects normally last for a maximum of 1 week.
After the procedure the patient should rest and take the appropriate pain killers and antibiotics. The day following the surgery the patient is advised to rinse gently with warm water and salt, and clean around the area with a soft brush. Also to use a mouthwash. Bleeding should be under control the following day, but if not you should consult your dentist.
One other note: The procedure, if limited to one wisdom tooth is normally done under local anaesthesia. If two or more impacted wisdom teeth are to be removed then a general anaesthetic in a hospital setting is advised. However the patient might want a general anaesthetic even for one extraction.
One final note: The difficulty or otherwise of removal of the wisdom teeth depends on the shape and size of the roots, and the type of bone surrounding it, and the type of impaction. Your dentist will advise you appropriately before hand of the procedure after an accurate study of x rays, and any complications which may possibly arise. Sometimes in difficult cases a referral to a specialist is warranted.