Those mysterious wisdom teeth
Wisdom teeth, also called third molars, are the last of your permanent teeth. They come in at the back of the dental arch between the ages of 18 and 21. Their development is slow and often problematic.
Due to lack of space, wisdom teeth can have trouble coming in or positioning themselves properly. All too often, they are too big for the space available.
Why does this happen?
- Over time, the human jaw may have gotten smaller as the size of our teeth remained the same. This would explain why so many people lack the space needed for wisdom teeth to come in properly.
- The evolution of our diet toward softer foods means our teeth don’t wear out as much. In the past, wear and tear may have made our teeth smaller, which would have left sufficient space in the dental arch to accommodate wisdom teeth.
- An improved diet and better oral hygiene mean that we may lose fewer teeth than our ancestors. Our teeth therefore stay in place longer and fill all the available space in our mouth.
It can be hard to predict how and when wisdom teeth will come in. They may grow in the wrong direction, come in partially (semi-impacted) or not at all (impacted).
1) Wisdom teeth growing in the wrong direction
When a wisdom tooth grows in the wrong direction, it puts pressure on the adjoining molar and causes other teeth to overlap or become misaligned.
And, if the wisdom tooth comes into contact with the root of an adjacent molar, it can cause that root to be reabsorbed. Over time, the root will disappear until the tooth becomes weakened or eventually falls out.
2) Partially erupted wisdom teeth
Sometimes a wisdom tooth only comes out partially, leaving part of the tooth under the gum. This can cause an infection since bacteria tend to penetrate the tissue. Pain, fever and complications, like abscesses or cysts, may occur. A semi-impacted wisdom tooth has to be tended to quickly and often requires an extraction.
3) Impacted wisdom teeth
Impacted wisdom teeth don’t come in at all. Even though the tooth is mostly formed, it remains under the gum. Nine out of ten people will have at least one impacted wisdom tooth. Sometimes this can cause problems and sometimes it has no consequences whatsoever.
4) No wisdom teeth (agenesis)
A complete lack of one or several wisdom teeth is also a common occurrence. Wisdom teeth are the most prone to agenesis. In most cases, this doesn’t cause a problem, unless the wisdom tooth on the opposite dental arch comes in. If a wisdom tooth does not have an opposing tooth to rest on during occlusion, it can become loose and may sometimes need to be extracted.
Oral health problems caused by wisdom teeth:
- Abscesses and cysts
- Gum infections where the tooth has partially erupted
- Deterioration of adjoining teeth
- Overlapping teeth on the dental arch
Extracting wisdom teeth
To avoid complications, it’s sometimes best to remove wisdom teeth. By regularly monitoring their development, the dentist can make sure they come in properly and that the space available is sufficient. X-rays will show what is happening under your gums and help the dentist determine if the teeth need to be removed before they cause problems.
Wisdom teeth are harder to extract than other teeth. Because they are located at the very back of the dental arch and are often impacted in the gum, it is a delicate surgical procedure. A complete exam of your mouth and an assessment of your overall health are needed before an extraction can be performed.
Surgery can be done using local anaesthesia, although general anaesthesia is sometimes recommended.