Why Are Some of Us Born Without Wisdom Teeth?

They say with age comes wisdom. However, does that guarantee wisdom teeth as well?

The eruption of wisdom teeth is different from one person to another. For some, wisdom teeth don't show up at all. If this happens to you, should you be worried? Does it mean that something is wrong with your oral health?

Our Clinical Head and General Dentist, Dr. Marwan Al-Obeidi, explains what wisdom teeth are and why others don’t have them.

SEE ALSO: Wisdom Teeth Removal: Go or No Go?

What are wisdom teeth?

Wisdom teeth are known in clinical and dental terms as third molars. On average humans have four wisdom teeth, one for each quarter of the mouth, however in certain cases the wisdom teeth may never develop and are sometimes missing. They are the last teeth to erupt and they come through at the back of the mouth, behind the last standing teeth. These teeth were named for the time at which they make their appearance at the very back of the mouth, which is usually between the ages of 17 and 25, when a young person might be pursuing wisdom with higher education.

Why do some people lack wisdom teeth?

Not everyone has wisdom teeth. In fact, a study shows that up to 35% of people have missing wisdom teeth. There are three main reasons why wisdom teeth may be lacking inside the mouth:

• They are present but still haven’t erupted yet. Wisdom teeth may never erupt if they are impacted (not enough space for them to grow) and may remain dormant in the jaw bone for many years.

• The lack of wisdom teeth related to genes. A study recently carried out in Princeton University shows evolution has a large role to play in the absence of wisdom teeth. The study shows that the expanding brain size over hundreds and thousands of years, meant that the head was no longer large enough to accommodate a larger brain and an extra set of teeth, therefore a gradual shift in jaw engineering doesn’t allow a third molar to form correctly as they are no longer needed because we mainly rely on our first and second molars to do the chewing, so the lack of the third set won’t prevent you from eating without difficulty.

Another study carried out by the University of Pennsylvania discovered a chromosomal mutation called MYH16. This mutation is explained as an evolutionary trait which has allowed modern humans to grow larger brains and also means humans have less need of and room for wisdom teeth.

Opponents of evolution place greater weight on the dietary shift that has occurred in humans and dental hygiene in lessening our reliance on wisdom teeth, discounting the role of our evolving jaws and brains. However, a simple comparison of ancient bones placing a prehistoric jaw and a modern jaw next to each other, the space is visibly smaller.

• Your wisdom teeth have already been removed.

Should people be worried if they don’t have wisdom teeth?

Not at all. The lack of wisdom teeth is common these days and in fact wisdom teeth are the most commonly missing teeth in the mouth. You may find that either one of your parents or both or even your grandparents may have been missing these teeth. The lack of wisdom teeth does not hinder our efficiency in chewing and in fact it is a blessing as this means you are less likely to have problems that need further treatment.

What are impacted wisdom teeth?

Wisdom teeth are frequently referred to as being impacted. This means that there is either not enough space for them to grow into the jaw in a normal position or they erupt at an angle or in an unexpected location. This poor positioning can cause pain and infection (called pericoronitis) and even if the teeth happen to come in correctly, without any problems, there is still a potential for future problems as wisdom teeth are difficult to clean, so they could become decayed over time and even affect adjacent teeth. There's also a study that attributes crowding of the teeth to wisdom teeth however this is cause for heated debate in the dental world and there is evidence to prove otherwise.

Should people have their wisdom teeth removed?

Wisdom teeth should be removed ONLY if there is good clinical reason to do so.

The NICE guidelines in the UK state that wisdom teeth should only be removed if pathology is observed. Pathology includes unrestorable decay in the wisdom tooth, non-treatable nerve damage, cellulitis, abscess and jaw infections as well as damage to the wisdom tooth or adjacent teeth. The guidelines also state that wisdom teeth can be removed if pain arises owing to the impaction of the wisdom tooth. The guidelines are clear however that the wisdom teeth should not be removed if there is no good clinical reason to do so.

Concerned about your wisdom teeth? Enquire today.

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