Wisdom teeth, also known as third molars, are the final set of molars located at the very back of the mouth. They are the last teeth to emerge into the oral cavity. Most individuals have four wisdom teeth, with two located in the upper jaw and two in the lower jaw. These teeth are a normal part of mouth development, although they often appear much later than other permanent teeth.
The Typical Eruption Period
Wisdom teeth typically emerge during a person’s late teens to early twenties (ages 17-25). This later appearance is why they are commonly referred to as “wisdom teeth,” as they come in at an age when individuals are considered to have gained more wisdom than in childhood. The process of tooth eruption involves the tooth moving from its developmental position within the jawbone to its functional position in the mouth, breaking through the gum line. This process is similar to the eruption of other permanent teeth. Some individuals may experience eruption slightly earlier or later.
Common Signs of Eruption
When wisdom teeth begin to emerge, individuals may experience physical sensations and visual cues. A common sign is a mild discomfort or a dull ache in the back of the jaw, near where the teeth are coming in. This discomfort can be intermittent at first, potentially becoming more consistent as the tooth continues its emergence.
The gums around the emerging wisdom teeth may also become tender, red, or swollen. Some individuals report a feeling of pressure or tightness in the back of the mouth as the teeth attempt to push through. While these signs are common, wisdom teeth can also erupt with no noticeable symptoms.
When Wisdom Teeth Don’t Erupt Normally
Not all wisdom teeth emerge in the typical manner; variations in their eruption are common. One variation is delayed eruption, where the teeth take longer to emerge than the usual age range, sometimes many years later.
Another common outcome is impaction, which occurs when a wisdom tooth is unable to fully emerge into the mouth. This can happen if the tooth gets stuck beneath the gum tissue or against an adjacent tooth, often due to insufficient space in the jaw. Impacted wisdom teeth can present in various orientations: mesial impaction, where the tooth angles forward; horizontal impaction, where it lies completely on its side; or vertical impaction, where it is upright but trapped beneath the gums or bone.
Agenesis refers to the absence of one or more wisdom teeth, meaning they never form. Between 5% and 37% of the population may be missing at least one wisdom tooth. This variation is influenced by genetic factors and is considered a normal occurrence.