As a term frequently interspersed in dialogues around oral health, wisdom teeth evoke curiosity and varied experiences, with their stories etched in the fabric of dental evolution.
Do Wisdom Teeth Grow for Everyone?
Wisdom teeth, the third set of molars at the back of the mouth, do not develop in every individual.
Research indicates a significant portion of the population is born without one or more of their third molars. A study by the American Journal of Public Health found that up to 35% of individuals may not develop wisdom teeth at all.
The absence of wisdom teeth can be attributed to a process called evolutionary regression or reduction.
Over time, ancestral human diets changed from tough, raw foods to softer, cooked diets, which reduced the need for the additional grinding power that wisdom teeth once provided.
Genetic mutations that disable the development of wisdom teeth may not have been selected because these teeth are no longer critical for survival.
Consequently, some individuals have inherited these mutations, resulting in a lack of wisdom teeth.
Genetic disposition plays a lead role in the absence of wisdom teeth.
Ancestors' dietary shifts may have led to alterations in human jaw size and the necessity of wisdom teeth.
Individuals who do not possess these teeth may carry specific genetic variations responsible for their absence.
Why do some people still develop wisdom teeth while others do not?
The answer lies in our genetic blueprint, which has been shaped by countless generations of evolution, with each adaptation or mutation contributing to the diversity seen in our species today.
Also read: How to get food stuck into wisdom teeth
Mysteries of Wisdom Teeth and Genetics
The genetic tapestry of tooth development is complex, with multiple genes interacting to determine not only the traits of teeth—such as size, shape, and number—but also whether wisdom teeth form at all.
Heredity is a fundamental factor in this process, meaning that a parent's dental history can offer a predictive glimpse into the dental future of their offspring.
The role heredity plays in the emergence of wisdom teeth is evident as patterns of presence or absence often run in families. While the average person develops four wisdom teeth in late adolescence or early adulthood, some may develop fewer, or none at all—a condition referred to as hypodontia.
Conversely, there are rare instances where individuals may develop more than four wisdom teeth, known as supernumerary teeth, due to genetic variations. These occurrences confirm that the blueprint for wisdom teeth is not a one-size-fits-all.
Researchers have identified certain genes, such as PAX9, MSX1, and AXIN2, as influential factors in tooth development.
Variations or mutations in these genes can lead to alterations in the normal pattern, including the absence of wisdom teeth.
The genetic instructions that guide tooth development are inherited, thus the number of wisdom teeth can be linked to family lineage.
The Evolutionary Tale of Wisdom Teeth
As humans evolved, both the brain and skull underwent remarkable changes, leading to a reduction in the size of the jaw. The larger brains of modern Homo sapiens required changes in skull shape and size that did not favor large jaws. Consequently, with smaller jaws, there was adequate space for the full complement of teeth that our ancestors had.
Reflect on the mighty mammoths that once roamed the Earth, bearing tusks of impressive length and girth. Just as those tusks became redundant and disappeared through evolution, so too are human wisdom teeth slowly becoming an obsolete convenience.
With the decrease in jaw size, many individuals now have jaws too small to accommodate the third set of molars.
This evolutionary mismatch between tooth size and jawbone can lead to the impaction of wisdom teeth, where they fail to emerge properly.
Estimates show fewer modern humans have the required space for wisdom teeth compared to our ancestors.
Humans have adapted to a new kind of environment, one where the physical demands on teeth are less strenuous. Researchers have found that the gene determining the number of teeth varies less in populations with softer, processed diets, supporting the link between ways of life and dental evolution.
Do You Need Wisdom Teeth?
Some individuals may wonder about the implications of lacking wisdom teeth. Unlike the absence of certain other body parts which can cause issues, not having wisdom teeth does not lead to direct health problems. In fact, most dental professionals consider the absence of these third molars a stroke of good fortune. Modern diets and advances in oral care have rendered these teeth largely unnecessary, and their absence can often eliminate the potential for dental complications.
When wisdom teeth are present, they may fail to erupt properly and cause crowding, infections, or cysts. Hence, the absence of wisdom teeth negates these risks. The human jaw has evolved to become smaller, leaving insufficient room for these molars to grow comfortably or correctly. Modern dental practices frequently involve the removal of wisdom teeth to prevent future issues. If a person has space in their mouth to accommodate these teeth without any complications, they typically do not have to be removed.
Individuals without wisdom teeth bypass a common rite of passage: extraction, which involves surgery, recovery time, and often discomfort.
Those without wisdom teeth can often avoid the associated potential orthodontic problems.
Radiographic evaluations can determine the absence or presence of wisdom teeth, guiding a dentist's recommendations.
Also read: Does everyone have wisdom teeth?
Understanding Impacted Wisdom Teeth
When wisdom teeth cannot emerge normally, they become impacted. The occurrence of impacted teeth results from several factors, with insufficient space in the jaw being a primary reason. As humans have evolved, smaller jaw sizes contribute to this lack of space. Teeth, in some cases, may align improperly as they make an effort to find their place in an already crowded mouth which can lead to impaction.
A smaller jaw translates directly to challenges in accommodating the full set of adult teeth. Impacted wisdom teeth can be a consequence of evolution's reshaping of the human skull and jaw - resulting in a mismatch between tooth size and jawbone volume. Moreover, dietary changes and the consequent alteration in jaw musculature play roles in how jaws develop and affect tooth impaction as well.
Impacted teeth may grow at an angle, either toward the second molars (mesial impaction), away from them (distal impaction), horizontally (horizontal impaction), or they may become completely trapped within the jawbone (vertical impaction).
The pressure from impacted wisdom teeth against other teeth can cause pain, swelling, and, over time, misalignment of other teeth. In addition, cysts or infections may develop leading to further dental issues.
Assessing the Need for Wisdom Teeth Removal
The decision to remove wisdom teeth does not follow a universal rule and hinges on individual circumstances. A dental professional assess factors like the angle of eruption, the impact on neighbouring teeth, and any present or potential discomfort or disease. A consultation often includes a thorough examination and imaging, such as panoramic X-rays, to determine the position and health of the wisdom teeth.
If the teeth are fully erupted and accessible, maintaining them with regular cleaning and monitoring for any changes may be sufficient.
Partial eruption poses a higher risk for pericoronitis, an inflammation of the tissue surrounding the tooth, which can necessitate extraction.
Any signs of damage to nearby teeth, nerves, or the jawbone will also merit removal to prevent more extensive issues.
Desire for orthodontic treatment or surgeries that necessitate removing wisdom teeth.
Routine monitoring and consultations with your dentist or an oral surgeon efficiently guide the best course of action. Removing wisdom teeth when the individual is younger can result in a simpler procedure and a swifter recovery due to the roots not being fully developed and the bone being less dense.
Alternatively, adults may experience a slightly more complex procedure and extended healing times.