How many teeth do you have? Your answer to that question varies according to multiple factors: age, surgical history the number of hockey games you’ve played. The most common change to your answer after reaching adulthood comes with the arrival of wisdom teeth.
Dentition: Tooth Arrangement and Placement
Wisdom teeth removal is one of the most common surgeries, with 85% of people undergoing it at some point in their lives. The appearance of our wisdom teeth signals a very old aspect of human biology. The old-world primates, which include humans in their number, have 2-1-2-3 dentition. New world monkeys have 2-1-3-3 dentition, and this orientation can be used to correctly identify the area of the world a primate skull originates from. Dentition is the arrangement and placement of the teeth in the mouth. The number code corresponds to the amount and type of teeth in each quarter of the mouth: two incisors, one canine, two pre-molars and three molars. All old-world primates have these, except humans. Removing our wisdom teeth makes our dentition 2-1-2-2. So, what happened to our teeth and jaws to incite this dental change?
Shrinkage: Dental Overcrowding
A change in humanity’s genetics is not the origin of the wisdom teeth problem. In early human skulls, scholars see little to no malocclusions, misplacements or disruptions in their dentition. Further, there is little evidence suggesting that humans select the traits for smaller jaws as it provides no evolutionary advantage. Also, enough time hasn’t passed for an evolutionary change like a decreased jaw to be feasible. Much more time and selection would be required for the human genome to encode smaller jaws. But the evidence in the skull of some sort of shift is undeniable. Many people must get their wisdom teeth removed because they don’t fit, a problem that does not exist in older skulls. So, what is causing this shrinkage that leads to the undeniable dental overcrowding?
Environment: Jaw Atrophy
-Changing Impetuses: Genetics alone does not determine the exact appearance of an individual. The environment a person lives in has an equal effect on their body’s development. An example would be how drinking caffeine stunts human growth. Genetically you could be disposed to being 5’10, but because you’ve drank three espressos every day since you were five, you end up being 5’5. Genetically, the human jaw is meant to house a 2-1-2-3 dentition. Environmentally, human behavior has changed from our impetuses, changes which result in less developed (and thus smaller) jaws.
-Softer Food: Humanities’ jaws have been shrinking since our paleolithic shift from hunting and gathering towards agriculture. Malocclusions begin as uncommon or even unseen in hunter-gathering societies, but as humans transition to agricultural societies they become more common. The hypothesized reason for this is the comparative softness of the foods humans eat post-agriculturalization. Early hunter-gatherers consumed tough foods like roots or raw meat, which require a strong jaw to properly chew. The comparative softness of grain and fruit results in decreased jaw usage. This decreased usage results in an under-developing of the muscles and soft tissues of the jaw, which creates a smaller jaw unable to accommodate teeth as genetically expected. And as human society has continued in agrarian ways, our jaws continue to remain atrophied.
-Softer Beds: Another more modern element of the underdeveloped jaw involves how humans sleep. The softness of our beds now, when compared to the hard ground we used to sleep on, leaves us more suspectable to our mouths falling open. This mouth breathing disturbs the intended facial muscle position, thus leading to misplacement.
Surgical Intervention and Preventative Measures
Thankfully, modernity has supplied many solutions to this problem outside of beginning to chew hard tubers every day. There is the surgical intervention of removing wisdom teeth, either as a preventative or reactionary measure. Predictive removal can prevent some of the painful and non-aesthetic effects that wisdom teeth’s arrival has on the mouth, like infection or dental shifting. If you are old enough to be reading this article though, there is nothing to be done to permanently remedy the underdevelopment of your jaw. There are, however, according to Stanford scholars, preventative measures that one can take with children to ensure proper jaw development. Adopting proper breathing and swallowing techniques, chewing sugar-free gum, and encouraging earlier introductions to solid foods can all aid in healthy jaw development.
Call Today
If you have questions or concerns about your child’s developing smile, our Westtown Dental Care team in West Chester, PA, is here to help! We offer pediatric dentistry and even tooth extractions to help your child’s jaw grow properly. Please call 484-887-0777 to learn more or to schedule your consultation with one of our skilled dentists, Dr. Sara Bekyan or Dr. Garrett McDowell.
Works Cited
Hadhazy, Adam. “A hidden epidemic of shrinking jaws is behind many orthodontic and health issues, Stanford researchers say.” Stanford UP, 21 July 2020, Stanford News.
Merrifield, Rex. “Wisdom teeth failing to appear as human jaw evolves.” European Union, 20 June 2016, European Commission.
“When Did Removal of Wisdom Teeth Begin?” Paradigm Dental.
“Why Do Most People Have Their Wisdom Teeth Pulled?” Corson Dentistry.