Bite Back:

Unveiling the Unexpected Design Flaws Behind Human Teeth's Surprising Setback.

The prevalence of dental issues like cavities and misaligned teeth has become a widespread concern, affecting a significant portion of the global population. Tooth decay, also known as dental caries, stands as the most common and pervasive chronic disease worldwide, with nine out of ten adults over the age of 20 experiencing some degree of tooth decay. Simultaneously, the need for braces is evident in over 4 million people in the United States alone.

The alarming frequency of these dental challenges prompts an annual expenditure of over $111 billion in the United States, reflecting the collective effort to address and rectify these issues. Strikingly, this dilemma is uniquely human, as most animals are born with naturally aligned and robust teeth. Even our hominid ancestors possessed an organized set of teeth, raising the question of how our oral health deteriorated over time.

The myriad of dental issues ranges from cavities caused by bacterial activity to the challenges posed by wisdom teeth, which often lack sufficient space for proper emergence, resulting in swelling, pain, and infection. Additionally, malocclusion, or misaligned teeth, affects 9 out of 10 individuals. To understand the root causes of these problems, a journey back 400 million years to the Cambrian era is necessary.

During this era, the first jawless vertebrates, or conodonts, roamed the seas, adorned with tooth-like plates made of calcium phosphate. Over time, these dental structures evolved into the teeth we recognize today, with even modern-day sharks having teeth similar to their ancient counterparts. Teeth played a pivotal role in the evolution of mammals, enabling them to support warm-bloodedness and the high energy demands associated with it.

Chewing became a crucial aspect of extracting energy from food, with different types of teeth adapted for different diets. Herbivores possess flat teeth for grinding plants, while carnivores boast sharp, scissor-like teeth for tearing meat. Humans, categorized as omnivores, exhibit a combination of sharp front teeth and molars for grinding. However, the root of our dental issues lies not in the teeth themselves but in the size of our jaws.

The industrial revolution marked a turning point as processed sugary foods replaced the tough grains and meats of our ancestral diet. This shift led to reduced jaw sizes, contributing to crowded palates and impacted wisdom teeth. Harvard evolutionary biologist Daniel Lieberman's research on hyraxes demonstrated that chewing stress during childhood determines jaw length, indicating that our industrialized diet played a pivotal role in our dental problems.

Modern humans, with smaller jaws and fewer teeth than most animal species, struggle with malocclusion and cavities due to the mismatch between our teeth and jaw sizes. The reduced chewing strain and processed diet have created an engineering catch-22, where our teeth aren't tough enough for the sugary foods we consume, and our jaws aren't equipped to accommodate our teeth properly.

While traditional lifestyles, involving tougher raw foods, have been associated with better dental health, the majority of the population, having already stopped growing, faces limitations in rectifying these design flaws. The challenge remains, and as scientists advocate for learning from those with traditional lifestyles, the call to address this oral health crisis becomes increasingly urgent.