Teeth and bones often get confused due to their shared hard, white appearance, and both being rich in calcium. However, despite these similarities, teeth and bones are quite different in terms of structure, function, and their role in the human body. In this blog, we’ll explore why teeth are not classified as bones and delve into the unique characteristics that set them apart.
Structure and Composition
At first glance, teeth and bones might seem similar because both are incredibly strong and contain a large amount of calcium. Your teeth and bones actually store 99% of the calcium in your body. This high calcium content is responsible for their hardness and durability. However, the similarity ends there when we examine the structure more closely.
Teeth Composition
There are three primary layers to teeth:
- Enamel: the toughest material in the human body and its outermost layer. Enamel is composed almost entirely of minerals, particularly calcium phosphate, and lacks living tissue. This is why teeth cannot regenerate if damaged.
- Dentin: Below the enamel is dentin, a softer, porous tissue that makes up the bulk of a tooth’s structure. It contains microscopic tubules that transmit signals to the nerves of the tooth.
- Pulp: The pulp, which is located in the center of the tooth, is home to the blood vessels and nerves that maintain the tooth.
Bone Composition
Bones, on the other hand, are living tissues made up of collagen (a protein) and calcium phosphate. The collagen provides flexibility, while calcium gives bones their strength. Unlike teeth, bones have the ability to regenerate and heal when broken. This is possible because of the living cells called osteocytes, which play a role in bone repair and growth.
Are Teeth Considered Bones?
Teeth and bones may appear alike and are indeed the hardest substances in the body. The teeth and bones contain nearly all of the calcium in the body—99 percent. However, the similarities largely end there. Despite both being composed of calcium, the internal structure and behavior of teeth and bones vary significantly. These differences determine how they heal, regenerate, and function.
What Are Bones Made Of?
Bones are living tissue composed of two primary components:
- Collagen: A protein that acts as the flexible framework of the bone.
- Calcium phosphate: A mineral that fills the framework, providing strength.
Bones are incredibly resilient and have a complex structure. Trabecular bone, which resembles honeycomb and is found inside bones, is covered in cortical bone, a denser layer. Because bones are living tissue, they are constantly being remodeled and regenerated throughout life. This enables bones to heal when broken, as bone cells rush to the damaged area and begin the regeneration process. Additionally, bones contain bone marrow, which produces blood cells. This vital function is absent in teeth.
What Are Teeth Made Of?
Teeth are made up of four distinct tissue types:
- Enamel: The hard, mineralized outer layer that protects the tooth from damage. Enamel is the hardest substance in the human body but lacks living cells, meaning it cannot repair itself.
- Dentin: The softer, porous layer beneath the enamel. It transmits signals to the nerves of the tooth and forms the majority of the tooth’s structure.
- Cementum: A covering that serves as the tooth root’s anchor in the jawbone.
- Pulp: The tooth’s interior region, which is home to connective tissue, blood vessels, and nerves.
While bones contain living tissue, teeth do not. Enamel lacks living cells and cannot regenerate once damaged, which is why maintaining proper oral hygiene is critical. Damage to enamel, such as through decay or injury, requires intervention because teeth do not have the self-healing ability that bones possess.
Regenerative Ability Why Bones Heal but Teeth Don’t
One of the key differences between teeth and bones is their ability to heal. A natural process involving bone cells will eventually mend a broken bone. However, if you damage a tooth—whether through a cavity, chip, or fracture—it will not repair itself. This is because teeth lack the living cells that bones have, which are responsible for healing and regeneration.
The enamel covering your teeth, while incredibly strong, is non-living tissue, meaning that once it’s gone or damaged, it cannot be replaced naturally. Dental procedures like fillings or crowns are required to fix damaged teeth because they can’t heal on their own.
Attachment to the Body Why Teeth Aren’t Considered Part of the Skeletal System
Teeth are embedded in the gums and attached to the jawbone, but they are not actually part of the skeletal system. While bones are connected to each other through joints and provide structure and support to the body, teeth are held in place by periodontal ligaments, which anchor them to the jawbone. This difference in attachment is another reason teeth are not classified as bones.
The Role of Teeth vs Bones in the Body
Bones serve many critical functions in the body, including:
- Support: Bones form the framework that supports the body.
- Protection: They shield important organs (the ribs shield the heart and lungs, for example, while the skull shields the brain).
- Movement: Bones, in conjunction with muscles, allow for movement.
- Blood Cell Production: Bone marrow produces red and white blood cells.
Teeth, on the other hand, have more specialized roles:
- Chewing: Teeth break down food into smaller pieces to aid digestion.
- Speech: Teeth help form words and sounds.
- Facial Structure: Teeth contribute to the shape of the face.
Teeth Don’t Produce Blood Cells
Another fundamental difference between teeth and bones is the production of blood cells. Bones, specifically bone marrow, are essential for the production of both red and white blood cells, a process known as hematopoiesis. Teeth do not participate in this function at all, as they lack the bone marrow found in bones.
Teeth and Bones Develop Differently
Teeth and bones also develop through different processes. Bones grow and remodel throughout life, responding to stresses by adding new bone where necessary. This process, called ossification, is vital for growth and healing.
Teeth, however, develop once and do not continue to grow or change after they fully emerge, except for wear and tear. You get two sets of teeth as an adult: your permanent teeth and your baby teeth. After that, they do not regenerate or remodel in the same way bones do.
Are Teeth Stronger Than Bones?
Despite the differences, teeth are, in fact, stronger than bones in some respects. The toughest material in the human body—even more resilient than bones—is the enamel that covers the outside of teeth. This strength is necessary for chewing and breaking down food. However, the downside is that once enamel is worn away, it cannot be rebuilt, while bones can regenerate and repair.
Why Do Teeth Need Special Care?
Since teeth can’t heal themselves like bones, they require special care to remain healthy. For the purpose of preventing cavities, gum disease, and other dental issues, brushing, flossing, and routine dental exams are essential. Once tooth enamel is lost, it’s gone for good, and procedures like fillings, root canals, or crowns may be needed to restore function.
Why Teeth Are Not Bones
While teeth and bones may seem similar at first glance, they are fundamentally different in composition, function, and regenerative abilities. Teeth are not bones because they cannot regenerate, lack bone marrow, and serve a more specialized role in the body, primarily related to chewing and speech. The lack of living cells in enamel is a crucial reason why teeth cannot heal themselves, emphasizing the importance of proper dental care.
You cannot naturally cure early damage to your teeth, thus it is imperative that you maintain appropriate oral hygiene. Understanding these differences between teeth and bones helps explain why they require such different approaches to care and health.
Conclusion
Teeth and bones share certain characteristics, but they differ significantly in composition, function, and regenerative ability. Teeth are not bones because they cannot regenerate, produce blood cells, or remodel like bones do. While they are both crucial parts of the body, teeth serve a more specialized role in chewing, speech, and facial structure. Proper dental care is essential for preserving the health of teeth, as they lack the ability to heal or repair themselves naturally, unlike bones.
