Complete Guide to Tooth Anatomy: Learn Parts, Names & Diagram

Overview of Tooth Anatomy

Teeth are important for breaking down food before we swallow it. In the tooth anatomy, we can find four types of teeth, each with a different job. Incisors cut food, canines tear it, and molars and premolars crush it. Most people have 32 teeth, but that can vary. The outside layer, called enamel, is the hardest part of our bodies. Teeth are stuck in either the upper or lower jaw and are kept safe by gums. Like many animals, humans get two sets of teeth in their lives. The first set, baby teeth, usually has 20 teeth. They start showing up around six months old, which might make babies a bit fussy. Sometimes, babies are even born with teeth called neonatal teeth.

Teeth anatomy studies tooth structure, such as how they grow and look. It helps dentists figure out teeth during treatments. While how teeth fit together isn’t part of dental anatomy, naming teeth and their parts is super important in this field.

Tooth Anatomy Diagram

Teeth Anatomy: Parts & Names

Crown
- Enamel
- Dentin
- Pulp
- Cementum
Root
- Root canal
- Periodontal Ligament
- Apical Foramen

Gingiva (Gum)
Alveolar Bone
Incisors
Canines
Premolars
Molars
Occlusal Surface
Cusp
Fissure
Ridge

Enamel rod
Enamel tuft
Cementoenamel Junction (CEJ)
Interdental Papilla
Apex
Dentin Tubules
Dentinoenamel Junction (DEJ)
Pulp Chamber

Tooth Anatomy

Crown

In dentistry, the crown is the top part of a tooth covered by enamel, visible when you smile. Accidents or decay can cause it to chip or break. Dentists use artificial crowns to cover damaged teeth or implants.

Bridges are used to fill the gaps when a tooth is missing. They can be attached to nearby natural teeth or implants. It is made from cement or stainless steel; cement bridges resemble regular teeth, while stainless steel can be silver or gold.

Enamel

Tooth enamel is a protective cover for your teeth. It is the hardest part of your body, even tougher than your bones. Enamel protects teeth from cavities, wear and tear, infections, and sensitivity to hot, cold, and sweet foods.

It is mostly made of calcium and phosphorus, which form super-strong crystals. The layer underneath (called dentin) the enamel can be different colors, like white or yellow.

Dentin

Dentine is a crucial part of teeth that provides support just under the enamel. It is made mainly of minerals, like hydroxyapatite, forming 70% of its composition. The rest includes water, collagen, and other organic stuff.

Inside the dentine are tiny channels called dentinal tubules, which carry sensations from the tooth’s surface to the inner pulp.

There are three types of dentine: primary, secondary, and tertiary. Primary dentine forms before the tooth comes out, while secondary dentine adds layers after erupting.

Tertiary dentine forms in response to damage, like from heat, chemicals, bacteria, or injury. It is denser and darker than the other types and has fewer tubules.

Pulp

The dental pulp is like the heart of a tooth. It has important nerves, blood vessels, and special cells that keep the tooth healthy.

It is protected by layers of hard stuff called dentin and enamel. But if you get holes in your teeth, cracks, or grind your teeth, the pulp can get exposed and need fixing.

The functions of dental pulp are diverse:

Immune cells fight germs to keep your mouth healthy.
Nerves feel hot/cold, and pressure changes to warn them of problems.
Dental pulp makes dentin to protect your teeth.
Makes important proteins to keep dentin strong.
Blood vessels in the pulp keep teeth moist to make them stronger.

Cementum

Cementum is a tough tissue, which is important for securing teeth in place. It covers the tooth’s root and connects to the periodontal ligament and dentin. Along with the ligament, bone, and gum, cementum forms a good support system for teeth.

This tissue develops gradually from cementoblast cells. Cementum reaches bone but lacks blood vessels, making it avascular.

It has a yellowish color and softer texture; compared to dentin, giving strength and flexibility, which is crucial for tooth stability.

Root

The root is the component of the tooth that is underneath the gums. The upper layer of the crown is enamel. Dentin is located beneath the enamel and surrounds the pulp.

The pulp contains the tooth’s blood vessels and nerves. Some teeth have one or two roots, whereas molars might have four.

Root Canal

A root canal is a tunnel inside your tooth. It has a big part at the top called the pulp chamber and smaller tunnels called root canals that go down into the roots. The dental pulp, like the tooth’s nerve, lives in these tunnels.

Sometimes, there are even smaller branches called accessory canals, mostly near the tips of the roots. The number of root canals varies depending on the tooth. Some have one, two, three, or even more; sometimes, one root can have more than one canal.

It is like a little network of tunnels inside your tooth; some teeth have more complicated tunnels than others.

Periodontal Ligament

The periodontal ligament (PDL) is a soft, stretchy band that connects your teeth to the bone around them. It is not the bone or gums that keep your teeth in place, but this special ligament.

It comprises different types of collagen and has tiny blood vessels and nerves running through it.

When you chew or grind your teeth, the PDL helps absorb the pressure and protects your teeth from damage. Instead of being stuck in a place like a nail, your teeth can be gently moved because of the PDL.

If you grind your teeth too much, the ligament can swell and make your teeth feel loose. But once the pressure stops, the PDL heals, and your tooth returns to normal.

Apical Foramen

In dental anatomy, the apical foramen is a tiny hole at the end of a tooth’s root. It is important because it is where blood vessels, nerves, and other tissues enter the tooth’s soft inner part, called the pulp.

This little opening also shows where the pulp and the tissues supporting the tooth meet. Usually, it is about 0.5mm to 1.5mm away from the tip of the root.

Gingiva (Gums)

The gums, called gingiva, are the pink tissue around your teeth. They are important for protecting your teeth and supporting their health.

Blood vessels from the carotid artery bring blood to the gums, while nerves from the trigeminal nerve give them feeling.

The gums are part of the periodontium, which includes structures that support your teeth. It consists of the periodontal ligament, alveolar bone, and cementum.

One important feature of the gums is the junctional epithelium, a protective barrier at the base of the gum line. It helps shield against damage and bacteria. The gums also help you sense things in your mouth and absorb nutrients.

Furthermore, the gum tissue plays a role in fighting off infections that can lead to gum disease.

Alveolar Bone

The alveolar bone is like a strong foundation for your teeth. It holds them in place and supports them while you eat. It comprises two main layers: dense bone on the outside and trabecular bone on the inside.

The dense bone is tough, like a protective shell, while the trabecular bone is softer and more flexible, providing cushioning.

The main job of the alveolar bone is to keep your teeth firmly anchored in your mouth and to absorb the pressure when you bite and chew.

It comprises two parts: the alveolar bone proper, which surrounds the tooth roots, and the supporting alveolar bone, which helps hold everything together.

The alveolar bone is essential for maintaining healthy teeth and a stable bite.

Incisors

Incisors are those front teeth that look like little chisels. They help us cut up our food. We have four on the top and four on the bottom.

In the upper jaw, they are called teeth 7 through 10; in the lower jaw, they are teeth 23 through 26.

Babies usually start getting these teeth between 6 and 16 months old. In each jaw, you have two types: central and lateral incisors. They are some of the earliest teeth to show up in your mouth!

Canines

Canines are the sharp teeth in mammal mouths. It is also known as fangs, cuspids, or dog teeth. Most mammals have four canines, two on top and two on bottom, but they vary in size and sharpness.

Some species, like sheep and deer, only have them on top. In some animals, like gorillas and pigs, males have larger canines than females. Rodents don’t have canines.

Humans have small canines with big roots. We get baby canines around 16-23 months and lose them around 9-12 years when adult teeth come in.

Premolars

Premolars, called bicuspids, are important teeth between canines and molars. Two premolars are in each section in adult human mouths, making eight in total.

They usually have two pointed parts and help transition food from front to back during chewing. Their mix of canine and molar traits helps grind food for digestion.

Molars

Molars are big, flat teeth in the back of your mouth. They help you grind food when you chew. In people, molars usually have four or five bumps on top.

Grown-ups have 12 molars in sets of three at the back. The last molar in each set is called a wisdom tooth. It usually shows up last, around age 20, but that can be different for everyone. Sometimes, people don’t get a wisdom tooth at all!

Occlusal Surface

The top surface of a tooth touches or comes close to touching the top surface of another tooth.

Each tooth has five surfaces:

Occlusal – the top surface that bites or chews.
Mesial – the front side.
Distal – the back side.
Buccal – the side facing the cheeks.
Lingual – the side facing the tongue.

Cusp

A cusp is like a little bump on your tooth, either on the top or the front. Canines, or “eye teeth,” have one bump each. Premolars, also called bicuspids, have two bumps each.

Molars usually have either four or five bumps. Sometimes, especially in certain groups of people, the big molars at the top of your mouth. The first ones especially have an extra bump on the inside called the Cusp of Carabelli.

Fissure

Fissures are tiny grooves and pits in teeth. Most tooth decay starts here. There are two types: external and internal.

External fissures only affect the outer layer of the tooth, called enamel. They usually don’t hurt but can still let in bacteria. Sealants can help prevent this.
Internal fissures go deeper into the tooth. They can be painful and may reach the sensitive parts inside. In serious cases, they might need special treatment to save the tooth.

Sealants can be put on any tooth with fissures as long as it is healthy and doesn’t already have fillings. They are often used on back teeth and are good for kids, teens, and adults who might get fissures.

Ridge

Mamelons are rounded bumps at the top of a tooth, which gives it a wavy look. They are common in kids’ teeth as they grow but can also seen in adults.

While they usually wear down naturally as we chew, they might stick around if teeth don’t align properly. If they are still there, then they can be permanent.

Enamel Tuft

Enamel tufts are tiny branches found where dentin and enamel meet. They stick out into the enamel. Sometimes, people mix them with enamel lamellae, straight lines instead of branches.

Enamel lamellae mostly go from the enamel surface toward the junction. In contrast, tufts go the other way, from the intersection toward the surface.

Cementoenamel Junction

The Cementoenamel Junction (CEJ) is where the tooth’s crown’s enamel meets the root’s cementum. It forms a kind of “neck” for the tooth.

It is important because it is the portion where the gums attach to the tooth, keeping it in place. Tooth loss can happen if there is resorption (loss of tooth structure) at this junction, which affects about 5 to 10 percent of people.

Dentists use the CEJ as a reference point for measuring gum health. It can vary between people and even between teeth in the same person.

Interdental Papilia

The interdental papilla, or gum tissue between teeth, sits above the gum line on the sides of your teeth. It is shaped like a cone for the front teeth and more flattened for the back teeth.

You might see a small space called a ‘black triangle’ between your teeth if missing. Dentists can sometimes fix this with braces.

Whether the papilla forms depends on how close the bone is to the space between your teeth; you may not have a papilla if there is more than 8mm of space. But if it is 5mm or less, you will have papilla.

Apex

The apex is like the root tip of a tooth. It is a little entrance known as the apical foramen, through which blood vessels and nerves enter.

Sometimes, there are many smaller doors around the main entrance, similar to those on the side entrance. These smaller ones, called auxiliary canals, are separated by hard tissue.

The main entryway, known as the foramen, links the tooth to the surrounding tissue. If the blood and nerve connections are lost, the tooth loses vitality. Typically, the primary door measures around 0.3 mm broad.

Dentin Tubules

Dentinal tubules are tiny channels in teeth that connect the pulp inside to the outer layers. They act like highways for substances to move in and out, which could potentially harm the tooth.

Researchers examined eight upper premolar teeth under a special microscope. They found more tubules near the top of the tooth, closer to the pulp.

These tubules vary in size, with larger ones near the pulp and smaller ones near the root tip. Inside the tooth, there are more tubules than outside.

The shape of the tubule openings changes: they are mostly round near the top but become irregular toward the root bottom.

Dentinoenamel Junction (DEJ)

The dentinoenamel junction (DEJ) is a vital boundary in your tooth where the outer enamel meets the inner dentin and cementum. It acts as a protective barrier, preventing cracks from spreading between these layers.

It is composed of tough materials like collagen, proteins (such as SIBLINGs), and molecules from your blood serum.

Its scalloped shape enhances its resilience, while enzymes, metalloproteinases, and lipoproteins play crucial roles in its formation and maintenance, ensuring the strength and health of your tooth.

Pulp Chamber

Inside a tooth, there’s a crucial part called the pulp chamber. It holds a jelly-like material called pulp. This chamber sits in the top part of the tooth, called the crown. It turns into the root canal as it goes down into the roots. The shape and how many canals there are depend on the tooth’s shape.