How many teeth do you have? What are their functions? What are the parts of the mouth, and how do they impact your dental health?
Brushing up on your dental anatomy can help you answer these questions, improve your oral hygiene, and avoid unpleasant dental procedures like root canals.
Keep reading this complete guide from Flossy on tooth anatomy to learn everything you need to know about your teeth.
What Is Anatomy?
Anatomy is a branch of science that studies physical structures (e.g., bones, organs, and cells) in the human body. A related discipline is physiology, the study of how these structures work together. It’s impossible to understand physiology without some knowledge of anatomy.
Anatomists split up the body into ten distinct systems. Your teeth belong to the skeletal system, which provides foundational support for the body, but they’re also related to other systems.
For instance, the tongue, which can change the alignment of the teeth, belongs to the muscular system. And the nutrient-rich blood that keeps your teeth healthy belongs to the cardiovascular system.
Even the nervous system is related to the teeth, as it’s responsible for sending tooth pain signals to the brain.
Is It Important To Know Tooth Anatomy?
If you’re not a dentist, you might be wondering why it’s important to understand tooth anatomy. What does it matter if you can’t tell a lateral incisor from a bicuspid or name all the parts of a tooth?
While it’s certainly not necessary to memorize all these details, understanding some fundamental parts of dentistry can give you a deeper appreciation of how your oral cavity functions.
In addition, knowing how your tooth is structured can help you to understand which behaviors harm your teeth and which behaviors benefit them. For instance, once you find out how bacteria can eat through layers of the teeth, you’ll be less likely to skip out on brushing and flossing.
Anatomy of the Mouth
The teeth aren’t an isolated structure. Instead, they belong to a complex structure known as the oral cavity, a.k.a the mouth. This space includes the maxilla, or upper jaw, and the mandible or lower jaw.
Here are the main parts that make up the oral cavity:
Your teeth are the most important part of your mouth. They define the shape of your mouth and contribute to the overall appearance of your face.
The teeth are made up of various soft tissues and hard tissues. They are covered by enamel, the hardest substance in the body, and include the soft periodontal ligament that fastens the root of the tooth to the bone in your jaw.
While each tooth has a distinct function, their purpose is essentially the same: helping you process food for digestion.
Also known as gingivae, the gums are connective tissue covered with mucous membranes. They are attached to the teeth and adjacent alveolar bone, allowing them to literally hold your teeth in place.
Contrary to popular belief, the tongue is not the strongest muscle in the body. Still, it plays a significant role in helping to digest food. It is also an essential element in producing human speech.
The Hard and Soft Palates
The hard and soft palates divide the oral cavity from the nasal passages. The hard palate is located in the front of the mouth, while the soft palate is near the throat's back.
The Salivary Glands
Your saliva plays a vital role in oral health, making the salivary glands a crucial structure. Their functions include helping with digestion and neutralizing acids that erode tooth enamel. Your mouth contains three major salivary glands in total.
The Different Types of Teeth and Their Functions
Now that we have a good understanding of your mouth’s anatomy, let’s look at the different types of teeth and how they function.
Your teeth first begin to develop around six months of age. These are called primary teeth. In childhood, it’s normal to have about 20 of these primary or “baby” teeth.
Gradually, primary teeth fall out and are replaced with about 32 permanent teeth. Usually, this process is complete by the age of 14.
We can categorize permanent teeth under the following four types.
There are four incisors on the top and four on the bottom, all located in the center of the mouth.
Incisors are thin with a flat shape, which makes them ideal for biting down on food. Because they are the most visible part of the mouth, they play a significant role in the appearance of our smile.
The canines are fang-like teeth located in the corners of the jaw adjacent to the incisors. There are four canines in total, and they are also known as cuspids.
The canines allow us to rip apart food, making them perfect for masticating food with a rough texture. Their shape also plays an essential role in guiding your bite into proper alignment.
The premolars are bigger than incisors and canines. They contain many ridges, which makes them ideal for grinding up food into smaller chunks.
A typical adult has eight premolars: two in each corner of the jaw. They are adjacent to the canines.
Molars are the largest teeth in the jaw. They have a flat surface that helps them grind food into a fine texture and aid in digestion.
There are three types of molars — first, second, and third — and they are categorized depending on where they’re located.
The third molars are essentially your wisdom teeth. Some people have four of them, while others have less or none at all.
Sometimes, the wisdom teeth can get impacted, which means they’re trapped in the gumline and unable to erupt properly. This increases the risk of tooth or gum infection and can even cause damage to surrounding teeth.
Because of the many problems associated with wisdom teeth, many people choose to have them removed with a preventative wisdom tooth extraction.
Anatomy of the Tooth
No matter which tooth type we’re talking about, they have the same basic anatomy. Four main components make up each tooth:
Below, we’ll describe each component in detail.
The enamel is the outermost part of the tooth, and it’s also the hardest. Enamel is made up of various minerals, such as calcium, which is responsible for its white color. Its main function is to protect the more delicate internal parts of the tooth.
Despite its hardness, the enamel is susceptible to wear and tear from poor oral hygiene, aggressive brushing, or teeth grinding. Once the enamel wears away, it sets the stage for tooth decay.
This layer of the tooth lies below the enamel. It is composed of a mixture of minerals and proteins. It has a slight yellow hue, which is why someone with tooth decay may have a discolored smile.
Dentine is made up of a porous material that allows it to transmit signals between its environment and the nerve-rich pulp that makes up the tooth's center. If you’ve ever felt increased sensitivity to cold or heat, dentine’s porous nature is at play.
The pulp makes up the innermost part of the tooth. It collects oxygen-rich blood from surrounding blood vessels and provides vital nutrients to the tooth. Because it contains many nerves, it can transmit pain signals — such as those from a tooth infection — to the brain.
True to its name, this part of the tooth literally “cements” the tooth into place. It’s made up of various minerals, which makes it an incredibly durable substance. Because of its location — deep inside the tooth structure —it’s rarely ever exposed to external elements.
Which Factors Influence Tooth Anatomy?
- Biological sex
- Preterm birth
- Body height and weight
- Socioeconomic factors
- Hormonal factors
No one is born with the same tooth anatomy as another person. While the essential structure is the same, people have many differences.
These are the seven factors that may influence tooth anatomy:
Your genes majorly affect how your teeth look and function. While the importance of oral care can’t be overstated, “bad” teeth may be in part to blame on your genetic material.
For instance, studies found that teeth anatomy was concordant in identical twins by as much as 90%. In non-identical twins, concordance rates were still high — much more than in people who weren’t related.
Aside from affecting the appearance of your teeth, your family history can also put your teeth at higher risk of certain disorders. For instance, some developmental conditions can make it difficult for enamel to form properly, while other diseases can result in improper jaw alignment.
2. Biological sex
Biological sex has a significant effect on the emergence of teeth. Girls develop permanent teeth about 4-6 months earlier than boys.
In addition, girls tend to complete developing teeth sooner than males. One possible explanation is that girls begin and finish puberty earlier than males, which can affect tooth development.
Although chronic malnutrition is rare in many countries, some developing nations continue to experience a high prevalence of malnutrition amongst children. If malnutrition extends beyond early childhood, then permanent teeth may erupt at a later date.
In addition, malnutrition can alter the development of the oral cavity, increasing the risk of oral disease while interfering with tissue healing. For this reason, early childhood malnutrition is linked to an increased risk of tooth infection and gum disease.
4. Preterm Birth
Being born at full term (between 39 and 40 weeks of gestation) is crucial for the proper development of organs and other physical structures in human infants. So a premature birth (a birth that occurs before 37 weeks of gestation) can negatively affect the development and eruption of the teeth.
Children who are born prematurely often have later teeth eruption than their peers. In addition, the structure of their teeth may be affected, with a greater likelihood of jaw asymmetry and various other dental problems.
Of course, preterm birth is not the only factor at play. Because children born prematurely are also less likely to receive proper care after birth, some lifestyle factors like poor nutrition can explain their greater likelihood of dental problems.
The correlation between height and teeth development supports this notion. Children who grow to a healthy height and receive adequate nutrition are more likely to experience normal tooth development. However, stunted children are more likely to experience dental problems.
5. Body Height and Weight
Even in children who aren’t born prematurely, taller height is associated with earlier tooth emergence.
Weight is also linked to earlier tooth eruption. Children who are overweight or obese tend to experience tooth emergence up to 1.5 years sooner than those with an average weight.
6. Socioeconomic Factors
Children from higher socioeconomic backgrounds may develop teeth sooner than those from lower socioeconomic backgrounds. This is likely because higher income is often linked to better healthcare, a more nutritious diet, and other factors that positively impact teeth development.
7. Hormonal Factors
Hormones regulate many functions in the body, including the teeth.
One of the most impactful hormonal factors is hypothyroidism, which is marked by abnormally low thyroid hormone levels. Since this is an essential hormone for regulating metabolism, people with hypothyroidism may experience delayed teeth eruption.
Conversely, accelerated teeth development is linked to an increase in androgen hormones, which are sex hormones that begin in puberty. They play a major role in whole-body growth and development — including, unsurprisingly, the teeth.
Disorders Related to Tooth Anatomy
Tooth anatomy plays an essential role in oral health, and proper development is vital for good dental outcomes. The following are some conditions linked to improperly-developed teeth, gums, and other oral cavity structures.
- Anodontia/Hypodontia: This is a hereditary condition in which one or more permanent teeth do not develop. If all permanent teeth are missing, then the condition is called anodontia; if only some teeth are missing, then it’s called hypodontia. Aside from the obvious loss of function from missing teeth, this condition can lead to altered jaw bone development.
- Amelogenesis imperfecta: This disorder results in the poor formation of tooth enamel, which can manifest as either poor enamel hardening or low amounts of enamel. Because enamel is needed to protect the teeth from decay, this condition increases the risk of a tooth infection or gum disease.
- Malocclusion: Also known as a “bad bite,” this condition is marked by either crowded or missing teeth. This results in the jaw being out of alignment. If not treated, malocclusion can damage the teeth and even lead to jaw problems like temporomandibular jaw dysfunction (TMJ).
- Cleft Lip/Cleft Palate: A cleft is an incomplete fusion of the lip or palate. This condition is linked to various dental problems like missing teeth, delayed tooth eruption, and abnormalities in tooth shape and size. Fixing this condition requires surgery.
In conclusion, tooth anatomy is closely linked to dental health. Poor tooth anatomy can lead to various dental problems that range in severity from mild to extreme.
If you have children, it’s important to support the healthy development of their teeth and gums. Proper nutrition and oral hygiene are essential for dental health.
As an adult, if you experience any dental conditions related to an anatomic abnormality, it’s important to get it addressed sooner rather than later. Conditions like tooth decay don’t exist in isolation and can impact the state of your entire body. For instance, tooth infections are closely linked to various chronic conditions like heart disease in other parts of the body.
Now that you understand your tooth anatomy, it’s important to do what you can to keep your teeth and gums healthy. Let Flossy connect you with a skilled dentist to care for your oral health — at a fraction of the cost of other providers.