Types of Teeth in Humans: Types, Function, Care, Diagram

What Are Teeth?

Teeth perform many vital functions in our daily lives. Teeth are essential for eating, articulation, and facial structure. They play an important role in the initial process of digestion where they tear down the food into small parts, which aids in better absorption of nutrients by the body. Teeth also form an important part of clear speech because, during articulation, they help in the formation of sound and enunciate the words properly.

Human Teeth and Dentition

One of the strongest organs in the human body is the tooth. It is mostly made up of minerals (calcium) and proteins (collagen). In addition to aiding in digestion, teeth are crucial for communication. Including the wisdom teeth, an adult will have 32 teeth. Humans have two sets of teeth during their lifetime:

• Primary (milk) teeth

• Permanent (secondary) teeth

Sets of Teeth in Humans

Humans have two sets of teeth:

Primary (Milk) Teeth

• Total number: 20 teeth

• Present in children

• Begin erupting at 6–12 months

• Fully replaced by permanent teeth by 6–7 years

Distribution:

• 8 incisors

• 4 canines

• 8 molars

Permanent (Secondary) Teeth

• 32 permanent or secondary teeth in total

• Begin erupting around 6 years of age

• All permanent teeth usually present by 21 years

Distribution:

• 8 incisors

• 4 canines

• 8 premolars

• 12 molars (4 wisdom teeth)

Types of Teeth in Humans

Types of teeth in humans are:

Incisors

• Pointed, chisel-shaped teeth at the front of the mouth.

• Four upper and four lower incisors in the centre and at the sides of the front of the mouth.

• Function: Helps in cutting and slicing food into manageable pieces.

• First baby teeth to erupt in children at the age ranging between 6-12 months.

• First to get replaced with permanent teeth at about 6-8 years.

Canines

• Pointed teeth and located beside the incisors.

• There are two upper and two lower canines.

• Function: Tearing and ripping food

• Single-rooted and longest root of any tooth in humans.

• Erupt in a child about 16-20 months and are replaced by permanent canines around 9-12 years.

Premolars (Bicuspids)

• Flat-crowned teeth with two cusps

• Located on either side of the canines, in front of the molars.

• Function: Grinding and crushing food.

• Have one or two roots and are exclusively permanent dentition teeth.

• Erupt at about 10-12 years of age.

Molars

• Large flattened teeth, located at the back of the mouth.

• Function: Grinding and mashing food.

• Molars have a large flat surface area with four to five cusps and 2-3 roots.

• Erupt at around 6 years of age and the second molars come into place at around 12 years of age.

Wisdom Teeth (Third Molars)

• Last molars in the dental series

• Usually erupt in late adolescence or early adulthood.

• Historically used to grind tough plant fibres, such as roots and leaves. Not as essential today due to dietary and food preparation changes.

• Wisdom teeth mostly develop problems resulting from the lack of space in the jaw to accommodate these extra teeth.

• Most of the time, they are extracted to save one from future dental complications.

Comparison Table — Types of Human Teeth

Humans have four major kinds of teeth, all fitted for some particular function associated with the preparing and articulating of food. They are: Incisors, Canines, Premolars, and Molars. The following shows their locations, functions, and numbers in both adults and children.

Development and Eruption of Teeth

Normal teeth development follows a definite pattern that begins at the period of infancy and proceeds through early adulthood.

Time Scale of Tooth Development

• 0-6 months: No teeth.

• 6-12 months: Primary teeth bud.

• 6-7 years: First permanent teeth replace primary teeth.

• 12-13 years: Most permanent teeth erupt.

• Late teens to early 20s: Wisdom teeth may erupt.

Human Teeth NEET MCQs (With Answers & Explanations)

Important questions asked in NEET from this topic are:

• Human teeth and dental formula

• Types of Teeth in human

Practice Questions for NEET

Q1. Which are regarded as Monophyodont Teeth ?

1. Premolars

2. Premolars and Molars

3. Wisdom teeth

4. Both 1 and 3

Correct answer: 4) Both 1 and 3

Explanation:

Monophyodont teeth are teeth that appear only once in a lifetime. In humans, these typically include the premolars and third molars (wisdom teeth). There are three such teeth in each quadrant of the mouth, so in total, humans have 12 monophyodont teeth.

Hence, the correct answer is option 4) Both 1 and 3.

Q2. The softer , living inner structure of teeth , is called

1. Enamel

2. Periodontal ligament

3. Pulp

4. Dentine

Correct answer: 3) Pulp

Explanation:

The pulp is the softer, living inner core of a tooth, surrounded by dentin. It contains a network of blood vessels, nerves, and connective tissue that extend from the pulp chamber in the crown to the root canals within the roots of the tooth. Blood vessels in the pulp supply essential nutrients and oxygen to keep the tooth alive, while the nerves provide sensory functions, enabling the tooth to detect sensations like pain, pressure, and temperature changes. The pulp plays a critical role during the development of teeth, contributing to the formation of dentin, and continues to support repair and maintenance throughout the tooth's life. If the pulp becomes infected or damaged, it can lead to significant pain and require treatments such as root canal therapy to preserve the tooth.

Hence, the correct answer is option 3) Pulp.

Q3. The part of teeth projecting above the gingiva is called

1. Root

2. Crown

3. Socket

4. Dentine

Correct answer: 2) Crown

Explanation:

Teeth are differentiated into three regions namely crown, neck and root. The part of the tooth projecting above the gum line or gingiva is called the crown.

Hence, the correct answer is option 2) Crown.

Also Read:

• MCQs on Teeth and their Types

• Pharynx

• Intestinal Glands

Recommended Video on Types of Teeth