Human teeth serve important roles in both eating and speaking, enabling us to chew food properly and articulate sounds clearly. The number of teeth a person has changes significantly throughout their life, transitioning from a childhood set to a permanent adult set. This natural progression involves different types of teeth, each with specialized functions.
The Count in Childhood
Children begin with a set of primary, often called “baby” or “milk” teeth, totaling 20 (10 in the upper jaw and 10 in the lower). Eruption usually starts around six months of age, with the lower central incisors often appearing first. Most children have their full set by approximately three years old.
These primary teeth act as placeholders, aiding jawbone and muscle development and reserving space for permanent teeth. Between the ages of six and twelve, children gradually lose these primary teeth, making way for the emerging permanent ones. The shedding process typically follows the order of eruption, with the central incisors usually being the first to fall out.
The Count in Adulthood
Adults have 32 permanent teeth, including four wisdom teeth. This complete set usually emerges by the early twenties, with most permanent teeth (excluding wisdom teeth) in place by around age 13.
Wisdom teeth, also known as third molars, are the last to emerge, generally between ages 17 and 25. Lack of space often leads to impaction or other problems. Due to potential issues like pain, infection, or crowding, wisdom teeth are often removed, reducing the total adult tooth count to 28.
Understanding Different Tooth Types
The 32 permanent teeth in an adult mouth are categorized into four distinct types, each designed for specific roles in chewing and processing food: incisors, canines, premolars, and molars.
Incisors
The eight incisors are located at the front of the mouth, four on the top and four on the bottom. These teeth have sharp, flat edges, similar to chisels, and are primarily used for biting into and cutting food into smaller pieces. They also contribute to speech articulation and help support the lips.
Canines
Next to the incisors are the four canine teeth, two in the upper and two in the lower jaw. These teeth are pointed and resemble fangs, earning them the nickname “eye teeth” due to their position directly under the eyes. Canines are designed for tearing and gripping food, particularly tougher items like meat or fibrous vegetables. They also play a role in guiding the jaw when it moves from side to side.
Premolars
Behind the canines are the eight premolars, also known as bicuspids, four in the upper and four in the lower jaw. Children do not have premolars; these teeth appear as part of the permanent dentition, typically between ages 10 and 12. Premolars have a flatter surface with ridges and two cusps, functioning to crush and grind food, acting as a bridge between the tearing action of canines and the grinding of molars.
Molars
Finally, at the back of the mouth are the 12 molars, six in the upper and six in the lower jaw, including the wisdom teeth. Molars are the largest teeth, featuring broad, flat surfaces with multiple cusps. Their primary function is to grind and chew food into a manageable consistency for swallowing, handling about 90% of the chewing process.