The path of a food through our gastrointestinal tract is made up of hundreds of processes, many of them only seen on molecular levels. For this processes to happen and in order for nutritious materials to be absorbed, food should be downsized to small pieces. The preparation starts in our mouth where teeth with every bite cut and crushes the food so that they can be easily digested by our body. During their lifetime, most people have two sets of teeth, a set of primary “baby” teeth occurring somewhere between sixth and tenth month of age and permanent or “adult” teeth where the first one is erupting around the sixth year. A number of teeth depend on various factors, age being the most important one. The question arises, how many teeth should an adult have?
These are also known as baby teeth, milk teeth or deciduous teeth. Their development begins while the baby is in the womb, the buds appearing in babies jaw around a fifth gestational week. At birth, there are 20 primary teeth hidden within the jaws (10 of them in upper and 10 in the lower jaw). In spite of this, they do not become visible until the baby reaches the age of 6 to 12 months. They consist of 4 central incisors, 4 lateral incisors, 4 first molars, 4-second molars and 4 cuspids (also known as eye teeth or canine teeth). Baby teeth represent a placeholder for the adult teeth; nevertheless, they should be taken care of the same way the adult teeth are taken care of. By doing this, children are developing healthy eating and brushing habits. Most children begin to lose their mild teeth at about the age of six and they are being replaced by longer life span adult teeth.
Also known as adult teeth or permanent teeth start to develop in the jaw after the child is born. At the age of six, the first adult teeth erupts, these four molars (two in each jaw) are emerging behind child’s existing primary teeth. Rest of them, such as incisors and canines, erupt into the gaps in the gum left by the shed of primary teeth. Like primary teeth, the timing for when the permanent teeth come through differ from one child to the next. Generally, the order of eruption and rough timeline for each type of permanent tooth is in the order:
- First Molars – between six and seven years
- Central Incisors – between six and eight years
- Lateral Incisors – between seven and eight years
- Canine Teeth – between nine and 13 years
- Premolars – between nine and 13 years
- Second Molars – between 11 and 13 years
- Third Molars (Wisdom Teeth) – between the ages of 17 and 21 years, if at all.
In some cases third molars do not develop, meaning that a set of 32, as well as 28 permanent teeth, is considered normal. They should all be developed by the age of 21.
The Types Of Permanent Teeth
- Incisors – teeth located at the front of the mouth taking a central position. There are eight of them, four in each jaw, placed at the entrance of oral cavity. The function of incisors is to bite the food we eat and they are the first of milk teeth to erupt approximately six months after birth. Baby incisors are replaced by adult ones at around 6 years of age.
- Canines – a function of these teeth, which is to tear the food, especially meat (they are very developed at carnivores), is making them the sharpest of all the teeth in our jaws. We have four of them located at each side of incisors. Baby canines usually grow 20 months after birth, upper set appearing first in contrast to the permanent ones. Adult canines are not to erupt before the age of 9.
- Premolars – eight of them, four in each jaw are there for grinding the food into small particles. They are also known as bicuspids and are erupting between 10 and 11 years of age.
- Molars – divided into the first (appearing at the age of 6) and second molars (appearing at the age of 13), they perform the task of chewing and grinding the food we eat. The adult has a total eight, four in each jaw.
- Third molars – four of them, the last to appear are also known as wisdom teeth. They are rarely appearing before the age of 17. However, a great number of people never grow them or they remove them early as they are known to cause a lot of pain when erupting and are the major reason for crowding the teeth.