Teeth develop according to a complex process and in a predetermined, sequential order. First, primary teeth come in, followed by permanent teeth that stay in place for life. The transition between primary and permanent teeth is a fascinating evolution marked by significant changes.
Primary teeth, also called baby or temporary teeth, start coming in when a child is six or seven months old, beginning with the lower incisors. All 20 primary teeth are usually fully developed by the age of two or three. The last teeth to come in are the second molars.
Primary teeth include:
- 8 incisors
- 4 cuspids
- 8 molars
As soon as the first teeth appear, start teaching your child about proper dental hygiene. During regular dental check-ups, the dentist can check that dentition is developing correctly, which is important for the arrival of permanent teeth.
Primary teeth are very different from permanent ones. Their enamel is thinner and translucent, making them seem paler. And, because of less mineralization, the enamel is less resistant to cavities. Baby teeth are particularly vulnerable to cavities, known as baby bottle tooth decay.
Primary teeth begin falling out around the age of five or six, making way for permanent teeth. Between the ages of six and eight, children transition from their temporary to their permanent teeth. This period is called the mixed dentition phase.
Not everyone’s primary teeth fall out at the same rate or in the same order.
Permanent teeth begin coming in around the age of six or seven. Molars appear first, at the back of the dental arch, behind the last primary teeth. Other permanent teeth gradually replace the temporary teeth until all adult teeth have developed, usually by age 12 or 13. Wisdom teeth only come in later, at the beginning of adulthood.
Permanent teeth – 32 in all:
- 8 incisors
- 4 cuspids
- 8 bicuspids
- 12 molars (including four wisdom teeth)
As it develops, the primary tooth reaches the root of the temporary tooth, causing it to resorb. The baby tooth becomes loose and unstable, until it finally falls out and the permanent tooth takes its place.
Insufficient space on the dental arch can lead to malocclusion of the permanent teeth. Orthodontics can correct the problem.
Dental agenesis occurs when a tooth doesn’t come in because it never developed. Although this happens more often with wisdom teeth, it can affect any tooth. If the primary tooth doesn’t fall out, it can stay in place.
The appearance of extra teeth is called hyperdontia. Extracting these teeth is usually the preferred option if they’re causing problems with other teeth.
Between the ages of 18 and 21, the wisdom teeth come in. These third molars are located all the way in the back of the dental arch. Their growth is slow and often problematic. Lack of space on the dental arch can prevent them from coming in or positioning themselves correctly.
The behaviour of wisdom teeth is unpredictable:
- They can grow in the wrong direction
- They can partially erupt
- They can get impacted in the gums
- They can fail to develop
They cause several problems, including:
- Abscesses and cysts
- Infections of the gums if the tooth has only partially erupted
- Damage to adjacent teeth
- Overlapping teeth on the dental arch
The solution: Extraction
Sometimes, it’s best to extract wisdom teeth to avoid any complications. Through regular monitoring of the development of your wisdom teeth, your dentist can determine whether extraction will be necessary. As a surgery, it’s more complex than with other teeth because of their position on the dental arch and their potential inclusion in gums.