The arrival of permanent teeth, often called “grown-up” teeth, is a significant developmental milestone for children. This transition begins as the 20 primary teeth are gradually replaced by up to 32 larger, more durable permanent teeth. The process typically starts around age six and continues for more than a decade, with the final teeth not appearing until the late teens or early twenties. This long phase of eruption, which involves the growth of the jaw and the establishment of a lifelong bite, is a fundamental step in a child’s physical maturation.
The Initial Timeline of Eruption
The first permanent teeth to emerge generally appear around the age of six, marking the beginning of the mixed dentition period where both primary and permanent teeth coexist. The first set of permanent molars are often the first to arrive, earning them the nickname “six-year molars.” These four molars erupt in the very back of the mouth, directly behind the last primary teeth, and do not replace any baby teeth.
This is a common point of confusion for parents, as these new teeth appear without a primary tooth falling out first. Almost simultaneously, the lower central incisors—the two bottom front teeth—are typically the first primary teeth to be lost and replaced. These first permanent molars are especially important because they help establish the foundation for the bite and the future positioning of the other permanent teeth.
The Eruption Sequence During Middle Childhood
Following the emergence of the first molars and central incisors, the replacement process continues in a generally predictable sequence throughout middle childhood, usually between the ages of seven and twelve. The lateral incisors usually erupt next, followed by the systematic replacement of the remaining baby teeth. This stage is characterized by a temporary, mixed appearance of small primary teeth and larger permanent teeth. The primary molars are replaced by the permanent premolars. Finally, the canines, or “eye teeth,” emerge, usually between the ages of nine and thirteen, often filling in the last remaining gaps.
Adolescent Teeth (Molars and Wisdom Teeth)
The dentition timeline nears completion in adolescence with the eruption of the second set of permanent molars. These teeth emerge behind the first molars, typically between the ages of eleven and thirteen, completing the set of 28 teeth a person normally has by their early teens.
The final four permanent teeth are the third molars, commonly known as wisdom teeth. These teeth typically begin to appear between the ages of seventeen and twenty-one, if they erupt at all. Due to the limited space in the jaw, wisdom teeth frequently become impacted, meaning they are blocked from fully erupting. Dentists often recommend removal to prevent pain, infection, or damage to neighboring teeth.
Caring for Newly Erupted Permanent Teeth
Protecting newly arrived permanent teeth is a priority. The permanent molars have deep grooves on their chewing surfaces that easily trap food particles and bacteria. Applying dental sealants, which are thin, protective plastic coatings, to these surfaces right after they erupt can effectively block out decay-causing agents and prevent cavities.
Establishing consistent hygiene habits is also important for these new teeth. Children should use a soft-bristled toothbrush and fluoride toothpaste to gently clean all tooth surfaces twice a day for two minutes. Daily flossing is necessary to clean between the tight contacts of the permanent teeth. Parents should also monitor for temporary issues like gaps or mild crookedness, which are common during this transition period before the jaw is fully developed.