The adult dentition is the complete set of permanent teeth that emerge during childhood and adolescence, replacing primary or “baby” teeth. Each tooth type serves a specific function in chewing and overall oral health.
Understanding Adult Teeth
A full set of adult teeth consists of 32 teeth, though this number can vary if wisdom teeth do not erupt or are removed. This includes 16 teeth in the upper jaw and 16 in the lower jaw. These permanent teeth are categorized into four main types: incisors, canines, premolars, and molars. Incisors are for biting, canines for tearing, and premolars and molars are for crushing and grinding food. Their eruption begins around age six and continues into the early twenties with the emergence of wisdom teeth.
Defining Nonsuccedaneous Teeth
Teeth in the adult dentition are classified based on their developmental origin relative to primary teeth. Succedaneous teeth are permanent teeth that replace a primary tooth. This group includes all incisors, canines, and premolars, which erupt into the spaces previously occupied by their primary predecessors. Their development is directly linked to the resorption of the primary tooth’s root, clearing the path for the permanent tooth to emerge.
In contrast, nonsuccedaneous teeth are permanent teeth that do not replace any primary tooth. Instead, these teeth emerge in areas of the jaw that expand as a child grows, behind the existing primary dentition. They do not have a primary tooth predecessor to succeed. This developmental pattern highlights that new teeth are added rather than simply replacing old ones.
The Number of Nonsuccedaneous Teeth
The adult dentition contains 12 nonsuccedaneous teeth. These are specifically the permanent molars: the first, second, and third molars in each of the four quadrants of the mouth. This means there are three molars on each side of the upper jaw and three on each side of the lower jaw, totaling 12 teeth.
The first permanent molars are often referred to as “six-year molars” because they are the first permanent teeth to erupt, around age six. They emerge behind the last primary molars, rather than replacing any baby teeth. Similarly, the second molars follow, and the third molars, commonly known as wisdom teeth, are the last to erupt, usually between the ages of 17 and 21. The unique emergence of these molars, without a primary tooth predecessor, is why they are classified as nonsuccedaneous.