The five-year-old stage represents a critical period in pediatric dental development, as the established set of primary teeth begins to prepare for transition. Parents often observe subtle changes and wonder about their child’s dental landscape at this age. The full set of primary teeth, also known as deciduous teeth, has been present for a couple of years, but the jaw is now actively making room for the larger adult teeth developing underneath.
The Total Count of Primary Teeth
A typical five-year-old has a complete set of 20 primary teeth. This count includes 10 teeth in the upper arch and 10 in the lower arch, which usually erupt by the time a child is three years old. The deciduous dentition is composed of three distinct types of teeth arranged symmetrically across the mouth. In each jaw, the set includes four incisors for biting, two canines for tearing, and four molars for grinding and chewing. These 20 teeth are the standard number for a child before the mixed dentition phase begins around age six.
The Essential Role of Baby Teeth
Although temporary, these 20 primary teeth serve several important functions beyond allowing a child to chew. They are important for proper speech development, guiding the tongue in forming sounds and words. Their most significant purpose is to act as natural space maintainers for the permanent teeth forming deep within the jawbone.
The roots of the primary teeth hold the correct space in the dental arch, ensuring that permanent teeth have a clear path to erupt. If a primary tooth is lost prematurely, adjacent teeth may shift into the vacant area, potentially blocking the path of the underlying permanent tooth. This shifting can lead to crowding or misalignment issues requiring orthodontic intervention. Maintaining the health of primary teeth is important, as cavities can compromise this natural spacing mechanism.
The Transition to Permanent Teeth
The process of losing primary teeth and gaining permanent teeth typically starts around age six. Jaw growth naturally creates small spaces between the primary teeth, signaling that the larger permanent teeth are preparing to emerge. This shift marks the beginning of the “mixed dentition” stage, where a child has a combination of primary and adult teeth.
The loss of a primary tooth is triggered by root resorption, where the permanent tooth developing beneath it begins to dissolve the primary tooth’s root. The first teeth to loosen are typically the lower central incisors, followed by the upper central incisors. Simultaneously, the first set of permanent molars erupt behind the primary molars without replacing existing teeth. Eventually, the 20 primary teeth will be replaced, and 12 new molars will be added, resulting in a full adult set of up to 32 permanent teeth, including wisdom teeth.