Tooth eruption is the process of teeth moving through the jawbone and breaking through the gums. This process occurs twice, with the first set of primary (or baby) teeth eventually falling out and being replaced by permanent teeth. Understanding the general sequence and timing for both sets is useful for monitoring dental health from infancy through early adulthood.
The Primary Teeth Eruption Timeline
The emergence of the 20 primary teeth begins in infancy, around six months of age, and concludes by age three. The process, often called teething, starts with the lower central incisors, the two bottom front teeth, which appear between 6 to 10 months. Their upper counterparts, the top central incisors, follow shortly after, emerging between 8 to 12 months.
Following the central incisors, the pattern of eruption moves outward. The lateral incisors, which sit next to the central ones, appear between 9 and 16 months. An exception to the outward pattern occurs next, as the first molars erupt before the canines, between 13 and 19 months.
The canine teeth, the pointed teeth between the lateral incisors and first molars, fill in the gaps between 16 and 23 months. Finally, the second molars, located at the very back of the mouth, complete the primary set between 23 and 33 months. This entire period can be accompanied by gum sensitivity, irritability, and increased drooling.
The Permanent Teeth Eruption Timeline
The transition to permanent teeth starts around age six and often does not finish until the early twenties. This process begins with the eruption of the first permanent molars, which emerge behind the existing primary teeth, and the lower central incisors. These first permanent molars do not replace any primary teeth but add to the total number of teeth.
Shortly after the first molars and lower central incisors appear, other primary teeth begin to fall out to make way for their permanent successors. The central and lateral incisors are replaced between the ages of six and eight. This means a child will lose their front eight baby teeth and gain their permanent replacements during these early school-age years.
The replacement sequence continues into the pre-teen and teenage years. The canine teeth and premolars—which replace the primary molars—erupt between ages nine and twelve. The second permanent molars emerge around age 12, and the third molars, commonly known as wisdom teeth, can erupt anytime between the late teens and early twenties, bringing the total number of permanent teeth to 32.
Variations in Eruption Patterns
The timelines for tooth eruption represent average ranges, and individual differences are common. It is not unusual for a child’s teeth to appear earlier or later than standard charts suggest. For instance, some infants may be born with natal teeth, while others may not see their first tooth emerge until after their first birthday. These variations are normal and not a sign of a developmental issue.
The order in which teeth appear can also differ from the typical sequence. While most children follow a general pattern, some may have their lateral incisors erupt before their central ones. Girls also sometimes get their permanent teeth slightly earlier than boys. Significant deviations or concerns about a child’s dental development should be discussed with a pediatric dentist.
Caring for Newly Erupted Teeth
Oral hygiene should begin as soon as the first primary tooth emerges. For infants, parents can gently clean the new tooth and the surrounding gum tissue using a soft, damp cloth or a piece of gauze. This action helps remove plaque and gets the child accustomed to daily mouth cleaning.
Once a few teeth have appeared, parents can transition to an infant-sized, soft-bristled toothbrush. A tiny smear of fluoride toothpaste, about the size of a grain of rice, is recommended for children under three. The American Dental Association suggests scheduling a child’s first dental visit after the first tooth erupts and no later than their first birthday. This appointment allows a dentist to check for proper development and provide guidance.