Molars are the large, flat teeth located in the back of the mouth, designed for grinding and crushing food. Understanding the timeline for their eruption—the process of a tooth breaking through the gum line—is important for maintaining good oral health. Humans develop two sets of teeth: 20 primary (deciduous) teeth and 32 permanent teeth. Both sets include molars that emerge at predictable stages, marking dental milestones from infancy into early adulthood.
Primary (Baby) Molars: Timing and Symptoms
The first primary molars typically erupt when a child is between 13 and 19 months old. These four teeth are generally the fourth teeth to appear. The second primary molars emerge later, usually between 25 and 33 months of age, completing the set of eight baby molars.
Eruption in infants is commonly referred to as teething, which causes discomfort. Symptoms include increased drooling, fussiness, and chewing on objects. Gums around erupting molars often appear swollen, red, and tender. While a slight temperature elevation may occur, a high fever is not attributable to teething and requires a healthcare consultation.
Permanent Molars: The Six-Year and Twelve-Year Sets
The first set of permanent molars, often called “six-year molars,” emerge between the ages of six and seven. These four molars do not replace baby teeth; instead, they erupt directly behind the second primary molars, adding new teeth to the dental arch. Because they appear without the loss of a baby tooth, their arrival can sometimes go unnoticed.
These six-year molars serve as the foundation for the permanent bite. They are highly susceptible to decay due to their location and deep chewing surfaces. Dental professionals recommend applying dental sealants to these molars shortly after they fully erupt to prevent cavities. Sealants are thin, protective coatings painted onto the grooves of the back teeth, preventing up to 80% of cavities by keeping out food particles and bacteria.
The second set of permanent molars, known as “twelve-year molars,” typically appear between the ages of 11 and 13. These four teeth erupt into the open space at the back of the jaw. Applying dental sealants to the twelve-year molars is also highly recommended as a preventive measure against decay once they have fully broken through the gums.
Understanding Third Molars
The final set of molars are the third molars, commonly known as wisdom teeth. They begin to emerge much later, typically between the ages of 17 and 25.
For many individuals, the jaw lacks sufficient space for these teeth, causing them to become impacted (trapped beneath the gum line or bone). Impaction can lead to pain, swelling, infection, or damage to neighboring teeth. Due to the potential for complications, dentists frequently monitor wisdom teeth with X-rays and may recommend removal before symptoms appear.
Eruption Care and Hygiene
Managing the pain associated with molar eruption involves several practical strategies. For infants, gently massaging the gums with a clean finger or providing a chilled teething ring can help soothe tender tissue. Over-the-counter pain relievers, such as acetaminophen or ibuprofen, can also be administered following dosage instructions for temporary relief.
Diligent oral hygiene is important, especially when new molars are breaking through the gums, as the tissue can be sensitive. Even before a baby tooth emerges, the gums should be cleaned twice a day with a soft cloth to reduce bacteria. Once permanent molars erupt, establishing a consistent routine of brushing twice daily and flossing helps prevent cavities. Regular dental check-ups are necessary to monitor eruption timing and ensure molars are coming in correctly and that sealants remain intact.