Baby Teeth: When Will They Come & How Long Will They Last?

You will typically have two sets of teeth in your lifetime: your primary (baby) teeth and your permanent (adult) teeth.¹

Babies are born with a set of 20 teeth that sit below the gumline. They usually start to come in around 6 months of age. The teething process can last up until a child’s 3rd birthday.

Right around the time a child starts school, usually age 5 or 6, the first adult teeth will start to come in and push the baby teeth out of the way. Generally, children have 28 of their total set of 32 teeth by their 13th birthday. They get the last four (wisdom teeth) prior to turning 21.

Usually, all of the baby teeth are gone by adolescence, but in some cases, they will stick around if there are no adult teeth to replace them. If you are missing permanent teeth, a dentist can help you build a successful plan to manage the issue.

When to Expect Baby Teeth

There is a time range when it comes to teething, but most babies will start this process around 6 months old.

Teething is when the baby teeth come in, or erupt, through the gums. This generally happens one or two teeth at a time. The first baby tooth can come in as early as 4 months old or as late as after a baby’s 1st birthday. In fact, some babies are even born with teeth.

In general, you can expect baby teeth to come in roughly the following order:²

• Bottom central incisors: 6 to 10 months

• Top central incisors: 8 to 12 months

• Top lateral incisors: 9 to 13 months

• Bottom lateral incisors: 10 to 16 months

• Top first molars: 13 to 19 months

• Bottom first molars: 14 to 18 months

• Top canines (cuspids): 16 to 22 months

• Bottom canines (cuspids): 17 to 23 months

• Bottom second molars: 23 to 31 months

• Top second molars: 25 to 33 months

Typically, most children will have all 20 of their primary teeth by 30 months old.

How Long Do Baby Teeth Last?

Primary teeth will start to fall out, or shed, as the adult teeth develop and come in. This usually starts around the time a child turns 6. The majority of the 28 permanent teeth are typically in place by age 13.

The wisdom teeth come in later, generally between the ages of 17 and 21. These make up the final four teeth to bring the total to 32 adult teeth.

Baby teeth, therefore, will last around six to eight years each. The baby teeth usually fall out just before a permanent tooth erupts, as an adult tooth pushes a baby tooth out of the way.

The first permanent teeth to come in are generally the first molars in the back of the mouth. These are “extra” teeth, so they do not push baby teeth out of the way.

The following is the order permanent teeth typically erupt in:

• Top and bottom first molars: 6 to 7 years

• Bottom central incisors: 6 to 7 years

• Top central incisors: 7 to 8 years

• Bottom lateral incisors: 7 to 8 years

• Top lateral incisors: 8 to 9 years

• Bottom canines (cuspids): 9 to 10 years

• Top canines (cuspids): 10 to 11 years

• Top first premolars (first bicuspids): 10 to 11 years

• Bottom first premolars (first bicuspids): 10 to 12 years

• Top second premolars (second bicuspids): 10 to 12 years

• Bottom second premolars (second bicuspids): 11 to 12 years

• Bottom second molar: 11 to 13 years

• Top second molar: 12 to 13 years

Adults & Baby Teeth

It is common for adults to be potentially missing one to two permanent teeth, especially second premolars or upper lateral incisors. When permanent teeth are replacing baby teeth, they push them out of the way as they come in. If a permanent tooth does not come in where a baby tooth is, it is also possible for the baby tooth to stay put.

The baby tooth’s root generally will not dissolve without the presence of a permanent tooth. In some cases, the baby tooth can stay into adulthood.

What to Do About Missing Adult Teeth

When permanent teeth are missing, this is called agenesis. In rare conditions, it is called anodontia (missing all teeth), hypodontia (missing between one and five teeth), or oligodontia (missing more than six teeth). These are typically genetic conditions.³

In the case of these uncommon conditions, with multiple missing permanent teeth, a dental intervention and treatment plan are necessary.

A dentist, and often a set of specialists, will need to work with you if you are missing multiple adult teeth. They will develop a treatment plan that may include the following:

• Dental implants

• Dentures

• Dental bridges

• Dental crowns

Your specific treatment plan will depend on which teeth are missing, how many, your age, and the state of your oral health.