Most babies get their first tooth between 6 and 12 months of age, but some don’t see that first white nub until well after their first birthday. In the vast majority of cases, this is simply a normal variation in development, not a sign of a medical problem. Still, understanding what influences the timeline can help you tell the difference between a baby who’s just taking their time and one who might need a closer look.
What Counts as “Normal” Teething
The typical window for a first tooth is broad: anywhere from about 6 months to 12 months. Some perfectly healthy babies don’t cut a tooth until 13 or 14 months. The lower front teeth almost always come in first, followed by the upper front teeth a few weeks or months later. By age 3, most children have all 20 primary teeth.
Because this range is so wide, pediatric dentists generally don’t consider teething truly “delayed” unless a child has no teeth by around 13 months. Even then, a dental X-ray often shows teeth sitting just below the gumline, ready to emerge on their own schedule. Most of the time, no medical tests are needed.
Genetics Is the Biggest Factor
If you or your partner were late teethers, your baby probably will be too. The timing of tooth eruption is heavily influenced by inherited genes, and the pattern tends to run in families with what researchers call variable expressivity. That means the same genetic trait can show up differently from one family member to the next: one sibling might get a first tooth at 8 months and another at 13 months, even though the same genes are at play.
In rare cases, specific gene variants can cause a condition called primary failure of eruption, where teeth don’t move along their normal path through the jawbone. This is uncommon and typically affects back teeth more than front teeth. For the overwhelming majority of late teethers, the genetic influence is simply a family tendency toward a slower schedule, not a disorder.
Premature Birth Shifts the Timeline
Babies born before 37 weeks often reach physical milestones later than full-term babies, and teething is no exception. The key concept here is “corrected age,” which accounts for how early a baby arrived. You calculate it by subtracting the weeks of prematurity from the baby’s actual age. A 12-month-old who was born 8 weeks early, for example, has a corrected age of about 10 months, placing them well within the normal teething window even if no tooth has appeared yet.
This adjustment matters because a preterm baby’s brain, bones, and developing teeth simply haven’t had as much time to mature as those of a baby born at 40 weeks. Pediatricians typically use corrected age for developmental milestones until a child reaches 24 months, at which point the gap usually closes.
Vitamin D and Nutrition Play a Role
Vitamin D is essential for the body to absorb calcium and build hard tissues like bone and teeth. Research has found that children with low vitamin D levels are more than twice as likely to experience delayed tooth eruption compared to children with adequate levels. Breast milk alone often doesn’t supply enough vitamin D, which is why pediatricians recommend a daily vitamin D supplement for breastfed babies starting in the first few days of life.
Calcium and phosphorus also contribute to tooth development. In well-nourished populations, outright deficiency is uncommon, but babies with feeding difficulties, restricted diets, or absorption problems may fall short. If your baby is growing well and eating a varied diet (or receiving appropriate formula or supplements), nutritional delays in teething are unlikely.
Medical Conditions Linked to Late Teeth
A small number of systemic conditions can slow tooth eruption as part of a broader pattern of developmental differences. These include:
- Congenital hypothyroidism: An underactive thyroid from birth slows growth and development throughout the body, including the teeth. Newborn screening catches most cases early.
- Down syndrome: Children with Down syndrome often get their first teeth several months later than typical and may erupt teeth in an unusual order.
- Cleidocranial dysplasia: A rare skeletal condition that affects bone and tooth development, sometimes causing baby teeth to persist much longer than expected.
- Congenital hypopituitarism: When the pituitary gland doesn’t produce enough growth hormones, overall development, including teeth, can be delayed.
These conditions are uncommon, and late teething alone is rarely the first or only sign. If your baby has other developmental concerns, such as slow growth, low muscle tone, or feeding difficulties, your pediatrician will likely investigate further. But a baby who is otherwise thriving and simply hasn’t sprouted a tooth yet almost certainly doesn’t have an underlying condition.
Physical Barriers in the Gums
Occasionally, teeth are present in the jaw but can’t break through because something is physically blocking them. Unusually thick or fibrous gum tissue, a condition called gingival fibromatosis, can prevent teeth from emerging even when they’re fully formed beneath the surface. Small cysts or extra tissue around a developing tooth can also act as barriers. These situations are rare and typically diagnosed with a dental X-ray. When a physical barrier is identified, a dentist can sometimes make a small opening in the gum tissue to help the tooth come through.
Does Late Teething Affect Permanent Teeth?
Parents often worry that late baby teeth mean late or problematic adult teeth. For most children, that’s not the case. A baby who gets teeth on the later end of normal will often lose them a bit later too, and the permanent teeth follow on a slightly shifted but perfectly healthy schedule.
Complications with permanent teeth are more closely tied to trauma or infection in the baby teeth than to the timing of eruption. Because the roots of baby teeth sit very close to the developing buds of adult teeth, injuries to baby teeth can occasionally affect the permanent tooth underneath. But simply being a late teether, on its own, does not increase the risk of problems with adult teeth.
What to Expect at a Dental Visit
The American Academy of Pediatrics recommends that children see a dentist by their first birthday or within six months of their first tooth, whichever comes first. If your baby has no teeth by 12 months, that first-birthday visit is a good time to bring it up. In most cases, the dentist will reassure you that the teeth are developing normally. If there’s any concern, a simple dental X-ray can show whether teeth are forming in the jaw and how close they are to breaking through. Blood tests or further workup are rarely necessary unless the dentist or pediatrician suspects a systemic condition.
For the vast majority of late teethers, the only “treatment” is patience. Those teeth are almost always on their way.