Premature babies do appear to get their first teeth later, but the delay is almost entirely explained by their early birth rather than a problem with dental development. When you count from their original due date instead of their actual birthday, preemies hit teething milestones at roughly the same time as full-term infants. The smaller and earlier a baby was born, the more noticeable this gap looks on the calendar.
How Much Later Teeth Typically Appear
Full-term babies get their first tooth around 30 weeks of age (about 7 months) on average, though anywhere from 4 to 12 months falls within the normal range. For preemies, that first tooth tends to show up a few weeks to a few months later by calendar age. One study found the average was about 7.5 months for preemies, but the difference was statistically significant compared to full-term peers.
Birth weight plays a big role in how large the gap is. Babies born weighing less than about 3.3 pounds (1,500 grams) got their first tooth at around 38 weeks of age on average, compared to about 31 weeks for babies born at a normal weight. That’s roughly a seven-week difference. Babies in the middle range, between 3.3 and 5.5 pounds, fell somewhere in between, with their first tooth arriving around 33 weeks. So if your baby was born very early and very small, the wait for that first tooth can feel long.
Why Corrected Age Changes the Picture
Here’s the key finding that should put most parents at ease: when researchers used corrected age (counting from the due date, not the birth date), the differences between preemies and full-term babies disappeared entirely. Babies under 1,500 grams, between 1,500 and 2,499 grams, and over 2,500 grams all got their first tooth at a corrected age of about 68 to 69 weeks from conception. The differences were not statistically significant across any of the weight groups.
This means the teeth themselves are developing on a normal biological schedule. A baby born two months early will look about two months “behind” on teething compared to a full-term baby of the same calendar age, but their teeth are arriving right on time relative to when they were supposed to be born. Pediatricians and developmental specialists generally recommend using corrected age for tracking milestones in preemies, and teething is no exception.
Why Preemies Face Extra Dental Challenges
The timing of tooth eruption is one thing. The quality of those teeth is another, and this is where prematurity can have a more lasting impact.
About 80% of the calcium and phosphorus a baby needs for bone and tooth development transfers from mother to baby during the third trimester. Babies born early miss some or all of that transfer window. The body prioritizes bone mineralization first, which means tooth development can take a hit when minerals are scarce. Teeth that were forming during the period of deficiency may end up with weaker or thinner enamel.
Studies show that enamel defects are significantly more common in preterm children. One study of children aged 5 to 10 found that 58% of those born preterm had enamel defects, compared to 24% of children born full-term. These defects can show up as white or yellow spots, pitting, grooves, or areas where the enamel is noticeably thinner. They can affect both baby teeth and permanent teeth, since the first permanent molars begin mineralizing around the eighth month of pregnancy and the front permanent teeth start mineralizing about three months after birth.
The Role of NICU Interventions
Medical treatments that keep preemies alive can also affect their teeth. Breathing tubes, in particular, have a well-documented connection to enamel problems. In one study of 157 preterm children, 86% of those who had been intubated showed enamel defects, compared to about 14% of those who were not intubated. The longer a baby spent on a breathing tube, the greater the chance of these defects. The upper front teeth, especially on the left side, are most commonly affected because of how the tube and instruments press against the developing tooth buds in the palate.
Even babies who were intubated through the nose rather than the mouth showed high rates of enamel defects, suggesting that the respiratory distress itself and associated low oxygen levels contribute to the problem, not just physical contact from the tube.
What This Means for Your Baby’s Teeth
If your preemie hasn’t cut a tooth yet and their full-term peers have, the most likely explanation is simply that their body is following its original developmental timeline. Using corrected age as your benchmark will give you a more accurate picture of where they stand. For a baby born at 28 weeks, for example, you’d subtract about three months from their calendar age when checking milestones.
Because enamel defects are so common in preterm children, early dental care matters more, not less, for preemies. The American Academy of Pediatric Dentistry recommends that all infants see a dentist within six months of their first tooth or by their first birthday, whichever comes first. For preemies, this visit is a good opportunity to check for any enamel weakness that might make teeth more vulnerable to cavities. Teeth with thin or pitted enamel can benefit from protective treatments like fluoride varnish, and your dentist can flag any areas to watch as more teeth come in.
The reassuring bottom line: a late first tooth in a preemie is almost always a reflection of early arrival, not a sign that something is wrong with how their teeth are developing. The teeth are coming. They’re just following the schedule the body originally set.