Most babies cut their first tooth somewhere around six to eight months of age, with the full set of twenty primary teeth typically in place by roughly age two and a half. That said, a perfectly healthy baby can sprout a tooth as early as four months or as late as twelve months without anything being wrong. The timing varies more than most parenting guides suggest, influenced by genetics, birth weight, and whether the baby was born full-term or premature.
When the First Tooth Usually Appears
Across multiple studies in different populations, the average age at first tooth emergence clusters between about seven and nine months. A study tracking Brazilian infants found the mean age of first primary tooth emergence was about seven and a half months, with the lower central incisor being first in roughly 82% of cases.1PubMed. Timing of emergence of the first primary tooth in preterm and full-term infants Research on Australian children pegged it slightly later, at an average of about eight and a half months.2PubMed. Primary tooth emergence in Australian children: timing, sequence and patterns of asymmetry A Jordanian cohort reported a similar figure of about eight months for the first tooth.3PubMed. Timing and sequence of emergence of deciduous teeth in Jordanian children The spread across these studies reflects real population-level variation, not disagreement. If your baby’s first tooth shows up at five months or at eleven months, both are well within the normal window.
The Full Eruption Sequence
Despite all the individual variation in timing, the order in which teeth come in is remarkably consistent across populations. The sequence follows the same pattern in studies conducted on different continents: central incisors first, then lateral incisors, first molars, canines, and finally second molars.2PubMed. Primary tooth emergence in Australian children: timing, sequence and patterns of asymmetry 3PubMed. Timing and sequence of emergence of deciduous teeth in Jordanian children Lower teeth generally beat their upper counterparts by a few weeks.
Here is roughly what to expect, keeping in mind that each child’s calendar can shift by several months in either direction:
- Lower central incisors: around 6–10 months, usually the very first teeth to appear.
- Upper central incisors: around 8–12 months.
- Lateral incisors: upper and lower arrive between roughly 9 and 16 months.
- First molars: around 13–19 months, often the most uncomfortable stage because these are larger teeth pushing through.
- Canines: around 16–22 months, filling in the gap between the incisors and molars.
- Second molars: around 23–33 months, completing the full set of twenty baby teeth.
The entire process from first incisor to last molar spans roughly two years. In the Australian data, the last primary teeth emerged at an average of about 28 months.2PubMed. Primary tooth emergence in Australian children: timing, sequence and patterns of asymmetry The Jordanian study reported a similar range of about eight months to about 28 months for the full set.3PubMed. Timing and sequence of emergence of deciduous teeth in Jordanian children
What Teething Actually Feels Like for Your Baby
The list of symptoms parents attribute to teething is long, but the research supports a shorter, more specific set. A clinical trial following infants during eruption found that drooling was by far the most common sign, reported in about 92% of teething episodes. Sleep disturbances came next at around 82%, followed by irritability at roughly 76%.4PubMed Central. Signs and symptoms associated with primary tooth eruption: a clinical trial of nonpharmacological remedies Other commonly observed signs include gum rubbing, increased biting behavior, facial flushing on the side of the emerging tooth, and a slight loss of appetite.
The symptoms tend to peak in the day or two before and after a tooth breaks the gum surface, then ease up until the next tooth starts moving. Many parents describe teething as a constant months-long misery, but the acute discomfort is actually intermittent, clustering around each individual eruption event. The molar stages tend to be rougher because the teeth have a larger surface area pushing through.
The Fever and Diarrhea Myth
One of the most persistent beliefs in parenting is that teething causes high fever and diarrhea. A survey found that nearly 75% of parents incorrectly attributed fever and diarrhea to teething.5PubMed. Challenging parents’ myths regarding their children’s teething The timing makes the confusion understandable: babies start teething around the same age that maternal antibodies fade and solid foods are introduced, both of which increase the chance of infections and digestive changes. So a baby who is teething and also has a fever probably has a mild viral infection happening at the same time.
This distinction matters because dismissing a real fever as “just teething” can delay treatment for something more serious. If your baby has a temperature above about 38°C (100.4°F), persistent diarrhea, or a rash that does not seem related to drooling, treat those as separate issues worth mentioning to your pediatrician rather than assuming the teeth are to blame.
Why Some Babies Teethe Early or Late
The biggest single predictor of when a baby’s teeth come in is whether they were born full-term or premature. Preterm infants tend to show delayed eruption across all primary teeth compared with term babies. A longitudinal cohort study found that when researchers corrected for the weeks of prematurity, the delay narrowed and only the central incisors still lagged, suggesting much of the apparent delay is simply the baby being younger in developmental terms than their calendar age implies.6PubMed Central. Effect of Neonatal Factors on the Eruption of Primary Teeth in Children: A Longitudinal Prospective Cohort Study Birth weight, birth length, and when solid foods were introduced also showed strong associations with eruption timing in the same study.
Sex plays a modest role as well: girls tend to get their teeth slightly earlier than boys on average, though the gap is small enough that you would not notice it with a single child. Genetics matters too, in ways that are hard to pin to individual genes. If you or your partner were very early or very late teethers, your child has a somewhat higher chance of following a similar schedule. Nutritional status, particularly vitamin D and calcium availability during the first year, can also shift timing at the margins.
Babies Born with Teeth
On rare occasions, a baby is born with one or more teeth already visible. These are called natal teeth; teeth that appear within the first thirty days of life are called neonatal teeth.7PubMed Central. Management of an infant having natal teeth The incidence is low, roughly one in every two to three thousand births, and the teeth are almost always lower central incisors.
These early teeth often look different from normal baby teeth. They tend to be smaller, somewhat cone-shaped, and yellowish, with underdeveloped enamel and little to no root formation. In a case-control study of 52 children with natal or neonatal teeth, about 28% of the teeth showed visible enamel defects, and roughly 31% of the children needed extraction because the teeth were so loose they posed an aspiration risk.8Scientific Reports. Natal and neonatal teeth in newborns and infants: a case-control study Complications can include difficulty breastfeeding, ulceration under the tongue from the tooth edge, and laceration of the mother’s breast.7PubMed Central. Management of an infant having natal teeth
If the tooth is stable, not causing feeding problems, and is otherwise asymptomatic, dentists often leave it in place. Extraction is typically reserved for teeth that are very mobile or causing injury. The decision is case-by-case, and a pediatric dentist can advise within the first days after birth if needed.
Relieving Teething Discomfort Safely
For a process that every human goes through, the evidence on teething treatments is surprisingly thin. A systematic review evaluating the available research found that teething rings were among the most effective non-drug approaches, particularly for reducing drooling, crying, gum irritation, and sleep disruption.9Brazilian Oral Research. Efficacy of treatments used to relieve signs and symptoms associated with teething: a systematic review Chilled (not frozen) rings or clean, wet washcloths give the baby something firm to bite on, which seems to provide counter-pressure that eases gum soreness. A pilot study also found that parents perceived their children as calmer and happier after using edible teethers, suggesting that the act of chewing and the sensory distraction play a real role.10PubMed Central. Soothing Effect of an Edible Teether: A Pilot Study in Children during Primary Dentition Age
What to avoid is just as important as what to try. Topical benzocaine gels, once widely sold for infant teething pain, carry a risk of methemoglobinemia, a condition where the blood loses its ability to carry oxygen effectively. A case report documented severe methemoglobinemia in a toddler from a 7.5% benzocaine product sold specifically for teething.11PubMed. Severe methemoglobinemia from topical benzocaine 7.5% (baby orajel) use for teething pain in a toddler The U.S. FDA has since warned against using benzocaine products in children under two. Homeopathic teething tablets have also drawn regulatory scrutiny after reports of adverse events linked to inconsistent belladonna concentrations. Amber teething necklaces, meanwhile, pose a strangulation and choking hazard with no demonstrated analgesic benefit.
For babies in genuine distress, an age-appropriate dose of infant acetaminophen or ibuprofen (the latter only for babies six months and older) remains the safest pharmacological option. Gum massage with a clean finger is a simple, no-cost approach that many parents find surprisingly effective.
When Baby Teeth Start Falling Out
The primary teeth that took two and a half years to assemble start departing around age six. The first permanent teeth to emerge are usually the lower central incisors or the first molars, and research shows which arrives first can vary by population. A Finnish study found that the lower central incisor beat the first molar to emergence in about 68% of children.12PubMed. Emergence of permanent teeth and dental age in a series of Finns The full transition from primary to permanent dentition unfolds over roughly six years, finishing around age twelve with the second permanent molars. Third molars, or wisdom teeth, are a separate and much more variable event, typically appearing (or not) in the late teens or early twenties.
The permanent tooth eruption process can produce its own discomfort, though it rarely gets the same attention as infant teething. Children sometimes complain of sore gums when the six-year molars come in, and the wobbling phase of a loose baby tooth can be annoying or mildly painful. These episodes are generally milder than infant teething, partly because older children can communicate what hurts and self-soothe more effectively.
A Long History of Getting Teething Wrong
For most of recorded medical history, teething was treated as a genuinely dangerous disease rather than a normal developmental milestone. Hippocrates wrote about teething-related fevers and convulsions. The ancient Romans, interestingly, considered being born with teeth a sign of future greatness. By the seventeenth and eighteenth centuries in Europe, teething was commonly listed as a cause of death on infant mortality records, and treatments ranged from lancing the gums to applying leeches.13Kaleidoscope history. History of Misconceptions Surrounding Teething
The nineteenth century brought what might be the most infamous chapter: over-the-counter soothing syrups containing morphine and alcohol, marketed specifically for teething infants. Mrs. Winslow’s Soothing Syrup was among the most popular, and infant overdose deaths were documented repeatedly before it was eventually pulled from the market. The progression from hare’s brain ointments (recommended by the Roman physician Soranus) to morphine syrups to today’s evidence-based approach has been slow, and echoes of the old thinking persist in the widespread parental belief that teething causes systemic illness.
How Human Teething Compares with Other Primates
The timing of tooth eruption in humans is markedly slower than in our closest relatives, and this difference tells a broader story about human development. In captive chimpanzees, the first permanent molar emerges at an average of about three years of age. In modern humans, that same tooth does not appear until about six years.14Scientific Reports. Diversity in tooth eruption and life history in humans: illustration from a Pygmy population Fossil evidence from Homo erectus suggests an intermediate schedule, with the second permanent molar erupting at roughly nine years, falling between the faster ape timeline and the even slower modern human one.
This slow dental schedule appears to be tied to our unusually prolonged childhood. In many primates, the eruption of the first permanent molar roughly coincides with weaning and greater independence. Humans have stretched that whole developmental phase out, which reflects our large brain size, extended period of dependence, and the long learning curve needed to function in complex social groups. Even among modern human populations, there is meaningful variation: research on Baka Pygmy populations found their dental emergence timing differed from other modern human samples, suggesting that ecological and nutritional factors continue to shape the pace of tooth development within our own species.14Scientific Reports. Diversity in tooth eruption and life history in humans: illustration from a Pygmy population
At the level of individual tooth roots, research comparing human and great ape deciduous teeth has found that the roots of human baby incisors, canines, and premolars accelerate their growth rate as the teeth approach the gum surface. Preliminary comparisons with chimpanzee and orangutan teeth show that ape deciduous roots extend in length more rapidly overall, consistent with their faster eruption timelines.15PubMed. Root growth and dental eruption in modern human deciduous teeth with preliminary observations on great apes The mechanisms driving these rate differences are still being worked out, but they appear to involve both genetic programming of tooth-forming cells and systemic growth signals that differ between species.