Most babies announce their first tooth with a cluster of mild, familiar signs: extra drooling, swollen gums, and a sudden urge to gnaw on anything within reach. These clues typically appear a few days before the tooth breaks through, usually somewhere around eight to nine months of age, though the range of normal is wide. The picture gets muddled because many symptoms parents blame on teething, from high fevers to diarrhea, have little to do with teeth at all. Sorting the reliable signals from the myths can save a lot of unnecessary worry.
When to Expect the First Tooth
The first baby tooth to show up is almost always a lower central incisor, one of the two bottom-front teeth. In a large Australian study, the average age at first eruption was about 8.6 months, and the last primary tooth appeared around 28 months.1PubMed. Primary tooth emergence in Australian children: timing, sequence and patterns of asymmetry A study of Romanian children confirmed the same general order: lower central incisors first, then upper central incisors, upper lateral incisors, lower lateral incisors, first molars, canines, and finally the second molars.2PubMed Central. Eruption Timing and Sequence of Primary Teeth in a Sample of Romanian Children By the time your child is about two and a half to three years old, all twenty primary teeth are usually in place.
That said, the “average” disguises a big spread. Some perfectly healthy babies sprout a tooth at four months; others are still gummy at their first birthday. If your child is a late bloomer, there is rarely anything wrong. Pediatric dentists generally do not investigate delayed eruption unless no teeth have appeared by about 18 months.
The Reliable Signs of Teething
A meta-analysis pooling data from over 3,500 children found that about 70% showed at least some signs or symptoms during tooth eruption.3Pediatrics. Signs and Symptoms of Primary Tooth Eruption: A Meta-analysis The most common were gum irritation, general crankiness, and drooling. A prospective study tracking individual tooth eruptions found that the following symptoms were consistently tied to teeth coming in:4Pediatrics. Symptoms Associated With Infant Teething: A Prospective Study
- Increased biting and chewing: Babies press hard objects against their gums because counter-pressure can soothe the ache of a tooth pushing through.
- Extra drooling: Saliva production ramps up, often enough to soak a bib in minutes.
- Gum rubbing: You may notice your baby dragging fingers or fists across the gum line.
- Irritability: Fussiness is the most widely reported behavioral change, though it tends to be mild and short-lived.
- Decreased appetite for solids: Sore gums can make chewing uncomfortable, so a baby who was enthusiastic about purees last week may suddenly refuse the spoon.
- Facial rash: Constant drool on the chin and cheeks can cause a mild reddish rash.
- Ear rubbing: The shared nerve pathways between the jaw and the ear mean some babies tug at their ears when gums hurt, which is easy to mistake for an ear infection.
One important detail from that same study: no single symptom appeared in more than about a third of teething babies, and no symptom was more than 20 percentage points more common during teething than during non-teething periods. In other words, every baby’s teething experience is a bit different, and many teeth slip through with barely a whimper.
What the Gums Actually Look Like
Before a tooth erupts, you can often feel a hard ridge under the gum if you run a clean finger along the gum line. The tissue over an incoming tooth may look slightly swollen and redder than surrounding gums. In some cases a small bluish or translucent bump appears, called an eruption cyst. These cysts form when fluid accumulates between the tooth and the gum tissue, and they almost always resolve on their own once the tooth pokes through. True eruption cysts that persist or become painful are rare enough that most pediatric dentists see only a handful in a career.
If you see what looks like a white or yellowish nodule on the gum ridge of a very young infant, that is more likely an Epstein pearl, a tiny benign cyst that has nothing to do with teething and disappears without treatment. Knowing the difference can spare you an unnecessary trip to the dentist.
The Fever Question
Few teething myths are as persistent as the idea that cutting a tooth causes a real fever. Research tells a more nuanced story. A clinical trial that took temperature readings on the day before, the day of, and the day after eruption found a slight bump in body temperature on the eruption day itself, averaging around 36.7°C (about 98.1°F), which is well below any definition of fever.5PubMed Central. Signs and symptoms associated with primary tooth eruption: a clinical trial of nonpharmacological remedies The meta-analysis of eruption signs reached the same conclusion: eruption can raise temperature slightly, but not to the level of a true fever.3Pediatrics. Signs and Symptoms of Primary Tooth Eruption: A Meta-analysis
A second prospective study reinforced this, finding that while irritability and drooling were strongly linked to tooth eruption, fever was not, and neither were diarrhea, vomiting, or cough.6Pediatrics. Prospective Longitudinal Study of Signs and Symptoms Associated With Primary Tooth Eruption The practical takeaway is straightforward: if your baby has a temperature above about 38°C (100.4°F), assume something other than teething is responsible and treat it accordingly. Blaming a real fever on teething can delay recognition of infections that need attention.
The historical roots of this myth run deep. In centuries past, infant mortality peaked between roughly six months and four years of age, exactly when teeth come in. Because the timing overlapped, teething was blamed for all manner of childhood illness and even death. That cultural echo still shapes what parents expect today.
Does Teething Actually Disrupt Sleep?
Ask any parent of a teething baby, and they will probably say yes. But a recent study using video-based sleep monitoring painted a different picture. Researchers compared objective sleep measures on teething and non-teething nights and found no significant differences in how long babies slept or how often they woke.7PubMed. Does Teething Disrupt Infant Sleep? A Longitudinal Auto-Videosomnography Study More than half the parents in that study reported that their baby’s sleep was worse during teething, but the cameras disagreed.
This does not mean parents are imagining things. Babies in the teething age range are also going through major developmental leaps, separation anxiety, schedule transitions, and ordinary viral illnesses. All of these can fragment sleep, and because a new tooth is visible evidence of change, it becomes the default explanation. For practical purposes, this means that “teething sleep regression” might respond better to consistent sleep routines than to teething remedies.
What Affects When Teeth Arrive
Genetics is the biggest driver of eruption timing, but several other factors nudge the schedule earlier or later.
Birth weight and gestational age have a clear influence. A study comparing preterm and full-term infants found a statistically significant delay in first tooth eruption among preemies when counting from birth. Babies who weighed less than 1,500 grams at birth had their first tooth appear at about 9.8 months on average, compared to about 8 months for heavier infants.8Egyptian Pediatric Association Gazette. Relationship between gestational age, birth weight and deciduous tooth eruption However, a separate study found that when researchers used “corrected age,” adjusting for how early the baby was born, the delay vanished. This suggests premature infants are not behind in dental development; they are simply younger than their birth date implies.9Journal of Applied Oral Science. The influence of gestational age and birth weight of the newborn on tooth eruption If your baby was born early, counting from your original due date rather than the actual birthday gives a more accurate sense of when to expect teeth.
Maternal factors play a role too. A large cohort study found that babies who were longer at birth tended to get their first tooth earlier and had more teeth at ages one and two. Maternal smoking during pregnancy was also linked to earlier eruption, and babies from more socially deprived areas were more likely to have advanced dental development by age two.10PubMed Central. Maternal and early life factors of tooth emergence patterns and number of teeth at one and two years of age The reasons behind these associations are still being worked out, but the takeaway for parents is that variation in timing is influenced by many factors beyond your control.
Soothing a Teething Baby
The evidence base for teething remedies is thinner than the marketing might suggest, but a few approaches have reasonable support. A systematic review of treatments found that teething rings were the most effective non-drug option, helping with drooling, gum irritation, crying, and sleep disruption in the majority of babies studied.11Braz. oral. res. Efficacy of treatments used to relieve signs and symptoms associated with teething: a systematic review Chilled (not frozen) rings seem to work by numbing the gum slightly and giving the baby something firm to bite. A clean, cool washcloth serves the same purpose.
Rubbing the gums gently with a clean finger provides counter-pressure that many babies find comforting. If your child seems genuinely miserable, infant-appropriate doses of acetaminophen or ibuprofen (for babies over six months) are widely recommended by pediatricians for short-term relief.
What you should avoid is more clear-cut. Topical benzocaine gels, sold over the counter for teething pain, carry a real risk. Benzocaine can cause methemoglobinemia, a condition where the blood’s ability to carry oxygen drops sharply, potentially leading to dangerous symptoms including difficulty breathing and seizures. The American Academy of Pediatrics recommends against using benzocaine products in young children.12PubMed Central. Pediatric Exposures to Topical Benzocaine Preparations Reported to a Statewide Poison Control System Homeopathic teething tablets have also drawn FDA warnings in recent years due to inconsistent ingredient levels. Amber teething necklaces pose choking and strangulation hazards with no plausible mechanism for pain relief.
When to Start Brushing
The arrival of the first tooth is the conventional signal to start oral hygiene. A systematic review and meta-analysis found that beginning tooth brushing by 12 months of age and brushing at least twice daily appeared protective against early childhood cavities.13PubMed Central. Optimal tooth brushing initiation age and frequency for preventing early childhood caries: a systematic review and meta-analysis You do not need a fancy toothbrush; a soft infant brush or even a damp gauze pad works for the first few teeth. Use a rice-grain-sized smear of fluoride toothpaste, which is enough to protect enamel without posing any concern if swallowed.
The American Academy of Pediatric Dentistry recommends a first dental visit by age one or within six months of the first tooth, whichever comes first. Early visits are mainly about establishing a dental home, checking for any eruption oddities, and giving parents guidance on cavity prevention rather than doing any real work in the chair.
Babies Born with Teeth
Occasionally a baby is born with a tooth already visible, known as a natal tooth. Teeth that appear in the first 30 days of life are called neonatal teeth. Natal teeth are about three times more common than neonatal teeth, though both are uncommon overall.14PubMed Central. Natal and neonatal teeth: an overview of the literature Most natal teeth are actual primary teeth that erupted early rather than extra (supernumerary) teeth, so removing them means that spot will stay empty until the permanent tooth arrives years later.
Natal teeth can cause practical problems. If the tooth is loose, there is a small aspiration risk. A sharp edge can also create ulcers on the underside of the baby’s tongue, a condition called Riga-Fede disease, which can interfere with breastfeeding. In one documented case, extracting a neonatal tooth that was causing oral ulcers allowed the sores to heal quickly and breastfeeding to resume.15PubMed Central. Neonatal tooth with Riga-Fide disease affecting breastfeeding: a case report The decision to extract or smooth the tooth is made case by case depending on how firmly it is attached and whether it is causing injury.
Teething and the Evolutionary Connection to Weaning
The timing of tooth eruption is not random; it tracks closely with the developmental window when babies begin eating solid food. Research on enamel growth in human infants has shown that the front incisors get a head start, with a larger proportion of their crown forming before birth compared to other tooth types. This prenatal “fast track” allows incisors to erupt right around the age when breast milk starts to be supplemented with other foods.16PubMed. Dental fast track: prenatal enamel growth, incisor eruption, and weaning in human infants In other primates, the eruption of the first permanent molar correlates with weaning age. In humans, the relationship is a bit more complex: deciduous incisors arrive when mixed feeding begins, and weaning is typically complete before permanent molars come in.
For parents, this is mostly interesting trivia, but it does reinforce a practical point. If your baby starts showing teething signs around five to seven months, that is also a reasonable window to begin introducing complementary foods. The teeth and the gut are getting ready at roughly the same time, which is not a coincidence but a piece of developmental choreography millions of years in the making.
Red Flags That Are Not Normal Teething
Because teething overlaps with the age when maternal antibodies wane and babies start catching more infections, it is easy to attribute illness symptoms to teeth. A few signs should prompt a call to your pediatrician rather than a reach for the teething ring:
- Fever above 38°C (100.4°F): As the research consistently shows, teething does not cause true fevers. A high temperature means something else is going on.
- Persistent diarrhea or vomiting: Neither symptom has been reliably linked to tooth eruption in controlled studies. Gastrointestinal illness in a teething-age baby deserves its own evaluation.
- Rash beyond the chin and cheeks: Drool rash stays local. A widespread rash could signal a viral illness or allergic reaction.
- Symptoms lasting more than a few days: Teething-related fussiness and appetite changes typically cluster around the day of eruption and fade quickly. If your baby has been miserable for a week straight, something else is likely contributing.
- Refusal to drink liquids: Decreased appetite for solids is common during teething, but turning down milk or formula is not a typical teething sign and could indicate throat pain or other illness.
The core principle is simple: teething causes mild, local discomfort. Anything that looks systemic, including a high fever, significant digestive upset, or lethargy, deserves a fresh look rather than an assumption that it will pass once the tooth comes through.