Teething usually announces itself through a cluster of mouth-focused behaviors rather than any single dramatic symptom. The most reliably reported sign across studies is increased biting, seen in roughly two-thirds of teething infants, alongside drooling, gum redness, and general fussiness. What trips up many parents is the list of symptoms teething gets blamed for but probably does not cause, including fever and diarrhea, which makes knowing the real signs worth a closer look.
When the First Tooth Usually Appears
Most babies cut their first tooth around seven to eight months of age, though the range is wide enough that seeing nothing at four months or seeing a tooth at three months are both within the bounds of normal. In a study tracking the timing of first tooth emergence, the average was about seven and a half months, with a standard deviation of nearly three months in either direction.1PubMed. Timing of emergence of the first primary tooth in preterm and full-term infants That same study found the lower central incisor was the first tooth to show up in about 82% of babies. This pattern held across a separate study of eruption sequences, which confirmed lower central incisors come first, followed by upper central incisors, upper lateral incisors, and then lower lateral incisors.2PubMed Central. Eruption Timing and Sequence of Primary Teeth in a Sample of Romanian Children
Premature babies tend to be on the later end. Because their development is measured differently, the corrected age often gives a better sense of when to expect teeth than the calendar age. By about thirty months, most children have all twenty primary teeth in place, though the molars and canines fill in over the second and third years.
The Local Signs That Actually Point to Teething
The symptoms most reliably linked to teething are the ones happening right at the gum line. A large systematic review and meta-analysis pooling data from studies around the world found that increased biting was the most commonly reported local symptom, appearing in about 66% of teething episodes.3PubMed. Global prevalence of teething problems in infants and children-A systematic review and meta-analysis That urge to gnaw on anything within reach, whether it is a toy, a finger, or their own fist, comes from the pressure a tooth puts on the gum tissue as it moves upward. Biting back against that pressure seems to give babies some relief.
Beyond biting, the signs pediatricians and dentists consider genuinely teething-related tend to be localized:
- Gum swelling and redness: The tissue over the emerging tooth becomes visibly puffy and may look redder than the surrounding gum. In some cases, a bluish blister called an eruption hematoma forms where blood pools under the gum surface.
- Drooling: Many babies drool more during active eruption periods. This can irritate the skin around the chin and neck, sometimes causing a rash that parents mistake for a separate illness.
- Gum rubbing and ear pulling: Babies often rub at their gums or tug at the ear on the same side as the emerging tooth. The ear pulling happens because the jaw, gums, and ear share nerve pathways, so discomfort in one area can feel like it is coming from another.
- Irritability: Fussiness that comes and goes in short bursts, often worsening in the days right before a tooth breaks through and easing once it does.
An observational study of pediatric patients tracked these local signs alongside systemic ones and found that a scoring system combining gum redness, swelling, pain on palpation, and caregiver-reported itching could help clinicians distinguish teething discomfort from other problems.4Pediatrics. Consilium Medicum. Infant teething syndrome: practical experience of a pediatrician. An observational study The key pattern is that real teething signs are mouth-centered and temporary. If something is happening far from the gum line or lasting more than a few days, it is worth considering other causes.
What Teething Probably Does Not Cause
Fever is the biggest misattribution. It is deeply embedded in parenting culture that cutting a tooth gives a baby a temperature, and nearly 75% of parents in one study incorrectly attributed fever to teething.5PubMed. Challenging parents’ myths regarding their children’s teething But the clinical evidence does not back this up. A cohort study that tracked infant temperatures on days when a tooth was actively breaking through the gum found almost no difference: average temperatures on “tooth days” were essentially the same as on non-tooth days. After adjusting for the baby’s age, neither low-grade nor high fevers were significantly more likely during eruption.6Pediatrics. Teething and Tooth Eruption in Infants: A Cohort Study
The same study, along with a well-known prospective study from the same journal, emphasized that diarrhea and rashes unrelated to drool irritation should not be chalked up to teething. A key takeaway from the research is straightforward: before attributing any sign of a potentially serious illness to teething, other causes need to be ruled out.7Pediatrics. Symptoms Associated With Infant Teething: A Prospective Study A genuine fever above 38°C (100.4°F) in a baby under twelve months old could signal an infection, and blaming it on teeth can delay treatment.
The timing overlap is part of the confusion. Babies tend to start teething around six to eight months, which is exactly the window when maternal antibodies are fading and infants start picking up more viral illnesses. They are also putting everything in their mouths, which increases exposure to germs. A runny nose and mild fever that happen to coincide with a swollen gum are easy to lump together, but the research suggests they are running on separate tracks.
Does Teething Actually Disrupt Sleep?
Ask almost any parent and they will tell you teething wrecked their baby’s sleep for days. A longitudinal study using overnight video recordings to objectively measure infant sleep told a different story. Researchers compared sleep on teething nights to non-teething nights and found no significant differences in how long babies slept, how often they woke, or how long those wake-ups lasted.8PubMed. Does Teething Disrupt Infant Sleep? A Longitudinal Auto-Videosomnography Study More than half of the parents in the study reported sleep disturbances during teething, but those reports did not match what the cameras actually captured.
This does not mean parents are imagining things. A baby who is fussier during the day and chewing on everything may seem more restless at night even if their measured sleep is about the same. Parents who are primed to expect disrupted sleep may also notice and remember normal brief awakenings they would otherwise sleep through themselves. The practical upshot is that if your baby’s sleep genuinely deteriorates for several nights running, teething alone is unlikely to be the full explanation, and looking into other causes like illness or a developmental leap is reasonable.
Soothing a Teething Baby Safely
The remedies with the best evidence are low-tech and free. A clinical trial testing five non-drug approaches found that teething rings produced the best results for symptom relief and recovery time, followed by cuddle therapy (simply holding and comforting the baby) and rubbing the gums with a clean finger.9PubMed Central. Signs and symptoms associated with primary tooth eruption: a clinical trial of nonpharmacological remedies A separate systematic review of teething treatments confirmed teething rings as the most effective option across multiple symptoms, including drooling, gum irritation, crying, and trouble sleeping.10Brazilian Oral Research. Efficacy of treatments used to relieve signs and symptoms associated with teething: a systematic review
A few practical notes on using these methods well:
- Chilled, not frozen: A teething ring placed in the refrigerator provides mild numbing and counter-pressure. Freezing it makes it too hard and can hurt the gums or crack if bitten.
- Solid rings over liquid-filled ones: Liquid-filled teethers can leak or, if frozen, become rigid enough to bruise.
- Clean hands for gum massage: Rubbing a clean, cool finger firmly along the gum ridge where the tooth is coming in often calms a fussy baby quickly.
- Wet washcloth: A damp washcloth that has been chilled in the fridge gives the baby something safe to gnaw on with a texture that works well against sore gums.
If your baby seems to be in real discomfort and non-drug methods are not enough, a weight-appropriate dose of infant acetaminophen or ibuprofen (the latter only for babies six months and older) can help. This is worth discussing with your pediatrician rather than making a habit of, since teething discomfort typically comes in short waves rather than sustained pain.
Remedies That Are Genuinely Dangerous
Two popular teething products carry real risks that outweigh any theoretical benefit.
Lidocaine-based teething gels have been linked to seizures, respiratory arrest, and death in infants and young children. The problem is dosing: a baby can easily swallow the gel, and the amount needed to numb a small mouth can approach a toxic dose in a small body. Both the American Academy of Pediatrics and the US Food and Drug Administration recommend against using topical lidocaine for teething.11PubMed. Are teething gels safe or even necessary for our children? A review of the safety, efficacy and use of topical lidocaine teething gels Benzocaine-containing gels carry a similar warning due to the risk of methemoglobinemia, a condition where the blood cannot carry oxygen properly. Homeopathic teething tablets have also been flagged by the FDA after reports of adverse events, partly because “homeopathic” does not always mean “no active ingredient” in unregulated products.
Amber teething necklaces are marketed on the claim that succinic acid from the amber beads absorbs through the skin and reduces inflammation. No peer-reviewed evidence supports this mechanism, and the risks are concrete: strangulation if the necklace catches on something during sleep, choking if a bead breaks free, and skin infections around the beads.12PubMed Central. Use of the amber teething necklace by the child population: risks versus benefits Case reports in emergency medicine literature document infant strangulation from these necklaces, and Health Canada has issued warnings against their use.13PubMed. Infant Strangulation from an Amber Teething Necklace If you have one, the safest course is to remove it.
When Teeth Show Up Unusually Early
Some babies are born with teeth already visible, called natal teeth, or sprout them within the first month of life, called neonatal teeth. This is rare, but it happens, and it can alarm parents who were not expecting to see a tooth in a newborn’s mouth. The teeth are almost always lower incisors, and they often come in pairs.14PubMed Central. Natal and Neonatal Teeth: A Tertiary Care Experience
Whether these teeth stay or go depends on how firmly rooted they are. A case-control study found that about 31% of infants with natal teeth needed extraction because the teeth were so loose they posed a risk of the baby swallowing or inhaling them.15Scientific Reports. Natal and neonatal teeth in newborns and infants: a case-control study Other complications included feeding difficulties in about a fifth of cases, nipple lacerations in breastfeeding mothers, and Riga-Fede disease, a condition where the sharp edge of a natal tooth repeatedly ulcerates the underside of the baby’s tongue. When the teeth are stable and not causing problems, dentists generally leave them in place.
A family history of natal teeth makes the occurrence more likely. In one tertiary-care study, about a quarter of affected babies had a relative who was also born with teeth.14PubMed Central. Natal and Neonatal Teeth: A Tertiary Care Experience If your newborn has a visible tooth, a pediatric dentist can assess whether it needs monitoring or removal.
Teething and Breastfeeding
Once teeth start coming in, some breastfeeding mothers notice bite injuries on their nipples and areolae. This is common enough that researchers have explored solutions specifically for it. One approach described in the dental literature is a custom-made soft bite appliance fitted over the baby’s erupting teeth, which acts as a barrier during nursing.16PubMed Central. Soft Bite Appliance for Teething Infants In practice, most parents will not pursue a custom dental device, but the underlying problem is real and can be managed with positioning changes and timing adjustments. A baby who bites is often doing so at the end of a feed when they are no longer actively swallowing. Unlatching your baby as soon as the sucking rhythm slows can prevent most biting incidents. Some lactation consultants recommend gently pressing the baby closer to the breast when a bite happens, which prompts them to open wider and release.
Teething is not a medical reason to stop breastfeeding, though it is sometimes cited as one. Most babies learn quickly that biting leads to the feed ending, and the phase tends to resolve on its own within a few days to a couple of weeks.
Why Confirmation Bias Makes Teething Seem Worse Than It Is
A striking pattern across the teething literature is the gap between what parents report and what objective measurements show. More than half of parents report sleep problems during teething, but video recordings of the same babies sleeping do not confirm the disruption.8PubMed. Does Teething Disrupt Infant Sleep? A Longitudinal Auto-Videosomnography Study Nearly three-quarters of parents attribute fever and diarrhea to teething despite clinical evidence showing no meaningful link.5PubMed. Challenging parents’ myths regarding their children’s teething
This is not parents being foolish. It is a feature of how the human brain handles coincidences during stressful periods. When your baby is uncomfortable and you are sleep-deprived, you notice and remember anything that seems to explain what is going on. A loose stool on a day the gum looks swollen gets filed under “teething.” A night with two extra wake-ups during a week when a tooth was emerging gets remembered as “teething ruined sleep for a week.” These connections feel real because our brains are wired to link nearby events, but the controlled studies consistently show that the systemic symptoms are not arriving any more often during eruption than at any other time.
The real danger of this bias is not the worry itself but the action it can lead to. A parent who is convinced teething causes high fevers may delay seeking care for an actual infection. A parent who believes diarrhea is just a teething thing may not watch for dehydration as carefully as they should. The safest rule of thumb is simple: local gum symptoms are fair game to attribute to teeth, but anything systemic deserves its own evaluation.
What Saliva Can Tell Us About Eruption
Researchers have started looking at what happens in a baby’s saliva during active tooth eruption, and the changes are measurable. A cross-sectional study comparing saliva samples from babies in different eruption stages found significant shifts in electrolyte concentrations. Calcium levels in saliva were highest during active eruption and dropped once the tooth had fully emerged, while potassium showed a different pattern across eruption phases.17PubMed Central. Salivary Protein and Electrolyte Profiles during Primary Teeth Eruption: A Cross-Sectional Study These findings are still in the early-research phase and have no clinical application yet, but they point toward a future where a simple saliva test could confirm whether a tooth is actively on its way through the gum, taking some of the guesswork out of the equation for parents and pediatricians alike.
The drooling that accompanies teething may itself be related to these compositional changes. Saliva production during eruption is not just increased in volume; it appears to be biochemically different, possibly as part of the body’s response to tissue remodeling in the gum. For now, this remains a research curiosity rather than a practical tool, but it underscores that teething is a genuine physiological event producing measurable biological changes, even when many of the symptoms traditionally blamed on it turn out to be coincidental.