When Do Babies Start Teething? The Complete Month-by-Month Timeline

Your baby is drooling, gnawing on your shoulder, and waking up at 1 AM screaming — and you're wondering: is this teething, and is this ever going to end?

The short answer is yes to both. But understanding the full teething timeline — which teeth come when, why some stages hurt more than others, and how to tell teething apart from illness — will help you navigate the next two and a half years with a lot less guesswork.

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When Do Babies Start Teething? The Timeline at a Glance

Most babies cut their first tooth somewhere between 4 and 7 months, though the normal range is 3–12 months. A small number of babies are born with teeth (natal teeth) or get their first tooth before 3 months; a small number don't see a tooth until after their first birthday. All of these can be normal.

The full set of 20 primary teeth typically comes in over the first 2.5 to 3 years, in waves. Here's the general sequence:

Teeth	When They Typically Arrive	Sleep Impact
Lower central incisors (bottom front 2)	6–10 months	Moderate — often the first disruption
Upper central incisors (top front 2)	8–12 months	Moderate; drooling peaks
Upper lateral incisors	9–13 months	Mild–moderate
Lower lateral incisors	10–16 months	Mild
First molars (upper and lower)	13–19 months	High — large surface area is most painful
Canines / cuspids	16–23 months	Moderate–high
Second molars	23–33 months	High — often most disruptive overall

Important caveat: these are averages. Your baby's timeline may run 2–3 months earlier or later and still be completely normal. What matters more is the sequence than the exact timing.

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How Each Teething Stage Disrupts Sleep Differently

Not all teething is equal. The front teeth (incisors) tend to cause less disruption than the back teeth. Here's why that happens and what to expect at each stage.

4–7 Months: First Incisors

This first round of teething often overlaps with the 4-month sleep regression, which makes it genuinely hard to tell the two apart. The 4-month regression is developmental and lasts 2–6 weeks; teething-related disruption is typically 1–3 nights per tooth.

Signs pointing to teething rather than regression: swollen gum ridge in front, visible white tissue under the gum, your baby chewing on everything and drooling heavily, irritability that improves once the tooth breaks through.

Sleep disruption at this stage: usually 1–3 rough nights per tooth, with the worst night being the one right before the tooth cuts through.

8–12 Months: Lateral Incisors and Full Front Set

By the time lateral incisors arrive, most babies have been through a few rounds of teething and have some tolerance for it. This is also the age where babies can self-soothe more effectively if they've been given the opportunity.

Sleep disruption at this stage: similar to the first round — 1–3 nights per tooth, but often better tolerated. If your baby has been building independent sleep skills, a tooth coming in is less likely to derail the whole sleep situation.

12–19 Months: First Molars

This is where teething gets harder. Molars have a much larger surface area than incisors, and they push through on four corners at once rather than breaking through one neat edge. Many families report that the first molars cause more discomfort — and more sleep disruption — than any teeth before them.

Sleep disruption at this stage: 2–5 nights per molar, sometimes longer. The molars also arrive during a period when the 12–18 month sleep regression and developmental leaps are common, so separating causes takes patience.

16–23 Months: Canines

Canines are pointed teeth that cut through a sharper tip — this can be uncomfortable, and some toddlers are particularly bothered by them. Night waking of 1–4 nights per canine is common.

23–33 Months: Second Molars

Second molars are typically the most disruptive. They arrive at the back of the mouth (harder to see or reach), have the largest surface area, and come in during the toddler years when sleep challenges are already common. Many families describe the second-molar period as the worst teething stretch overall.

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Distinguishing Teething Pain from Illness

This is genuinely important, because teething gets blamed for things it doesn't cause — and when you assume teething, you might miss something that needs a doctor's attention.

Teething CAN cause:

• Drooling (sometimes significant)
• Swollen, red, or bulging gum tissue where a tooth is emerging
• Mild fussiness and irritability
• Gnawing and biting
• Slightly looser stools (mild — from swallowed saliva)
• Mild temperature elevation (up to 99.9°F / 37.7°C at most)
• 1–5 nights of sleep disruption per tooth

Teething CANNOT cause:

• Fever above 100.4°F (38°C) — this is not teething; call your pediatrician
• Significant diarrhea or vomiting
• Runny nose, congestion, or cough
• Rash beyond minor drool rash around the mouth
• Weeks of sustained sleep disruption with no new tooth appearing

The key diagnostic question: Is a tooth actually coming through? If you look in your baby's mouth and see swollen gum tissue or a white shadow under the gum, and sleep is rough for 1–3 nights, that's teething. If sleep has been fragmented for 2–3 weeks with no tooth to show for it, look at sleep associations and wake windows instead.

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6 Safe Soothing Methods at Night

When teething is genuinely causing nighttime discomfort, these approaches can take the edge off:

1. Cold pressure on the gums. This is the most effective non-medication option. A chilled (not frozen) teething ring applied 10–15 minutes before your bedtime routine can significantly reduce gum inflammation. A cold, damp washcloth also works. Cold numbs, and the pressure provides counter-stimulation to the pain signal.

2. Infant acetaminophen (Tylenol). For babies 2 months and older, appropriate-dose acetaminophen can be given for genuine teething discomfort. Talk to your pediatrician about correct weight-based dosing. Reserve this for nights when there are clear signs of active teething pain — not as a preventive every night.

3. Infant ibuprofen (Motrin/Advil). For babies 6 months and older, ibuprofen provides slightly longer-lasting relief and has anti-inflammatory properties that may help with gum swelling. Check with your pediatrician for dosing.

4. Gum massage. A clean finger applying gentle, consistent pressure on the swollen gum area can provide relief. Some babies love this; others object. Worth trying during the bedtime routine.

5. Your consistent bedtime routine. A predictable wind-down sequence — bath, dim lights, feed, song, crib — is calming to a baby's nervous system even through discomfort. Keeping the routine intact during teething nights prevents a temporary disruption from becoming a lasting habit change. See our baby bedtime routine guide for the full sequence.

6. Extra check-in, not full rescue. If your baby wakes crying at night from teething pain, it's appropriate to go in, comfort them briefly, offer the teething ring or gum massage, and then put them back down. This is different from nursing or rocking all the way to sleep — you're addressing the pain without rebuilding a sleep dependency that will outlast the tooth.

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What NOT to Use for Teething Pain

Not everything marketed for teething is safe. A few things to avoid:

Benzocaine gels (Baby Orajel and similar): The FDA has warned against topical benzocaine products for babies under 2, due to the risk of methemoglobinemia — a rare but serious condition that reduces the blood's ability to carry oxygen.

Belladonna-containing homeopathic tablets: Products like Hyland's Teething Tablets have been linked to reports of seizures and serious adverse events in infants. The FDA recommends avoiding them entirely.

Amber teething necklaces: No scientific evidence supports their effectiveness, and they pose a choking and strangulation hazard. The American Academy of Pediatrics recommends against them.

Frozen teething rings: A frozen (not just chilled) ring is too hard and can damage tender gum tissue. Refrigerate, don't freeze.

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When to Call the Dentist

The American Academy of Pediatric Dentistry recommends scheduling a baby's first dental visit by the first birthday or within 6 months of the first tooth appearing — whichever comes first.

Call your dentist (or pediatrician) if:

• Your baby has no teeth by 12–13 months
• A tooth appears to be coming in significantly crooked or out of order
• You notice a discolored or damaged tooth
• Gum swelling is severe, hot to the touch, or has been present for more than a week with no tooth emerging
• Your baby seems to be in unusual pain that doesn't improve with the methods above

Most teething is uncomfortable but normal. But the first dental appointment is also a chance to talk about brushing technique, fluoride, and what to avoid (fruit juice, prolonged bottle use) before habits get established.

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Frequently Asked Questions

My 4-month-old is drooling a lot and seems fussy. Is this teething?

Possibly — but probably not causing sleep disruption yet. Drooling can begin weeks or months before a tooth actually appears, as salivary glands mature. At 4 months, the 4-month sleep regression is a more likely cause of sleep disruption than actual tooth pain. Look for visible gum swelling and a tooth emerging before attributing sleep problems to teething.

Can teething cause a fever?

Teething can cause a very mild temperature elevation — up to about 99.9°F (37.7°C). It does not cause a true fever (100.4°F / 38°C or above). If your baby has a fever, something else is going on. Call your pediatrician.

My baby seems to be teething for months with no tooth. What's happening?

Teething symptoms can precede an actual tooth by 6–8 weeks. However, if you've been attributing sleep disruption to teething for more than a few weeks without a tooth appearing, it's worth looking at other causes — sleep associations, wake windows, or growth spurts are more likely explanations for sustained disrupted sleep.

The second molars are really bad. How do I get through it?

Second molars (23–33 months) are genuinely the hardest teething round for many families. Use the soothing methods above, give appropriate doses of children's ibuprofen for the inflammatory pain, and keep your toddler's bedtime routine as consistent as possible. It typically takes 2–4 weeks for all four second molars to fully emerge. Consistency on your end means the sleep disruption is less likely to create lasting habit changes.

When is teething finally over?

All 20 primary teeth are typically in place by age 2.5–3 years. After the second molars come through, you get a long break — the first permanent teeth don't arrive until age 5–7. So there's a light at the end of the tunnel; it just takes a few years to reach it.

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The Bottom Line

Teething starts between 4–7 months for most babies and continues in waves until the second molars emerge around age 2.5–3 years. The front teeth are manageable; the molars are harder. Each wave causes sleep disruption for 1–5 nights per tooth — not weeks.

The key to surviving teething without lasting sleep damage: address the pain (cold pressure, gum massage, infant pain reliever when appropriate), keep your bedtime routine absolutely consistent, and don't introduce new sleep dependencies that will outlast the tooth. Comfort your baby through the hard nights, then put them back down in the crib.

Teeth come and go. Sleep habits are what stick.