Most 18-month-olds have between 8 and 16 teeth, with 12 being a common midpoint. By this age, the four upper and four lower front teeth have typically come in, along with some combination of the first molars and canines. But the range is wide, and some perfectly healthy toddlers at 18 months have fewer than eight.
The Typical Timeline for Baby Teeth
Baby teeth follow a roughly predictable order, though the timing varies significantly from child to child. The lower central incisors (the two bottom front teeth) usually appear first, around 6 to 10 months. The upper central incisors follow shortly after. By 12 months, most babies have about four to eight teeth.
Between 13 and 19 months, the first molars start to come in. These are the larger, flat teeth toward the back of the mouth, and they often arrive in pairs on the top and bottom. Around the same time or slightly after, the canines (the pointed teeth between the front teeth and molars) begin to emerge. This is why the 12-to-16 range is so common at 18 months: your toddler may have all their incisors plus some or all of the first molars, or they may still be waiting on a few.
By age 3, most children have their full set of 20 primary teeth.
Why Some Toddlers Have Fewer Teeth
If your 18-month-old has only six or eight teeth, that’s not automatically a concern. Genetics play a major role in teething pace. If you or your partner were late teethers, your child likely will be too. Premature or low-birth-weight babies also tend to get their teeth later than full-term babies.
Nutritional factors can slow things down as well. Vitamin D deficiency interferes with the body’s ability to use calcium for building teeth and bone. Calcium deficiency itself can delay tooth buds from pushing through the gums. In rarer cases, delayed eruption is linked to hypothyroidism, Down syndrome, or pituitary gland conditions.
The general threshold dentists use: if a child reaches 12 months with no teeth at all, it’s worth a dental visit to check for underlying causes. An 18-month-old with at least a few teeth is almost certainly on a normal, if slower, schedule.
First Molars Can Be Rough
If your toddler seems especially fussy right now, the first molars may be the reason. Because they’re larger than incisors, they tend to cause more discomfort as they break through. Common signs include red or swollen gums in the back of the mouth, increased drooling, difficulty sleeping, loss of appetite, and constant chewing on objects.
A slight rise in temperature can happen during teething, but a true fever (above 100.4°F or 38°C) is not caused by teething and should be evaluated separately. For pain relief, a chilled (not frozen) teething ring or gentle gum massage with a clean finger works well. The FDA warns against using numbing gels or creams containing benzocaine or lidocaine on children’s gums. These products offer little benefit for teething and carry serious risks, including a rare but potentially fatal blood condition that reduces the blood’s ability to carry oxygen. Homeopathic teething tablets carry similar safety concerns.
Protecting New Teeth From Decay
Tooth decay can start as soon as teeth appear, and toddler teeth are especially vulnerable. The biggest risk factor at this age is prolonged contact between teeth and sugary or starchy liquids, particularly at night. Putting a toddler to bed with a bottle of milk, juice, or formula bathes the teeth in sugars for hours while saliva production drops. That combination shifts the chemistry in the mouth toward breaking down enamel rather than rebuilding it.
Nighttime and on-demand breastfeeding after 12 months carries a similar risk once other dietary carbohydrates are part of your toddler’s diet. The lactose sits against the teeth longer at night because there’s less saliva to wash it away. This doesn’t mean you need to stop breastfeeding, but cleaning your child’s teeth before bed becomes more important.
A few practical steps reduce the risk significantly:
- No bottles in the crib. If your child needs a bottle to fall asleep, fill it with water only.
- Transition to a cup. Aim to wean from bottles by 12 to 14 months. Sipping from a bottle or no-spill cup throughout the day keeps teeth bathed in whatever liquid is inside.
- Limit sugary snacks between meals. Frequency of exposure matters more than total amount. Five sips of juice spread across the day is worse for teeth than the same juice consumed at one sitting.
How to Brush an 18-Month-Old’s Teeth
Start brushing as soon as teeth appear, using a soft-bristled toothbrush sized for infants. The American Academy of Pediatric Dentistry and the American Dental Association recommend fluoride toothpaste for all children, using a “smear” the size of a grain of rice for kids under 3. The CDC takes a slightly more cautious position, suggesting parents consult with their child’s dentist before starting fluoride toothpaste before age 2. In practice, most pediatric dentists now recommend the rice-grain smear from the first tooth onward.
Brush twice a day, especially before bed. At 18 months, your toddler will want to hold the brush themselves. Let them practice, but do the actual cleaning yourself. Focus on the gum line and the chewing surfaces of any molars that have come in, since those grooves trap food easily.
When to Schedule a First Dental Visit
The American Academy of Pediatric Dentistry recommends a first dental exam by the time the first tooth erupts, and no later than 12 months of age. If your child is 18 months old and hasn’t seen a dentist yet, it’s a good time to schedule that visit. The appointment is usually quick and focused on checking for early signs of decay, evaluating how the teeth are coming in, and giving you guidance on brushing and diet specific to your child’s mouth.