Pacifiers don’t typically cause gaps between teeth, but they do cause a different problem that looks like one. The most common dental issue from pacifier use is an anterior open bite, where the front upper and lower teeth don’t meet when the mouth is closed, leaving a visible space. This can look like a gap, but it’s actually the teeth being pushed apart vertically rather than sideways. The good news: if the pacifier is stopped early enough, the bite usually corrects on its own.
What Pacifiers Actually Do to Teeth
When a child sucks on a pacifier, the nipple sits between the upper and lower front teeth while the tongue presses against the lower teeth. Over time, this repeated pressure pushes the upper front teeth slightly forward and outward while preventing the front teeth from coming together normally. The result is an anterior open bite, a visible opening between the top and bottom teeth even when the jaw is closed.
Across multiple studies involving thousands of children, anterior open bite is by far the most consistent dental finding in pacifier users. The numbers vary widely depending on how long the pacifier was used, but they’re striking. In some studies, as many as 75 to 87% of children who used pacifiers developed an open bite. Even in studies with more conservative findings, pacifier users showed open bite rates of 23 to 49%, compared to around 14% in children who never used one.
Pacifiers can also cause two other bite problems. A posterior crossbite happens when the upper back teeth sit inside the lower back teeth instead of outside them, because the sucking motion narrows the upper jaw. Increased overjet, where the upper front teeth protrude noticeably beyond the lower ones, is the third common finding. Together, these three issues account for most pacifier-related dental changes.
Duration Matters More Than the Pacifier Itself
A baby using a pacifier for the first several months of life faces very little dental risk. The problems emerge with prolonged use, and the research draws some clear lines. Children who used a pacifier for more than 11 months had a posterior crossbite rate of 7%, compared to just 1% for those who stopped before 11 months. That’s roughly a sevenfold increase in risk.
The age-related pattern is even more dramatic for open bite. One study found that 18.8% of children under age 3 who used pacifiers had an anterior open bite. Among children over age 3 who were still using pacifiers, that number jumped to 65.1%. Another study found malocclusion rates of about 71% in children who continued sucking habits past 48 months, compared to 32% in those who stopped between 36 and 48 months.
Frequency and intensity also play a role. A child who uses a pacifier only at bedtime is exposing their teeth to far less pressure than one who sucks throughout the day. The duration, frequency, and intensity of sucking all influence how severe any bite changes become.
When to Stop to Prevent Problems
The American Academy of Pediatric Dentistry recommends stopping pacifier use by 36 months (age 3) to prevent lasting dental effects. But there’s a more nuanced timeline worth knowing. After 12 months, pacifier use starts increasing the risk of ear infections. After 18 months, when the canine teeth begin emerging, the developing jaw and bite become more vulnerable to crossbite. The AAPD recommends limiting or discontinuing pacifier use around that 18-month mark to reduce crossbite risk specifically.
The 36-month cutoff isn’t arbitrary. Multiple studies confirm that anterior open bite caused by pacifier use will generally improve on its own after the pacifier is eliminated before age 3. The jaw and teeth are still developing rapidly at this stage, and once the abnormal pressure is removed, the teeth tend to drift back toward their natural positions. One study tracking children over time found that 19.5% of pacifier users had an open bite at age 3, but by age 5 (after stopping), that number dropped to 8.7%.
Do the Effects Reach Permanent Teeth?
This is the question most parents really want answered. If a child uses a pacifier too long, will they need braces later? The evidence suggests that stopping before age 3 makes lasting effects on permanent teeth unlikely. The primary teeth and jaw have enough developmental plasticity to recover.
Prolonged use beyond age 3 is a different story. Research tracking children from toddlerhood into later childhood found that pacifier sucking at 15 months was associated with spaced upper front teeth that persisted at age 5. There’s also evidence that bite problems can carry into the permanent dentition, though at lower rates. The longer the habit continues, the more the underlying bone and jaw structure are affected, not just the baby teeth sitting in them.
Orthodontic Pacifiers: Do They Help?
Pacifiers marketed as “orthodontic” have a flattened nipple shape designed to mimic the natural position of the breast during nursing. They do appear to cause less damage than conventional round-bulb pacifiers. One study comparing the two found that conventional pacifiers were associated with more severe anterior open bite and overjet, while orthodontic pacifiers showed significantly lower rates of open bite.
Newer computational research has tested even more specialized designs. Compared to a conventional pacifier, newer ergonomic models reduced tooth displacement by 73 to 79%. One oval-shaped design outperformed a symmetrical design by an additional 15 to 17%. These are meaningful reductions, but no pacifier design eliminates the risk entirely. An orthodontic pacifier used all day for three years will still cause problems.
Pacifiers vs. Thumb Sucking
Both habits create similar dental issues: open bite, protruding front teeth, and crossbite. The key difference is practical. You can take a pacifier away; you can’t take away a thumb. Thumb sucking tends to be a harder habit to break, which means it often continues longer and causes more persistent changes. Digit sucking for at least 12 months more than doubled the prevalence of crowding compared to sucking for less than 6 months (36% vs. 16%).
Both the American Academy of Pediatric Dentistry and the American Association of Orthodontists consider pacifiers the lesser concern of the two, largely because parents have more control over when the habit ends. If your child is going to have a sucking habit beyond infancy, a pacifier is generally easier to phase out on a timeline that protects their teeth.