Dental and oral development
Baby Teeth and Speech Development: How Are They Connected?
Discover how baby teeth impact your child’s speech development. Learn about oral motor milestones and when delayed tooth eruption may need dental attention.
- Expert Reviewed
- Plain Language
- Patient Focused
Key takeaways
- Teeth matter for a small, specific set of sounds — mainly /s/, /z/, /f/, /v/ and /th/. They matter much less for the sounds children learn first, which is why babies babble happily with no teeth at all.
- Late teeth are usually just late. A meta-analysis of 42,109 children found the first tooth erupting at 6 months in North America and 13.5 months in Asia — the “normal range” depends on which population the chart was built from.2
- There is little direct evidence that delayed eruption causes speech problems. Most of what circulates borrows evidence about a different situation — early tooth loss — and applies it to eruption timing.
- Early loss of front baby teeth shows a signal for distortion only. Higher odds of speech distortion, but no significant difference for leaving sounds out or swapping them, and the certainty of evidence was rated low to very low.1
- The speech milestones on most parenting sites are out of date. Current normative data puts all liquids at 5 years 11 months and all fricatives at 6 years 11 months on the 90% criterion — considerably later than age five.3
- A first dental visit by 12 months is the American Academy of Pediatric Dentistry recommendation, and is the single most useful thing on this page for most families.4
- Blowing bubbles and horns does not improve speech sounds. Practicing actual words does.6
- 6 vs 13.5 moage of the first tooth in North American and Asian populations — the same milestone, seven months apart
- 5.5xodds of speech distortion after early loss of front baby teeth, on low-certainty evidence, with a confidence interval running from 1.7 to 17.7
- 6;11age by which 90% of children produce all fricatives, including /s/ and /th/ — not age five
How teeth actually contribute to speech
Speech sounds are made by shaping and interrupting airflow with the lips, tongue, teeth and palate. Teeth are involved in a specific subset, and it is a smaller subset than most people assume.
| Sound | How it is made | How much teeth matter |
|---|---|---|
| /s/, /z/ | Tongue grooves airflow toward the front teeth | A lot — the incisors channel the airstream. This is the classic lisp sound |
| /f/, /v/ | Upper teeth contact the lower lip | A lot — these need upper incisors by definition |
| /th/ | Tongue between or against the upper teeth | A lot — interdental by definition |
| /sh/, /ch/, /j/ | Tongue near the palate, airflow past the teeth | Moderate |
| /t/, /d/, /n/, /l/ | Tongue tip on the ridge behind the teeth | Less than people assume — these are alveolar, not dental |
| /p/, /b/, /m/, /w/ | Lips only | Not at all |
| /k/, /g/, /ng/, /h/ | Back of the tongue or the throat | Not at all |
Two things follow from that table, and together they are most of the answer to this page’s question.
The sounds most affected by teeth are the ones children learn last anyway. Fricatives develop late. A three-year-old with a gap in their front teeth who cannot say /s/ clearly may simply be a three-year-old.
The sounds that come first do not need teeth. Babbling, first words, and most of a toddler’s early inventory — /p/, /b/, /m/, /d/, /n/, /w/, /h/ — are made with lips, tongue and airway. Which is why babies babble happily before they have any teeth at all.
What normal eruption actually looks like
The normal range is wider than most eruption charts imply, and the reason is worth understanding: the chart depends on the population it was built from.
A systematic review and meta-analysis pooled 42 studies covering 42,109 children aged 0 to 83 months. It found the lower central incisor — usually the first tooth — erupting at 6 months in North America and 13.5 months in Asia, and the lower second molar at 20.1 months in Europe and 29 months in South America. Eruption was earliest in European populations, then North American, African and Oceanic, and latest in South American.2
The most useful thing on this page for most families is not a chart at all. The American Academy of Pediatric Dentistry recommends that the first dental examination happen at the time the first tooth erupts and no later than 12 months of age.4 That visit is largely prevention and coaching rather than treatment. Our guide to preparing your child for a first dental visit covers what to expect.
Delayed eruption: when it matters
The commonly used clinical threshold is no sign of any tooth by 18 months. Before that, variation is expected, and a delay of several months in an otherwise healthy child is usually unremarkable. The threshold is a prompt to investigate, not a diagnosis.
- Family history is the most common explanation
If a parent was a late teether, the child frequently is too. This is worth mentioning at the appointment because it often ends the question.
- Local causes create a physical obstacle
A tooth in the path of eruption, not enough room in the arch, or infection. These are things a dentist can see, and often on a radiograph confirming the teeth are present and developing under the gum.
- Systemic causes are why the threshold exists
Less common, but they are the reason not to simply wait indefinitely. Prematurity and low birth weight are documented factors, as are nutritional deficiencies, and generalized delayed eruption is seen in some endocrine and genetic conditions. Where one is suspected the referral is usually to a pediatrician rather than a specialist dentist.
Does delayed eruption actually affect speech?
Here is where this page has to be more careful than the version it replaces, and more careful than most of what you will find elsewhere.
There is very little direct evidence that late eruption of baby teeth causes speech sound difficulties. The claim circulates widely, but following the citations usually leads to evidence about a different exposure — children who lost front teeth early, to decay or trauma — which is then applied to eruption timing.
Those two situations are not the same. A child whose incisors are running three months behind spends a brief window without them, during a period when they are not attempting /s/ and /th/ anyway. A child who has upper incisors extracted at three loses teeth they had been using, at an age when fricatives are actively developing. Borrowing the evidence from the second to make claims about the first is the error this page used to make.
What is reasonable to say: if a child has no teeth at 18 months, the thing to investigate is why — because the underlying cause may itself have developmental implications. In that situation the teeth are a signal rather than a mechanism. That is a genuinely good reason to take late eruption seriously, and it is a completely different argument from “no teeth means no /s/.”
What about losing baby teeth early?
This is the situation with actual evidence behind it, and the shape of that evidence is the answer.
A systematic review and meta-analysis screened 2,234 studies and pooled four of them on speech outcomes after premature loss of front baby teeth. What it found, separated by type of speech error:
| Type of speech error | What it means | Finding |
|---|---|---|
| Distortion | The sound is attempted but comes out imprecisely — a slight lisp on /s/ | Higher odds in children who lost anterior teeth: odds ratio 5.466, 95% CI 1.689 to 17.692, p = .005 — on low certainty evidence |
| Omission | The sound is left out altogether | No statistically significant difference (OR 1.157 and 1.393), on very low certainty evidence |
| Substitution | A different sound is used in its place | No statistically significant difference (OR 1.071 and 1.218), on very low certainty evidence |
All figures from the meta-analysis; the authors note the included articles present low-level evidence-based quality and that new studies should be performed.1
How to read that. The signal is for distortion and nothing else — a lisp, not a child who stops producing sounds. And the confidence interval on that distortion figure runs from 1.7 to 17.7, which is wide enough that the size of the effect is genuinely uncertain even though its direction is not. The honest version is: early loss of front teeth may make /s/ imprecise for a while; it does not appear to change which sounds a child produces.
Children also compensate. Most of what is lost is precision on one or two sounds, in a mouth that is going to change again when the adult teeth arrive. If your child has lost front teeth to trauma or decay, the questions worth asking are about the cause — our page on how baby bottle use can impact oral development and what white spots on teeth really mean cover early decay, and dental signs of sensory processing differences covers why brushing goes wrong for some children.
Speech sound milestones, and why most charts are wrong
This is the correction that matters most on this page, because the old version would have had you worried a year too early.
The previous version said children master “more complex consonants like s, r, and l” by three to five years. A systematic review of 15 studies covering 18,907 children acquiring English in the United States puts it considerably later. On the 90% criterion:
Age by which 90% of children produce the sound accurately. Individual variation is substantial.3
So /l/ and /r/ are not expected of a five-year-old, and /s/ and /th/ are not expected of a six-year-old, on this data. A child with a gap in their front teeth and an imprecise /s/ at four is doing two normal things at once.
A better everyday benchmark. Research on intelligibility growth in typical children concluded that children should be at least 50% intelligible by 48 months, with considerable variation and growth continuing through age nine for children at median and lower percentiles.5 The practical test is whether an unfamiliar adult can follow your child without you translating. That test does not require you to know which sounds are due when.
Our page on typical speech and language milestones from birth to seven covers the wider picture, and our guide to lisps covers frontal and lateral lisps specifically.
What actually helps
- Practicing actual words
Motor learning is task-specific. If the target is /s/, the practice that transfers is producing /s/ in real words, not exercising the muscles that happen to be involved.
- Reading together, and modeling rather than correcting
Saying the word back correctly in the flow of conversation does more than asking a child to repeat it. Correction tends to reduce how much a child says, which is the opposite of what you want.
- Treating the cause where teeth were lost early
If decay took the teeth, the decay is the thing to address. Our guide to brushing from a very young age covers prevention.
- Getting hearing checked if speech is the concern
Undetected hearing difficulty produces speech difficulty and is common, treatable and easy to overlook. It comes before any dental explanation.
Skip the blowing exercises, horns and whistles
A Cochrane review of non-speech oral motor treatment found three studies involving 22 children in total and concluded that no strong evidence suggests these are an effective treatment, or an effective adjunctive treatment, for developmental speech sound disorders.6 Those studies covered only the sounds /s/ and /z/, so the review is narrow — but the theoretical objection is broader: training non-speech oral tasks is not supported by principles of motor learning, which favor practicing the thing you are trying to learn.6
When to see whom
| Concern | Who to see | When |
|---|---|---|
| No teeth at all by 18 months | Pediatric dentist, and your pediatrician if other things are also delayed | At 18 months — do not keep waiting |
| Front teeth lost to decay or trauma | Pediatric dentist | Promptly, for the cause as much as the gap |
| Speech unfamiliar adults cannot follow at four | Speech-language pathologist, plus a hearing check | Now — this is the benchmark that matters most |
| A lisp on /s/ at five or six | Worth mentioning; often within typical range | Raise at a routine visit rather than urgently |
| /r/ or /l/ imprecise at five | Usually within typical range on current data | Monitor; raise if it persists past six |
| Routine prevention | Pediatric dentist | First visit by 12 months, then as advised |
You can find a speech-language pathologist or browse providers by state through our directory. If feeding as well as speech is a concern, our page on how to spot oral development delays early covers the milestones and how to get a free evaluation.
Popular next reads
Frequently Asked Questions
Do baby teeth affect speech development?
For a small, specific set of sounds — mainly /s/, /z/, /f/, /v/ and /th/ — yes. For the sounds children learn first, no: babbling and early words are made with lips, tongue and airway, which is why babies babble before they have any teeth. The sounds teeth matter most for are also the ones children acquire last, so a young child with a gap and an imprecise /s/ is usually doing two normal things at once.
When should my baby get their first tooth?
There is a wide normal range, and it depends on population. A meta-analysis of 42 studies covering 42,109 children found the lower central incisor erupting at 6 months in North American populations and 13.5 months in Asian populations. That is the same milestone arriving seven months apart, which is the clearest reason not to read a single eruption chart as a deadline.
My child has no teeth at 12 months. Should I worry?
Probably not on its own. The commonly used clinical threshold for investigating is no sign of any tooth by 18 months, and family history is the most common explanation — if a parent was a late teether, the child often is too. Mention it at your child's dental visit, which the American Academy of Pediatric Dentistry recommends should happen by 12 months anyway.
My child has no teeth at 18 months. What now?
That is the point at which it warrants investigation, and the reason is not speech. It is that the underlying cause — prematurity, a nutritional deficiency, an endocrine or genetic condition — may itself have developmental implications. A dentist will examine, take a history including family and birth history, and may take a radiograph to confirm the teeth are present under the gum. Often they simply are, and running late.
Does delayed teething cause speech delay?
There is very little direct evidence that it does. The claim circulates widely, but following the citations usually leads to evidence about early tooth loss, which is a different situation. A child whose incisors run three months behind is without them during a window when they are not attempting /s/ and /th/ anyway.
Does losing front baby teeth early affect speech?
There is a signal, and it is narrower than people expect. A meta-analysis found higher odds of speech distortion — imprecision, a slight lisp — in children who lost front baby teeth early, but no statistically significant difference for omitting sounds or substituting them. The certainty of the evidence was rated low for distortion and very low for the other two, and the confidence interval on the distortion finding is wide.
My child knocked out a front tooth. Will they lisp?
They may become less precise on /s/ for a while, which is the one outcome with evidence behind it. What the evidence does not show is children leaving sounds out or swapping them after early tooth loss. Mention it to your dentist and to your child's teacher, and raise it with a speech-language pathologist if it persists or if it affects how well your child is understood.
At what age should my child say the /s/ sound clearly?
Later than most charts suggest. On the 90% criterion, all fricatives including /s/ and /th/ are acquired by 6 years 11 months. A five-year-old with an imperfect /s/ is within typical range on this data. What matters more than any single sound is whether unfamiliar adults can follow your child.
At what age is the /r/ sound mastered?
All liquids, including /r/, are acquired by 5 years 11 months on the 90% criterion. The commonly repeated claim that children master /s/, /r/ and /l/ between three and five years does not match current normative data, and it is worth knowing that before you worry about a four-year-old who says "wabbit".
How much of my three-year-old’s speech should a stranger understand?
The benchmark from intelligibility research is that children should be at least 50% intelligible by 48 months, with considerable variation between children and growth continuing through age nine for those at median and lower percentiles. The practical version is whether an unfamiliar adult can follow your child without you translating.
Do blowing exercises or whistles help my child’s speech?
No good evidence supports them. A Cochrane review of non-speech oral motor treatment found three studies with 22 children in total and no strong evidence that these are effective for developmental speech sound disorders. Motor learning favors practicing the thing you are trying to learn, so for speech sounds that means saying words.
Does thumb sucking cause a lisp?
Prolonged thumb sucking is associated with an anterior open bite, and an open bite is the bite type most likely to affect how /s/ is produced. So the link runs through the bite rather than directly. Our guide to when thumb sucking becomes a problem covers the timing and what to do about it.
Sources
- Premature loss of primary anterior teeth and its consequences to primary dental arch and speech pattern: a systematic review and meta-analysis. International Journal of Paediatric Dentistry. 2020;30(6):687–712. PMID 32243000. 2,234 studies screened, six included in qualitative synthesis and four in the speech meta-analysis. “Children who lost anterior tooth presented higher chance of suffering speech distortion, than children without tooth loss (OR 5.466 [1.689, 17.692] P = .005) with low certainty of evidence. On the other hand, there were no statistically differences between premature loss of primary anterior teeth and omission (OR 1.157 [0.439, 3.049] P = .767 and OR 1.393 [0.434, 4.70] P = .577) or substitution (OR 1.071 [0.581, 1.974] P = .827 and OR 1.218 [0.686, 2.163] P = .5), both with very low certainty of evidence.” The authors note the included articles present low-level evidence-based quality.
- Global variations in eruption chronology of primary teeth: a systematic review and meta-analysis. Archives of Oral Biology. 2024;158:105857. PMID 38128337. 42 studies, 42,109 children aged 0 to 83 months. “The mandibular central incisor was the first tooth to erupt at 6 months in North America and 13.5 months in Asia while the mandibular second molar erupted at 20.1 months in Europe and 29 months in South America.” The authors recommend population-based eruption charts for clinical practice.
- Crowe K, McLeod S. Children’s English consonant acquisition in the United States: a review. American Journal of Speech-Language Pathology. 2020;29(4):2155–2169. PMID 33181047. Fifteen studies, 18,907 children. “On average, all plosives, nasals, and glides were acquired by 3;11; all affricates were acquired by 4;11; all liquids were acquired by 5;11; and all fricatives were acquired by 6;11 (90% criterion).”
- American Academy of Pediatric Dentistry. Periodicity of examination, preventive dental services, anticipatory guidance/counseling, and oral treatment for infants, children, and adolescents. aapd.org best practices — “The first examination is recommended at the time of the eruption of the first tooth and no later than 12 months of age.” Checked August 29, 2026.
- Hustad KC, Mahr TJ, Natzke P, Rathouz PJ. Speech development between 30 and 119 months in typical children I: intelligibility growth curves for single-word and multiword productions. Journal of Speech, Language, and Hearing Research. 2021;64(10):3707–3719. PMID 34491793. Children should be at least 50% intelligible by 48 months; for children at median and lower percentiles intelligibility growth continues through 9 years.
- Lee AS-Y, Gibbon FE. Non-speech oral motor treatment for children with developmental speech sound disorders. Cochrane Database of Systematic Reviews. 2015;(3):CD009383. PMID 25805060. Three studies involving 22 children in total, covering the sounds /s/ and /z/. “Currently no strong evidence suggests that NSOMTs are an effective treatment or an effective adjunctive treatment for children with developmental speech sound disorders.”
Medical disclaimer. This page is for general educational purposes and does not constitute medical advice, diagnosis, or treatment. It is not a substitute for evaluation by a qualified clinician who knows your child. If your child's speech cannot be followed by unfamiliar adults at four, ask for a hearing check and a speech-language assessment rather than looking first at their teeth.