In short
- Most evidence that mouth breathing shapes the face comes from children, whose jaws are still growing, and a 2021 meta-analysis only included children under 18.
- We found no study showing that mouth breathing reshapes the bones of an adult face that has finished growing.
- A 2026 systematic review of adults linked mouth breathing with forward head posture, jaw joint problems and changes in chewing muscle activity, but rated the evidence very low certainty.
- Switching to nasal breathing hasn't been shown to change an adult's face, and an existing receding chin in adults is treated with orthodontics or jaw surgery.
- Nose breathing is still worth it for comfort at night, and adults with a clear nose can use mouth tape to keep their lips closed while they sleep.
Probably not in the way social media suggests. The research linking mouth breathing to a long face, a recessed chin and a weak jawline is mostly in children, whose faces are still growing. We found no study showing that mouth breathing reshapes an adult face that has finished growing. Adult studies do link it to forward head posture and changes in jaw muscles, but that evidence is weak, and nose breathing won't undo bone that has already formed.
Where does the idea of "mouth breathing face" come from?
Research: limited (what this means)From research in children. Cleveland Clinic describes what it calls mouth breathing face: a child who breathes through the mouth instead of the nose may develop a narrow face, a receding chin or jaw, and upper and lower teeth that don't line up.
A 2021 systematic review and meta-analysis in BMC Oral Health pooled 10 studies and backs this up with measurements. Every child in it was under 18. Compared with nose-breathing children, the mouth-breathing children's upper and lower jaws tended to be rotated backward and downward, and their airways were narrower.
Cleveland Clinic is clear about who this applies to. It says mouth breathing in children can affect growth and may change the shape of the face, while mouth breathing in adults isn't a serious health issue. If you're worried about a child, mouth breathing in children is the place to start.
What does the research show in adults?
Much less, and none of it shows bones changing shape. The best summary is a 2026 systematic review in The Laryngoscope, which looked only at adults. It found 12 studies of chronic or induced mouth breathing. Compared with nose breathers, the mouth breathers:
- More often had problems with the jaw joint (TMD)
- Held their heads further forward and had a deeper curve in the lower back
- Chewed less efficiently
- Showed less activity in two chewing muscles, the masseter and temporalis, and more in the muscles under the chin
The reviewers rated the certainty of all this as very low and urged caution in reading it. No study in the review looked at pain.
A 2025 study in BMC Oral Health adds one detail. It used ultrasound to measure the masseter, the big chewing muscle at the angle of the jaw, in 50 adult mouth breathers and 50 controls. The muscle was thinner in the men who mouth breathed, but there was no difference in the women. It's one small study, but it fits the review's picture of changes in muscles rather than bone.
Can mouth breathing cause forward head posture?
It's linked to it, but cause and effect aren't settled. The 2026 review found adult mouth breathers tended to adopt a forward head posture. But the reviewers rated that evidence very low certainty, so it can't tell you whether mouth breathing causes the posture or simply tends to come with it. Since posture is something you can work on, this is the part of the "mouth breathing face" picture that is most open to change in adults.
Does mouth breathing affect your jaw joint?
Possibly. In the 2026 review, adults who breathed through the mouth had a higher rate of temporomandibular joint dysfunction (TMD), problems with the joint that hinges your lower jaw to your skull. They also chewed less efficiently. As with posture, the certainty was very low, and none of the studies measured pain directly.
Jaw shape matters here too. Cleveland Clinic notes that a receding chin can itself lead to TMJ disorders and obstructive sleep apnea, so the chin and the joint problems can be linked without mouth breathing being the cause. If your jaw bothers you, a dentist is a good first stop.
Can a recessed chin from mouth breathing be reversed?
In young children, partly. A 2011 study followed 33 mouth-breathing children aged 3 to 6 who had their adenoids or tonsils removed and went back to nose breathing. About 28 months later, the direction of their jaw growth had largely normalised. Their faces were still longer than those of children who had always breathed through the nose, though.
In adults, breathing differently hasn't been shown to move bone. Cleveland Clinic says that for kids and teens with mild retrognathia (a receding chin), orthodontics can correct the jaw position as they grow. For severe cases in people with fully developed jaws, it says corrective surgery may be the best option, and many people need jaw surgery and orthodontics together. Its page on jaw surgery notes that the combined treatment usually runs over two to three years, and that surgeons may wait until the jaw has stopped growing.
If the shape of your jaw or chin bothers you, an orthodontist or oral and maxillofacial surgeon can tell you what's possible.
Is nose breathing still worth it as an adult?
Yes, for reasons that don't depend on your face. Breathing through your mouth at night leaves many people with a dry mouth, a sore throat, bad breath and snoring. 9 effects of mouth breathing at night covers what the studies show.
The first step is finding out why you breathe through your mouth. Cleveland Clinic lists causes such as a deviated septum, enlarged turbinates, nasal polyps and congestion from allergies or colds. Our two-minute nose test is a quick way to check how open your nose feels.
Can mouth tape help?
Not with face shape. No study shows mouth taping changes the jaw or chin, and we cover where that claim comes from in does mouth taping change your jawline?
What tape can do is keep your lips together at night so you breathe through your nose. The Sleep Foundation describes it as a gentle reminder that promotes nasal breathing, for people without nasal blockage or sleep apnea. The research is still small. A 2025 review in PLOS One found 10 studies with 213 patients in total and warned of a potentially serious risk for people who tape with a blocked nose. So check your nose first, skip tape when you're congested, never use it on children, and see a doctor first if you snore loudly or might have sleep apnea. How to start mouth taping walks through the first week.
Check this first. Skip mouth tape and see a doctor if you snore loudly, wake up gasping, have been told you stop breathing in your sleep, or can't breathe comfortably through your nose. More on safety
If you want to try it for comfortable nose breathing at night, our pick is Titan Bamboo Silk Mouth Tape. Titan says its adhesive is made to grip through stubble and full beards without tugging hair, and it offers a 30-night guarantee.
Read next
- Does mouth taping change your jawline?
- What is mouth breathing?
- Can you train yourself to nose breathe?
Common questions
Can mouth breathing change your face as an adult?
There's no good evidence that it reshapes the bones of a fully grown face. The studies that link mouth breathing to a longer face and a recessed chin are mostly in children. Adult studies point to posture and jaw muscle differences instead, and that evidence is weak.
Can you reverse mouth breathing face as an adult?
Not by breathing differently alone, as far as the research shows. Cleveland Clinic says severe receding chins in adults with fully developed jaws may need jaw surgery, often combined with orthodontics. Posture and habits are the parts that can change without surgery.
Does mouth breathing cause forward head posture?
A 2026 systematic review found adult mouth breathers tended to hold their heads further forward than nasal breathers. The reviewers rated the certainty of that evidence very low, so it's an association worth knowing about, not a proven cause.
Can mouth breathing cause a recessed chin?
In children it's linked to a backward and downward rotation of the jaws, which can look like a receding chin. Cleveland Clinic lists a receding chin or jaw among the signs of mouth breathing face in children. Adults aren't described as developing one from mouth breathing.
Will mouth tape fix my jawline?
No. No study shows mouth taping changes face shape, and we don't suggest it for that. Tape is a simple way for adults with a clear nose to keep breathing through the nose at night, which helps with things like dry mouth.
Is it too late to fix mouth breathing as an adult?
No. The breathing habit itself can usually change once the cause is dealt with, whether that's allergies, a deviated septum or a mouth that falls open in sleep. What doesn't change by itself is bone that has already finished growing.
Sources
- Mouth breathing: symptoms, complications and treatment
- Effects of mouth breathing on facial skeletal development in children: a systematic review and meta-analysis
- Changes in facial morphology after adenotonsillectomy in mouth-breathing children
- The musculoskeletal consequences of mouth breathing in adults: a systematic review
- Evaluation of masseter muscle thickness of mouth breathing patients using ultrasonography
- Retrognathia (receding chin)
- Jaw surgery (orthognathic surgery)
- Breaking social media fads and uncovering the safety and efficacy of mouth taping in patients with mouth breathing, sleep disordered breathing, or obstructive sleep apnea: a systematic review
- Mouth taping for sleep: does it work?
- Bamboo Silk Mouth Tape
About this article
- Research
- 10 published sources, listed above.
- Evidence
- Limited. How we rate it
- Last checked
- October 10, 2026
- Funding
- Paid partner of Titan Recovery. Their ads are labeled.
- Found an error?
- Tell us. We log fixes on the corrections page.
* This content is for informational and educational purposes only and is not medical advice. It is not intended to diagnose, treat, cure or prevent any disease or health condition. Talk to a qualified healthcare provider about your health.
