What is it?
In healthy breathing, air is moistened, warmed and filtered as it passes through the nose. When the nose is blocked, or when the habit has settled in, that job is left to the mouth. The dry air passing through the mouth dries the lips, the gums and the surface of the tongue, and saliva largely loses its washing and acid-buffering effect.
In a dry mouth, plaque becomes stickier and acid stays active on the tooth surface for longer. The gums around the front teeth redden, swell and bleed when you brush; inflammation that carries on in this area despite good care is one of the typical marks of mouth breathing. A coated tongue, bad breath and dryness in the throat are common companions.
In children the effect may not stay inside the mouth. Where the tongue does not rest against the palate and the lips do not close, the upper jaw is more exposed to the pressure coming from the cheeks; the palate can be narrow and high, and the upper front teeth tipped forward. How marked these effects are varies from person to person and cannot be put down to a single cause.
Signs
You will not necessarily have all of these at once.
Why does it happen?
- 01
A blocked nose
Allergic rhinitis, enlarged turbinates, a deviated septum and repeated sinusitis make it harder for air to pass through the nose. This group is the most common cause, and assessing it belongs to an ear, nose and throat doctor.
- 02
Enlarged adenoids and tonsils
When the lymphoid tissue behind the nose enlarges in childhood, the airway narrows at its upper end. Snoring at night, sleeping with the mouth open and a restless sleep pattern are common companions.
- 03
It turning into a habit
Mouth breathing can carry on even after the cause of the blockage has been dealt with. Slack lip muscles and a low tongue position can make this pattern permanent.
- 04
Structures that affect the position of the lips and tongue
A short upper lip, upper front teeth tipped forward and a tongue tie that restricts the movement of the tongue can stop the lips closing comfortably. In such cases the mouth stays open at rest as well.
How does it progress?
- Baby teeth
The years when the first signs show
Sleeping with the mouth open, snoring, sweating and a damp pillow stand out. Looking into the cause at this age is worthwhile, because it limits the effects on later development.
- Mixed dentition
When the effects on development become visible
A narrow palate, crossbite and changes in the position of the front teeth are noticed in these years. The right window for an orthodontic assessment also falls in this period.
- Teenage years
Signs inside the mouth settle in
Gum inflammation at the front that does not clear, dryness and bad breath come to the fore. Facial growth is largely finished, so the options for correcting the structure narrow.
- Adult
Ongoing dryness and gum problems
The symptoms are mostly morning dryness, burning in the throat, bad breath and repeated gum inflammation. At this age it may also be necessary to look into breathing problems during sleep.
How is it treated?
The first job is to find the cause. A blocked nose, allergy and enlarged adenoids and tonsils are assessed by an ear, nose and throat doctor; where allergy is involved, treatment can be planned together with the relevant specialist. Without removing the cause, measures aimed only at the inside of the mouth stay temporary.
The work done on the dental side is to limit the damage the dryness leaves in the mouth. Clearing up gum inflammation, rebuilding your brushing technique at the front, fluoride applications and shortening the interval between check-ups all belong here. If dryness at night is marked, drinking water, raising the humidity of the room and mouth-moistening products are discussed.
If a narrow palate or a bite problem is found in a child, an orthodontic assessment is carried out; exercise programmes for the lip and tongue muscles can be added to the treatment. Methods such as taping the mouth to force breathing through the nose are not considered safe while the nose is not clear, and should not be tried without an assessment by a doctor.
- Seeing your child stop breathing during sleep
- Difficulty swallowing or a change in the voice alongside sleeping with the mouth open
- A nose blocked on one side together with foul-smelling or bloody discharge
- Not being able to close the mouth during the day and running out of breath while talking
How is it prevented?
- Do not brush a blocked nose aside as seasonal; once it persists, it needs to be assessed.
- Watch how your child sleeps; snoring, sleeping with the mouth open and sweating are not accepted as normal.
- If you breathe through your mouth, shorten the interval between your check-ups together with your dentist.
- When you brush, give the outer surface of the front gums its own time; inflammation settles here most of all.
Frequently asked questions
- Does mouth breathing really damage the teeth?
- It does not cause decay directly, but by drying the mouth it creates conditions that suit decay and gum inflammation. Redness and bleeding that do not clear despite good brushing can be seen, especially on the outer surface of the front teeth. In children, the development of the palate and the jaws can also be affected by this pattern.
- Would taping my mouth at night solve it?
- This method is not considered safe while the nose is not clear, and it can hide an underlying breathing problem. The cause of the blocked nose should be looked into first and, if needed, a sleep assessment carried out. Make the decision together with your doctor rather than trying it on your own.
- My mouth only falls open at night. Is that a problem?
- Dryness at night on its own can raise the risk of decay and gum inflammation. Mouth breathing at night can also be a sign of a blocked nose and, in some cases, of breathing problems during sleep. If morning dryness, snoring and daytime tiredness come together, it is reasonable to ask for an assessment.
This content is for general information and does not replace an in-person examination. Symptoms overlap between conditions, and a diagnosis can only be made clinically.