Mouth Breathing

Breathing is a vital function of the human body, normally done through the nose. Abnormal, habitual breathing through the mouth instead of the nose is known as mouth breathing. It is a common clinical problem in children and is detrimental to their health. Mouth breathing may be due to blockage in nasal passage, deviated nasal septum, enlarged adenoids or an infection in the nose & throat. Mouth breathers with enlarged adenoids (a mass of tissue at the back of the nasal cavity) develop “Adenoid Faces” manifested by elongated face with an expressionless and open-mouthed appearance. Mouth breathing may cause dryness of mouth leading to bad breath and gingivitis. Classification of mouth breathing and determining its type in a patient is very important for effective treatment. Obstructive mouth breathing is best treated by a rhinologist, whereas habitual mouth breathing is corrected by a pedodontist or orthodontist.


Sassouni defined mouth breathing as the habitual respiration through the mouth instead of the nose.

Merle suggested the term oro-nasal breathing instead of mouth breathing.





Mouth breathing has general, extra-oral, and intra-oral symptoms.

General symptoms are:

  • Nasal voice
  • Pigeon chest deformity
  • Mild inflammation of oesophagus
  • Decreased sense of smell
  • Poorly developed sinuses

Extra-oral symptoms are:

  • Short upper lip
  • Gummy smile
  • Dry and cracked lips
  • narrow nostrils
  • Adenoid facies

Intra-oral symptoms are:

  • Proclined upper anterior teeth with spacing
  • Enlarged tonsils or adenoids
  • Inflamed gums
  • Constricted upper arch and posterior cross bite




  • Enlarged nasal turbinates (network of bones in the nasal passageways) due to allergies, infections, pollution, or hot and dry climatic conditions and enlarged tonsils or adenoids
  • Intranasal defects such as deviated nasal septum, thickness of septum, allergic rhinitis, and nasal polyps
  • Hereditary
  • Short upper lip
  • Obstructive sleep apnoea syndrome






Identification of the exact cause of mouth breathing is important for its treatment. Clinical and functional tests are performed to differentiate it from habitual mouth breathing. Diagnosis is made on the basis of patient’s history of repeated respiratory infections, clinical examination of the patient such as extra-oral and intra-oral examination, observing patient’s breathing and checking for nasal voice. If required, an ENT (Ear, Nose, and Throat) specialist can also be consulted.

Following are the clinical tests carried out for diagnosis:

  • Lip seal test
  • Mirror test
  • Massler’s Butterfly test
  • Water holding test
  • Rhinomanometry
  • Cephalometrics





• Obstructive mouth breathing:

Increased resistance or complete obstruction of normal air flow through the nasal passage forces the child to breathe through his/her mouth

• Habitual mouth breathing:

When a child breathes through his/her mouth out of habit, usually at night and is mostly unaware of it

Anatomical mouth breathing:

Caused due to incompetent (or short) upper lips which do not permit closure without effort





Treatment of mouth breathing depends on its cause and should be done at an early age. Nasal congestion can be treated with the help of decongestants and nasal sprays. The child should also be examined for problems such as nasal obstructions and obstructive sleep apnoea, and should be treated accordingly. A surgery (tonsillectomy, septoplasty or adenoids removal) may be required to treat some cases of nasal obstruction. Dentists may recommend use of certain orthodontic appliances (oral screen, chin cap, activator appliance) under appliance therapy to correct malocclusion. Application of petroleum jelly on gums to prevent them from dryness and inflammation is also helpful. Habit interception appliances are recommended for the treatment of habitual mouth breathing.





  • PUBLISHED DATE : Jul 08, 2019
  • CREATED / VALIDATED BY : Dr Rida Ziaul
  • LAST UPDATED ON : Jul 08, 2019


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