Message Boards
Today's Active Topics Browse Forum Categories My Recent Activity My Messages Private Groups My Marked Threads My Subscriptions
Today's Active Images Today's Active Polls Most Active Topics Global Townie Map Advanced Message Board Search Message Board Terms of Use

Perio Reports

View Comments (4)

Perio Reports  Vol. 25, No. 9
Perio Reports provides easy-to-read research summaries on topics of specific interest to clinicians. Perio Reports research summaries will be included in each issue to keep you on the cutting edge of dental hygiene science.
Nasal Breathing Delivers More Oxygen to the Blood than Mouth Breathing

Nitric oxide gas is produced in the paranasal sinuses and delivered continuously into the nasal airways. With each breath in, nitric oxide is added to the air reaching the lungs. When breathing through the mouth, no nitric oxide is inhaled. Nitric oxide is a vasodilator and enhances the uptake of oxygen by the blood.

Researchers in Sweden evaluated the effects of inhaled nitric oxide on oxygen uptake in the lungs. There were two parts to the study. The first evaluated the effects of nasal and oral breathing on oxygen uptake in the blood of healthy subjects. The second part evaluated intubated patients, who are deprived of nasal-airway-produced nitric oxide. They wanted to see if adding nitric oxide to their inhalation would influence arterial oxygenation. To do this, air from the patient’s nose was aspirated and fed into the inhalation limb of the ventilator.

In six out of eight healthy subjects, blood oxygen uptake was 10 percent higher during nasal breathing compared to mouth breathing. In six out of six long-term intubated patients, the oxygen uptake by the blood increased 18 percent when nitric-oxide-rich nasal air samples were added to the ventilator.

These findings show an increase in uptake of oxygen by the blood during nasal breathing compared to mouth breathing in healthy subjects. Intubated patients benefited from the addition of their own nitric-oxide-rich nasal air.

Clinical Implications: Self-inhaled nitric oxide plays an important role in pulmonary function confirming one of the many benefits for nasal breathing over mouth breathing.

Lundberg, J.O., Settergren, G., Gelinder, S., Lundberg, J.M., Alving, K., Weitzberg, E.: Inhalation of Nasally Derived Nitric Oxide Modulates Pulmonary Function in Humans. Acta Physiol Scand;158(4):343-347, 1996.

Mouth Breathing Linked to Poor Posture and Reduced Respiratory Muscle Strength

Mouth breathing syndrome is characterized by a variety of functional, structural, postural, biomechanical, occlusal and behavioral issues. Body posture necessarily adjusts to mouth breathing with forward neck and head posture. Postural changes result in muscle imbalances, especially within the abdominal area and linked to the diaphragm. Core muscle strength is lost. Mouth breathing impacts nerves regulating the depth of each breath, keeping it in the upper thoracic area and not involving the diaphragm. This reduces thoracic expansion and the amount of air reaching alveoli within the lungs. Mouth breathing is evident from shoulder and upper chest movement, compared to nose breathing focusing on slow, deep belly breaths, using the diaphragm.

Researchers at the State University of Campinas, Brazil measured exercise tolerance, respiratory muscle strength and body posture in a group of children, ages 8-11 years. The test group included 45 mouth-breathing children and the control group was made up of 62 nasal-breathing children. The children were examined for nasal obstructions and were evaluated for posture. During a six minute walking exercise, breathing pressure was evaluated.

Abnormal head posture was evident in 80 percent of mouth breathers and 48 percent of nose breathers. Respiratory muscle strength, inhalation and exhalation measurements were generally lower in mouth breathers. Mouthbreathing children develop postural abnormalities in the cervical spine and decreased respiratory muscle strength compared with nose breathers.

Clinical Implications: Look for signs of mouth breathing in very young patients in order to correct the problem and prevent long-term deformities.

Okuro, R., Morcillo, A., Sakano. E., Schivinski, D., Ribeiro, M., Ribeiro, J.: Exercise Capacity, Respiratory Mechanics and Posture in Mouth Breathers. Braz J Otorhinolaryngol 77(5):656-662, 2011.
Long Face Syndrome

Long face syndrome, also called adenoid face, results from mouth breathing rather than nasal breathing. Switching from nose to mouth breathing leads to a deviant cranio-facial growth pattern. Total face height increases, specifically the lower anterior region. Nasal apertures narrow, the upper lip is shorter and the lips rest apart in an open-mouth posture. The angle of the mandible increases. Low tongue posture occurs with mouth breathing. When the tongue no longer sits in the palate or pushes into the palate with each swallow, the palate grows narrow and high.

A contrary opinion is held that the long face is actually genetically inherited and has nothing to do with mouth breathing. The inherited narrow nasopharnyx leads to mouth breathing, rather than the other way around. However, there is no scientific evidence to support this theory. Despite that fact, debate continues as to the importance of a patent airway and whether dental professionals should be addressing mouth breathing to prevent abnormal facial growth.

Several theories suggest a cascade of events explaining the morphologic changes associated with Long Face Syndrome. For some, the obstructed airway comes first and for others it is a result of several other factors. One theory suggests changes in posture lead to a forward head posture which leads to soft tissue stretching which puts forces on the skeletal bones leading to changes that cause airway obstruction leading to mouth breathing.

Conversely, research shows that plugging the nostrils of young monkeys for two years leads to mouth breathing and morphogenic changes characterized by the Long Face Syndrome.

Clinical Implications: Intervene early with young children showing signs of mouth breathing, to prevent Long Face Syndrome.

Tourne, L.: The Long Face Syndrome and Impairment of the Nasopharyngeal Airway. Angle Orthodontist 60:(3)167-176, 1990.

Young Mouth Breathers Prone to Forward Head Posture

Forward head posture is associated with mouth breathing as it helps open the pharynx to allow air to enter through the mouth. Mouth breathing is associated with a high frequency of nasal obstruction and enlarged tonsils. Mouth breathing is more often focused in the upper chest rather than deeper breaths from the belly. Mouth breathing bypasses the filtration provided by the nose, leading to allergic rhinitis.

Researchers at the State University in Campinas, Brazil evaluated children over the age of five years, comparing a group of 306 chronic mouth breathers and a control group of 124 healthy nasal breathers. The study was conducted at the university hospital where all the children were examined medically and dentally and underwent medical endoscopy to measure nasal obstruction. Posture was also evaluated for all the children.

There were more male mouth breathers than female. The children in the mouth breathing group were more likely to have significant nasal obstruction and larger tonsils than the nose breathing children. Mouth breathers also had a higher incidence of allergic rhinitis than nose breathers. Narrow palates were also more frequent in mouth-breathing children.

Postural changes with rounded shoulders and forward head position were significantly more frequent among mouth breathers compared to nose breathers. Mouth breathing seems to be a syndrome rather than a single condition.

Clinical Implications: Forward head posture is one sign of mouth breathing and is easy to evaluate in children before looking into the mouth. Early intervention and interdisciplinary treatment is essential to overall health.

Conti, P., Sakano, E., Ribeiro, M., Schivinski, C., Riberiro, J.: Assessment of the Body Posture of Mouth-Breathing Children and Adolescents. J Pediatr (Rio J) 87 (4):357-363, 2011.
Nasal Obstruction in Children Linked to Dental Abnormalities

Otolaryngologists see more and more children with nasal airway obstruction leading to changes in facial skeletal growth, snoring and sleep apnea. For more than a century, orthodontists have debated whether a cause and effect relationship exists between mouth breathing and dentofacial development. Some believe that muscles of the cheeks, lips and tongue play a role in facial development while others believe it is strictly genetic.

This controversy includes both medical and dental professionals as 60 percent of craniofacial growth occurs during the first four years of life and is 90 percent complete by age 12. Growth of the mandible is generally complete by age 18. To prevent facial changes due to mouth breathing, intervention should be at a very early age. Medical and dental professionals should be checking all patients for mouth breathing. Although there are children who are either mouth or nose breathers exclusively, many combine both nasal and mouth breathing, being more likely to mouth breathe at night, dropping the tongue from the palate and opening the mouth.

The term "adenoid face" was introduced in 1872 and related all dento-facial changes associated with nasal airway obstruction to adenoid enlargement. Today, there are many reasons for a child to switch from nose to mouth breathing so the term "long face syndrome" is more accurate. This is characterized by mouth breathing, difficulty keeping lips together, open bite, cross bite, elongation of the lower face, retrognathia, narrow arch, high palate and a gummy smile.

Clinical Implications: Nasal obstruction and mouth breathing in children are issues that dentists, hygienists, myofunctional therapists, orthodontists, pediatricians and otolaryngologist need to address as a team.

Schreiner, C., Deskin, R., Quinn, F.: Nasal Airway Obstruction in Children and Secondary Dental Deformities. UTMB, Dept. of Otolaryngology, Grand Rounds Presentation, 1996.

Tongue Thrusting

During normal swallowing, the tongue pushes against the roof of the mouth without touching the teeth, the teeth contact momentarily and peri-oral muscles are not activated. With tongue thrusting, the tongue contacts the maxillary anterior teeth and the peri-oral muscles contract. Tongue thrusting is the predominant swallowing pattern in infants, with a mature swallow developed by age two to four years.

Researchers at Dental College and Hospital Nerul in Mumbai, India screened 864 children ages eight to 14 and found tongue thrust in 46 children. Based on parental consent, they selected 21 with tongue thrust and 21 without tongue thrust. The children underwent a thorough clinical exam, impressions of both arches and a lateral cephologram.

More children with tongue thrust showed lip incompetency, 86 percent versus 14 percent. These figures were the same for lisping. Mouth breathing was found in 38 percent of tongue thrusters versus none in the control group. Hyperactive mentalis muscle activity was observed in 24 percent of tongue thrusters versus none in the controls. The upper lip was found to be thicker in those with a tongue thrust as well as a more acute naso-labial angle.

Open bite was found in half the tongue thrusters and none of the controls. Most of the children without tongue thrust had a 1-2mm overjet. The angle of the maxillary anterior teeth in children with a tongue thrust was increased. No significant skeletal differences were observed between groups.

Three controls showed lip incompetence with no mouth breathing, having a palatal tongue position rather than down and forward.

Clinical Implications: Check young children for signs of tongue thrusting.

Dixit, U., Shetty, M.: Comparison of Soft-Tissue, Dental, and Skeletal Characteristics in Children with and without Tongue Thrusting Habit. Contemp Clin Dent 2013;4:2-6, 2013.
Sponsors
Site Menu
Message Boards Articles Continuing Education Podcasts Blogs Classifieds News Events Townie® Poll Ebooks Townie Choice Awards
Company Info
Contact Us Advertise With Us Howard Farran DDS, MBA Policies and Agreements
Site Help
Sally Gross, Member Services Specialist
Phone: +1-480-445-9710
Email: sally@farranmedia.com
©2024 Hygienetown, a division of Farran Media • All Rights Reserved
9633 S. 48th Street Suite 200 • Phoenix, AZ 85044 • Phone:+1-480-598-0001 • Fax:+1-480-598-3450