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NASO RESPIRATORY
FUNCTION
INDIAN DENTAL ACADEMY
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RESPIRATION
Respiration the term is generally used, includes
two processes external respiration, the absorption
of O2 and removal of CO2 from the body as a
whole; and internal respiration, the utilization of
O2 and production of CO2 by cells and the
gaseous exchanges between the cells and their
fluid medium.

The respiratory system is made up of a gas exchanging
organ (the lungs) and a pump that ventilates the lungs. The pump
consists of the chest wall; the respiratory muscles, which
increase and decrease the size of the thoracic cavity; the areas in
the brain that control the muscles; and tracts and nerves that
connect the brain to the muscles.
At rest, a normal breathes- 12-15 times/min.
(about 500ml/breath or 6-8lit/min)

This air mixes with the gas in the alveoli, and by simple
diffusion O2 enter the blood in the pulmonary capillaries while
CO2 enters the alveoli. In this manner, 250 ml of O2 enter the
body per minute and 200 ml of CO2 is excreted.

External nose
It is pyramidal in shape with its root up and the base directed
downwards. Nasal pyramid consists of osteocartilaginous frame
work covered by muscles and skin.
Osteocartilaginous framework
Bony part
Upper one third of the external nose is bony while lower
two thirds are cartilaginous. The bony part consists of two nasal
bones which meet in the midline and rest on the upper part of the
nasal process of the frontal bone and are themselves held
between the frontal processes of the maxillae.
Cartilaginous part
It consists of Upper lateral cartilages
Lower lateral cartilages,
Lesser alar (or sesamoid) cartilages and Septal cartilage.

Nasal musculature
Osteocartilaginous framework of nose is
covered by muscles which bring about movements of the nasal
tip, ala and the overlying skin. They are the procerus, nasalis
(transverse and alar parts), levator labi superioris alaque nasi,
anterior and posterior dilator nares and depressor septi.
Nasal cavity proper
Each nasal cavity has a lateral wall, a medial wall, a roof
and a floor.
Lateral wall: It is marked by three scroll like bony
projections called turbinates (superior,middle&inferior).
Sometimes a fourth turbinate, concha suprema, is also present.
Below and lateral to each turbinate is the corresponding meatus.


•Medial wall: Nasal septum forms the medial wall.
Roof: Anterior sloping part of the roof is formed by nasal bones;
posterior sloping part is formed by the body of sphenoid bone;
and the middle horizontal part is formed by the cribriform plate
of ethmoid.
Floor: It is formed by palatine process of the maxilla in its
anterior three-fourths and horizontal part of the palatine bone in
its posterior one-fourth.


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PHYSIOLOGY OF NOSE
Functions of the nose are classified as:
1. Respiration.
2. Air conditioning of inspired air.
3. Protection of lower airway,
4. Vocal resonance.
5. Nasal reflex functions.
6. Olfaction.
Nose is the natural pathway for breathing.
(Mouth breathing is acquired through learning). The nose also
permits breathing and eating to go on simultaneously. During
quiet respiration, inspiratory air current passes through middle
part of nose between the turbinates and nasal septum. Very little
air passes through inferior meatus or olfactory region of nose.
Therefore, weak odorous substances have to be sniffed before
they can reach olfactory area.

During expiration, air current follows the same course as
during inspiration, but the entire air current is not expelled
directly through the nares. Friction offered at limen nasi converts
it into eddies under cover of inferior and middle turbinates and
this ventilates the sinuses through the ostia.
The inflow of air is regulated by the swelling and
shrinkage of the anterior end of inferior turbinates.
Nasal cycle. Nasal mucosa undergoes rhythmic cyclical
congestion and decongestion, thus controlling the air flow
through nasal chambers. When one nasal chamber is working/
total nasal respiration, equal to that of both nasal chambers, is
carried out by it. Nasal cycle varies every few hours and may be
characteristic of an individual.

STRUCTURE OF PHARYNGEAL WALL
From within outwards it consists of four layers:
1. Mucous membrane
2. Pharyngeal aponeurosis (pharyngo- basilar fascia)
3. Muscular coat
4. Buccopharyngeal fascia
DIVISIONS OF PHARYNX
Anatomically, pharynx is divided into three parts:
1. Nasopharynx
2. Oropharynx
3. Hypopharynx or Larvngopharynx.


Nasopharynx (epipharynx)
It lies behind the nasal cavities and extends from the base
of skull to the soft palate or the level of the horizontal plane
passing through the hard palate
Functions of Nasopharynx
1. Acts as a conduit for air.
2. Through the eustachian tube, it ventilates the middle ear and
equalizes air pressure on both sides of tympanic membrane.
3.Elevation of the soft palate
4. Resonating chamber
5. Drainage channel for the mucus


Oropharynx
Oropharynx extends from the plane of hard palate above to
the plane of hvoid bone below. It lies opposite the oral cavity with
which it communicates through oropharyngeal isthmus. The later is
bounded above, by the soft palate; below, by the upper surface of
tongue, and on either side, by palaloglossal arch (anterior pillar).
Functions of Oropharynx
1. As a conduit for passage of air and food.
2. Helps in the pharyngeal phase of deglutition.
3. Forms part of vocal tract for certain speech sounds.
4. Helps in appreciation of the taste.
5. Provides local defense and immunity against harmful intruders
into the air and food passages. This function is subserved by
subepithclial masses of Ivmphoid tissues scattered as Waldeyer's
ring.

HYPOPHARYNX (LARYNGOPHARYNX)
Hypopharynx is the lowest part of the pharynx and lies
behind and partly on the sides of the larynx. Its superior limit is
the plane passing from the body of hyoid bone to the posterior
pharyngeal wall, while the inferior limit is lower border of
cricoid cartilage where hypopharynx becomes continuous with
oesophagus. Hypopharynx lies opposite the 3rd, 4th, 5th, 6th
cervical verterbrae. Clinically, it is subdivided into three regions
—the pyriform sinus, post- cricoid region and the posterior
pharyngeal wall.
Functions:
Laryngopharynx, like oropharynx, is a common
pathway for air and food, provides a vocal tract for resonance of
certain speech sounds and helps in deglutition.

VELOPHARYNX
VELOPHARYNGEAL MUSCLES
•Normally, the most anterior part of the soft palate has no
muscle fibres, but the rest of the velum is to a large extent
formed by muscles, and its movements are produced by these
muscles. They are all paired.
• The levator veli palatini is a slender muscle which pulls
the velum upwards and backwards.
The levator muscles are the most important
ones in accomplishing velopharyngeal closure, as evidenced
by electromyography.
• The palatopharyngeus muscle is the largest velopharyngeal
muscle.
When the palatopharyngeus muscles contract, the velum
is pulled backwards and downwards, the lateral pharygeal
walls are brought medially, and the larynx and pharyngeal
walls are elevated.
• The palatopharyngeus muscles are moderately active in
speech, often in synchrony with the levators.

• The salpingopharyngeus muscle is inconsistently found in
dissections. The salpingo-pharyngeus muscle has probably
very little, if any, functional significance.
• The superior pharyngeal constrictor muscles form the
muscular coat of the upper pharynx
When the superior constrictor contracts, the pharynx is
narrowed and the velum is pulled backwards. In speech, the
constrictor acts in synchrony with the levator, but, like the
palatopharyngeus, it contracts much more forcefully during
swallowing.
In some clefts patients, a transverse fold. a shelf-like inward bulging, of the posterior pharyngeal wall may be
observed during speech. This is called Passavants ridge. It
is, no doubt, produced by contraction of constrictor fibres.
It is most often located some-what below the normal
velopharyngeal closure level and does not meet the elevated
velum.
• The Tensor veli palatini is a flat muscle of triangular
shape,

• The tensor is of vital importance for the opening of the
auditory tube. When contracting, it also makes the soft
palate tense and depresses its anterior part (Bloomer 1953).
Electromyographic recordings from the tensor muscle have
failed to demonstrate any systematic, consistent activity
during speech, but as far as we know it is always active
during swallowing (Fritzell 1979)
• The palatoglossus muscle is small. These muscles
contract, the velum is lowered and drawn forward. In
speech, palatoglossus is active in the production of sounds
which require elevation of the back of the tongue, and-often
in the production of nasal sounds, although perhaps not in
all subjects.
•The uvular muscle has its origin from the palatal
aponeurosis somewhat behind the posterior margin of the
hard palate, close to the mid-line.
The uvular muscles by contracting produce a bulge on the
upper side of the velum, which contributes to
velopharyngeal closure.

VELOPHARYNGEAL CLOSURE
• During swallowing and speech, as well as during
other activities like blowing and whistling, the
oropharynx must be separated from the nasopharynx.
This is done by velopharyngeal closure. Its main
component is elevation of The soft palate to meet the
posterior pharyngeal wall
• Inward movement of the side walls of the pharynx
also contributes to velopharyngeal closure
•
Graber et al (1959) observed that the length of
the velum is greater during function than at rest. This
velar stretch was studied by Mourino and Weinberg
(1975). And they noted that in their subjects…. The
length of the anterior portion of the soft palate
measured during speech was not significantly different
from anterior resting length.

Theories of Velar Function
• Moll and Shriner (1967) hypothesized that the velum
function in only two modes, on and off.
Their hypothesis, which is more complex then has
generated much research and discussion.
• Lubker’s data (1967) supported Molls’ earlier observation
(1962) of systematic variation in velar motion and position
with change in vowel height.
• Seaver and Kuehn (1980) used electromyography to
measure action potentials simultaneously in the levator,
palatoglossus, and palatopharyngeus muscles.
The authors wrote:

“Changes in velar positioning 'during the product of non-nasal speech are a
result of the interaction of number of variables operating simultaneously. Any
attempt to relate only one of these variables to the activity of the velum may
represent an oversimplification of this complex mechanical system.”


Lubker (1975) stressed the importance of considering the
coordinated function of the several velopharyngeal muscles
in velopharyngeal function during speech.(electromygraphy)
Lubker wrote:
“Velopharyngeal

closure appears to be a complex
and highly coordinated act. The muscles responsible function
more or less forcefully to achieve more or less tight
velopharyngeal closure. The lightness of the closure achieved is
not a random variable, but is dictated by the speaker's needs, ie.
the production of a phonemes that is perceptually acceptable,
and by certain physical constraints such as timing. likewise, the
variability of muscle effort is not random, out is also dependent
partly upon the speaker's needs and partly upon what the
pharyngeal system has been required to do for the processing
phonemes. The clear implication is that of precise programming
required in the central nervous system ”

Etiology of naso respiratory
dysfunction




Developmental and morphologic anomalies
a.asymmetry of the face
b.hereditary
c.abnormal development of the nasal cavity
(or)turbinates
d.short upper lip
Partial obstruction
a.Deviated nasal septum
b.localised benign tumour
c.narrow nasal passage(maxilla)

Infection

and infllammation

a.Chronic Infections of the mucosa (allergic

rhinitis, Atrophic rhinitis,asthma)
b.Enlarged adenoids or tonsils
c. Nasal polyp
d.sinusitis
Traumatic
Genetic

injuries

pattern


Assessment of disturbed nasal function.
Frequency of ENT diseases
Case history
Mode of sleeping, habits and allergies
Clinical examination

Should determine
Lip competency

methods

* Mouth mirror
* Cotton wool test
* Hold a sheet of card board
between the lips (or) some
amount of water in the
mouth.

Size of the adenoids

Indicates whether passage

and tonsils on lateral

is free or partially or totally

cephalographs can be

obstructed

estimated
Visualization of the nasal turbinates through the nostrils also is helpful.

Determination of nasal resistance
Identification of specific methods to provide valid measurement
of nasorespiratory function can help clinicians to (1) make an
informed judgment regarding postulated relationships between
respiration and growth, (2) test the validity of a diagnosis of
impaired nasal respiration or "mouth breathing," and (3) evaluate
the efficacy of treatment for nasal obstruction.
A method that has been frequently used to quantify
nasorespiratory function is nasal resistance measurement or
rhinomanometry
Rhinomanometric methods are categorized as active or passive
and anterior or posterior..
 Anterior rhinomanometry involves locating the measuring
catheter within the anterior nares; the posterior method measures
transnasal pressure without disrupting the nasal mucosa.


Active

posterior rhinomanometry is one commonly used
method which measures the rate of nasal airflow while
simultaneously recording the pressure differential between the
oropharynx and the external nares

Measurement

of nasal airway resistance was determined for the
subjects by the posterior rhinomanometric technique described
by Warren. (The technique involves calculating nasal resistance
by measuring pressure and airflow during breathing by means of
an equation analogous to Ohm's law for electrical circuits. Nasal
resistance (R) is equal to the ratio of pressure drop across the
nose (dP) over the volume rate of nasal airflow.)


ADENOIDS
•The nasopharyngeal tonsils, commonly called “adenoids”,
is situated at the junction of the roof and posterior wall of
the nasopharynx.
•It is composed of vertical ridges of lymphoid tissue
separated by deep clefts and covered by ciliated columnar
epithelium. Like palatine tonsils, adenoids have no crypts
and no capsules.
• Adenoid tissue is present at birth, shows physiological
enlargement up to the age of six years, and then tends to
atrophy at puberty and almost completely disappears by the
age of 20.

ADENOID FACIES
•Historically,restricted nasal airway function has been
believed to be casually related to specific facial, skeletal and
occlusal features, those of the Adenoid facies or Long face
syndrome (VERTICAL MAXILLARY EXCESS).
•It is based on the Premise that restricted nasal airway
function leads to “MOUTH BREATHING” a combination of
oral and nasal respiration ,which in turn results in a lowered
tongue function and open mandibular posture.
•If this altered posture is sufficiently prolonged during
growth, then narrowing of the maxillary dental arch and may
result, together with increased lower facial height and
maxillary-mandibular plane angle. The features often are
associated with the following:


.An elongated vertical development of the face
.An increased open anterior bite,
.Hyperplastic and inflamed gingival tissues,
.A high palatal vault
.Narrow maxilla leading to posterior cross bite
.A steep mandibular plane
.Class II malocclusion and
.Lip incompetence.

Theories
• A number of theories have been proposed on this concept a
few are discussed below
• First proposing the existence of a relationship between
mouth breathing and facial form stated that oral respiration
alters normal air currents and pressures through the nasal
and oral cavities, which causes impaired development of these
structures.
A Second theory
Held that oral respiration disrupts the muscle forces exerted
by the tongue, cheeks, and lips upon the maxillary arch.
mouth breather was believed to position the tongue in a more
downward and forward manner in the oral cavity, a position
in which it could not exert adequate buccal pressure to
counteract the inward forces from the lips and cheeks upon
the maxilla.


A third school of thought

•Denies a significant relationship between facial
morphology and mode of breathing. Kingsley was among
the first to consider the V- Shaped maxillary arch and deep
palate a congenital trait not related to mouth breathing.
•Gwynne Evans and Ballard also subjectively evaluated the
relationship between facial morphology and breathing
conditions over a period of 15 years. They reported that
facial morphology remains constant during growth
regardless of breathing patterns. They also stated that “
mouth breathing does not produce deformities of the jaws
and malocclusions and does not results in the development
of the adenoidal facies”


One of the most frequently cited papers dealing
with the subject of nasal airway function and
dentofacial morphology is by Linder – Aronson.
he hypothesized that enlarged adenoids give
rise to mouth breathing, which leads in turn to
a change in tongue position and this is then
followed by changes that are reflected in the
dentitional variables.


Cephalometric evaluation and measurement of the upper
airway
The use of lateral cephalometric radiographs to evaluate
the upper airway is somewhat limited as they provide 2dimensional images of the nasopharynx, which consists of
complex 3-dimensional anatomical structures. Not withstanding
this observation some workers have found that a significant
correlation exists between the results of posterior rhinoscopy and
radiographic cephalometry in the assessment of adenoid size.
Cephalometric evaluation measurement of the upper airway
done by Preston, Lampasso, and Tobias . (Seminars in
orthodontics 2004). Show the area of the adenoid tissue
contained within the trapezoid that depicts the nasopharynx.

MCNAMARA’S ANALYSIS:
Upper pharynx
Upper pharyngeal width is measured from a
point on the posterior outline of the soft plate to the closest point
on the pharyngeal wall. This measurement is taken on the
anterior half of the soft palate outline. The average nasopharynx
is approximately 15 – 20 mm in width. A width of 2 mm or less
in this region may indicate airway impairment.
Lower pharynx
Lower pharyngeal width is measured from point
of intersection of the posterior border of the tongue and the
inferior border of the mandible to the closest point on the
posterior pharyngeal wall. The average measurement is 11 to 14
mm, valve for the lower pharynx is of little consequence.

NASAL OBSTRUCTION
Angle, in describing his Class II, division 1 malocclusion,
stated that his form of malocclusion is always accompanied and
atleast in its earlystages, aggravated, if not caused by mouth
breathing due to some form of nasal obstruction.
Nasal airway resistance must be directly related to the mode of
respiration— namely, nasal/oronasal.
Nasal airway resistance is dependent on the anatomic
characteristics of the nasal airway, which is subject to
modification through the erectile tissue by many factors such as
infections, allergies, temperature, humidity, posture, and the
nasal cycle.
Volume flow, on the other hand, is related more to the
metabolic requirement of the subject and the muscular effort of
respiration until the obstruction is considerably increased.

•Watson and associates calculated nasal airway
resistance in forty- five children between the ages of 9
and 17 years by directly measuring Tran nasal
pressures with nasal airflow at a constant expiratory
flow rate.
• No significant relations were found to exist between
skeletal type, occlusion, and mode of breathing was
determined subjectively by clinical observation.
•The age at onset and the duration of nasal
obstruction were not evaluated.
Second, only
anteroposterior
cephalometric
dimensions
were
evaluated.
•Studies in humans have established that total nasal
obstruction is rarely encountered and that the most
common respiratory mode is a combination of oral and
nasal airflow

Linder Aronson. Showed that Subjects who are mouth
breathers are those who, for the most part, despite their
ability to ventilate through the nasal airway, breathe
through their mouth.
This observation is in support of one which notes that,
when nasal airway resistance is high, mouth breathing
invariably results although skeletal deformity does not
always occur. thus 23% of mouth breathers do so out of
habit rather than out of necessity while a variety of facial
types and malocclusions exists in conjunction with mouth
breathing.
Hyponasality:
Hyponasality is defined as a condition in which the nasal
consonants "m," "n," and "ng" and adjacent vowels are
produced with less than the normal amount of nasal
resonance .This condition is assumed to be the result of
upper airway obstruction.

ALLERGY AND NASAL OBSTRUCTION






The allergic conditions that have the greatest impact
on the development of malocclusion include rhinitis,
both allergic and vasomotor, and to a lesser extent
asthma of atopic origin.
Rhinitis is an inflammatory process that develops in
the nasal mucosal membrane
Following repeated exposure to an offending agent,
an antigen-antibody reaction occurs on the surface of
these cells resulting in a complicated cascade of
inflammatory mediators (histamine, bradykinin,
thromboxane, and leukotrienes)which induces
vasodilation of the blood vessels within the nasal
mucosa..

This

results in extravasation of plasma proteins and the
hallmark of rhinitis mucosal congestion.The presence of
nasal congestion can result in airflow obstruction and
the development of mouth breathing.
After the first year of life, air-borne particles may be
a significant cause of allergy in children. Proper
humidification to reduce the number of floating
particles, air cleaners, elimination of house dust and
removal of pets are some of the steps that can be taken
to promote nasal airway health in children with familial
histories of allergy.
.


ASTHMA
Asthma

is considered a chronic inflammatory disorder of the

airway similar to allergic rhinitis.
.In

the presence of inflammation ,airway hyper reactivity

develops resulting in changes in airway tone and thus airflow
changes in nasal function induced by rhinitis may lead to the
development of bronchial asthma via the loss of the natural
filtering mechanism of the nasal passage due to the development
of edema.


This change in nasal function may lead to increased

presentation of antigens to the airway additionally, the
inflammatory reaction once initiated in the nose may lead to
airway inflammation www.indiandentalacademy.com
via a systemic pathway.

The

nose will display swelling of the turbinates with
evidence of mucoid compaction. This will often result in
nasal obstruction to breathing, and a postnasal drip that is
frequently associated with coughing.
The

pharynx will show posterior cobble stoning with
adherent mucous secondary to the postnasal drip as well as
hypertrophy of the tonsillar tissues and although not seen
clinically, hypertrophy of the adenoids.
These

changes result in decreased airflow within the
nasal passages and the development of mouth breathing,
which depending on the age of onset, may develop into
malocclusion disorders.

Treatment modalities
• Although orthodontic treatment is required to
correct the presenting malocclusion, early
treatment of the allergic disorder may result in
fewer orthodontic complications.
• Treatment of the allergic phenomenon center
around avoidance of the offending agent
and patient education.
• Pharmacological treatment is the mainstay .This
treatment will take the form of:
a.Immunotherapy,
b Antiinflammatory medication,
c.Bronchidilatators,&
d.antibiotics therapy

Nasorespiratory function and head posture

• A natural head position roentgenocephalogram
was used to measure the craniovertical angulations,
craniocervical angulations, and cervical spine
inclination.
•A complete blockage of the nostrils causes an
immediate elevation of head posture in children
with nasally obstructed adenoids and who have
asthma
•In children with enlarged tonsils has been found to
be altered after therapeutic measures for improving
normal nasal breathing.
•These reactions in head balance could be
explained by the fact that an increased pharyngeal
airway dimension has been demonstrated with
extension of the head.

• Statistically slight significant difference was
observed in the craniovertical angulations.
(Women were holding their head in a more
elevated position than men).
•Study illustrates the favorable effect on the
nasorespiratory function on head extension.
Thus to provide normal breathing function, an
otherwise smaller than average airway space is
compensated by extension of the head.
•In nonobstructed subjects, this enlarges the
airway considerably, whereas in obstructed
subjects, this compensatory mechanism is not
enough even for providing a normal breathing
pattern.

OBSTRUCTIVE SLEEP APNEA SYNDROME
• In 1976, Guilleminault et al, first defined obstructive sleep
apnea syndrome.
•Broadbent in an 1877 issue of The Lancet. “ There will be
perfect silence through two, three, or four respiratory periods
in which there are ineffectual chest movements; finally air
enters with a loud snort, after which there are several
compensatory deep inspirations”.
• Cessations of breathing for ten seconds or longer are termed
apneas (from the Greek - without breath). When thirty or
more apneic episodes occur in the course of seven hours of
sleep, resulting in excessive sleepiness during the waking
hours, a person is described as having sleep apnea syndrome.
This condition may begin at any age, but the incidence
increases with age.
•Sleep apnea, a breathing abnormality that occurs during
sleep, has been divided into three types:

1. Central— stoppage of airflow from lack of respiratory
effort
2.
3.

Obstructive— stoppage of airflow despite great effort to
take in air
Mixed—starting as central, followed by obstructive

•

Partien et al subdivided patients with OSA en the basis of
BMI, respiratory disturbance index (RDI). airway size, and
hyoid bone position. However, the categorization was
carried out only on a subjective basis.

•

Lowe et al. divided patients into four skeletal subtypes
according to conventional cephalometric criteria.

•

Chronic, persistent snoring is a common symptom that
increases in prevalence throughout the lifespan

•

The snoring sound is produced by the vibration of the
soft palate or other oropharyngeal tissues. It can become
a medical concern because it is a key symptom of
obstructive sleep apnea syndrome (OSA).

Physiology and Pathophysiology

•Negative airway pressure is generated by the activity
of the diaphragm and intercostals muscles during
inhalation.
•Oropharyngeal muscles are normally activated in a
rhythmic mode in coordination with each inspiration.
•OSA Patients show greater pharyngeal dilator muscle
contraction during sleep. Suggesting that an imbalance
between negative airway pressure and dilator muscle
contraction is responsible for the obstruction.
•The role of negative intrapharyngeal pressure as a
stimulus to dilator muscle contraction is reinforced by
studies of the impact of nasal continuous positive air
pressure (nCPAP) on pharyngeal muscle function.


•Sleep apnea has been associated with various
syndromes, including Franceschetti Treacher-Collins,
Apert, Crouzon, and Pierre Robin.
•Although OSA can be induced by external factors,
such as alcohol ingestion, it is accessed to be an
"intrinsic sleep disorder," which implies that its primary
etiology is abnormalities in physiological or pathological
processes and/or anatomical structures.
•Studies focus considerable attention on the tongue in
the pathogenesis of airway occlusion during sleep, it
has been hypothesized that individuals with OSA have
impaired genioglossal function, allowing the prolapse of
the tongue against the posterior pharyngeal wall with
inspiratory effort during sleep.


TREATMENT MODALITIES FOR OSA
• Non surgical treatment alternatives, nasal continuous
positive airway pressure (nCPAP) has been shown to be more
effective than oral appliance therapy in improving respiratory
disturbances.
•However, many patients initially refuse or cannot tolerate
this treatment and patient prefer for oral appliances.
• Some patients do not improve or become worse despite
improvement of some symptoms, eg. snoring.
• It is not yet possible to predict the most advantageous
appliance type for a particular patient.
• Oral appliance treatment may last for many years, but
patients must be informed that these devices require periodic
replacement, which may be a financial consideration should
insurance coverage not be available.


•Treatment modalities for OSA and snoring most typically
include nasal continuous positive airway pressure CPAP),
oral appliances, and adjunctive measures such as weight
loss, medication, avoidance of sedating medication, and
body positioning.
•Surgery options include soft palate surgery such as
uvlopalatopharyngoplasty
(UPP)
or
laser
assisted
uvulopalatoplasty (LAUP), radiofrequency (RF) tissue
ablation, nasal surgery, genioglossus tongue advancement,
and mandibular advancement surgery.
•The first line of non surgical treatment is nCPAP in terms of
effectiveness.
• Oral appliance treatment includes inorder of decreasing
usage, adjustable and non adjustable mandibular posturing
devices interior tongue repositioners, and soft palate or
uvular lifting devices.
• The adjustable or titratable advancement devices were the
most prescribed.

• 1934, Pierre Robin first described the concept of

advancing the mandible with a monobloc functional
appliance to treat airway obstruction in infants with
micrognathia.
• 1985 that Meier-Ewert and coworkers next
described an intraoral protraction device for the
treatment of sleep apnea. Many articles followed
showing therapeutic efficacy in treating OSA with
various one-piece, hard acrylic, nonadjustable
advancement appliances.
• The first investigator to use a two-piece adjustable
advancement device with Herbst hardware was Rider
in 1988. His report was largely positive.
• In support of the findings of Rider, Clark and
coworkers found the Herbst appliance to be effective
in reducing the apnea index.
.


Peter T. George: A Modified Functional Appliance for
Treatment of Obstructive Sleep Apnoea -– AJO-DO
Volume 1987
• Designed the Nocturnal Airway Patency Appliance (NAPA)
to keep the airway open during sleep by 1) posturing the
tongue more anteriorly, 2) inhibiting wide jaw opening, and
3) assuring adequate air intake through the mouth whenever
nasal obstruction exists.
• The appliance protrudes the mandible about threequarters of the distance between centric occlusion and full
protrusion. The mandible is opened vertically just enough to
permit an airway between the incisors.
• Long lower lingual acrylic flanges and a high upper labial
wire bow prevent mandibular extrusion and guide the
mandible back into the appliance if the teeth become
dislodged.
•To assure adequate air supply, an oral breathing beak (a
horizontal acrylic tube) parts the lips and permits air to
enter between the incisors.

Taka.: A tongue retaining device and sleep-state
genioglossus muscle activity in patients with
obstructive sleep apnea-Angle Orthodontist (1996).
• Defined the effect of a tongue retaining device (TRD)
on genioglossus (GG) muscle activity in seven
obstructive sleep apnea subjects, two overnight sleep
studies were carried out with two TRDs.
•The time lags with TRD-A and TRD-B differed
significantly for the first-E and the last-E during NREM
sleep and for the first-E during REM sleep.
• The TRD reduces AH severity, normalizes the time
lag, and counteracts fluctuating Genioglossus EMG
activity observed when no bulb is present.


Effect of upper airway function on tongue
and mandibular position
•The effect of reduced nasorespiratory
function on tongue and mandibular positions
has been postulated to be that of impaired
nasal function causing a downward and
forward position of the tongue in the mouth
in order to maintain oral respiration.
• This altered tongue posture causes an
inferior repositioning of the mandible and
induces concomitant changes in neck and
facial muscular activity.
• The net result said to be development of
dentofacial features characteristic of the
long- face syndrome.

THE SURGICAL APPROACH OF HE
PHARYNGEAL AIRWAY PROBLEMS:
The indications for adenoidectomy have evolved from
the early 1900s when tonsillectomy and adenoidectomy were
routinely and almost universally prescribed for children.
Currently these surgical procedures are less frequently performed
and indicated only when.
a.Hypertrophy of the adenoidal tissue results in nasal
obstruction.
b.. Recurrent, or persistent otitis media is present in children in
the age range 3 to 4 years.
c. Recurrent or chronic sinusitis is present.
 Relative contraindications include:
a.The presence of a severe bleeding disorder
b. A high risk of velopharyngeal insufficiency
.

Tonsillectomy

and adenoidectomy are usually preferred over
more conservative treatment approaches in the presence of
certain entities such as long-term chronic middle ear infection
peritonsillar abscess, tuberculosis, and carcinomatous changes in
these tissues.

Tonsillectomy

is most frequently performed when attempts at
conservative treatment fail to cure chronic tonsillitis.

The

treatment for a deviated nasal septum is based on the
severity of the problem, but septoplasty, remains the treatment
of choice for a moderately to severely nasal septum.

The

treatment modalities that may be used to treat hypertrophic
nasal tubinates include radio frequency ablation of the mucosa,
electrocautery of the mucosa, infracturing of the turbinates, and
turbinate resection

Bony

hypertrophy of the nasal turbinates is treated with
submucous resection of the affected turbinate bone.

Patients

who have undergone maxillary surgical impaction
typically demonstrate broadening of the alar base and expansion
of the anterior nares.
Turvey, Hall, and Warren found that a reduction in nasal
resistance accompanied maxillary impaction. They suggested
that the decrease in resistance may be due to dilation of the nares
and opening of the liminal valve (point of greatest constriction at
the anterior nares).



The

liminal valve may play an important role in regulating
airflow and act as a respiratory brake for modulating airflow out
of the lungs.

REVIEW OF LITERATURE
Experimental manipulation of head posture – AJODO Volume 1980 March Vig,Shofety &philiphs
• Three experiments were done concerning (1) total
nasal obstruction, (2) visual feedback deprivation and
(3) a combination of (1) and (2) on the posture of the
cranium measured relative to a gravity-defined true
vertical reference plane.
•The cranio vertical angle was
protractor and a plumbline device.

measured

by

a

•The results indicated that total nasal obstruction
cases both in group (1) and (3) showed an extended
head position.


Weber, Preston, and Wright: Resistance to nasal
airflow related to changes in head posture – AJO-DO
Volume 1981
• They determined whether artificially induced extended
head posture decreases the resistance to nasal airflow.
Readings were obtained in both the normal and 10degree extended head posture position, and the results
were compared.
•In this study a angle finder, which is a type of
protractor plumb line device was used to measure
cranial extension.
•No association could be found between 10 degrees
extended head posture position
and a decreased
resistance to nasal airflow.


Quantative evaluation of nasal airflow in relation to
facial morphology AJO 1981.vig,sarver,hall,,warren
•Examined the relationship between facial morphology
and nasal respiration. Nasal resistance to expiratory
airflow, average volume flow rate, and temporal
characteristics of the respiratory cycle were measured for
twenty eight adults.
•Subjects were categorized as having normal facial
proportion with competent lips (n=10), (2) normal facial
proportions with incompetent lips (n=9) and (3) long
vertical face height (n=9).
•Results indicated that the three groups do not differ
significantly in terms of nasal airflow. Lip incompetence is
not synonymous with mouth breathing. Although long
faced subjects as a group had a higher mean value of
nasal resistance, the range of variation was so great as to
preclude the diagnosis of nasal obstruction from an
assessment of facial morphology.

O'Ryan, Gallagher, LaBanc, and Epker:
Relationbetween nasorespiratory function and
dentofacial morphology – AJO-DO Volume 1982.
•Presented a critical review of the literature concerning
nasal airway function upon dentofacial morphology.
•This review critically examined the most frequently
cited papers reporting a relationship between
nasorespiratory function and dentofacial morphology.
•The papers were divided into (1) cross sectional
studies & (2) longitudinal investigations.
•In Summary, this critical review failed to support a
consistent
relationship
between
obstructed
nasorespiratory function and the adenoid facies or
long-face syndrome. Additional objective evaluations of
this relation are encouraged.

Guenthner, Sather, and Kern: Effect of Le Fort I
maxillary impaction on nasal airway resistance –
AJO-DO Volume 1984.
• Evaluated the effect of maxillary superior movement
via Le fort I osteotomy on nasal airway resistance
• eleven caucasian patients whose surgical orthodontic
treatment included LE Fort I impaction (range 2 to 8
mm, mean 5.3)
•Nasal airway resistance in these patients were
determined
before few days and approximately 8
weeks after the LE fort I surgical procedure.
•Contrary to the predicted negative effects of maxillary
superior movement on nasal airway function, there was
a statistically significance improvement in nasal airway
resistance after maxillary superior movement.

Warren,Lehman,and Hinton: Analysis of stimulated
upper airway breathing – AJO-DO Volume 1984.
•This study was done to
develop and validate a
quantitative technique to estimate nasal airway
dimensions
so
that
normal
and
impaired
nasorespiratory function could be defined.
•In this study they employed a plastic model of the
upper airway .(simulate physiologic parameters) and a
pneumatograph was used to measure the airflow.
•The results indicated that the technique should
enable clinicians to (1) estimate size of the airway
during breathing(0.4cm), (2) distinguish between
normal and impaired nasal respiratory function, and
(3) determine quantitatively the effects of surgical
and/or orthodontic treatment for improving nasal
respiration.

Warren Hairfield, Seaton, Morr, and Smith: Nasal
size and nasal breathing -– AJO-DO Volume 1988 Nov.
•116 adult subjects were involved in the study (1)
assess the relationship between nasal impairment and
nasal-oral breathing, (2) determine the switching range
from nasal to nasal-oral breathing, and (3) quantify the
term mouth breathing.
•The pressure flow technique was used to estimate
nasal airway size; inductive ptethysmography was used
to assess nasal-oral breathing in normal and, impaired
breathers.
•Their findings indicated that the switching range from
nasal to nasal-oral breathing is very narrow and in
adults an airway <0.4 cm2 is impaired.
•It also concludes that the term mouth breathing
should be used with some caution.

Luc P.M Toume: The long face syndrome and
impairment of the nasopharyngeal airway – Angle
Orthodontist 1990
•Suggested that altered muscular function can influence
craniofacial morphology.
•The switch from a nasal to an oronasal breathing pattern
induces functional adaptations that include an increase in
total anterior face height and vertical development of the
lower anterior face.
•While some animal studies have suggested predictable
growth patterns may occur, studies in human subjects
have been much more controversial.
•Therefore, individual variations in response should be
expected to be the alteration of a long face syndrome
patient's breathing mode.

Spalding and Vig External nasal morphology
respiratory function – AJO-DO Volume (1990) March.
•

and

nasal casts were produced from impression of 60

postpubertal white subjects from which four measures
were made to characterise nasal morphology (1) nasal base
Shape, (2) miniumum orifice width, (3) nasai orifice shape,
and (4) nasal orifice area.
• Nasal function was evaluated by measuring nasal airway
resistance by means of posterior rhinomanometry and by
measuring the air respired nasally and orally by means of
the simultaneous nasal and oral respirometric technique.
• No significance were found between external nasal
morphology and nasorespiratory function.


Warren, Hairfield, and Dalston:
Nasal airway
impairment – AJO-DO Volume (1991) April
•Assessed the oral response to severe nasal airway
impairment in patients with cleft palate.
•Inductive plethysmography was used to measure the
percent of nasal breathing, and the pressure-flow
technique was used to estimate nasal area in 15
persons with severe nasal airway impairment.
•Analysis revealed a strong correlation between nasal
size and percent of nasal breathing in this selected
group.
• These data support the concept that the mouth acts
as a variable resistor to maintain an optimal
respiratory tract resistance when the nasal airway is
impaired.

Mats Bernhold, DDS: A magnetic appliance for
treatment of snoring patients with and without
obstructive sleep apnea – AJO-DO Volume (1998)
February
• Investigated the effects of an intraoral magnetic

appliance on snoring, daytime sleepiness, and blood
oxygen saturation, as well as to analyze the effects on
the craniomandibular complex and investigate the
response of the device to craniofacial Structure.
•25 male patients with snoring and osa participated.
•The appliance had 4 neodymium boron magnets in a
upper and lower occlusal acrylic splint.
•All patients easily accepted the magnetic appliance.
After 6 months the main symptoms decreased
significantly. The blood oxygen saturation during sleep
was also improved.


CONCLUSION
From the outset it is recognized that not all research
workers have reported significant
evidence that a
relationship exists between altered nasorespiratory
function and dentofacial morphology.
Recently, many concepts concerning the role of
respiration in the etiology of malocclusion are based on
subjective impression and anecdotal reports.
With the development of reliable objective methods
and technologies it is with us (orthodontists) to evaluate
identify and rely upon the appropriate conclusion and
improve or change the altered nasorespiratory function.


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