Upper airway

UPPER AIRWAY CONSTRICTION
&
ITS EFFECT ON GROWTH AND TREATMENT
www.indiandentalacademy.com

CONTENTS
1.HISTORY
2.UPPER AIRWAY STRUCTURE – PARTS
3.RESPIRATORY MECHANICS
4.CAUSES OF UPPER AIRWAY CONSTRICTION
5.NASO – REPIRATORY FUNCTION AND CRANIOFACIAL GROWTH
6.HEAD POSTURE
7.DIAGNOSIS
8. HISTORY AND PHYSICAL EXAMINATION
9.CLASSIFICATION OF RESPIRATORY OBSTRUCTION
10.LONG FACE SYNDROME
11.MOUTHBREATHING AND DENTOFACIAL DEFORMITIES
12.ROLE OF TONSILS AND ADENOIDS
13.RHINITIS
14.SEQUELA OF UPPER AIRWAY CONSTRICTION
15.MUSCLES IN IMPAIRED NASAL AIRWAY
16.INVESTIGATIONS
17.TREATMENT
ADENOIDECTOMY AND TONSILLECTOMY
SEPTOPLASTY & TURBINATE RESECTION
RHINITIS
ORTHODONTIC TREATMENT – Myofunctional appliances
RAPID MAXILLARY EXPANSION
ORTHOGNATHIC SURGERY
18.ROLE OF ORTHODONTISTS
19.CONCLUSION www.indiandentalacademy.com

INTRODUCTION
Human beings are normally nasal breathers. The nasal and oral cavities
serve as pathways for respiratory airflow. Ordinarily, the inspiratory and
expiratory airstreams are channeled through the nose because the mouth
is usually closed. However, in some individuals, because of nasal airway
inadequacy or habit, the oral cavity becomes the predominant route for the
passage of respiratory airflow.

HISTORY
According to Angle, 1907, Cl II DI malocclusion is always accompanied and
atleast in its early stages aggravated, if not caused by mouth breathing due to
some form of nasal obstructions.
Derichsweiler (1956) argued against nasal obstruction being a primary
etiologic factor in dentofacial deformity. Watson and Colleagues (1968) are
also of similar opinion and suggested that when resistance was high mouth
opening invariably resulted, but skeletal deformity did not always occur.
Korkhaus (1960) on the other hand, suggested that maxillary arch form is a
primary factor in determining nasal cavity size and hence breathing mode.
Linder-Aronson (1970) and Tully (1966) described a special facial
type “Adenoid facies” as characteristics of persons with enlarged adenoids and
mouthbreathers.
Hunter (1971) did not find a relationship between allergic rhinitis and
malocclusion, but demonstrated that frequency of mouthbreathing increases
as nasal airway resistance increases

Harvold in 1973 simulated hypertrophied adenoids in primates with acrylic
blocks and found that within 9-15 months the palatal vault increased in height
creating an anterior open bite.
Sten Linder-Aronsen’s study of human children establishes correlation that
conditions which can obstruct nasal air flow may cause deviations in
craniofacial growth, particularly increased face height.
Vig, et al. found that the long-faced group had a higher mean value of nasal
resistance but that the individual range of variation was too great. In an
assessment of anteroposterior relationships, Watson, et al. found that the
magnitude of nasal resistance and the subject’s anterior-posterior skeletal
classification were independent of one another.

STRUCTURE OF UPPER AIRWAY
The structures of upper airway are the nose
and the pharynx with its 3 divisions (ie,
nasopharynx, oropharynx, hypopharynx).
Changes in the dimensions of the
respiratory tract i.e. constriction will
decrease the airflow(Solow and Greieve`79)
Nose: The internal nasal valve, the septum,
and the choana are areas of special
concern.
Nasopharynx: This area is particularly
important in children because the adenoids
are commonly hypertrophied, producing
obstruction.
Oropharynx: The soft palate, tonsils,
palatoglossal and palatopharyngeal arches,
and the tongue are structures of concern.
Hypopharynx: The base of the tongue is
the most influential structure in this area.

RESPIRATORY MECHANICS
When the diaphragm contracts, its dome moves downwards
into the abdomen, thus enlarging the thoracic cavity. Simultaneously, the
inspiratory muscles move the rib cage upward and outward, also increase the
volume of the thoracic cavity. This enlarges the volume of air within the lungs,
pressure falls below atmospheric and air is drawn into the expanding lungs.
While inspiration is an active process involving muscles, normal expiration is a
passive event. As the thorax and lungs spring back to their original sizes,
pulmonary air becomes temporarily compressed so that its pressure exceeds
atmospheric and air flows from the lungs to the outside.

AIRFLOW MECHANICS
Air flows from one region to another because of a difference in pressure
between the two regions. There is a pressure differential (drop) in the direction of
airflow. The relationship between this pressure drop and airflow depends upon
Reynolds number.
Rn = P ~d / µ Where p is the density, ~ is air velocity, d is
the diameter of the structure and µ is the density of the air.
When Rn < 2000. the flow is smooth or laminar.
Laminar →  P = K1 V
(P – Pressure, K1 – proportionality constant which includes air viscosity
and length and radius of the str, and v is airflow)
When Rn > 2000, airflow is turbulent.
Turbulent →  P = K2 V2

PATHOLOGIES CAUSING CONSTRICTION
Nose
Choanal atresia,nasal septal deviation, hypertrophy of turbinates, Polyposis,
Dermoid cyst, Tumors
Nasopharynx
Adenoidal hypertrophy ,Stenosis,Pharyngeal flap for cleft palate,Tumors ,
Mouth and oropharynx
Hypertrophied tonsils, Macroglossia , Micrognathia, Epignathus,
Temporomandibular joint ankylosis
Larynx
Tracheal atresia,Intrinsic tracheal lesions,Extrinsic compression
(goiter),Laryngeal and tracheal webs,Kimura disease (Okami, 2003)

NASO – REPIRATORY FUNCTION AND CRANIOFACIAL GROWTH
Dentofacial morphology can be altered by nasorespiratory
obstruction depending on the magnitude, duration & time of occurrence.
Quinn in 1978 reiterated that mouth breathing is one of the early
symptoms of unnatural acts of breathing and that dramatic deformities of
the face, jaws and dentition can be caused by inability to breathe through
the nose properly.
Ricketts in 1979 stated that when there is a lack of function in the
nose, there can be a growth inhibition. Under normal function in breathing,
a pressure develops.In the abnormal, this pressure is changed to vacuum
and the maxillary complex is sucked inward, restricting the basal cone.

3 mechanisms were found by which adenoid-mouth breathing relationship
influences the etiology of facial form and dentition
1.Compression
2.Disuse atrophy – theory of inactivity
3.Altered air pressure
In 1918, Norlund introduced the ‘compression theory’ which stated that
constriction of the maxillary arch is related to the absence of the lateralizing
pressure of the tongue against the palate. In response to nasal obstruction,
the tongue drops and the medializing effects of the buccal musculature is left
unopposed. The effect is further enhanced by a pressure differential across
the hard palate in the absence of nasal airflow, leading to a narrow, high-
arched palate.
Norlund also put forward the ‘theory of inactivity’, according to which there is
reduced growth of the nasal cavity, due to its inactivity, as suggested by
Korner (1891) and Bentzen (1903).

The airpressure theory described by Kantorowicz (1916) and James &
Hastings (1932) holds that a change to mouth breathing causes the
normal negative pressure in the anteriorly sealed oral cavity produced by
nasal respiration to be lost, and the palate thus is not carried downward
with the growth of the maxillary alveolar process.
The excavation theory proposed by Bloch (1903) and Michel (1908)
states that an upward stream of oral airflow presses on the palate
leading to higher palatal vault.
Recent study by Chang proposed that the degree of impact caused by
nasal obstruction may vary with different facial types. A brachycephalic
or broad faced pattern with strong facial musculature and a deep bite
may be less affected by nasal obstruction, whereas dolicocephalic faces
with narrow, more elongated pattern may be more susceptible.

Although the literature is replete with statements that airway impairment
alters facial and dental growth, there is substantial evidence to the contrary.
Conversely, Bushey found no relationship between nasal respiration and
linear measurements of the adenoids on lateral skull cephalograms before
and after surgical removal of the tonsils and adenoids. As opposed to these
studies, Kingsley (1989) noted normal craniofacial development in children
with severe nasal obstruction and Whitaker described severe palate
malformations in patients who had undergone adenoidectomy at an early
age.
More recent findings suggest that nasal-oral breathing per se is not
necessarily harmful to craniofacial growth. However, in instances where the
nasopharyngeal or oropharyngeal airspace is small, exaggerated postural
responses in obligatory mouthbreathers may be detrimental to craniofacial
growth.

HEAD POSTURE
The extended head posture which was observed in mouth breathers is found to
influence the position of the mandible. The SN/vertical angle was found to be
less in patients with extended head posture .
Schwarz in his studies in 1926,1931 found that the extension of the
head in relation to the body, particularly during sleep, led to the distal
displacement of the mandible and the development of class II M.O.
Bjork (1955, ’60, ’61) noticed that individuals with a flattened cranial
base and a retrognathic facial type carried their head in an extended position,
while those with a marked bend of the cranial base and a prognathic facial type
carried their head in a lower position.
Solow and Tallgren (1976) observed that subjects who had a large
cranio-cervical angulation resembled that of subjects who had a large
mandibular plane inclination. This suggests that the factors responsible for the
postural differences may also be responsible for differences in mandibular
plane inclination and facial type.

SOFT TISSUE STRETCHING HYPOTHESIS (Solow and Kreiborg `77)
An extension of the head in relation to the cervical column would entail the
passive stretching of the facial soft tissue layer draping the face and neck.The
effect of this would be slight backward and downward forces exerted by the
soft tissue layer on the facial skeleton thereby restraining the forward and
increasing the downward component of the maxillary and mandibular growth
relative to the cranial base.

DIAGNOSIS
Parents may fail to appreciate symptoms in their children.Accordingly, to be
alerted to the possibility of chronic nasal obstruction in children and to assess
its severity, clinicians often must rely on their own observations of clinical
signs.
The cause of nasal obstruction in children can usually be determined by a
thorough history and physical exam. The goals of the evaluation are to
determine specific causes of problems, the severity of the obstruction, and the
presence of associated medical complications

HISTORY AND PHYSICAL EXAMINATION
The general well-being of the child, including growth and development, must
be determined.
• Pertinent past history include birth trauma, early childhood trauma, previous
hospitalizations, medications, and surgical history.
•Sleep history may often reveal loud irregular snoring, restless sleep, abnormal
sleep position, and nocturnal mouth breathing. Enuresis may also be present.
Swallowing difficulties may be noted.
•Voice quality (degree of nasality) and clarity, daytime hypersomnolence, and
school/behavioral difficulties should be evaluated.
•History of rhinorrhea, epistaxis and allergy should
be noted.

A complete examination of the head and neck is performed.
• Resting mouth position is noted.
• "Adenoid facies" is characterized by an open mouth, dull facial appearance,
and short upper lip. This is nonspecific for chronic nasal obstruction.
• Other craniofacial anomalies may be associated with these symptoms
including cleft palate, Down syndrome, etc.
•Tonsillar hypertrophy, macroglossia and oropharyngeal masses should be
evaluated
•The nasal cavity was inspected for the presence of secretions, edema and
erythema of the nasal mucosa .
•The ears should be evaluated as otitis media certainly is associated with nasal
obstruction problems.
• Bony nasal anomalies, external masses, pits, etc. should be evaluated.

Evaluation of the voice quality includes as assessment of nasality and clarity.
Having the child to speak words that enhance nasality such as lemon, milkman,
Mickey Mouse, ninety nine, bananas are normally nasal transmitted words and
words such as baseball and Jack are normally non-nasal transmitted words.
In a hyponasal child, resonance is poor even with the nostrils open, and closing
of the nostrils results in little or no reduction in resonance.
Mouth breathing, particularly in children, does not ,always signify severe nasal
obstruction

CLASSIFICATION OF RESPIRATORY OBSTRUCTION
Respiratory obstruction can occur due to adenoids or as result tonsils
both.The obstruction can be intermittent, when it is caused by acute
inflammation or persistent due to chronic inflammation.
•Mild obstruction is characterized by snoring and distortion of speech.
•Moderate obstruction – features of mild featuresof disturbance in sleep and
apnoea.
•Severe obstruction – more pronounced degrees of signs and symptoms
noted in moderate obstruction and also periods of O.S.A

THE LONG FACE SYNDROME
In 1872, C.V. Tomes coined the term
“Adenoid Facies” or ‘Long Face Syndrome’
to describe the dentofacial changes
associated with chronic nasal airway
obstruction.Any condition that causes nasal
obstruction could lead to this typical facial
morphology. This syndrome is
characterized by an increased
LAFH,increased dentoalveolar
height,gummy smile,high arched palate
,steep mandibular plane,excess incisal
show,anterior marginal gingivitis and long-
standing nasal obstruction may lead to
"disuse atrophy" of the lower lateral
cartilages , resulting in as slit-like external
nose with a narrow nasal vault.

The "long face syndrome" is often associated with crossbite, tension nose,
and a Class-II (mandibular retrognathic) occlusion. Another group of
children develop Class-III occlusion (mandibular prognathic) occlusion
which may be due to anterior displacement of the tongue due to tonsillar
hypertrophy. This creates a pressure affects on the lingual aspect of the
lower dental arch, causing a prognathic mandible and undererupted lower
teeth.
Children who have hypertrophied adenoids, tonsils and inferior
turbinates develop long face syndrome 30 percent of the time. In contrast,
children with normal respiratory airways develop long face syndrome 2
percent of the time.

PROPOSED SEQUENCE OF EVENTS as described by Principato
Prolonged periods of oral respiration lead to extensive eruption of the posterior
molars which exerts a downward vector of force on the mandible, causing the
lower jaw to rotate down and back in a "clockwise" direction. Because of the
backward mandible rotation, retrognathia and open bite deformities are
common. With a lowered tongue position, the lateral expansile forces of the
tongue on the palate are lost, and the unopposed medial forces of the
buccinator and masseter muscles leads to a narrow, high arched palate. The
incomplete lateral expansion of the maxilla often leads to a unilateral or posterior
crossbite.

DENTOFACIAL DEFORMITIES AND MOUTHBREATHING
One or all of the three neuromuscular responses must be present for
malocclusion and altered skeletal relationship to occur.
1.Altered mandibular posture-Mandible rotates down and back in response to
the etiologic factor.
2.Altered tongue posture-Tongue moves superiorly and anteriorly in response to
the etiologic factor.
3.Extended head posture-The mandible is held in position while the cranium and
maxilla rotate upward.

Mouth breathing is thought to predispose to the development of the "long face
syndrome" or "adenoid facies”. Vig et al. found that there was an increase in
anterior open bites, lower face height, and a tendency to hold the head higher.
The open mouth breathing position often results in an unusually long narrow
appearance. In order to breath through the mouth the lower jaw is dropped,
the head is tilted back and the tongue is lowered from contact with the palate
and protruded to provide a greater oral airway. Tooth crowding, narrow palate,
high palatal vault, asymmetrical growth of the upper and lower jaws and/or an
abnormal swallowing pattern are often noted.

ROLE OF TONSILS AND ADENOIDS IN
THE OBSTRUCTION OF RESPIRATION
The tonsils and adenoids are composed of
lymphatic tissues. Together, they are part of a
ring of glandular tissue (Waldeyer's ring)
encircling the back of the throat. The tonsils
are the two masses of tissue on either side of
the oropharynx. The adenoids are located
high in the nasopharynx behind the nose and
soft palate and, unlike the tonsils, are not
easily visible through the mouth.

The purpose of the tonsils and adenoids
The tonsils and adenoids are thought to assist the body in its defense against
incoming bacteria and viruses by helping the body to form antibodies.
However, this function may only be important during the first year of life. In
fact, there is no evidence to support a significant role of the tonsils and
adenoids in immunity.

INVOLUTION OF ADENOIDS
The adenoids are small at birth .The adenoids enlarge and eventually outstrip
the growth of the nasopharyngeal space at 3-5 years,thereby reducing the
nasopharyngeal size.After the age of 5,expansion of the bony nasophayngeal
space continues due to the maxillary growth.Percentile distance curve for the
amount of soft tissue and adenoids on the posterior pharyngeal wall show a
peak at age 5 and 10 to 11 years.Thereafter, a steady decline in these tissues
occurs as the child matures with the concurrent increase in the
nasopharyngeal area .If these tissues do not atrophy,the patient may be at a
risk of developing dentofacial abnormalities.TourneAJO`91
In boys the area of the nasopharyngeal soft tissue
is constant after the age of 6 while in girls
this area decreases slowly from 9 to
19 years of age(Jeans) seminar in
orthoMar 2004

Tonsillitis and Its Symptoms
Tonsillitis is an infection in one or both
tonsils. One sign is swelling of the
tonsils. Other signs or symptoms are:
Redder than normal tonsils
A white or yellow coating on the tonsils
A slight voice change due to swelling
Sore throat
Uncomfortable or painful swallowing
Swollen lymph nodes (glands) in the
neck
Fever
Bad breath
The root of the tongue pushes large tonsils against the posterior pharyngeal
wall, causing constriction or obstruction during articulation with the tongue in the
back of the mouth.Guttural voice quality as an associated clinical finding in
children with large tonsils has been reported

Enlarged Adenoids and Their Symptoms
Breathing through the mouth instead of the nose most of the time
Nose sounds "blocked" when the person speaks
Noisy breathing during the day
Recurrent ear infections
Snoring at night
Breathing stops for a few seconds at night during snoring or loud breathing
(sleep apnea)

RHINITIS
Allergy is by far the most common and important cause of nasal obstruction.
Allergy must be screened out first. Allergy is an exagerrated normal protective
response to proteins and large polypeptide molecules which ordinarily do not
warrant such an extreme response.
Clinical evaluation
History- itch, sneezing and rhinorrhoea are usually early symptoms;
congestion presents later; itch affects soft palate and external auditory canal;
sneezing often occurs , sinus congestion, mouth breathing and disturbed sleep
patterns; conjunctivitis can accompany nasal symptoms.
Examination.-Allergic facies – pallor
allergic shiners,
allergic mannerisms - allergic salute;
nose - swollen and mucoid;
throat - inflamed with lymphoid follicles (cobblestones or granular
pharyngitis);
ears - otitis media with effusion

Classification
Allergic rhinitis
Symptoms develop when persons inhale airborne antigens (allergens) to which
they have been previously exposed and have made IgE antibodies. These include
salivary proteins, horse dander, murine urinary proteins, pollens, house dust mite feces,
and mold spores. These IgE antibodies bind to IgE receptors on mast cells in the
respiratory mucosa and to basophils in the peripheral blood. When IgE molecules on their
surface are bridged by allergen, mast cells release preformed, granule-associated
chemical mediators. They also generate other mediators and cytokines that lead to nasal
inflammation and, with continued allergen exposure, chronic symptoms.

2.Nonallergic rhinitis with nasal eosinophilia syndrome (NARES) is
characterized by perennial symptoms, an older average age than in patients
with allergic rhinitis (39 years vs 25 years), and less nasal itching and
sneezing. Formation of IgE to inhalant allergens is unusual. The clear nasal
secretions contain > 25% eosinophfls. Fifty percent of patients with NARES
have sinusitis, 33% have nasal polyps, and 14% have asthma.
3.Vasomotor rhinitis is a common form of perennial nonallergic rhinitis
associated with chronic nasal congestion intensified by rapid changes in
temperature and relative humidity, odors due to nasal autonomic nervous
system dysfunction. Patients have little nasal itching or sneezing and often no
family history of allergy, but headaches, anosmia, and sinusitis are common.

SEQUELA OF UPPER AIRWAY OBSTRUCTION
Some of the effects of impaired nasal respiration reported are: Abnormal
facial development, headaches, malocclusion, poor sleep, sore throats,
excessive daytime sleepiness, dry mouth, frequent infections, earaches
and sinus problems.
It may cause significant problems such as.:
1. Dento-facial abnormalities
2. Hypersomnolent O.S.A syndrome
3. Alveolar hypoventilation
4.Pulmonary hypertension and cor pulmonale

MUSCLES AND NASAL AIRWAY RESISTANCE
Vargervik et al.found that tonic electromyographic activity of digastric muscle
and geniohyoid muscle was seen in nasal airway obstructed animals.
Vargervik et al. found that the masseteric stretch reflex, plays an important role
in controlling mandibular position.The masseteric muscle may function as an
accessory respiratory muscle when the nasal airway is threatened.
Basner et al.showed greater EMG activity in the genioglossus muscle during
nasal respiration than during oral respiration .Mathew et al.demonstrated that
the inspiratory activity of the genioglossus muscle was increased by nasal
obstruction,although there was no significant change in diaphragm EMG
activity

Obstruction of the nasal airway in the cat significantly inhibited the
masseteric stretch reflex and discharges of masseteric motor units but did
not affect the EMG activity of the diaphragm. Takashi Ono, Yasuo Ishiwata
suggested that masseteric electromyographic activity is inhibited during
masseteric muscle contraction in the rat.oral respiration and that the g-
system is involved in this inhibition. AJO1998
Electromyographic signals from the ala nasi, orbicularis oris superior,
genioglossus, mylohyoid muscles, and the diaphragm were recorded by fine-
wire electrodes. Results showed that when resistance was gradually
increased, nasal breathing resulted in a greater increase in muscle activity
than did tracheal breathing ,except in the diaphragm. Hyung-Geun Song
AJO 2001

INVESTIGATION
ASSESSMENT OF NASAL AIRWAY STRUCTURE
Structural abnormalities of the nose may be evaluated objectively by clinical
examination,roentgenographic investigations, fiberoptic rhinoscopy,
rhinostereoscopy, or radiologic studies (CT and MRI).
RADIOGRAPHS
1. Panoramic radiographs gives an idea about the nasal septum
and the nasal cavities
2.Sinus xrays are used to view the maxillary and other sinuses
3.Most commonly used are the lateral cephalograms

Cephalometry
The roentgenographic ratings is the gold standard during investigations
because roentgenographic assessment constitutes the only generally
available, objective, noninvasive means of estimating the extent of
encroachment by the adenoid on the nasopharyngeal airway.
It is also the case that roentgenographic assessments have been found to
correlate well with the volume of adenoid tissue observed or removed at
surgery.
Although positive correlations between airflow and airway measurements
have been made on cephalometric radio-graphs, the three-dimensional
aspects have been neglected.

DISADVANTAGES
1.There is the geometric limitation that a cephalogram produces only a two-
dimensional representation of the space involved.
2.The nasal airway is a convoluted and anatomically irregular structure and
by superimposition and lack of soft-tissue detail this is obscured on
traditional lateral or frontal cephalograms.
Preferably the xrays are to be taken with the subjects maintaining their
natural head position without the use of cephalostat.

In 1987, Weimert published a study of 1360 patients referred to
otolaryngologists by orthodontists. Most patients had undergone PA and
lateral cephalometric examinations which are utilized by orthodontists .They
found evidence nasal obstruction in 72% of cases and they reported a 96%
correlation between the adenoid size on x-rays and intraoperatively.
Others feel cephalometric analysis is a useful screening exam but have not
shown them to consistently predict adenoid size and degree of obstruction
(Poole 1980).

Fiberoptic rhinoscopy is the insertion of a flexible telescope into the nasal
cavity which allows the detailed visualization of the posterior two thirds of
the nose not visible with a nasal speculum inserted into the anterior nares.
Disadvantages
It is unlikely to detect structural or mucosal displacement of the medial or
lateral wall of the nasal valve < 1 ram, a distance that nonetheless may
exponentially affect nasal resistance or patency. These changes in
resistance and airflow are readily detectable by rhinomanometry or acoustic
rhinometry.
Rhinostereoscopy uses a precise surgical microscope to make direct and
noninvasive topographic measurements of the nasal mucosa.

Video nasopharyngeal endoscopy allows direct visualization and dynamic
evaluation of the nasopharynx, including details such as color, texture, and
volume. These images can also be recorded on videotape or in a digital
format.
Daniel studied the degree of diagnostic reproducibility between
lateral cephalometric radiography and nasopharyngeal videoendoscopy and
found that lateral cephalometric radiography appears to be sufficiently
reproducible for diagnosing hypertrophy of the middle and inferior turbinates
and of the region caudal to the inferior turbinate

2. cephalometric radiography gives high sensitivity but low for specificity in
diagnosing hypertrophy of the inferior and middle turbinates when compared
with nasopharyngeal endoscopy.
3. nasopharyngeal videoendoscopy is sufficiently reproducible for diagnosing
anterior and posterior septal deviation and hypertrophy of the inferior and
middle turbinates, but its ability to diagnose rhinitis is limited
4.nasopharyngeal videoendoscopy is more suitable for diagnosing diverse
obstructions of nasopharyngeal origin.Daniel AJO 2001

ASSESSMENT OF NASAL AIR FLOW AND RESISTANCE
Dynamic measurements of nasal congestion include nasal peak flow,
rhinomanometry, and acoustic rhinometry.
1.Nasal Peak Flow
Nasal peak flow test is inexpensive, easy to perform and can be done at
home. However, it is highly effort dependent, and results may vary widely,
especially between patients.Nasal peak flow measurements correlate well
with measurements of resistance and have their greatest usefulness in the
detection of large changes in nasal patency in individual subjects.

This technique involves measuring the peak inspiratory nasal airflow with a
modified peak flow device (eg nasal inspiratory
flowmeter;pneumotachograph).As the air flows across the flowmeter the
pressure drops and is recorded by the tranducer.
An abnormal peak flow should prompt consideration of more detailed
studies, such as rhinomanometry or acoustic rhinometry.

2.Rhinomanometry
Rhinomanometry, the measurement of nasal airway resistance, is probably the
test most frequently performed because it measures both flow and resistance.
It is classically divided into passive or active phases, and into anterior or
posterior rhinomanometry.
1.Active rhinomanometry requires the subject to generate airflow through the
nose by their own effort. Active rhinomanometry is a quick test to perform, and
the International Committee on Standardization of Rhinomanometry
recommends it for most studies.
2.Passive rhinomanometry utilizes external generation of a constant flow of
air at a given pressure and requires no respiratory effort.

Anterior and posterior rhinomanometry differ in the location of the transducer
used to measure posterior pharyngeal pressure.
Anterior rhinomanometry may be 'affected by deformation of the anterior
nares and/or valves, nasal cycling, and by the instrument inserted to the nares
for measurement.
Posterior rhinomanometry does not have these disadvantages, but is more
expensive and requires more patient cooperation, with approximately 15% of
subjects being unable to place the probe properly in the oral cavity.
It is an excellent tool for determining the degree of airflow obstruction before and
after surgical procedures and medical interventions .
2.It may also help to distinguish functional causes of upper airway obstruction
from structural causes.

Gurley and Vig reported a technique , which for the first time enabled the direct
and simultaneous measurement of inspired and expired air, both orally and
nasally. The technique is called SNORT, an acronym which stands for
Simultaneous Nasal Oral Respirometric Technique.
Using a custom fitted face mask with separate valves attached to the nose
and mouth and attached to a flow meter, air pressure transducer, recorder and
computer, it can give the nasal versus the oral inspiration, expiration and their
ratios. SNORT permits the objective quantification of the ratio of oral to nasal
airflow and permits a numerical determination of both normal and pathological
states of breathing mode.

Vig reported that it is not surprising to find the statistical correlations between
visually determined mouthbreathing and NRR-values to be inconsistent
throughout the experimental literature Angle 1990 Luc P.M. Tourne.
Principato has established age-related norms of nasal resistance using an
anterior rhinomanometric technique.
Normal nasal resistance for an adult is 2.5 to 3.5 cm of water per liter per
second.
At readings above 7.0 at rest, an individual must go to mouth breathing to get
adequate air.
Between 4.0 and 7.0, orthodontic intervention is the treatment of choice.
Above 7.0, surgery is usually considered.

3.Acoustic Rhinometry
Acoustic rhinometry, evaluates nasal obstruction by analyzing reflected sound
waves introduced through the nares.
• It is generally easy to perform, is noninvasive, and does not require patient
cooperation like many of the other evaluation procedures.
• It produces an image that reflects variations in the cross-sectional dimensions
of the nasal cavity and closely approximates nasal cavity volume and minimal
cross-sectional area.
• The short measurement period makes this procedure easy to use in all
patients, even children.

4.Plethysmograph
Niinima et al quantified nasal and oral
airflow simultaneously with a nasal
mask attached to a
pneumotachograph and “head-out”
exercise body plethysmograph. The
airflow was derived by subtracting
nasal from total respiratory volume.
Most of the subjects switched from
purely nasal to oronasal breathing
when exercise caused the total
respiratory volume to increase.

5.CT & MRI
The limiting factor, that
determines the capacity for
airflow is the minimal cross-
sectional area of the passage.
This narrowest portion can occur
at any point along the
nasopharyngeal trajectory and
can only be accurately
visualized by computed
tomography. Eg Newtom
generated computed
tomography

Attempts are being made to quantitate the adenoid mass and
pharyngeal space by linear measurement and/or surface calculation as
a complement to the clinical examination..eg MRI
MRI

Other Dynamic Methods To Measure Nasal Patency
Chilled mirrors or other polished surfaces The patient exhales through the
nose against a polished surface held close to the nostrils, and dimensions of
the two resulting areas of condensation are noted and compared. Camera
recordings of thermographic surfaces or calibration by concentric markings
on the condensing surface enhances this technique.
Oscillometry measures impedance in order to calculate NR. A
loudspeaker is applied first to the nostrils and then to the mouth to generate
sinusoidal oscillations that are superimposed on normal breathing. The
difference between the two impedance measurements provides data for
resistance calculations

RHINITIS INVESTIGATION
Skin-prick test - most sensitive allergy test;
total serum IgE - poor sensitivity and specificity;
allergen-specific IgE tests- more accurate
X-rays - used primarily for detection of complications;
endoscopy.

TREATMENT
TONSILLECTOMY AND ADENOIDECTOMY
Over 75% of tonsil/adenoid operations are performed on children less than
15 years of age, and 60% on children under 6 years of age. The usual
age of children undergoing of this surgery is five years.
INDICATIONS FOR SURGERY
Tonsillectomy and adenoidectomy, either in combination or separately, are
most frequently performed to correct
• Recurrent or chronic throat infection
• Hypertrophy
• Recurrent attacks of otitis media or chronic otitis media with effusion.

TONSILLECTOMY INDICATIONS
Recurrent tonsillitis defined by a history of atleast 7 episodes in the preceding
year, or 5 episodes in each of the last 2 years, or 3 episodes in each of the last 3
years.
Chronic tonsillitis persisting for atleast 6 months despite intensive antibiotic
therapy.
ADENOIDECTOMY
Persistent obstruction – due to enlarged adenoids
Recurrent otitis medial with effusion
CONTRAINDICATIONS
Velopharyngeal incompetent patients
Patients with bleeding disorder

Early intervention to correct nasal obstruction may lead to reversal of the
associated craniofacial changes. Normalization of face form following
adenoidectomy in a child can take five years. Delay in intervention may result
in unsuccessful orthodontic treatment which may require orhthognathic surgery
at an older age. If chronic mouth breathing persists or recurs after
adenoidectomy, allergic rhinitis with turbinate hypertrophy should be ruled out.
If a submucous cleft palate is
identified, the surgery must be
weighed against possible
complications.

Linder-Aronson reported in children who had adenoidectomy &returned to
nasal breathing had demonstrated craniofacial growth changes. There was
a relatively greater increase in the upper incisor inclination during the first
year after adenoidectomy along with the normalization of the lower incisor
The arch width and nasopharynx showed an increase during the 1st year
postoperatively.The size of the ML/NL angle was found to decrease after a
change from mouth to nose breathing.
As opposed to these studies, Kingsley (1989) noted normal craniofacial
development in children with severe nasal obstruction and Whitaker
described severe palate malformations in patients who had undergone
adenoidectomy at an early age.

TURBINATE RESECTION
Hypertrophy of the erectile tissue of the turbinates due to rhinitis or other
causes can be treated by turbinate resection, electrocautery, or
cryosurgery .Recently, the introduction of lasers and radiofrequency
ablation are used .

SEPTOPLASTY
Although controversy still exist over whether nasal deformities in children
can be safely corrected without disrupting the normal nasal growth pattern,
this concern is being overcome by the increased recognition that prolonged
nasal obstruction can result in significant abnormalities in the growing child.
A sublabial approach to septoplasty in children has provided excellent
exposure and involves in removing minimal septal cartilage so as to avoid
the collapse of the nose. A reasonable approach is to favor early repair in
the severely affected child in whom complications are present (obstructive
apnea) or in patients in whom the facial growth is over.

CONGENITAL MALFORMATIONS
Congenital malformations such as choanal stenosis and rarely unilateral
atresia may be missed early in life. Bilateral choanal atresia is usually
identified in the neonatal period. Radiologic evaluation of the nose and
nasopharynx by CT scanning is helpful in establishing the diagnosis as well
as the extent of disease. Choanal stenosis or atresia would be repaired by
transpalatal approach with prolonged stenting.

RHINITIS
Allergy treatment is based upon three general modalities:
environmental control or avoidance of offending substances
Medications such as steroids and antihistamines
immunotherapy (allergy shots).
Probably the most important thing a concerned dentist can do to help prevent
allergy is to counsel and educate mothers on the importance of breast-feeding. If
mothers must bottle-feed, the dental profession can begin the education process
by recommending use of soy formulas which are not as allergenic.
According to a six-year study be Glaser, bottle fed children have four times as
many respiratory conditions as breast fed children.

ORTHODONTIC TREATMENT
Orthodontic treatment is directed towards the prevention and correction of the
malocclusion or to an adaptation of the dentition to the existing skeletal
pattern or its predicted future growth which are obtained through the use of
extractions,headgear therapy and classII elastics.

Oral myofunctional therapy has been shown to be effective in correcting oral
myofunctional disorders such as tongue thrust swallow, improper tongue and
mouth resting posture, improper use of muscles of the mouth, tongue, and lips
for chewing and swallowing, and late thumb/finger sucking habits.
PREVENTION – MYOFUNCTIONAL APPLIANCES

Oral myofunctional therapy has two main goals:
establishing an oral/facial resting posture with the tongue away from the teeth,
against the palate, and lips together
establishing oral, lingual, and facial muscle patterns which promote correct
function of these structures during drinking, and chewing, collecting and
swallowing of food.
These goals are accomplished by a series of exercises which focus first on
retraining the oral, lingual and facial muscles so that the correct rest postures
may be achieved; and then utilizing these new muscle patterns for habituating
the correct labial/lingual rest postures and correct chewing and swallowing.

Children as young as four years of age may benefit.Habits such as mouth
breathing, reverse swallowing and thumb sucking are corrected along with the
alignment of the developing teeth. This will help future orthodontic treatment by
making it less complex and decreasing the need for extractions.

RAPID MAXILLARY EXPANSION
Brown, a rhinologist, was a vigorous supporter of midpalatal suture opening for
the purpose of overcoming nasal stenosis. Widening the upper jaw enlarges the
nasal airway and at the same time corrects lower jaw development gives the
tongue more space and enhances the flow of air in the throat.
Maxillary deficiency or constriction of the maxillary dental arch, concomitant with
a high palatal vault, is a manifestation of a skeletal development syndrome. This
syndrome evidences certain rhinologic as well as dental characteristics. Some of
the more typical features of this syndrome are (1) decrease in nasal permeability
resulting from nasal stenosis, (2) elevation of the nasal floor, (3) mouth
breathing, (4) bilateral dental maxillary cross-bite along with a high palatal vault,
and (5) because of enlargement of the nasal turbinates, a decrease in nasal
airway size.

Rapid maxillary expansion (RME) broadens the maxillary arch which also
serves to widen the nasal vault and improve nasal patency. The treatment is
nonoperative and can be accomplished in about 3 weeks in patients 3 to 20
years of age. RMA alone is seldom sufficient to improve severe cases of nasal
obstruction..
Donald Timms, in a study of 26 patients treated with Rapid Maxillary
Expansion, reported a 37 percent mean drop in nasal resistance with 7 mm of
expansion. In another larger study of children with a previous history respiratory
disease treated with Rapid Maxillary Expansion, 82 percent reported
improvement in number of upper respiratory tract infections and 60 percent
reported improvement of allergic rhinitis.

RME and nasal airflow.
Anatomically, there is an increase in the width of the nasal cavity immediately
following expansion, particularly at the floor of the nose adjacent to the
midpalatal suture. As the maxillae separate, the outer walls of the nasal cavity
move laterally. The total effect is an increase in the intranasal capacity. The
nasal cavity width gain averages 1.9 mm, but can widen as much as 8 to 10 mm
at the level of the inferior turbinates, while the more superior areas might move
medially. AJO 1987 Bishara and Staley.
A number of rhinologists, including Gray, Braun, and Kressner, indicate
that RME, in addition to its widening procedure, results in correction of septal
deformity as a result of the lowering of the floor of the nasal cavity

Hershey, Stewart, and Warren, and Turbyfill reported a reduction of nasal
airway resistance by an average of 45% to 53% with RME. Wertz
concluded that opening the midpalatal suture for the purpose of increasing
nasal permeability cannot be justified unless the obstruction is shown to be
in the lower anterior portion of the nasal cavity and accompanied by a
relative maxillary arch width deficiency.
Graber believes that the claims of improved nasal breathing apparently as
a result of RME are most likely only temporary. Spontaneous regression of
lymphoid tissues during growth automatically improves nasal breathing,
even if nothing is done to the palate.
Therefore, it can be concluded that the effect of RME on the nasal airway
will to a great extent depend on the cause, location, and the severity of the
nasal obstruction

Mean cross-sectional nasal cavity enlargements
of between 1.4 mm and 4 mm for rapid
expansion, 0.8 mm for a quad helix, and 0.5
mm for a removable appliance have been
reported.
Rapid expansion exerts its effect by
dilating the anterior nares, through the
preferential expansion of the anteroinferior
aspect of the nasal cavity. If, for example, the
obstruction is posterior, rapid expansion will
have little effect. Therefore expansion remains
an unpredictable way of improving the nasal
airway.
Rhinometric studies after RME indicate that
there is no increase in percentage of nasal
breathing, nor is there a predictable decrease in
nasal resistance

ORTHOGNATHIC SURGERY
If the difference between the maxillary and the mandibular unit length is greater
than 16mm at the age of 12 in classII malocclusion and greater than 29mm at
the age of 12 in class III dysplasias,surgical intervention is necessary.
Surgical superior impaction of the maxilla has become an accepted treatment
for the correction of vertical maxillary excess and it does reduce nasal
resistance, but it does not increase the percentage of nasal airflow. The nearer
the patient is to completion of growth, the less likely it is that the long-term
outcome will be affected by continuing growth.
A mean decrease in nasal resistance has been demonstrated after surgical
maxillary impaction. It has been speculated that this change may be associated
with the common postoperative increase in interalar width and widening of the
external nares, which result in an opening of the liminal valve.

Even indirect evidence of forward movement of the base of the tongue, as a
consequence of mandibular advancement with either protrusive appliances or
orthognathic surgery,can still be inconclusive as the hyoid bone seems to move
anteriorly with surgical advancement, but it subsequently moves back toward
its preoperative position, yet remarkably its relationship with the cervical spine
remains constant. The reason for this seems to involve an alteration of head
posture, and cervical column angulation, which probably occurs as a
physiologic adaptation to maintain the airway.Similarly, even though the tongue
elongates anteriorly, and thickens posteriorly subsequent to surgical mandibular
advancement, in the long term it also returns towards its preoperative shape.
Therefore, in summary, the evidence of nasal airway improvement, after either
maxillary expansion or mandibular advancement as reviewed, still remains too
incomplete to offer substantiation. AJO 1994 Jul Chate

ROLE OF ORTHODONTIST
In 1987, Weimert published a study of 1360 patients referred to
otolaryngologists by orthodontists because of suspicion of nasal obstruction.
Although it was not a solid scientific study, the findings suggest that
orthodontists can effectively screen for nasal obstruction. The most common
reasons for referral were: dentofacial characteristics suggestive of upper
airway obstruction, inability to retain a dental appliance, and unsatisfactory
results from an orthodontic program.
Dentists are important as both referrers and treating doctors. As
referrers, one has to know when and whom to refer. Allergies generally must
be treated first, before consideration of any surgery. The greatest number of
surgical failures are in allergic patients. The greatest number of orthodontic
relapses are in patients who have not had their breathing problems
successfully treated..

Orthodontic therapy is affected by the function of the lips, tongue, and
masticatory musculature, all of which may accommodate to nasal
obstruction in ways which can effect occlusion. Effective orthodontic
therapy may require the elimination of the nasal obstruction to allow for
normalization of the facial musculature surrounding the dentition.
According to Meredith, the growth of the face (excluding the mandible)
is completed at a relatively early age. 60% of craniofacial development
takes place during the first 4 years of life and 90% by age 12.
Development of the mandible is not complete until around age 18. Based
on these observations, any intervention to open the airway must take
place at an early age.
As a referring doctor, one has to decide between allergist, ENT, pediatrician
or sleep lab. Referrals should always be for an evaluation by the specialist of
choice, accompanied by a note of one’s findings.

Bushey`74 has differentiated the different facial types and adenoid/tonsil
enlargement and proposed different treatment modalities.

CONCLUSION
Evaluation of children with nasal obstruction and dental abnormalities
requires a multidisciplinary approach and a clear cooperation between the
orthodontists ,pediatricians, and otolaryngologists is imperative. The
orthodontists must be familiar with the dental literature regarding dentofacial
development and basic concepts of orthodontic intervention so as to provide
optimal care for pediatric patients as they have an opportunity to examine
and institute treatment to the patients at a very early age.

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