Airway assessment

1. NASORESPIRATORY
CONSIDERATIONS IN ORTHODONTICS

2. INDEX
◊ HISTORY
◊ ANATOMY
◊ RESPIRATORY MECHANICS
◊ NASAL AIRWAY MECHANICS
◊ EVOLUTION OF THE AIRWAY
◊ PATHOLOGIES CAUSING CONSTRICTION
◊ NASORESPIRATORY FUNCTION AND CRANIOFACIAL GROWTH
◊ HEAD POSTURE AND CRANIOFACIAL MORPHOLOGY
◊ ADENOIDS
◊ RHINITIS
◊ OBSTRUCTIVE SLEEP APNOEA
◊ DIAGNOSIS
◊ TREATMENT

3. HISTORY
• Angle, 1907, Cl II DI malocclusion is always accompanied and at least 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

4. ANATOMY
• The air way consist of
• The nose.
• The pharynx.
• the nasopharynx.
• The oropharynx.
• the laryngopharynx.
• The larynx.
• The trachea.
• The bronchi and the bronchioles.

5. EXTERNAL NOSE
• The external nose has a skeletal framework that is partly bony
and partly cartilaginous. The bones are the nasal bones, which
form the bridge of the nose, and the frontal processes of the
maxillae. The cartilages are the superior and inferior nasal
cartilages, the septal cartilage, and some small cartilages.

6. NASAL CAVITY
It extends from the external nares (nostrils) to the posterior nasal
apertures, and is subdivided into right and left halves by the nasal
septum. Each half has a roof, a floor, and medial and lateral walls.
Each half measures about 5 cm in height, 5 to 7 cm in length, and 1.5
cm in width near the floor. The width near the roof is only I to 2 mm.
The roof is about 7 cm long and 2 mm wide. is formed by the nasal
part of the frontal bone,nasal bone, and the nasal cartilages.

7. NASAL SEPTUM
It is median osteocartilaginous partition between the two
halves of the nasal cavity. On each side it is covered by
mucous membrane and forms the medial wall of both nasal
cavities

8. PHARYNX
• The pharynx is a wide muscular tube, situated behind the nose, the mouth and
the larynx.. The upper part of the pharynx transmits only air, the lower part
(below the inlet of the larnyx), only food, but the middle part is a common
passage for both air and food, (but only one at a time).
NASOPHARYNX
• This is the upper part of the pharynx situated behind the nose, and above the
lower border of the soft palate. It resembles the nose structurally as well as
functionally.
OROPHARYNX
• This is the middle part of the pharynx situated behind the oral cavity. Above, it
communicates with the nasopharynx through the pharyngeal isthmus. In front, it
communicates with the oral cavity through the oropharyngeal isthmus . Below, it
opens into the laryngopharynx at the level of the upper border of the epiglottis.
Behind, it is supported by the body of the axis vertebra and the upper part of the
body of the third cervical vertebra. Its lateral wall presents the tonsil which lies
in the tonsillar fossa.

10. RESPIRATORY MECHANICS
The lungs fill the thoracic cavity, and its outer surface (visceral pleura) is in
intimate contact with the inner surface of the thoracic cavity . The 2
pleural layers are in apposition, separated only by a thin film of fluid
which enables the lungs to slide freely within the cavity. Whenever the
chest cage enlarges the lungs also enlarge.
At the end of expiration, when the respiratory muscles are relaxed,
pressure within the lungs is atmospheric and there is no airflow. This is
the resting position. Both the lungs and the chest wall contains
considerable elastic tissue, and at resting position these pull with equal
forces but in opposite directions, creating a balance of elastic forces.
When contraction of the diaphragm and intercostal muscles occurs during
inspiration, the volume of the thoracic cage enlarges and the elastic
forces of the two units change. 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.

11. 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.

12. Nasal Airway Mechanics
The nose is now recognized as being the major site of inspiratory
airflow resistance to normal breathing in humans. The funnel-
shaped nasal vestibule leads from the external nostril to the
nasal valve region which constitutes the major airflow
resistance segment of the respiratory airways. The cross-
sectional area of only approximately 30 mm2 is the smallest
cross-section of the whole respiratory tract.
Control of nasal airflow within the valve region is complex, and
is influenced by the rigidity of the aperture, the actions of
dilator muscles, as well as the degree of mucosal congestion
within the nasal passages. Consequently, the human nose
counts for about 40-60% of the total respiratory resistance in
normal subjects at rest. .

13. A typical feature of nasal airflow resistance is that the resistance of
the two separate nasal cavities often differs markedly. There is a
spontaneous reciprocating cycle of nasal congestion and
decongestion that is well recognized and has been called the nasal
cycle. During exercise, there is a decrease in nasal resistance at any
given flow due to vasoconstriction of the nasal mucosa. The supine
posture is associated with a slight increased in nasal resistance
compared with the upright posture. In addition, during sleep there is
an additional small rise in nasal resistance values.

14. The alae nasi muscles are important for stabilizing the nasal
valve and vestibule region, and act to prevent inspiratory
collapse of the valve region, particularly during exercise and
hyperventilation. Although nasal resistance values tend to
be increased in obstructive sleep apnoea (OSA) patients,
the role of nasal resistance in the genesis, maintenance or
severity of OSA remains unclear. Nevertheless, diseases
leading to nasal obstruction may cause larger pharyngeal
collapsing pressures during inspiration, thus promoting
pharyngeal collapse and obstruction in OSA patients.

15. EVOLUTION OF THE AIRWAY
The human pharynx is unique in the animal kingdom.
Postmortem dissections on many types of mammals reveal
that the epiglottis extends up behind the soft palate to
directly join the larynx to the nasopharynx This provides a
firm, uninterrupted air channel from the external nares,
through the nasal cavities and nasopharynx, past the
larynx, and down to the trachea and lungs. As such, no
pharyngeal muscles were designed specifically to maintain
upper-airway patency, since none were necessary. In
addition, the tongue is located anteriorly, entirely within
the oral cavity and separate from the pharynx, so it cannot
impact the pharyngeal space at any time. This allows the
animal to eat and breathe at the same time, preserving the
sense of smell so necessary for survival.

16. EVOLUTION OF THE AIRWAY

17. Over time, however, human evolution has given rise to the
separation of the epiglottis and the soft palate to create an upper
airway that is longer and more flexible. This separation allows the
tongue to reside partially within the pharynx to create a soft-
walled oropharynx unique to modern humans, which provides a
resonating chamber for refined vocalizations. Unfortunately, it
also provides the opportunity for sleep-induced collapse of the
upper airway. To complicate matters, continuing evolution of our
species resulted in an erect posture that brought the facial
skeleton to lie below the frontal region of the braincase, rather
than in front of it as in most quadruped animals. This facial
migration, known as klinorynchy, constricts the available
subcranial space to the extent that a change in pharyngeal and
laryngeal morphology is necessitated.

18. It is interesting to note at this
point that the pharyngeal
anatomy of the human
newborn and very young
infants closely approximates
the anatomy of the upper
airway of non-human
mammals.Specifically, the
epiglottis and soft palate
overlap and the tongue is
completely anterior to the
airway. No oropharynx, per se,
is present. This allows for the
simultaneous suckling of milk
and breathing. By
approximately 18 months of
age, however, the laryngeal
complex has migrated
caudally, giving rise to the
oropharynx, the ability to
vocalize, and the concomitant
predisposition to sleep-induced
upper-airway collapse.

19. 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, Temporomandibular
joint ankylosis.
Larynx
• Tracheal atresia,Intrinsic tracheal lesions,Extrinsic compression
(goiter),Laryngeal and tracheal webs,Kimura disease (Okami, 2003)

20. NASORESPIRATORY FUNCTION AND CRANIOFACIAL GROWTH
It is assumed that nasorespiratory function can exert a dramatic effect upon
the development of the dentofacial complex. Specifically, it has been stated
that chronic nasal obstruction leads to mouth breathing, which causes
altered tongue and mandibular positions. If this occurs during a period of
active growth, the outcome is development of the "adenoid facies" .
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.

21. 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.

22. 3 theories have been proposed regarding the effects of mouth
breathing on the facial form & dentition.
A) Compression according to Norlund (1918) constriction of the
maxillary arch is related to the absence of lateral pressure of the
tongue against the palate. This occurs in response to nasal
obstruction wherein the patient tries to breath through the mouth
instead of the nose. Therefore the tongue drops down leading to
increase in the buccal musculature force thereby causing
constriction of the arch. This 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.
B) 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).
C) Air pressure theory :- this theory proposed by Kantorowicz (1916) &
James & Hastings (1932) states that when the breathing of a
person changes from nasal to mouth, it causes the normal negative
pressure in the anteriorly sealed oral cavity to be lost & thereby the
palate does not descend down with the growth of the maxilla.

23. • Linder Aronson did a 5 yr follow up study of
children undergone adenoidectomies to clear
obstructed nasal passages.
• Purpose of the study was to evaluate the changes
seen in U/L incisal inclination , Upper arch width,
Sagittal depth of nasopharynx., Anterior facial
height.and Inclination of the maxilla to mandible
after the shift from oral to nasal breathing .Results
showed that the values became normal after five
years with most of the changes occurring in the
first year after surgery.

24. • Harvold and associates have shown that obstruction of
the nares in monkeys is followed by the recruitment of
muscles to lower the mandible and spread the lips to
establish an oral airway.All experimental animals with
their nares blocked kept their mouth open continuesly.in
most animals the upper lip gradually developed a notch in
the middle.Tounge became more narrow and
pointed.Cephalometric finding showed increased gonial
angle
• The experimens demonstrated that the recruitment of the
orofacial muscles for respirationhad significant effect on
muscle development.This in turn,changed the morphology
of the upper lip,the tongue and the oro pharyngeal port

25. • Robert M. Rubin ( AJO 1980 ) conducted studies on
mode of respiration and facial growth, and stated that
spatial relationship of mandible to craniomaxillary
complex is influenced by function of muscular elevators
of mandible. One factor acting on the elevators of the
mandible is the rest position of the mandible, which may
be influenced by the patient’s mode of respiration.
Obstruction of the nasal airway is followed by the
lowering of the mandible to establish an airway.
• Peter S Vig ( AJO 1981 ) studied the relationship
between facial morphology and nasal respiration.
Concluded that 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 prelude the
diagnosis of nasal obstruction from an
assessment of facial morphology

26. • Behlfelt et al (EJO 1989) studied the dentition in children
with enlarged tonsils compared to control group and
concluded that children with enlarged tonsils have more
retroclined lower incisors, more anteriorly positioned
upper incisors, small overbite. Large overjet shorter
lower dental arches, narrower upper arches and an
increased frequency of lateral cross bite, obstruction of
oropharynx by enlarged tonsils is responsible for
functional and/or morphological disorders causing an
open posture of the mouth, a lowered anterior posture of
the tongue and a low position of the hyoid bone are
thought to be associated with the differences in the
dentition between the two groups.
• Tu lin Arun, et al ( AO 2003 ) studied on vertical growth
changes after adenoidectomy and concluded that when
compared with the control group, the adenoidectomy
group showed a more vertically directed growth pattern.

27. • Tetsuro Yamada, D (AJO 1997) studied on influences of
nasal respiratory obstruction on craniofacial growth in
young macaca fuscata monkeys,this study was conducted
to investigate the influences of artificial nasal respiratory
obstruction on craniofacial growth
• . Nasopharyngeal respiratory obstruction was associated
with downward and backward rotation of the mandible,
upward and backward growth of the condyle, divergent
gonial angle ,anterior open bite, and spaced dental arch in
the lower anterior region.
• Solow, Siersbaek-Nielsen, and Greve ( AJO 1984) studied
associations between airway adequacy, head posture,
and craniofacial morphology, and found that obstructed
nasopharyngeal airways were, on the average, seen in
connection with a large craniocervical angle and with
small mandibular dimensions, mandibular retrognathism,
a large mandibular inclination and retroclination of the
upper incisors.

28. • Pushker ( AJO 2001) had done study on
pharyngeal airway space changes after
counterclockwise rotation of the
maxillomandibular complex to evaluate the
effects of double-jaw surgery with
counterclockwise rotation of the
maxillomandibular complex on the pharyngeal
airway space and velopharyngeal anatomy in
patients with high occlusal plane facial
morphology and concluded that the
counterclockwise rotation of the
maxillomandibular complex may cause a
significantly greater reduction in the PAS than is
observed with non counterclockwise movements
when mandibular setback is performed.

29. Shiva Shanker et al (Semi. Orthod. March 2004) performed
a longitudinal study for a period of 4 years in growing
children to determine the upper respiratory parameters &
dentofacial morphology & their interrelationships.
Modified simultaneous nasal & oral Respirometric technique
(SNORT) & post rhinomanometry were performed for the
children.
The dentofacial variables measured were,
a) Lower face height % = LFH / TFH
b) Facial Index = Facial height / Facial width
c) Overbite
d) Palatal arch width
They concluded in their study that – children switch
between oral & nasal respiratory mode & Respiratory
mode had no relationship to Ethnicity, Gender /
dentofacial morphology.

30. Ricketts in 1979 stated that when there is a lack of
function in the nose, there can be a growth
inhibition.
Another group of researchers 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.

31. In a subjective evaluation of 1,033 children, Humphrey and
Leighton reported an approximately equal distribution of
malocclusions in nose and mouth breathers. They noted
that, of those children who kept their mouths open while
breathing, almost half respired nasally.
Gwynne-Evans and Ballard also subjectively evaluated the
relationship between facial morphology and breathing
conditions over a period of 15 years. They reported that
orofacial 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 result in the development
of the adenoidal facies."

32. Leech examined the relationship between lip competence and
mode of breathing in subjects undergoing evaluation in a
research clinic for upper respiratory disease and found that
fewer than one third of the lip-incompetent persons were
mouth breathers. Thus, many theories have been proposed
and much confusion remains regarding the relationship
between nasorespiratory function and dentofacial
morphology.

33. HEAD POSTURE AND CRANIOFACIAL MORPHOLOGY
A recent trend for research has been to focus on the possible role of
extrinsic factors that are able to affect cranial posture in a manner that
could be associated with aspects of specific malocclusions In this
regard, extension and flexion of the head away from the natural head
position has been observed to be associated with certain morphologic
patterns Accordingly, adults who display habitually extended cranial
positions also exhiibit, among other specific facial features, greater
lower facial heights, obtuse gonial angles, and a relative manndibular
retrognathism.
A functional relationship appears to exist between the temporomandibular
and craniocervical regions, and head movements apparently are an
integral part of natural jaw opening and closing. Functional jaw
movements comprise concomitant mandibular and head-neck
movements, which involve the temporomandibular, the atlantooccipital,
and the cervical spine joints, caused by jointly activating the jaw and
neck muscles

34. Although the posture of the head may be related primarily to efforts
expended in resisting the force of gravity, nevertheless the physiologic
requirements associated with respiration, deglutition, sight, balance,
and hearing also must affect cranial deportment.
Thurow demonstrated how the hyoid bone is pulled forward by passive
stretch of the suprahyoid muscles when the head is extended. In this
respect the midline raphe of the musculus mylohyoideus consists
largely of fibrous tissue with little scope for stretching Such cranial
extension is seen commonly in mouth breathers, and this postural
change could represent an important component for nasal airway
inadequacy.
In this study, the induced bite opening caused a downward displacement
of the mandible, thereby releasing the tension on the suprahyoid
muscles. One postulation is that the hyoid bone, when deprived of the
upward and anterior pull of the suprahyoid muscles, would move
posteriorly and reduce the pharyngeal airvvay. The head would extend
in a compensatory movement to pull the hyoid bone forward via the
resultant increase in tension of the mylohyoid raphe.

35. The relationship between head posture and craniofacial morphology was
emphasized by Schwarz , who found that extension of the head in
relation to the body, particularly during sleep, led to distal
displacement of the mandible and the development of Class II
malocclusion Bjork ('55, '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 headin a lower position.
Bench ('63) in a radiographic study of the growth of the cervical
vertebrae noted a tendency for the neck to be curved in subjects with
square faces, and straight with a long cervical column in subjects with
long faces.

36. A systematic analysis of the correlations between craniofacial morphology
and the positional relationship of the head to the true vertical and to the
cervical column was carried out by Solow and Tallgren ('76). They
found that of the postural variables, the craniocervical angulation
showed the most comprehensive correlation with craniofacial
morphology, i.e., the position of the head in relation to the cervical
column seemed to be more closely related to craniofacial form than the
position of the head to the true vertical.
The correlations indicated that, on the average, extension of the head
relative to the cervical column was seen in connection with large
anterior and small posterior facial heights, small anteroposterior
craniofacial dimensions, large inclination of the mandible relative to the
anterior cranial base and to the palatal plane, facial retrognathism, a
large cranial base angle, and a small nasopharyngeal space.

37. The findings regarding the relationship between craniocervical
angulation and craniofacial morphology were confirmed by
Thompson Posnick ('78). Solow and Tallgren ('76) further
observed that differences in craniofacial morphology
between subjects with large and small craniocervical
angulations were remarkably similar to those between
subjects with large and small mandibular plane inclinations.
A direct comparison showed that the average craniofacial
morphology of a group of subjects who had a large
craniocervical angulation resembled that of a group of
subjects who had a large mandibular plane inclination .
Similarly, the craniofacial morphology of a group of subjects
characterized by a small craniocervical angulation was very
like that seen in a group of subjects characterized by a
small 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. A similar relationship between facial type
and craniocervical angulation was reported by Opdebeek
and co-workers ('78).

38. Hypothesis of soft tissue stretching(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 theface 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.

39. PROPOSED SEQUENCE OF EVENTS
Based on numerous studies over the past century, a plausible
sequence of events can be pieced together as described
by Principato . Long standing nasal obstruction appears to
affect craniofacial morphology during periods of rapid facial
growth in genetically susceptible children with narrow facial
pattern. A change from nasal to oral respiration likely
occurs when nasal resistance reaches two to three times
normal. Since nasal resistance increases in the supine
position, borderline airways may convert to oral respiration
at night. During oral respiration, the mandible rotates to a
more open position and the tongue assumes a lower
position in the mouth and is no longer in contact with the
palate. Prolonged periods of oral respiration lead to
extensive eruption of the posterior molars, in response to a
lack of surface contact.

40. These overerupted teeth exert 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. Tongue posture changes with
chronic oral respiration can also affect the teeth. 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
lead to a narrow, high arched palate in susceptible
children. The incomplete lateral expansion of the maxilla
often leads to a unilateral or posterior crossbite.
•

41. ADENOIDS
Adenoids are on the posterior nasopharyngeal wall posterior to the
nasal cavity . They develop from a subepithelial infiltration of
lymphocytes in the 16th week of gestation. They are a component of
the Waldeyer ring of lymphoid tissue, which is a ring of lymphoid
tissue in the oropharynx and nasopharynx that consists mainly of
the adenoids, the palatine tonsils, and the lingual tonsils.
Adenoids are present at birth and then begin to enlarge. They, along
with the tonsils, continue to grow until individuals are aged 5-7
years. The adenoids usually become symptomatic, with snoring,
nasal airway obstruction, and obstructed breathing during sleep,
when children are aged approximately 18-24 months. By the time
children reach school age, the adenoids normally begin to shrink,
and, by the time children reach preteen or teenage years, the
adenoids are usually small enough for the child to become
asymptomatic.

43. 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.
Enlarged adenoids can cause nasal airway obstruction, with clinical
symptoms of nasal congestion, snoring, and breathing through the
mouth, by physically blocking the back of the nose. Symptoms of nasal
airway obstruction may overlap with chronic sinusitis symptoms, and
the physical obstruction may add to sinusitis itself by blocking normal
nasal flow posteriorly, resulting in a stasis of secretions and an
obstruction in the sinus outflow tract.
Often, enlarged adenoids (with the tonsils) can obstruct breathing patterns
in children and can cause obstructive breathing, including apneas, at
night. Obstruction is based on their size alone. However, when
enlarged, the adenoids may have a chronic infection

44. Rhinitis
Introduction
Rhinitis means inflammation of the lining of the nose. The
mucous membrane that lines the nose becomes inflamed,
causing swelling and blocking the airflow. Rhinitis also
causes over activity of the glands in the mucous
membrane, causing excessive mucus production and a
watery discharge.
Rhinitis is a symptom of the common cold and of hay fever
(allergic rhinitis). Hay fever is an allergy to grass, weed and
tree pollens, moulds, hair, feathers, skin scales (dander),
house mites, house dust or other airborne substances. It
causes sneezing, stuffiness and a watery discharge from
the nose.

45. There are several varieties of rhinitus:
Vasomotor rhinitis happens when the nerves that control the
blood vessels supplying the mucous membrane are
disturbed. The membrane becomes over-sensitive to
hormonal, climate or psychological changes, and causes
sneezing and a watery discharge. Vasomotor rhinitis is an
intermittent condition, meaning that it can come and go.
Hypertrophic rhinitis happens when there has been repeated
or long-term inflammation of the mucous membrane. The
lining of the nose thickens, causing a feeling of stuffiness
that dosent go away.
Atrophic rhinitis happens when the mucous membrane
shrinks, usually as a result of sarcoidosis, tuberculosis or
nose surgery (rhinoplasty). The symptoms are dryness,
crusting and loss of the sense of smell.

46. Symptoms
The most common symptoms are:
• sneezing,
• blocked or stuffy nose,
• runny nose (rhinorrhoea), and
• itchy nose, throat and eyes.
• Often, a person with rhinitis my also have hay fever,
asthma or eczema. Asthma and eczema may start or
become much worse in the summer or when the pollen
count is high.
Causes
• Rhinitis due to the common cold is caused by cold viruses
and secondary infection with bacteria.

47. OBSTRUCTIVE SLEEP APNOEA
• OSA is a common sleep disorder charecterised by repetitive partial or
complete ceaastion of air flow , associated with oxyhemoglobin
desaturation and increased effort to breath.
• Middle age obese men are at particular risk but its also seen in women
and young children.
• The human pharynx is unique in the animal kingdom in that it is
predisposed to collapse during sleep. In each and every one of us, the
upper airway tends to diminish in size and shape to some degree from
the relaxing influence of our nocturnal slumber. Most of us, fortunately,
manage to breathe silently and effectively despite this ominous
challenge to our well-being. This is not so for millions of others,
however. Sleep-disordered breathing (snoring and obstructive sleep
apnea) affects tens of millions of people worldwide.

48. On the most basic of levels, the human organism has but three
critical needs for survival: eating, sleeping, and breathing.
For those who suffering from sleep-disordered breathing
(SDB), two out of three of these requirements are in
jeopardy every time their head hits the pillow. As sleeping
and breathing are compromised night after night for years
on end, the most recent research demonstrates that they
are at greater risk for hypertension, heart attack, stroke,
depression, and diabetes.
it has been shown that patients with OSA are involved in
traffic accidents two to three times more often than the
general population and are at increased risk for injury in the
workplace.

49. The human pharynx is intimately involved with swallowing, breathing, and
speaking; hence, it is called upon to be alternately stiff or flexible
depending on the task at hand. The tendency, during sleep, for the
upper airway to partially collapse (as in the case of snoring) or to
completely obstruct (as with OSA) is multifactorial. Upper-airway
patency is a delicate balancing act pitting pharyngeal anatomy and
baseline muscle tone against the negative pressures created upon
inhalation. During waking hours, patency is easily maintained.
However, with the relaxing influence of sleep and the gravitational effects
of the supine position, maintaining a clear airway becomes a titanic
struggle for many people. Multiple stresses arise from intermittent
airway occlusion, which include repetitive oxygen desaturation, carbon
dioxide retention, and disrupted sleep from the arousals secondary to
these blood gas discrepancies. As such, there are strong associations
between OSA and the risk for cardiovascular disease and metabolic
dysfunction.

50. CLINICAL SYMPTOMS
during sleep
• Snoring.
• Abnormal motor activity during sleep.
• Nocturnal sleep disruption.
• Chocking during sleep.
• Esophageal reflex.
• Nocturia and nocturnal enuresis.
• Heavy sweaeing at night.
Daytime symptoms
• Excessive daytime sleepiness EDS.
• By product of EDS.
• Hypnagogic hallucinations.
• Changes in personality.
• Sexual problems.
• Headaches.
• Loss of hearing.

51. Treatment modalities for OSA and snoring at the present time 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 uvulopalatopharyngoplasty (UPPP) or laser-assisted uvulopalatoplasty
(LAUP), radiofrequency (RF) tissue ablation, nasal surgery, genioglossus
tongue advancement, and mandibular advancement surgery. .Oral appliance
treatment includes, in order of decreasing usage, adjustable and nonadjustable
mandibular posturing devices, anterior tongue repositioners, and soft palate or
uvulalifting devices. An appliance that advances the tongue, or tongue and
mandible together with adjacent soft tissue, increases the posterior airway
space, increases the activity of the genioglossal and lateral pterygoid muscles
and effects a stretch induction of the pharyngeal motor system.
Mandibular advancement devices also alter position of the hyoid and modify the
hypopharyngeal airway space. Soft palate or uvula lifters reduce soft tissue
vibrations that result in snoring. With respect to the many variations of appliance
designs, it is not possible to predict what device will be most effective for a
particular patient. In 1934, Pierre Robin first described the concept of advancing
the mandible with a monoblock functional appliance to treat airway obstruction
in infants with micrognathia. 1985 that Meier-Ewert and coworkersl described an
intraoral protraction device for the treatment of sleep apnea.

53. CPAP therapy is based on counteracting the negative airway
pressure during inspiration, and hypoglossal nerve
stimulation was suggested to enhance pharyngeal dilator
muscle contraction. Other procedures such as
uvulopalatopharyngoplasty (UPPP), and mandibular
advancement (either surgical or with a mandibular
advancement oral appliance) are based on the principle of
pharyngeal enlargement to reduce the degree.of negative
intrapharyngeal pressure during inspiration. The translation
of these basic concepts into realized therapeutic benefits
does not occur consistently, especially in the arena of
surgical management.

54. Orthodontic Diagnosis (JCO 2005)
Although the physician is the health professional responsible for the
diagnosis of nasopharyngeal obstruction, the orthodontist can
contribute through the use of lateral cephalograms and panoramic x-
rays. Regular contact with the patient also allows constant evaluation
of the patient's treatment needs and facial growth.
The cephalogram can reveal many obstructive processes in the
nasopharynx, including hypertrophy of the nasal or inferior turbinates,
maxillary sinus radiopacity or cystic lesions, hypertrophy of the
adenoids or tonsils, and the status of the nasopharyngeal airway
orthodontist can associate the information obtained from the
cephalogram with a good clinical questionnaire. And clinically can
evaluate the color, volume, and texture of the mucosa in the front of
the nasal cavity, he or she can suggest an initial diagnosis of allergic
rhinitis or chronic hypertrophic rhinitis with associated hypertrophy of
the nasal turbinates. The diagnosis can then be confirmed or overruled
by the otorhinolaryngologist.

55. Special attention must be paid to the caudal portion of the
inferior turbinate, because hypertrophy of this turbinate can
obstruct the posterior nasal cavity and impede normal nasal
breathing. The lateral cephalogram can also be useful in an
analysis of the paranasal sinuses, especially the maxillary
sinuses. Sinusitis is suggested when radiopacity is
observed. A valid diagnostic agreement between
endoscopic and radiographic findings has been found in
observing the severity of adenoid hypertrophy and, in
particular, the patency of the nasopharyngeal space. The
panoramic x-ray can indicate an initial diagnosis of, for
example, an anterior septal deviation This may be
corroborated in clinical examination simply by lifting the tip
of the nose with the fingers A more accurate evaluation
can then be made by the otorhinolaryngologist with anterior
rhinoscopy.

56. The panoramic x-ray can also reveal the severity of
hypertrophy of the inferior and middle nasal turbinates in
the frontal region . Such hypertrophy can be a consequence
of chronic hypertrophic rhinitis, medicational rhinitis, or a
compensatory hypertrophy, as with a deviated septum. The
otorhinolaryngologist can perform a nasopharyngeal video
endoscopy to validate the initial diagnosis suggested by the
orthodontist.

57. DIAGNOSIS
• Proper diagnosis of airway could be made with the help of,
• Thorough clinical examination,
• Investigations
– Radiographs,
– Fiberoptic Rhinoscopy,
– Rhinostereoscopy
– CT & MRI
– Polysomnography
• Clinical examination:
• 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.
• 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 should be inspected for the presence of secretions,
edema and erythema of the nasal mucosa .

58. • 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.

59. Radiographs:
• Panoromic radiographs – to depict the nasal septum & the nasal cavities.
• Lateral Cephalograms - to eavluate the airway.
• Analysis used are,
– Cephalometric Analysis by Brian preston et al (Semi orthod March 2004)
– Airway Analysis by McNamara.
• Cephalometric Analysis by Brian
• Anatomically the skeletal limits of Nasopharynx
• Anteriorly :- by the bony structures constituting the choanal openings which are the
dorsal borders or the choanal crest of the vomer.
• Superoposteriorly :- the pharyngeal surface of the body of the sphenoid bone & of
the basilar part of the occipital bone.
• Posteriorly :- the cranial half of the anterior surface of the anterior arch of the atlas.
• Caudally :- the nasopharynx is defined osteologically by a straight line that joins the
posterior nasal spine to the most anterior point AA on the anterior arch of the atlas.

60. 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.
Airway Analysis by McNamara:
• McNamara has divided the airway analysis into two, Upper & Lower
Airway analysis.
• Upper airway measurement:
• Upper pharyngeal width is measured form a point form the posterior
outline of the soft palate to a closest point on the pharyngeal wall. The
average width is 15-20 mm.
• If the width is 2mm or less than the normal, it may indicate airway
impairement

61. Lower airway measurement:
• Lower pharyngeal width is measured from the point of
intersection of posterior border of the tongue & the inferior
border of the mandible to the closest point on the posterior
pharyngeal wall.
• The average width is 11-14 mm independent of age. If the
width is greater than the average, it’s suggestive of a
possible anterior positioning of the tongue which may be
due to a Habitual posture / due to tonsillar enlargement.

62. Fiberoptic rhinoscopy
It is the insertion of a flexible telescope into the nasal cavity
which allows the detailed visualization of the posterior
two thirds of the nose which may not be visible with a
nasal speculum inserted into the anterior nares.
Disadvantages:
Structural / mucosal displacement of medial / lateral wall of
the nasal valve may not be detected by this method.

63. 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 (AJO 2001), evaluated the degree of diagnostic reproducibility
between lateral cephalometric radiography and nasopharyngeal
videoendoscopy. He 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.
Nasopharyngeal videoendoscopy is sufficiently reproducible for diagnosing
anterior and posterior septal deviation and hypertrophy of the inferior
and middle turbinates & most suitable for diagnosing diverse
obstructions of nasopharyngeal origin, but its ability to diagnose rhinitis
is limited.

64. ASSESSMENT OF NASAL AIR FLOW AND RESISTANCE
Measurements include,
Nasal Peak Flow:
less expensive, easy to perform. The flow measurements correlate well
with measurements of resistance & are useful for detecting large
changes in the nasal patency of each subject.
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.

65. Rhinomanometry
Rhinomanometry is well established as a useful clinical method for
objective assessment of nasal patency. Nasal resistance to airflow is
calculated from measurements of nasal airflow and transnasal pressure.
In 1983, standardisation of rhinomanometry was established and
accepted worldwide The nasal resistance is calculated from the
measurement of the nasal airflow at a fixed transnasal pressure point.
Three types of rhinomanometry can be used: active anterior
rhinomanometry (AAR), active posterior rhinomanometry (APR), and
passive anterior rhinomanometry (PAR).
AAR uses a face-mask and one nostril is sealed off with adhesive tape. A
hard plastic tube is passed through this tape to measure the
nasopharyngeal pressure. It is a dynamic test that studies nasal
ventilation, showing the nature of the air stream and a difference in the
shape of the inspiratory and expiratory limbs of the individual nasal
cavity. This method is well standardised and it is the most common and
accurate method for clinical use. The major disadvantage of this method
is that it cannot be performed in the presence of a septal perforation or a
complete unilateral nasal blockage.

66. B) Acoustic rhinometry
In contrast, acoustic rhinometry does not measure airflow parameters but
explores the geometry of the nasal cavity. The principle of acoustic
rhinometry is that an audible sound (150 - 10,000 Hz), propagated in a
tube, is reflected by local changes in acoustic impedance This method
provides estimates of cross-sectional endonasal areas and the endonasal
volume. It helps to define objectively the structural and mucosal
components of the nasal passage. Since its introduction, there has been
an explosion of research using this tool. Due to the rapid acquisition of
data that can be completed in a minute, it has become a valuable clinical
and research tool. Patient tolerance is excellent, even in children.
Advantages:
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.

67. CT
CT scanning produces excellent resolution of images to
evaluate both the soft tissue and the osseous structures of
the pharynx-larynx complex. It has the advantage of
producing axial and coronal cuts. .
The advantages of CT scanning are its wide availability and
the quickness with which newer scanners can perform
studies. Volumetric and 3-dimensional reconstructions of the
airway and other peripharyngeal structures are possible.
The study is performed in the supine position.
Disadvantages of the study are that radiation is involved,
limiting the number of studies that can be performed. CT
scanning is also relatively expensive.

68. Magnetic resonance imaging
MRI provides a detailed view of the fat and soft tissue of the pharyngeal
walls and its relation with the airway. Obtaining sagittal, coronal, and
axial images, as well as 3-dimensional reconstructions, is also possible.
Measurements of the different structures and their volume are possible.
It has the advantage of being radiation free, thus making performance of
several studies possible.
Although the noise and the cumbersome design of the machine makes
sleeping in it difficult, MRI has been used during sleep to study the
effects of continuous positive airway pressure (CPAP) therapy. In
addition, performing dynamic studies is possible because of faster
equipment.
MRI is beginning to have a role in the evaluation of patients before and
after surgeries such as uvulopalatopharyngoplasty, resection of tongue
base, or geniohyoid muscle surgery. MRI is an expensive study,
especially with the newer technologies, making its price the real limit to
the number of studies that can be performed.

69. TREATMENT
Suggested remedies include surgical removal of adenoids,
turbinectomy, and correction of septal deviation. More
conservative approaches include rapid maxillary expansion,
medications, and special dietary regimens.
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.

70. 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 at least 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 at least 6 months despite intensive
antibiotic therapy.

71. ADENOIDECTOMY
• Persistent obstruction – due to enlarged adenoids.
• Recurrent otitis medial with effusion.
• Contraindications: No absolute contraindications exist, except for
conditions in which general anesthesia cannot be performed.
• Relative contraindications for total adenoidectomy.
• A severe bleeding disorder, which could be overcome by preoperative,
intraoperative, and postoperative coagulation medicines and
techniques, is a relative contraindication to adenoidectomy.

72. • ROLE OF ADENOIDECTOMY AND
TONSILECTOMY
• Adenoidectomy with or without tonsillectomy is by
far the most common treatment for nasal
obstruction in children. 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. The
deleterious effects of nasal obstruction are
virtually complete by puberty so the window of
opportunity is relatively brief. Delay in intervention
may result in unsuccessful orthodontic treatment
which may require orhthagnathic surgery at an
older age

73. RHINITIS
There is no specific treatment for cold rhinitis, but it seldom lasts for longer
than about a week.
Allergic rhinitis is treated with antihistamine drugs or local steroid sprays.
Various drugs can be used to dry up excessive watery nasal secretions,
and decongestants can sometimes be helpful.
Atrophic rhinitis is very difficult to treat. Sometimes a syringe, antibiotics or
moistening sprays may be used to remove the crust blocking the
airways.
Antihistamine drugs, taken by mouth, are convenient and relieve eye
symptoms, running nose, sneezing and nasal irritation, but not nasal
congestion. All are equally effective, but different people may find
different methods more or less effective.

75. 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.

76. PREVENTION – MYOFUNCTIONAL APPLIANCES
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.
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.

77. 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.

78. • Murat Ozbek.( AO 1998) This study evaluated the use of
functional –orthopedic devices in increasing
oropharyngeal airway dimensions in children with class II
skeletal pattern and clinically deficient mandibles .
Comparisons were made between twenty six treated
patients and fifteen controls. Of the twenty six treated
cases, fourteen were treated using Harvold type activator
and twelve were treated with Harvold type activator in
conjunction with occipital high-pull head gear. Records
were taken after class I relationship had been obtained.
Compared with controls, oropharygeal airway dimensions
increase significantly in treated patients especially those
with sagittally smaller and more retrognathic
maxillomandibular complexes and smaller oropharyngeal
airway dimensions.

79. RAPID MAXILLARY EXPANSION
Rapid maxillary expansion (RME) has been recommended for the
correction of transverse maxillary deficiencies with the additional
benefits of increasing nasal airflow. The technique of RME was
originated by Angel in 1860. In 1886 Eysell, an otorhinolaryngologist,
proposed that the lateral expansion may relieve nasal obstruction.
Since this time, there has been a long-standing controversy over the
efficacy of RME in improving nasal respiration. During the course of
RME, the maxillary and palatine bones are disarticulated along the
mid-palatal suture and move laterally. These movements are rotatory
the axis being beneath the cranial base with the most anterior and
inferior partsmoving furthest. The expansion carries the lateral walls of
the nasal air passages outwards increasing the trans-alar width.

80. The nasal valve in the normal nose presents the
smallest nasal cross-sectional area and provides
the most significant airflow resistance during
breathing. The valve is in the region between the
upper and lower lateral cartilages and the pyriform
aperture, just beyond the anterior ends of the
inferior turbinates. Aerodynamic studies and
cadaver dissections have found the cross-
sectional area of the nasal valve to be between
0.3 and 0.4 cm2 in each nostril.
.

81. Warren studied the effects of RME and surgical expansion on nasal
crosssectional area. Patients treated with RME resulted in an increase
in nasal cross-sectional area of 45 per cent. Similarly, those patients
treated with a total maxillary segmental osteotomy increased the
cross-sectional area by approximately 55 per cent post-operatively.
Despite a general increase in airway patency approximately one third
of the subjects in both groups did not achieve enough improvement to
eliminate the probability of obligate mouth breathing.
Nasal airway resistance (NAR) using posterior rhinomanometry in 26
patients receiving RME was studied by Timms. Reductions in nasal
airway resistance were recorded in all cases with an average of 36.2
per cent.
Hartgerink, Vig and Abbot, have shown that despite a reduction in NAR
following RME, this did not change the respiratory mode of the patient.
The difficulty in treatment therefore lies with the inadequacy of
determining which patients will respond to therapy

82. • Niall J McGuinness and James P. McDonald
(EJO 2006) studied the relationship between
RME and the change in natural head position
resulting from the consequent change in airway
resistance. A sample of 43 adolescent patients
with uni or bilateral crossbite in the permanent
dentition underwent RME as part of normal
orthodontic treatment. Cephalograms in NHP
were taken before, immediately after expansion
and one year post expansion. No significant
changes in the craniofacial angles were
observed immediately after expansion. One year
after expansion a statically significant reduction
is seen with improved nasal respiration.

83. 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.

84. 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.

85. ORTHOGNATHIC SURGERY
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.

86. 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.

87. • CONCLUSION
• Evaluation of children with nasal obstruction and
dental abnormalities requires a multidisciplinary
approach. The medical and dental literature
concerning the issue is vast and many question
remain unanswered so clear cooperation
between the pediatricians, orthodontists and
otolaryngologists is important
• 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