methods of evaluation of airway

8/11/2019 Methods of Evaluation of Airway

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Rajeev

kumar Mishra

2/15/2013

Department of Orthodontics and Dentofacial

Deformities, Centre for Dental Education and

Research, All India Institute of Medical Sciences

Methods of evaluation of airway and itsrole in orthodontics


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Contents Introduction

Anatomy

Methods of evaluation

Orthodontic consideration

Adenoid facies

Variations in airway

Effect of treatment

Obstructive sleep apnoea

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Introduction

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From the late 1800s until now, the relationship betweenpharyngeal structures and dentofacial pattern has beenintensively researched

Meyer in 1872 reported thinned nose, flattened from sideto side, and the nostrils collapsed and narrow in patientssuffering from obstruction of nasopharyngeal cavity.

According to the functional-matrix hypothesis proposed byMoss, soft-tissue units guide the hard tissues to an extent


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2/15/2013


Deformities,

Centre for Dental Education and Research,

All India Institute of Medical Sciences

Some authors claim that patients with deficient respiratory

functions present with so called adenoid facies (Ricketts,1968)

However, there is still a dispute whether this relationshipbetween craniofacial morphology and respiratory functioncauses dentofacial anomalies ( Leech, 1958,Vig ,1998)


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It is a general belief that the upper airway structures play asignificant role over the development of craniofacial complex(El &Palamo, 2011)

There exists a close relationship between the pharynx and thedentofacial structures, a mutual interaction is expected to occurbetween the pharyngeal structures and the dentofacial pattern, andtherefore justifies orthodontic interest.(Ceylan et al)

2/15/2013Department of Orthodontics and Dentofacial Deformities,

Centre for Dental Education and Research, All India

Institute of Medical Sciences


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ANATOMY

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Methods of evaluation of

Airway

Lateral Cephalogram

Dynamic MRI

CT/CBCT

PolysomnographyAcoustic reflection test

Fluoroscopy

Nasopharyngoscopy

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Lateral cephalogram

Two dimensional image but useful in evaluation of airway

Recorded at the end of expiration and not at deglutition

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Lateral head film studies of the airway have included bothlinear and area measurements based on specificcephalometric landmarks and subjective classification of

airway restriction based on an ordinal scale

Linear measurement are considered unreliable and areameasurement more meaningful in airway evaluation

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Deformities, Centre for Dental Education and Research,



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A number of reference measurements are attributed to theairway and several studies have attempted to establish

normal values for some of these

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McNamara (1984)

Upper pharynx-point on the posterior outline of the softpalate to the closest point on the posterior pharyngealwall.(measurements of less than 5 mm are of concern).

Lower pharynx -intersection of the posterior border of thetongue and the inferior border of the mandible to theclosest point on the posterior pharyngeal wall. (averagevalues, 10-12 mm). Any value over 15-16 mm is of

concern

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Cervical axis(od-C5c)

Odontoid tangent

Pterygoid vertical

1 Anterior cranial base

2 Posterior cranial base

3 Effective cranial base length

4 Length of palate(floor of nasal

cavity)

5 Posterior height of nasal cavity(S-

PNS)

6 Vertical diameter of choanal

opening(ho-PNS)

7 Length of pharyngeal clivus(ba ho

8 Length of floor of nasopharynx(AA

to PNS)9 Depth of nasopharynx(Ba-PNS)

10 Effective length of maxilla(TMJ to

ANS)Some important linear measurements used in radiographic

cephalometric studies of upper airway





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1 Saddle angle(N-S-ba)

2 SNA

3 Angle between palatal plane a

Cranial base

4 The angle of nasopharyngeal

depth and included angle of baS-PNS

5 The angle of nasopharynx and

included angle of PNS-ba-S

6 The angle of roof of

nasopharynx and include angl

ba -ho-PNSDepartment of Orthodontics and DentofacialDeformities, Centre for Dental Education and



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Basic cephalometric

analysis for OSA patient

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Deformities,



PAS Distance between posterior

pharyngeal wall and base oftongue measured on line B-

Go

11

mm

PNS-

P

Length of soft palate 35

mm

MPH Distance of hyoid bone

measure don perpendicularfrom MP to anterior superior

point of hyoid bone

15

SAS Distance from pharyngeal wall

to maximum convexity of soft

palate

15-

20

MAS Minimum anteroposteriorairway space in lower pharynx

9-11

G width of soft palate 8


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Limitations

Two dimensional representation of a three dimensionalstructure

Differences in magnifications

Superimposition of the bilateral craniofacial structures

Low reproducibility as a result of difficulties in landmarkidentification

No information about lateral structures

Cannot be performed dynamically

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Deformities,




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Nasopharyngoscopy

Widely available Easy to perform

No radiation

Can be performed in the sitting

and supine positions Imaging during wakefulness and

sleep

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Deformities,




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Limitations lnvasive

Evaluates only airway lumen, not surrounding soft tissuestructures

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Deformities,




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Muller maneuver, performed during the procedure, mayprovide insight into the location of upper airway closure bypotentially simulating obstructive apnoeas

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Deformities,




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FluoroscopyAdvantages

Provides dynamic airwayimaging during wakefulness

Can also be performed duringsleep

Limitations Significant radiation exposure

Poor sensitivity

Not capable of cross sectionaimaging

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Acoustic Reflection Technique based on analyzing reflected sound waves from the

respiratory system, which provides a calculation of the upperairway area as a function of distance from the incisors (mouth)

Advantages

Noninvasive

No associated radiation

Easily repeated

Dynamic imaging ,can determine location of obstruction

Determine effect of mandibular advancement and protrusion onairway

Can be done in an orthodontic clinic

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Deformities,




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Limitations

Primarily used as a research tool; clinical usefulness has not beenadequately assessed

Technique is performed through the mouth, which alters upper airw

anatomy

Does not provide high resolution anatomical representation of theairway or soft tissue structures

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Deformities,




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Polysomnography Multi-parametric test

Gold standard for diagnosis of apnoea Electroencephalogram

Electrooculogram

Electromyogram

Electrocardiogram

Respiratory flow

Pulse oxymetry

Provides apnoeahypnoea index

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Deformities,




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Magnetic Resonance Imaging

Since the shape of upper respiratory tract continuouslychanges with the respiratory movement, conventional MRlacks sufficient temporal resolution to diagnose the severitof obstruction

Dynamic MRI provides excellent temporal resolution todefine dynamic changes of the upper airway, requires noexposure to ionizing radiation and provides a pharyngeal

airway view on the sagittal plane

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Accurate assessment of upper airway cross-sectional area andvolume

Excellent airway, soft tissue and fat resolution

Direct sagittal, coronal, and axial images without radiation,therefore studies can be performed and repeated duringwakefulness and sleep

Three dimensional reconstruction of soft tissue structures (tongusoft palate, lateral parapharyngeal fat pads, lateral pharyngealwalls) and airway

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Technique not widely available

Expensive

Weight limitation of approximately 300 pounds

Claustrophobia is a problem

Cannot be performed in patients with ferromagnetic clips orpacemakers

2/15/2013Department of Orthodontics and Dentofacial




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Computed Tomography

Excellent airway and bony resolution

Accurate assessment of upper airway cross-sectional area and

volume

Three dimensional reconstruction of craniofacial structures andairway

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Deformities,




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Limitations

High radiation exposure

High cost

Poor resolution for upper airway adipose tissue at leastcompared with MR imaging

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Cone Beam CT Low radiation exposure

Possible to visualize sites of interest by adjusting the imageorientation and rotation

Different gray-level intensities that allow visualization of soft tissas well as hard tissue with different tissue densities

Low cost

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Deformities,




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Scans are converted to DICOM image

Image analyzed with special software

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Deformities,




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Mimics (Materialise, Leuven, Belgium),

ITK-Snap

OsiriX (Pixmeo, Geneva, Switzerland)

Dolphin3D (Dolphin Imaging & Management Solutions,Chatsworth, Calif)

InVivo Dental (Anatomage, San Jose, Calif)

Ondemand3D (CyberMed, Seoul, Korea)

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Segmentation

Manual

Semiautomatic

Image thresholding Static

Dynamic

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Anterior Posterior Superior Inferior


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boundary boundary boundary boundary

Nasopharynx Line extending from

sella (S) to the

posterior

nasal spine (PNS)

Line extending from

S to

the tip of the

odontoid

process

Line extending

the PNS to tip o

the

odontoid proce

Oropharynx Line extending from

the

posterior nasal

spine (PNS)

to the base of the

epiglottis

Line extending from

the

tip of the odontoid

process

to the posterior-

superior

border of CV 4

Line extending from

the PNS to the tip

of the odontoid

process

Line extending

the

base of the

epiglottis

to the posterior

superior

border of CV 4

Hypopharynx Line extending from

the

base of the

epiglottisto the inferior

border

of the symphysis

Line extending from

the

posterior-superior

cornerof CV 4 to the

posteriorinferior

corner of CV 4

Line extending from

the

base of the

epiglottisto the posterior-

superior

corner of CV 4

Line extendin

from the

posterior-infe

corner ofCV 4 to the

inferior borde

of the symphySmith T, Ghoneima A, Stewart K, Liu S, Eckert G, Halum S, Kula K.Threedimensional computed tomography analysis of airway volume changes after rapid maxillary expansion. Am J Orthod Dentofacia

2/15/2013
http://www.ncbi.nlm.nih.gov/pubmed?term=Smith%20T[Author]&cauthor=true&cauthor_uid=22554756http://www.ncbi.nlm.nih.gov/pubmed?term=Ghoneima%20A[Author]&cauthor=true&cauthor_uid=22554756http://www.ncbi.nlm.nih.gov/pubmed?term=Stewart%20K[Author]&cauthor=true&cauthor_uid=22554756http://www.ncbi.nlm.nih.gov/pubmed?term=Liu%20S[Author]&cauthor=true&cauthor_uid=22554756http://www.ncbi.nlm.nih.gov/pubmed?term=Eckert%20G[Author]&cauthor=true&cauthor_uid=22554756http://www.ncbi.nlm.nih.gov/pubmed?term=Halum%20S[Author]&cauthor=true&cauthor_uid=22554756http://www.ncbi.nlm.nih.gov/pubmed?term=Kula%20K[Author]&cauthor=true&cauthor_uid=22554756http://www.ncbi.nlm.nih.gov/pubmed?term=Kula%20K[Author]&cauthor=true&cauthor_uid=22554756http://www.ncbi.nlm.nih.gov/pubmed?term=Halum%20S[Author]&cauthor=true&cauthor_uid=22554756http://www.ncbi.nlm.nih.gov/pubmed?term=Halum%20S[Author]&cauthor=true&cauthor_uid=22554756http://www.ncbi.nlm.nih.gov/pubmed?term=Halum%20S[Author]&cauthor=true&cauthor_uid=22554756http://www.ncbi.nlm.nih.gov/pubmed?term=Eckert%20G[Author]&cauthor=true&cauthor_uid=22554756http://www.ncbi.nlm.nih.gov/pubmed?term=Liu%20S[Author]&cauthor=true&cauthor_uid=22554756http://www.ncbi.nlm.nih.gov/pubmed?term=Stewart%20K[Author]&cauthor=true&cauthor_uid=22554756http://www.ncbi.nlm.nih.gov/pubmed?term=Ghoneima%20A[Author]&cauthor=true&cauthor_uid=22554756http://www.ncbi.nlm.nih.gov/pubmed?term=Ghoneima%20A[Author]&cauthor=true&cauthor_uid=22554756http://www.ncbi.nlm.nih.gov/pubmed?term=Ghoneima%20A[Author]&cauthor=true&cauthor_uid=22554756http://www.ncbi.nlm.nih.gov/pubmed?term=Smith%20T[Author]&cauthor=true&cauthor_uid=22554756


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`

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Nasopharynx morphology is complex, and its volume measurement hasless reliability than does oropharynx volume measurement

El H, Palomo JM. Measuring the airway in 3 dimensions: a reliability and accuracy study. Am J

Orthod Dentofacial Orthop 2010;137: S50.e1-9

Poor soft tissue resolution

More noise and movement artifact

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O th d ti id ti


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Orthodontic considerationsAdenoid facies

Term coined by Tomes(1872)

Studies by Linder-Aronsen supported the relationship betwenasal obstruction and craniofcial and dental patterns

Harvold suggested the role of neuromuscular changes

Solow & kreiborgSoft tissue stretch theory

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Clinical features

Excessive lower facial anterior facial height

Incompetent lip posture

Gummy smile

Flattened nose, poorly developed nostrils

Steep mandibular plane

Posterior cross bite

Open mouth posture Short upper lip and fuller lower lip

Narrow V shaped upper jaw and high narrow palatal vault

Class II skeletal relationship

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Diagnosis

History Clinical examionation

Assesment of mode of respiration

Water holding test

Mirror condensation test Cotton wisp test

Cephalometric analysis

Rhinomanometric examination

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Deformities,




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Orthodontic implication Effective orthodontic therapy necessitates elimination of

nasal obstruction

Early intervention

Appliances

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Deformities,



CBCT study of airway in different malocclusion type


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CBCT study of airway in different malocclusion type

Investigators Samplesize Age Measurement

modality

Conclusion

El &

Palamo(201

1)

140(m-70,f-

70)

Class I,Class

II & Class III

14-18 yrs CBCT/IN

vivo

OP volume-Class II


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2/15/2013


Deformities,



El &

Palamo(20

11)

101(m-57,f-

44)

Class I

Class II

MaxP

Class II Man

R

Class III

max R

Class IIIManP

14-18 CBCT/IN

Vivo Posterior airway space, area of the most

constricted region at the base of the

tongue (minAx), and OP volume were

significantly higher for the CIIIMandP

group, whereas CIIMandR subjects had

the lowest values. The only significant

difference for the NP volume was

between CI and CIIMandR groups where

a smaller volume for the CIIMandRgroup was observed.

Cephalometric studies


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Cephalometric studiesINVESTIGATOR SAMPLE Conclusion

Ceylan and Oktay

(1995)

90(M-45,f-45)

oropharynx areas of patients with ANB 5

degrees

Kirjavainen and

Kirjavainen (2007)

120

Class II div1-40

Class I-80

children with Class II malocclusion had a wider or

similar nasopharynx than the controls but narrower

oropharyngeal (OP) and hypopharyngeal areas

Martin et al(2011) 162

Class I(M-55,F-

36)

Class III(M-33,F-

38)

Upper airway thickness is greater in those with

ideal occlusions than in Class III patients, in

contrast to lower

pharynx dimension, which is greater in Class III

patients

No significantdifferences in lower airway

thicknesswere found. However, the Class III group showed

a statistically significantconstricted airway at this

region because of reduced aerial thickness and

greater adenoidal tissues

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Deformities,




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However some studies have concluded that malocclusion typedoes not influence pharyngeal airway width (de Freitas et al.,2006; Alves et al., 2008).

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Deformities,



Investigator Sample Method Conclusion

De Freitas et al 80

Male -32Female -48

Mean age -11.64

McNamara analysis on

lateral cephalogram

No difference ina

airway width of ClassI and Class II subject

Alves et al 60

Male-30

Femle-30Mean age-17.32-

18.21.2

Spiral computed

tomography

No statistical

difference

between skeletalpattern of classes II

and III


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Variations due to growth pattern

Hyperdivergent patients had a narrower antero-posteriorpharyngeal dimension especially in the nasopharynx at thelevel of hard palate and in the oropharynx at the level of thetip of the soft palate and mandible

Patients with long faces tended to have an extremely narrowairway, both antero-posteriorly and coronally, when compareto patients with normal faces(Grauer et al 2009)

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Subjects with Class I and Class II malocclusions and verticalgrowth patterns have significantlynarrower upper pharyngealairways than those with Class I and Class II malocclusions andnormal growth patterns however growth pattern doesntinfluence volume of lower pharyngeal airway(de Feritas et

al,2006)

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Department of Orthodontics and Dentofacial Deformities,

Centre for Dental Education and Research



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Trenouth and Timms (1999) who measured the length of

mandible between gonion and menthon and found thatoropharyngeal airway was positively correlated with length ofthe mandible.

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Deformities,




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Effect of Treatment

Godt et al (2011)evaluated the changes in upper airway widthassociated with Class II treatments (headgear vs activator) anddifferent growth patterns

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Deformities,




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Dimensional changes in the pharyngeal area within the

overall context of orthodontic treatment were only minor,and even the differences noted between various treatmentmodalities were small.

However they also noted that pharyngeal width reductionscan occur in the phase of isolated headgear treatment whichmay exacerbate any preexisting OSAS or may result indecompensation of compensated OSAS.

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E i i


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Extraction vs non-extraction treatment

No statistically significant oropharyngeal airway volumechanges were found between cases treated with theextraction of four premolars and nonextraction groups.(Valiathan et al ,2010)

The pharyngeal airway size became narrower after thetreatment in cases treated with extraction of all fourpremolars compared to non extraction case(wang et al,2012

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Deformities,

Centre for Dental Education and Research


Effect of RME /Maxillary protraction

CBCT t di


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CBCT studies

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Deformities,



Ribeiro etal

15

Males-8,Females-7Mean age-7.5 yrs

Bonded Hyrax RME is able to increase thetransverse width of the nasal cav

but it does not have the same effe

in the nasopharynx

Smith et al

20Males-8,Females-12

Mean Age-12.3 yrs +

1.9 months

Banded hyraxRME causes significant increase in

nasal cavity volume and nasophary

volume

Investigators Sample

size/averag

Intervention

Done

Duration Imagig

Modalitie

conclusion


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Centre for Dental Education and Research, All India

e age of

sample

Sayinsu et al,2006 19(12M+7F)/

10.51+1.15 yrs

RPE+face mask 6.78+0.93 mth Lateral

Cephalograp

h

Increase in

Nasopharyngeal

airway,no change inoropharymgeal airway

Oktay et al, 2008 20(5M+15F)

11.5+1.54 yrs

Face Mask 8+2.5 mth Lateral

Cephalograp

h

Maxillary protraction

caused the upper airway

dimension to increase

Kilinc et al,2008 18(11F+7M)

10.5+0.93

Protraction

headgear+RPE

6.94+0.56

mth

Lateral

Cephalograms

Improved naso and

oropharyngeal airwaydimension

Kaaygisiz et

al,2009

25(11F+14M)

11.32+1.08 yrs

Reverse Head

Gear

6.94+0.91 mth

with follow up

upto 4 yrs

Lateral

Cephalograp

hs

Improved airway

dimension initially which

was maintained in long

term followup

Tiziano Baccetti etal,2010

22(12F+10M)

8.9+1.5 yrs

Bite block+ facemask

LateralCephalograp

h

No significant change inoropharyngeal &

nasopharyngeal airway

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Orthodontic consideration in Obstructive sleepapnoea


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apnoea

Craniofacial anomalies associated with OSA

Mandibular deficiency-Posterior positioning of tongueleading to airway obstruction

Maxillary deficiency-approximation of soft palate withposterior pharyngeal wall

Combination of both

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Deformities,




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Role of Orthodontist in Multidisciplinary teamAnalysis of craniofacial anatomy and upper airways

Design and fabrication of appliance for mandibularadvancement

Institute orthodontic treatment during orthognathicsurgery/distraction osteogenesis

Treatment of mandibular deficiency by functional

applainces


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Oral appliance therapy Primary snoring

Mild to moderate OSA not responding to CPAP

Unsuitable for behavior modificaton procedures

Most of oral appliance work by placing mandible forwardand thus increases the distance between posteriorpharyngeal wall and tongue

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Deformities,




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Mandibular advancement device(MAD) Monoblock appliances

Splint

Acivator

BionatorKarwetzky activator

Twin block appliances

Removable herbst appliance

Twin block

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Deformities,




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Tongue retaining devices

Tongue repositioning manoeuvre with oral shields

Titrable MADS

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Deformities,




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Limitations of MADs

Treatment outcome cant be predicted

Acclimatization period is required

Uncertainty about selection of maximum dosage

Potential long term complications irt TMJ and

occlusion

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Deformities,



References


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References

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Deformities,



Kharbanda O P. Orthodontics diagnosis and management of malocclusion anddentofacial deformities .2nd edition.2012

Graber T M,Vanarsdall R L,Vig K W L.Orthodontics current principles andtechnique.4thedition.2005

El H, Palomo JM. Airway volume for different dentofacial skeletal patterns. Am JOrthod Dentofacial Orthop. 2011 Jun;139(6):e511-21

El H, Palomo JM. An airway study of different maxillary and mandibular sagittalpositions. Eur J Orthod. 2011 Oct 31. [Epub ahead of print]

Aboudara C, Nielsen I, Huang JC, Maki K, Miller AJ, Hatcher D. Comparison ofairway space with conventional lateral headfilms and 3-dimensional reconstructionfrom cone-beam computed tomography. Am J Orthod Dentofacial Orthop. 2009

Apr;135(4):468-79


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German DS, German J. Cone-beam volumetric imaging: a two-minute drill. J Clin Orthod. 2010Apr;44(4):253-65

Valiathan M, El H, Hans MG, Palomo MJ. Effects of extraction versus non-extraction treatment onoropharyngeal airway volume. Angle Orthod. 2010 Nov;80(6):1068-74

Grgl S, Gokce SM, Olmez H, Sagdic D, Ors F. Nasal cavity volume changes after rapid maxillaryexpansion in adolescents evaluated with 3-dimensional simulation and modeling programs.Am JOrthod Dentofacial Orthop. 2011 Nov;140(5):633-40

Ucar FI, Uysal T. Orofacial airway dimensions in subjects with Class I malocclusion and differentgrowth patterns. Angle Orthod. 2011 May;81(3):460-8

Oh KM, Hong JS, Kim YJ, Cevidanes LS, Park YH. Three-dimensional analysis of pharyngeal airwayform in children with anteroposterior facial patterns. Angle Orthod. 2011 Nov;81(6):1075-82

Hong JS, Oh KM, Kim BR, Kim YJ, Park YH. Three-dimensional analysis of pharyngeal airway volume

in adults with anterior position of the mandible. Am J Orthod Dentofacial Orthop. 2011Oct;140(4):e161-9.


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Grauer D, Cevidanes LS, Styner MA, Ackerman JL, Proffit WR.Pharyngeal airway volume and shape from cone-beam computed

tomography: relationship to facial morphology. Am J Orthod DentofacialOrthop. 2009 Dec;136(6):805-14

Alves M Jr, Baratieri C, Mattos CT, Brunetto D, Fontes Rda C, Santos JR,Ruellas AC. Is the airway volume being correctly analyzed? Am J OrthodDentofacial Orthop. 2012 May;141(5):657-61

Martin O, Muelas L, Vias MJ. Comparative study of nasopharyngealsoft-tissue characteristics in patients with Class III malocclusion. Am JOrthod Dentofacial Orthop. 2011 Feb;139(2):242-51

Oktay H, Ulukaya E. Maxillary protraction appliance effect on the size ofthe upper airway passage. Angle Orthod. 2008 Mar;78(2):209-14

El H, Palomo JM. Measuring the airway in 3 dimensions: a reliability andaccuracy study. Am J Orthod Dentofacial Orthop. 2010 Apr;137(4Suppl):S50.e1-9

Weissheimer A, Menezes LM, Sameshima GT, Enciso R, Pham J, GrauerD. Imaging software accuracy for 3-dimensional analysis of the upperairway. Am J Orthod Dentofacial Orthop. 2012 Dec;142(6):801-13

methods of evaluation of airway

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