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ABOMS > Orthognathics > Flashcards

Orthognathics Flashcards

1
Q

What impairments and comorbidities often exist with orthognathic patients

A

1-Appearance
2-Function
-mastication
-speech
-breathing
-socialization
3-TMJ disease
4-OSA
5-Myofascial pain

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2
Q

What does a presurgical work-up require for orthognathic surgery

A

1-Clinical photographs
2-Dental models
3-Cephalograms
4-Panoramic radiograph

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3
Q

Upper Third Facial Exam (5 pts)

A

1-Area form the hairline (trichion) to glabella
2-Assess eyebrow shape, position, and symmetry
3-Male eyebrows are larger, more horizontal and level with the supraorbital rims.
4-Female eyebrows slope upward, peaking about 10 mm above the supraorbital rims
5-The superior orbital rims should project 10 mm in front of the cornea

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4
Q

Middle 1/3rd facial exam (6 pts)

A
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5
Q

Lower 1/3rd facial exam ( 8 pts)

A
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6
Q

base of the nose

A

subnasale

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7
Q

subnasale

A

base of the nose

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8
Q

menton

A

base of the chin

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9
Q

What is the nasolabial angle on average

A

100 degree +/- and is usually greater in females

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10
Q

What is the average range for incisal show at rest and what factors affect it

A

0.5-5 mm
-Decreases with age
-Females show more than males
-Ethnicity, Whites>Asians>Blacks
-Upper lip length
-Incisal attrition

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11
Q

What does lip width coincide with?

A

inter pupillary distance

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12
Q

What does intercanthal distance coincide with?

A

the alar base

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13
Q

What is the normal chin-throat angle

A

110 degrees

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14
Q

The upper lip should constitute _% of the lower third

A

30%

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15
Q

Steiner analysis with SNA angle

A

It was believed that the cranial base was alike in al individuals but now we know there is a large variation with the cranial base (SN) so this should be used with cuation

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16
Q

Ricketts analysis

A

Uses maxillary depth
-Draw the NA line (line that crosses the Nasion and A point)
-Draw Frankfort horizontal line (line that crosses the upper margin of the external auditory canals (porion) and the lowest point of the infraorbital rim (orbital)
-Measure the angle at the intersection of these lines

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17
Q

porion

A

upper margin of the bony external auditory canal

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18
Q

orbitale

A

lowest point of the infraorbital rim

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19
Q

McNamara Analysis

A

Measures the distance from A to N perpendicular
1-Draw N perpendicular ( a line that crosses N and is perpendicular to FH
2-Measure the distance from A to N perpendicular
3-If A is in front of N perpendicular, the number is positive, if it is behind, the number is negative

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20
Q

What is the purpose of Steiner, Ricketts, and McNamara analyses

A

To determine the AP maxillary position

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21
Q

Measurements associated with AP maxillary retrognathism and prognathism

A
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22
Q

How can you assess the AP mandibular position?

A

-Steiner analysis using the SNB position
-Downs analysis using the facial angle
-McNamara analysis measures the distance from Pog to N perpendicular

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23
Q

Steiner analysis for AP mandibular position

A

-Uses the SNB angle
-As with the SNA angle, this measurement should be interpreted with caution because of possible distortion caused by an anterior cranial base that is either too steep or too flat.

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24
Q

Downs analysis for AP mandibular position

A

Uses the facial angle
1-Draw the facial plane as a line that crosses N and pogonion (Pog)
2-Measure the angle at the intersection of the facial plane and FH (Frankfort horizontal)

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25
Q

McNamara analysis measures teh distance from Pog to N perpendicular

A

1-Draw N perpendicular, the line that crosses N and is perpendicular to FH
2-Measure the distance from Pog to N perpendicular
3-If Pog is in front of N perpendicular, the number is positive, if it is behind, it is negative.

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26
Q

Steiner, Downs, and McNamara analysis for AP mandibular positoin

A
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27
Q

Steiner analysis assesses the discrepancy between the maxilla and mandible by

A

using the ANB angle, which measures the difference in AP position between one jaw and the other.

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28
Q

What is the A-B point in cephalometric analysis?

A

It represents the apical bases of the maxilla and mandible respectively.

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29
Q

What should the ANB angle be for Steiner analysis

A

Normal is 4 to 0 degrees
Skeletal class II >4 degrees
Skeletal class III <0 degrees

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30
Q

Wits appraisal, why is it used

A

Measures position of one jaw with respect to the other (apical base)
1-Draw the occlusal plane as a line that crosses the tips of the mandibular first molar and premolars
2-Project A on the occlusal plane: Draw a line that crosses A and is perpendicular to the occlusal plane; fine the point where the perpendicular line crosses the occlusal plane and call this point AO
3-Do the same fo B and call this point BO
4-Measure the distance from BO to AO: if BO is behind AO, give the distance a negative sign; if BO is in front, give the distance a positive sign.

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31
Q

McNamara analysis: purpose?

A

-Measures the maxillomandibular discrepancy, which is the size discrepancy between the maxilla and mandible.
1-Measure the mid facial length, the distance from condition (Co to A)
2-Measures the mandibular length, the distance from Co to Pog
3-Calculate the maxillomandibular discrepancy by subtracting the midfacial length from the mandibular length.

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32
Q

What are the averages of Steiner, Wits appraisal, and McNamara analyses for Max/mand relationship

A
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33
Q

How do you assess maxillary incisor inclination?

A

Steiner maxillary incisor inclination analysis.
1-Draaw the long axis of the maxillary incisors
2-Draw the NA line, a line that crosses N and A
3-Measure the superior angle of where the lines cross

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34
Q

Normal inclination of the maxillary incisors according to Steiner

A

Normal: 16 to 28
Retroclined <16
Proclined >28

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35
Q

How do you assess mandibular incisor inclination?

A

Steiner mandibular incisor inclidation

-or-

Incisor Mandibular Plane Angle (IMPA) of Downs and Tweed

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36
Q

Steiner mandibular incisor inclination

A

1-Draw the long axis of the mandibular incisor
2-Draw the NB line, a line that crosses the N and B
3-Measure the interior angle where the lines cross

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37
Q

Incisors mandibular plane angle of Downs and Tweed

A

1-Draw the long axis of the mandibular incisor
2-Draw the mandibular plane as a line
3-Measure the superior angle where the lines cross

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38
Q

What is the normal lower incisor inclination for Steiner?

A

18 to 32 dgrees
Retroclined < 18 degrees
Proclined > 32 degrees

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39
Q

What is the normal lower incisor inclination for Downs & Tweed?

A

Normal: 85-95 degrees
Retroclined: <85 degrees
Proclined: >95 degrees

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40
Q

How do you assess the facial type

A

Steiner mandibular plane angle analysis

-or-

Frankfort mandibular plane angle (FMA) of Downs and Tweed

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41
Q

How doe Steiner assess the face

A

Steiner mandibular plane angle
1-Draw the SN line
2-Draw the mandibular plnae
3-Measure the angle at the intersection of the mandibular plane and SN

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42
Q

How does Downs and Tweed assess the face

A

-Measure the angle at the intersection of the mandibular plane and FH

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43
Q

What is normal facial type for Steiner

A

-30-34 degrees: Normal
Short face: < 30 degrees
Long face: >34 degrees

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44
Q

What is normal for Downs and Tweed for facial analysis?

A

Normal: 21-27 degrees
Short face < 21 degrees
Long face > 27 degrees

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45
Q

Short face characteristics ( 5 pts)

A

-Long ramus,
-acute gonial angle,
-horizontal growth,
-over-closed mandible,
-decreased lower facial height

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46
Q

Long face characteristics ( 5 pts)

A

-Short ramus,
-obtuse gonial angle,
-vertical growth,
-mandible is rotated open
-increased lower facial height

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47
Q

How do you assess the chin?

A

Holdaway ratio
1-Draw the line that crosses N and B (NB)
2-Measure the distance from NB to the incisal edge of the mandibular incisor and the distance from NB to Pog
3-Calculate the ratio of the distance NB to incisal edge of mandibular incisor (NB to Pog)

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48
Q

What is the ideal foldaway ratio for men? women?

A

men: 1;1 ratio
women: 0.5: 1

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49
Q

Growth cessation for orthogathics can be determined by what 4 techniques.

A

1-Serial physical exams
2-Serial cephalograms
3-A hand-wrist film
4-Looking at the maturation of cervical vertebrae on a lateral cephalometric radiograph.

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50
Q

Describe what you are looking for on cervical vertebrae for maturation

A

1-There are 6 stages of cervical vertebral maturation
2-Mandibular and craniofacial grow peak along with statue in stages 3 and 4
3-As cervical vertebrae mature, they develop a conacavity on the inferior border an assume a more rectangular shape.

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51
Q

What is the goal of presurgical orthodontics? (2 pts

A

To normalize and coordinate the dental arches.

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52
Q

A dental arch is normalized when…(7 pts)

A

1-The teeth are aligned (orderly arrangement in the arch); the teeth are not displaced, tipped, or rotated
2-The teeth are leveled; they are vertically even–there are no steps in the incisal edges or marginal ridges
3-The curve of Spee is flat or minimal
4-The lingual cusps of the mandibular posterior teeth are 1 mm below the buccal cusps
5-The palatal cusps of the maxillary posterior teeth are 1 mm below the buccal cusps
6-All interdental spaces are closed unless they are needed to manage a tooth-size discrepancy.
7-All dental compensations have been removed

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53
Q

The dental arches are coordinated when…(3 points)

A

1-The maxillary and mandibular dental arches have the same shape
2-The maxillary and mandibular dental arches have corresponding sizes
3-The tooth sizes of the maxillary and mandibular teeth correspond–they have the correct size ratio.

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54
Q

Class III malocclusion nature’s incisors compensations

A

1-The maxillary incisors are inclined labially; the mandibular incisors are inclined lingually

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55
Q

Class II malocclusion nature’s incisors compensations

A

The maxillary incisors can be tipped labially (division I) or lingually (division II)
-the mandibular incisors are tipped labially

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56
Q

What is an important consideration for a Class II deep bite malocclusion with a deep curve of spee

A

-It may be advantageous to do surgery before the curve of Spee is leveled; this prevents intrusion of the mandibular incisors by orthodontic mechanics and foreshortening of the lower face

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57
Q

To be surgery ready from an ortho perspective ( 3pts)

A

1-Archwires should be passive ( no more movement)
2-Rectangual orthodontic wires should be fully engaged in the slots
3-Surgical hooks (soldered or crimped) should be in place to facilitate MMF

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58
Q

Indications of a LeFort I Osteotomy

A

-Correction of deformities that affect the size, position, orientation, and shape of the maxilla.

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59
Q

What 4 things must be exposed for the LeFort incision intramurally.

A

1-Piriform rim
2-Infraorbital foramen
3-Zygomatic buttresses
4-Pterygomaxillary fissure

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60
Q

What 3 things must be exposed intranasally for the Lefort

A

1-Nasal floor
2-Caudal septum
3-Lower aspect of lateral nasal wall

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61
Q

How far above the teeth should the osteotomy be for a Lefort I

A

At least 5 mm

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62
Q

What is the average distance from the piriform rim to the Descending palatine artery?

A

34 mm

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63
Q

What can be caused when osteotoming the septum?

A

Fx of the cribriform plate causing anosmia

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64
Q

What is the average height of the pterygomaxillary suture?

A

14.6 mm

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65
Q

What is a rule for down fracture?

A

Use fingerpressure

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66
Q

To advance the maxilla once downfractured, what must you do?

A

Push maxilla forward form the tuberosities

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67
Q

Is it necessary to preserve the descending palatine artery?

A

No it is not mandatory, but advisable since it provides good blood supply to the maxilla and contributes to flap nourishment

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68
Q

What are the advantages of cuts between the lateral incisors and canines? (4 pts)

A

1-Allows change in axial inclination of anterior teeth
2-Faciliates management of tooth-size discrepancy (narrow maxillary lateral incisors
3-No need to open interrradicular spaces orthodontically as there is naturally enough space to cut
4-Less risk of iatrogenic too injury: Cutting between two uni-radicular teeth (2s and 3s) is less dangerous than cutting between one uni-radicular and one bi-radicular tooth (3s and 4s)

69
Q

What is the advantage to cut between premolars and canines? ( 1 pt)

A

Larger anterior segment, more blood supply

70
Q

What is the purpose of the alar cinch suture

A

Prevents widening of the alar base

(fibroareolaer extension of the lower lateral cartilage)

71
Q

What is the purpose of the VY advancement

A

Prevents loss of visible vermillioin

72
Q

SARPE

A

Surgically Assisted Rapid Palatal expansion
-A 2 piece Le Fort I osteotomy without down fracture

73
Q

When is a SARPE indicated?

A

-Correction of severe >10 mm transverse deficiency after the mid palatal suture is closed for correction of isolated transverse deficiencies

74
Q

When does activation of the exapander begin in a SARPE

A

Activation of expander begins 5-7 days after surgery at 0.5 mm/day
-One turn 0.25 mm 2x/day

75
Q

Where is a SARPE placed?

A

Can be tooth/bone borne expander

76
Q

What are the probably sources of bleeding in a LeFort I osteotomy?

A

1-Pterygoid venous plexus
2-Descending palatine artery
3-Sphenopalatine artery
4-Internal maxillary artery
5-Posterior alveolar artery

77
Q

How can one reduce bleeding to an area after a LeFort downfracture

A

1-Put the patient in Reverse T (10 degrees)
2-Local vasoconstrictors (Injection of epi around the wound), application of cocaine, oxymetazoline on nasal mucosa
3-Hypotension

78
Q

Where the DPA descend through

A

The descending palatine artery descends through the pterygopalatine canal, emerging from he greater palatine froarmen.
-The LeFort procedure breaks the ptergyopalatine canal horizontally placing the vessel at risk.
-An overt injury requires ligation or clips.

79
Q

Unwanted Fx in a Lefort

A

-To the skull base
-Through the septum and the cribriform plate
-Horizontal fx of pterygoid process can leave the end of the process and medial ptergyoid muscle attached to the maxilla and limit maxillary advancement; if this occurs, separate the pterygoid process form the tuberosity.

80
Q

What is anosmia and how is it caused in a LeFort

A

Fx of the cribriform plate, loss of smell

81
Q

What can cause blindness in a LeFort osteotomy?

A

1-Base of skull fx
2-Hypoperfusion of the optic nerve
3-Arterial aneurysm

82
Q

T/F: Data encourages ax after LeFort?

A

True

83
Q

Silk Deficiency

A

-One or more vessels not ligated, cauterized or welded at surgery

84
Q

What are late postoperative bleeds in a LeFort caused from?

A

1-Clot lysis around occult vessel injury
2-Rupture of false aneurysm or AV fistula

85
Q

Risks of surgery and delayed healing for a LeFort osteotomy

A

1-Inferior maxillary repositionig
2-Large movements
3-Bruxism
4-Unoperatied mandible
5-Hardware failure
6-Poor blood supply
7-Heavy elastics
8-Occlusal interferences

86
Q

How to manage delayed healing and a nonunion in a LeFort?

A

1-Occlusal equilibration
2-Discontinuation of heavy elastics
3-Non-chewy diet
4-MMF

For nonunion, surgical revision with the removal of fibrous union, re-application of rigid fixation and bone grafting

87
Q

Avascular necrosis in a LeFort I osteotomy? Probability? Risk Factors (11)

A

Rare-less than 1%

Risk Factors
-Smoking
-Vascular Disease (atherosclerosis
-Thrombopheilia
-Cleft Palate
-Previous surgery
-Large surgical movements; AP and transverse
-Maxillary segmentation
-Long operating time
-Laceration of Palatal tissues
-Impingement on palatal tissues from segmental osteotomies
-Impingement on mucosa by splint

88
Q

Treatment for avascular necrosis following LeFort I (3 pts)

A

-HBO,
-debridement and reconstruction,
-HBO therapy,

89
Q

What is a vertical ramus osteotomy primarily used for?

A

Correction of mandibular prognathism

90
Q

What is a sagittal split osteotomy primarily used for

A

Correction of deformities that affect the size,position, orientation and shape of the mandible

91
Q

What is an Inferted-L osteotomy used for?

A

Correction of severe deformities that affect the size, position, orientation, and shape of the mandible.

*This is for more severe deformities that cannot be corrected by the SSO

92
Q

Advantages of an SSO? (4 pts)

A

1-No MMF required
2-Occlsuion can be checked intraoperatively and immediately postoperatively
3-Bone graft not often needed
4-Can be used to correct most mandibular deformities,
-retrognathism,
-micrognathia,
-prognathism,
-macrognathia,
-open bite,
-malrotation, and
-distortion.

93
Q

Advantages of VRO (2 pts)

A

1-IAN injury is rare
2-Not associated with iatrogenic TMJ disc displacement or condylar regeneration

94
Q

Advantages of Inverted L-Osteotomy (3 pts)

A

1-Allows for large translations and rotations
2-No MMF is required
3-Occlusion can be checked intraoeprativelyand immediately postoperatively

95
Q

Disadvantages of SSO (3 pts)

A

1-Moderate risk of IAN disturbance
2-Unfeasible when large movements are needed
-Very large advancements >15 mm
-Very large counterclockwise rotations
-Big yaw or roll rotations, needed to correct severe asymmetries–that move the proximal segment out of alignment
3-Can produce iatrogenic TMJ disc displacement and condylar degeneraiton

96
Q

Disadvantages of VRO (5 pts)

A

1-Requires MMF
2-Possible condylar sage
3-Occlusion cannot be checked intraoperatively
4-Postoperatively, occlusion can only be checked after the bone has healed
5-Cannot be used to correct retrognathia, micrognathia, or anterior open bite.

97
Q

Disadvantages of Inverted L-Osteotomy (2 pts)

A

1-Bone graft is required when used for advancement
2-Advancement requires external approach
-Scar
-Longer Surgery
-Possible facial nerve injury

98
Q

Where is the IAN closest to the teeth and the buccal cortex?

A

3rd molar region

99
Q

Where is the IAN lowest from the teeth and farthest from the buccal cortex?

A

1st molar region.

100
Q

Where is the vertical osteotomy placed to minimize nerve damage

A

Between the 1st and 2nd nerve.

101
Q

Where does the Masseteric artery pass in reference to the sigmoid notch?

A

8 mm above, consider in reference to IVRO>

102
Q

Where is the internal maxillary artery in relation to the condylar neck?

A

medial and posterior

103
Q

What is the average distance of the mandibular foramen from the posterior border?

A

7 mm

104
Q

Where does the facial nerve lie in relation to an inverted L-osteotomy?

A

within the superficial layer of the deep cervical facscia, (investing layer)

105
Q

Is the facial nerve medial or lateral to the facial vein?

A

lateral to the facial vein

106
Q

What happens to the facial nerve when the patient’s head is rotated?

A

it dips lower than the 1.2 cm where it normally lies.

107
Q

What 3 approaches extra orally can e used to perform a IVRO?

A

1-Risdon
2-Retromandibular
3-Submandibular approach

108
Q

What is the Dalpont modification?

A

Extending the anterior extent of the BSSO osteotomy to the inter proximal space between the 2nd and 3rd molars.

109
Q

Is the IAN in the distal or proximal segment.

A

Should be the distal segment

110
Q

in an IVRO, is the vertical cut anterior or posterior to the Mandibular foramen.

A

Posterior

111
Q

What is the ideal shape and location of the three positional bicortical screws?

A

1-Place in inverted L configuration, two up, one down

112
Q

Pediatric considerations of lingual?

A

-More superior and posterior mandibular foramen and lingula

113
Q

At 20 months, who will still have sensory deficits due to lower jaw surgery

A

1/3rd of patients

114
Q

When should 3rd molars be removed for surgery

A

At least 9-12 months before

115
Q

What to do if a bad split occurs?

A

1-Complete the split as intended
2-Repair the fx with rigid fixation, reestablishing proximal and distal segments
3-Positiion the Proxima and distal segments as planned and fix the osteotomy

If th repair is tenuous, use postoperative MMF; if the reduction is poor, postpone any additional procedures.

116
Q

Changes in intercondylar width with BSSO?

A

-Widening or narrowing are usually caused by lag screws when they are used to close a transverse inter fragmentary gap and displace the proximal segment

117
Q

T/F: It is okay for the proximal segment to be medial

A

False, it is not.

118
Q

What may cause immediate malocclusion in a BSSO? (2 pts)

A

1-Condylar malposition
2-Mechanical deformation (warping_ caused by bendable fixation and/or large mechanical loads (eg, large advancements)

119
Q

What might cause late IVRO malocclusion (2 pts)

A

1-Occlusal interferences caused by postoperative orthodontics
2-Dental relapse

120
Q

What might cause Late malocclusion in Inveted L-Osteotomies? (4 pt)

A

1-Hardware failure and nounion
2-Occlusal interferences caused by postoperative ortho
3-Dental relapse
4-Condylar resorption.

121
Q

3 indications for genioplasty

A

1-Microgenia
2-Chin asymmetry
3-Macrogenia- avoid moving chin backward which can result in chin ptosis

122
Q

How do you camouflage macrogenia

A

Clockwise rotation of both jaws

123
Q

How to tell the difference between mentalist muscles versus orbicular oris muscles

A

-Orbicular oris muscles run horizontal
-Mentalis muscles run vertical

124
Q

Neuropraxia

A

Neuropraxia is the mildest form of traumatic peripheral nerve injury. It is characterized by focal segmental demyelination at the site of injury without disruption of axon continuity and its surrounding connective tissues.

125
Q

What are important considerations when making the osteotomy for a genioplasty?

A

1-> 5 mm below apices of the teeth
2->5 mm away from the mental foramina, the IAN loops in front fo the mental foramina

126
Q

What is another name for chin ptosis?

A

Witch’s chin

127
Q

Which movements are more stable: Class II or Class III during the first post surgical year

A

Class II are more stable than Class III problems

128
Q

Three most stable movements considered “highly stable.”

A

1-Maxillary impaction
2-Mandibular advancement
3-Genioplasty in any direction

129
Q

Three movements considered “stable.”

A

1-Maxillary advancement
2-Maxillary impaction & Mandibular advancement
3-Maxillary advancement & Mandibular setback

130
Q

Three movements considered “unstable.”

A

1-Isolated mandibular setback
2-Maxillary inferior repositioning
3-Widening of the maxilla; greater replace in the molar region.

131
Q

Bony and dental changes seen after the first post surgical year.

A

Not a result of surgery, but are the result of growth, adaptive dental movements, or pathologic conditions (condylar resorption)

132
Q

After the first post-surgical year, changes > 2 mm are often seen in Class II or Class III patients?

A

Class II patients.

133
Q

T/F: Early surgery in a skeletal class III pt will likely result in relapse

A

True, it is recommended for waiting for growth completion unless significant psychosocial problems exist and the patient is willing to accept a second operation

134
Q

T/F: Early surgery in a skeletal class II pt will likely result in relapse

A

False, if the deformity is impairing the airway or the patent’s psychosocial development, consider early surgery, because a hypoplastic mandible has limited growth potential and risk for release is low.

135
Q

According to Lam, when is maxilla first surgery recommended?
2 situations

A

1-When the mandibular osteotomy is a VRO
2-When the mandibular deformity leaves doubt in the ability to achieve stable fixation; a bd split may make rigid fixaiton of the mandible impossible.

136
Q

According to Lam, when is maxilla first surgery recommended?
3 situations

A

1-Mandible not in CR: In certain patient’s
2: Maxillary surgery moves the mandible past the point of pure condylar rotation
3-Maxillary bone is very thin.

137
Q

3 types of management for idiopathic condylar resorption

A

1-Orthognathic surgery (posible relapse)
2-Arthroplasty with prosthetic replacement (issues for young patients given no growth potential)
3-Arthroplasty with rib autograft (possible overgrowth)

138
Q

OSA

A

Obstructive sleep apnea characterized by repetitive collapse of the upper airway during sleep

139
Q

What issues are caused by sleep apnea (5 pts)

A

1-Sleep fragmentaiton
2-Hypoxemia
3-Hypercapnia
4-Marked swings in intrathoracic pressure
5-Impaired cognition

140
Q

Nocturnal Symptoms of OSA

A

1-Loud snoring
2-Witnessed breathing interruptions
3-Awakenings due to gasping or choking
4-Nocturia

141
Q

dirunal Symptoms of OSA

A

-Waking up refreshed
2-Morning headaches
3-Daytime sleepiness: Should be quantified used the Epworth Sleepiness Scale; score ranges form 0 to 24; normal ranges from 0-8
4-Impaired concentration and memory

142
Q

Criteria for OSAS diangosis

A

1->5 or more obstructive events per hr of sleep & presence of symptoms
2-15 or more obstructive events per hr of sleep, irrespective of symptoms

143
Q

Apnea

A

Breathing interruption > 10 seconds

144
Q

Hypopnea

A

More than 50% decrease in nasal airflow or more than 2/3 decrease in TV with 3% decrease in oxygen saturation

145
Q

Respiratory efforts related arrousals (RERAs)

A

1-More than 50% decrease in nasal pressure and increased work of breathing associated with arrousal

146
Q

AHI

A

Apnea Hypopnea Index: Apneas and hypopnea per hour

147
Q

RDI

A

Respiratory Disturbance Index: Apneas, hypopnea & RERAs per hr

148
Q

Indexes that report the frequency of obstructive events

A

AHI
-RDI

149
Q

Indexes that report severity of hypoxia

A

-Oxygen saturation nadir
-Total time of Hypoxia

150
Q

OSA Severity based on RDI and AHI

A
151
Q

Cephalometry of OSA patients should be measured at 3 places

A

1-Soft palate length
2-Posterior airway space
3-Hyoid to mandibular plane distance

152
Q

In terms of OSA, what is the mean of soft palate length

A

Mean: 35 m
-Distance form posterior nasal spine to uvula tip

153
Q

In terms of OSA, what is the mean of posterior airway space?

A

-Mean: 11 mm
-Smallest anteroposterior distance between the base of the tongue and the posterior pharyngeal wall:

154
Q

In terms of OSA, what is the mean of hyoid to mandibular plane distance?

A

Mean: 15 mm
-From the anterosuperior limit of the hyoid to the mandibular plane
-The distance is proportional to height of the pharynx.

155
Q

What is sleep endoscopy

A

-1-Propofol is used to induce sleep and a nasopharyngoscopy is performed while the patient is sleeping
-Proponents believe that the findings help them stratify surgery patients into phase I or phase II treatment; they reason that
-Patients with limited airway obstruction wll do well after phase I surgeries
-Those with complete collapse are better off skipping phase I, moving to MMA

156
Q

Fujita classification

A

Classification of anatomical sites of obstruciton in the upper airway.

157
Q

Fujita classifications Type I

A

Type I: Narrow oropharynx (redropalatal); Large tonsils, uvula and pillar webbing

158
Q

Fujita classifications Type II

A

Type II: Oral & hypo pharyngeal obstruction (retorpalatal and retrolingual; how arched palate and large tongue

159
Q

Fujita classifications Type III

A

Hypoharyngeal obstruction (retrolingual only); retrognathia, floppy epiglottis, enlarged lingual tonsils

160
Q

Treatment for OSA pts

A

-Behavior modification
-Exercise
-Not laying supine
-Weight Loss
-Avoid alcohol and sedatives
-CPAP
-Oral appliances
-For all users, success is 47%
-

161
Q

Treatment for OSA pts

A

-Behavior modification
-Exercise
-Not laying supine
-Weight Loss
-Avoid alcohol and sedatives
-CPAP
-Oral appliances
-For all users, success is 47%

162
Q

Oral appliances have better outcomes for what type of patients

A

-Smaller BMI
-Mild to moderate OSAS
-Supine OSAS
-Better tolerated than CPAP
-Can produce jaw pain and/or malocclusion.

163
Q

Surgical methods for OSA

A

1-Bariatric surgery
2-Nasal Surgery
3-Tonsillecotmy and or adenoidectomy
4-Orthognathics (maxillary and mandibular retrognathia)

164
Q

Phase I Surgery for OSA patients

A

MultiLevel surgery

-Including Uvulopalatopharyngoplasty (shortens the soft palate and removes the tonsils)
-Base of tongue reduction ((increases retroglossla airway)removes tissue from base of tongue
-Hyoid suspension (increases retroglossla airway)
-Geniglossus advancement-ADvances the bony segment that contains the attachments of the genial muscles (prevents upper airway collapse)

165
Q

Which muscles are advanced with a geniglossus advacement

A

1-genioglossus
2-geniohyoid

166
Q

Phase II Surgery for OSA patients

A

Maxillomandibular advancement-

167
Q

What is 100% curative if Phase I or II don’t work

A

Tracheostomy

168
Q

Success rate of Phase I surgeries for OSA

A

55% defined as AHI <20 and >50% reduction in AHI

ABOMS (9 decks)

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