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1. Facial Keys To Orthodontic DiagnosisFacial Keys To Orthodontic Diagnosis
And Treatment Planning.And Treatment Planning.

2. Majority of the diagnostic procedureMajority of the diagnostic procedure
in day to day orthodontics is basedin day to day orthodontics is based
onon Model analysisModel analysis or onor on OsseousOsseous
Cephalometric standardsCephalometric standards withoutwithout
complete examination of the face .complete examination of the face .

3. Orthodontics if is mainly focused onOrthodontics if is mainly focused on
correction the bite , can negativelycorrection the bite , can negatively
impact facial esthetics, especially ifimpact facial esthetics, especially if
pretreatment esthetics are not definedpretreatment esthetics are not defined
before treatment.before treatment.

4. Patients turn up to the orthodontist forPatients turn up to the orthodontist for
the correction of the proclination ofthe correction of the proclination of
incisors or esthetics of the face.incisors or esthetics of the face.

5. Why?Why?
Do we spend the least amount of time andDo we spend the least amount of time and
attention on the examination of the face.attention on the examination of the face.

6.  Lack of organized , comprehensive facialLack of organized , comprehensive facial
analysis .analysis .
 Lack of complete knowledge collectivelyLack of complete knowledge collectively
at one place about the various aspects toat one place about the various aspects to
the be examined and the standards to bethe be examined and the standards to be
compared with.compared with.

7. This articleThis article 19 key facial traits19 key facial traits areare
explained that can be used as anexplained that can be used as an
adjunctive treatment planning tooladjunctive treatment planning tool

8. These traits are not compeletly new or Traits that weThese traits are not compeletly new or Traits that we
never knew.never knew.
We failed toWe failed to
 implement them properlyimplement them properly
 do not know the proper standards to compare withdo not know the proper standards to compare with
 do not know the correct way to examinedo not know the correct way to examine

9. Patients are examined inPatients are examined in
Natural head postureNatural head posture
Centric relation,Centric relation,
Relaxed lip posture.Relaxed lip posture.

10. Two views of the patient are used for
identification of problems in three planes
of space:
I. Frontal II. Profile

11. Frontal viewFrontal view
RELAXED LIPS FUNCTIONAL ANALYSIS
CLOSED LIPS SMILING

12.  Outline form andOutline form and
symmetrysymmetry
 Facial levelFacial level
 Midline alignmentsMidline alignments
 Facial one thirdsFacial one thirds
 Lower third evaluationLower third evaluation
 Profile angleProfile angle
 Nasolabial angleNasolabial angle
 Maxillary sulcus contourMaxillary sulcus contour
 Mandibular sulcusMandibular sulcus
contourcontour
 Orbital rimOrbital rim
 Cheekbone contourCheekbone contour
 Nasal base lip contourNasal base lip contour
 Nasal projectionNasal projection
 Thorat length and contourThorat length and contour
 Subnasale pogonion lineSubnasale pogonion line
FRONTAL VIEW PROFILE VIEW

13. FRONTAL VIEWFRONTAL VIEW
THE THINGS TO BE CHECKED WHILETHE THINGS TO BE CHECKED WHILE
EXAMINING THE FRONTAL VIEW AREEXAMINING THE FRONTAL VIEW ARE
. NATURAL HEAD POSITION. NATURAL HEAD POSITION
. CENTRIC RELATION. CENTRIC RELATION
. RELAXED LIPS. RELAXED LIPS

14. 1.} The widest
dimension of the face
is the zygomatic width
2.} The bigonial width
is approximately 30%
less than the
bizygomatic dimension.
3.} The height to width
proportion is 1.3:1 for
females and 1.35:1 for
males

16. 1.} vertical maxillary excess
2.} Mandibular protrusion
3.} Dental interferences
leading to open bite.
MAXILLARY OR MANDIBULARMAXILLARY OR MANDIBULAR
SURGERYSURGERY
CHEEKBONE AUGMENTATIONCHEEKBONE AUGMENTATION
AUGMENTATION OF THEAUGMENTATION OF THE
MANDIBULAR ANGLESMANDIBULAR ANGLES
REDUCTION GENIOPLASTYREDUCTION GENIOPLASTY

17. 1.} Deep bite1.} Deep bite
2.} Vertical maxillary2.} Vertical maxillary
deficiencydeficiency
3.} Masseteric hyperplasia3.} Masseteric hyperplasia
MAXILLARY OR MANDIBULARMAXILLARY OR MANDIBULAR
SURGERYSURGERY
AUGMENTATION GENIOPLASTYAUGMENTATION GENIOPLASTY
BUCCAL LIPECTOMIEES .BUCCAL LIPECTOMIEES .

18. The maxilla should rarely be moved up andThe maxilla should rarely be moved up and
back. This movement decreases lipback. This movement decreases lip
support, increases the nasolabial folds,support, increases the nasolabial folds,
decreases incisor exposure, and candecreases incisor exposure, and can
make the facial outline appear short andmake the facial outline appear short and
wide.wide.

19. Assement of symmetryAssement of symmetry
The most common to least common sites ofThe most common to least common sites of
facial asymmetryfacial asymmetry
1.} Chin,1.} Chin,
2.} Mandibular angles,2.} Mandibular angles,
3.} Cheekbones.3.} Cheekbones.

20. Pupil line
Upper dental arch line
Lower dental arch line
Chin jaw line

21. Olussal cant or
Assymetry present,
At what level the deviation is
present
Correction in the bite in
growing phase or
Single jaw or double jaw
surgery
Mandibular deviations
commonly have upper and
lower occlusal cants with chin
and jaw line canting
associated

22. Nasal bridge
Nasal tip
Upper incisor midline
Philtrum
Lower incisor midline
Chin mipoint

23. MIDLINE ALIGNMENTSMIDLINE ALIGNMENTS
 Midlines are assessed with uppermostMidlines are assessed with uppermost
condyle position and first tooth contactcondyle position and first tooth contact..
 Filtrum is usually a reliable midlineFiltrum is usually a reliable midline
structure and can be used as the basis forstructure and can be used as the basis for
midline assessment most often.midline assessment most often.

24.  Dental midline shifts are the result of multipleDental midline shifts are the result of multiple
dental factors including:dental factors including:
1. Spaces1. Spaces
2. Tooth rotations2. Tooth rotations
3. Missing teeth3. Missing teeth
4. Buccally or lingually positioned teeth4. Buccally or lingually positioned teeth
5. Crowns or fillings which change tooth mass5. Crowns or fillings which change tooth mass
6. Congenital tooth mass difference from left to6. Congenital tooth mass difference from left to
rightright

25. The face divides vertically
into thirds from
a.] hairline to midbrow,
b.] midbrow to subnasale,
c.} subnasale to soft
tissue menton .
The thirds are within a
range of 55 to 65 mm,
vertically.

26. Increased lower one-Increased lower one-
third heightthird height
 Vertical maxillaryVertical maxillary
excess andexcess and
 Class IIIClass III
malocclusionsmalocclusions
(lack of interdigitation(lack of interdigitation
opens verticalopens vertical
height).height).

27. Decreased lower one-Decreased lower one-
third height isthird height is
associated withassociated with
 vertical maxillaryvertical maxillary
deficiency anddeficiency and
 mandibular retrusionmandibular retrusion
deep bites.deep bites.

28. Decreased lower one-Decreased lower one-
third height isthird height is
associated withassociated with
 vertical maxillaryvertical maxillary
deficiency anddeficiency and
 mandibularmandibular
retrusion deepretrusion deep
bites.bites.

29.  Production of correct proportion influences theProduction of correct proportion influences the
choice of surgical procedure used to correct thechoice of surgical procedure used to correct the
occlusion (i.e., maxillary impaction to correctocclusion (i.e., maxillary impaction to correct
Class II malocclusion associated with long lowerClass II malocclusion associated with long lower
one-third rather than mandibular advancement).one-third rather than mandibular advancement).
 The equality of the middle and the lower thirdsThe equality of the middle and the lower thirds
not determiningnot determining
 landmarks like incisor exposure, interlabial gaplandmarks like incisor exposure, interlabial gap
etc are more within the lower third are moreetc are more within the lower third are more
importantimportant

30. Upper and lower lipUpper and lower lip
lengthslengths
1.] The normal length from1.] The normal length from
subnasale to upper lipsubnasale to upper lip
inferior isinferior is 19 to 22 mm.19 to 22 mm.
2.] If the upper lip is2.] If the upper lip is
anatomically short ( 18anatomically short ( 18
mm or less).mm or less).
3.] The lower lip is3.] The lower lip is
measured from lower lipmeasured from lower lip
superior to soft tissuesuperior to soft tissue
menton and normallymenton and normally
measures in a range ofmeasures in a range of
38 to 44 mm.38 to 44 mm.

31. If the upper lip is anatomically short ( 18 mm or less), an increased interlabial gap
and incisor exposure is seen with a normal lower face height. This should not be
confused with vertical maxillary excess (increased interlabial gap, increased upper
incisor exposure, increased lower one-third facial height).

32.  The lower lip isThe lower lip is
measured frommeasured from
lower lip superior tolower lip superior to
soft tissue mentonsoft tissue menton
 Measures in a rangeMeasures in a range
ofof 38 to 44 mm38 to 44 mm

33.  Anatomic short lower -------Anatomic short lower -------
Class II malocclusionClass II malocclusion
{ cephalometrically{ cephalometrically
lower anterior dental height (lowerlower anterior dental height (lower
incisor tip to hard tissue menton;incisor tip to hard tissue menton;
women, 40 mm ± 2 mm,women, 40 mm ± 2 mm,
men, 44 mm ± 2 mm).men, 44 mm ± 2 mm).
Anatomic short lower lip shouldAnatomic short lower lip should
not be confused with a short lowernot be confused with a short lower
lip secondary to posture (upperlip secondary to posture (upper
incisor interferences) seen inincisor interferences) seen in
Class II deep bite cases withClass II deep bite cases with
normal anterior dental height.normal anterior dental height.
Anatomic short lower lip can beAnatomic short lower lip can be
lengthened with a lengtheninglengthened with a lengthening
genioplasty.genioplasty.

34.  Anatomic long lower lip can be associatedAnatomic long lower lip can be associated
with Class III malocclusions.with Class III malocclusions.
 Must be verified with the cephalometricMust be verified with the cephalometric
anterior dental height measurement.anterior dental height measurement.
 A closed lip position must not used duringA closed lip position must not used during
examination as the lip elongates to close.examination as the lip elongates to close.

35.  The normal ratio of upper to lower lip isThe normal ratio of upper to lower lip is
1:2.11:2.1
 Proportionate lips harmonize regardless ofProportionate lips harmonize regardless of
length; disproportionate lips may needlength; disproportionate lips may need
length modification to appear in balance.length modification to appear in balance.

36. Lip redundancyLip redundancy
 is seen in cases of vertical maxillary deficiencyis seen in cases of vertical maxillary deficiency
and mandibular retrusion with deep bite and,and mandibular retrusion with deep bite and,
rarely, long lip lengths.rarely, long lip lengths.
 To accurately assess lip lengths with redundantTo accurately assess lip lengths with redundant
lips, the patient's bite must be opened {pinklips, the patient's bite must be opened {pink
base plate wax bite} until the lips separate.base plate wax bite} until the lips separate.
 The face is examined in that posture, andThe face is examined in that posture, and
vertical skeletal increases are planned.vertical skeletal increases are planned.

37. Upper tooth to lip relationshipUpper tooth to lip relationship
The distance from upper lipThe distance from upper lip
inferior to maxillary incisalinferior to maxillary incisal
edge is measured .edge is measured .
The normal range is 1 to 5The normal range is 1 to 5
mm. [ more in women ]mm. [ more in women ]
Surgical and orthodonticSurgical and orthodontic
vertical changes must bevertical changes must be
based primarily on thisbased primarily on this
measurementmeasurement

38.  Conditions of disharmony are producedConditions of disharmony are produced
by four variables:by four variables:
1. Increased or decreased anatomic upper1. Increased or decreased anatomic upper
lip length (infrequently).lip length (infrequently).
2. Increased or decreased maxillary skeletal2. Increased or decreased maxillary skeletal
length (frequently).length (frequently).

39. 3. Thick upper lips expose less incisor than3. Thick upper lips expose less incisor than
thin upper lips.thin upper lips.
4. The angle of view changes the amount of4. The angle of view changes the amount of
incisor visible . The three variables thatincisor visible . The three variables that
contribute arecontribute are
(1) the patient's height,(1) the patient's height,
(2) the observer's height, and(2) the observer's height, and
(3) the distance from the facial surface of(3) the distance from the facial surface of
the upper lip to the incisive edge (increasedthe upper lip to the incisive edge (increased
lip thickness reveals less relative toothlip thickness reveals less relative tooth
exposure).exposure).

40. INTERLABIAL GAPINTERLABIAL GAP
is measured in relaxed lipis measured in relaxed lip
position from upper lip inferiorposition from upper lip inferior
(ULI) to lower lip superior(ULI) to lower lip superior
(LLS).(LLS).
1 to 5 mm1 to 5 mm
{ Females larger gap within{ Females larger gap within
the normal range}the normal range}
This measurement is alsoThis measurement is also
dependent on lip lengths anddependent on lip lengths and
vertical dentoskeletal height.vertical dentoskeletal height.

41. Increases in interlabialIncreases in interlabial
gapgap
1.} anatomic short1.} anatomic short
upper lip,upper lip,
2.} vertical maxillary2.} vertical maxillary
excess,excess,
3. } mandibular3. } mandibular
protrusion with openprotrusion with open
bite secondary tobite secondary to
cusp interferences.cusp interferences.

42.  Decreased interlabialDecreased interlabial
gapgap
1.} Vertical maxillary1.} Vertical maxillary
deficiency,deficiency,
2.}Anatomically long2.}Anatomically long
upper lipupper lip
3.}Mandibular retrusion3.}Mandibular retrusion
with deep bite.with deep bite.

43. CLOSED LIP POSITIONCLOSED LIP POSITION
Reveals disharmonyReveals disharmony
between skeletal andbetween skeletal and
soft tissue lengths.soft tissue lengths.
1.} Mentalis strain1.} Mentalis strain
2.} Lip strain, and2.} Lip strain, and
3.} Alar base narrowing3.} Alar base narrowing
can be observedcan be observed

44. Smile position lip levelSmile position lip level
Three-quarters of the crown height to 2 mm ofThree-quarters of the crown height to 2 mm of
gingivagingiva,,
{females more than males}{females more than males}
Variability in gingival exposure is related toVariability in gingival exposure is related to
(1) lip length,(1) lip length,
(2) vertical maxillary length,(2) vertical maxillary length,
(3) maxillary anatomic crown length, and(3) maxillary anatomic crown length, and
(4) magnitude of lip elevation with smile.(4) magnitude of lip elevation with smile.

45. Excess gingival exposure may be caused byExcess gingival exposure may be caused by
1.} a short upper lip1.} a short upper lip
2.}vertical maxillary excess2.}vertical maxillary excess
3.} short clinical crown, and/or3.} short clinical crown, and/or
4.} large lip elevation with smiling.4.} large lip elevation with smiling.

46. Surgical shortening of theSurgical shortening of the
maxilla is indicatedmaxilla is indicated
a.} increased interlabiala.} increased interlabial
gap,gap,
b.}increased toothb.}increased tooth
exposure,exposure,
c.}increased lower facec.}increased lower face
height,height,
d.] and/or mentalis strain.d.] and/or mentalis strain.

47. Deficient exposure etiologicDeficient exposure etiologic
factorsfactors
a.} a long upper lip,a.} a long upper lip,
b.} vertical maxillary deficiency,b.} vertical maxillary deficiency,
c.} and/or minimal smile lipc.} and/or minimal smile lip
elevation.elevation.
 Treated with maxillaryTreated with maxillary
lengtheninglengthening

48. In case of short clinical crowns A 3 to 4
mm repose incisor exposure may expose
unacceptable amounts of gingiva when
smiling
This situation can be treated by placing
normal length crowns (veneers) on the
maxillary incisors. The "gingival smile" is
never treated to ideal at the expense of
underexposing the incisors in the relaxed
lip position.

49. PROFILE VIEWPROFILE VIEW
To accurately assess profile.To accurately assess profile.
a.] Natural head posturea.] Natural head posture
b.] Centric relation, andb.] Centric relation, and
c.] Relaxed lipsc.] Relaxed lips

50. The angle is formed byThe angle is formed by
connecting soft tissueconnecting soft tissue
glabella, subnasale, andglabella, subnasale, and
soft tissue pogonion .soft tissue pogonion .

51. General harmony of the forehead, midface, and lower face is
appraised with this angle. Maxillary and mandibular basal bone
anteroposterior discrepancies are easily visualized.

53. CLASS I _165° to 175°
CLASS II < 165°
{maxillary protrusion (rare), vertical
maxillary excess (common), and
mandibular retrusion (common}
CLASS III >175°
{maxillary retrusion (common), vertical
maxillary deficiency (rare), and
mandibular protrusion (common).}

54. This angle is formedThis angle is formed
by the intersection ofby the intersection of
the upper lip anteriorthe upper lip anterior
and columella atand columella at
subnasalesubnasale
85° to 105°85° to 105°
{{Female more obtuse}Female more obtuse}

55. Factors to be considered in treatment planning to correctlyFactors to be considered in treatment planning to correctly
achieve this angle are as follows:achieve this angle are as follows:
1.1. Existing angle.Existing angle.
2.2. Tilting versus bodily movement of maxillary teethTilting versus bodily movement of maxillary teeth
3.3. Estimation of lip tension presentEstimation of lip tension present..
Tense lips move more posteriorly with tooth and basalTense lips move more posteriorly with tooth and basal
bone movement and less anteriorly. Flaccid lips maybone movement and less anteriorly. Flaccid lips may
move less with posterior tooth and basal bonemove less with posterior tooth and basal bone
movement and less with anterior.movement and less with anterior.
4.4. Anteroposterior lip thicknessAnteroposterior lip thickness..
Thin lips (6 to 10 mm) may move more with toothThin lips (6 to 10 mm) may move more with tooth
retraction movement than thick lips (12 to 20 mm)retraction movement than thick lips (12 to 20 mm)

56. 5.5. The magnitude of the mandibular retrusionThe magnitude of the mandibular retrusion
(overjet). The larger the overjet distance, the(overjet). The larger the overjet distance, the
more retraction of the maxillary incisors will bemore retraction of the maxillary incisors will be
necessary, thus opening the nasolabial angle.necessary, thus opening the nasolabial angle.
6. The following factors affect the anteroposterior6. The following factors affect the anteroposterior
movement of incisor teeth after extractions:movement of incisor teeth after extractions:
 Amount of anterior crowding,Amount of anterior crowding,
 Tooth mass proportion (upper versusTooth mass proportion (upper versus
lower), posterior rotations,lower), posterior rotations,
 Curve of Spee (upper versus lower), andCurve of Spee (upper versus lower), and
anchorage (headgear, Class II elastics).anchorage (headgear, Class II elastics).
 SpacesSpaces

57. 7. Extraction versus nonextraction.7. Extraction versus nonextraction.
8. Extraction pattern (first versus second premolars).8. Extraction pattern (first versus second premolars).
According to the author the maxilla should not be movedAccording to the author the maxilla should not be moved
posteriorly in treating dentofacial deformities, especiallyposteriorly in treating dentofacial deformities, especially
in combination with superior repositioning. This createsin combination with superior repositioning. This creates
nasal elongation, alar base depression, and opening ofnasal elongation, alar base depression, and opening of
the nasolabial angle, all of which create facial prematurethe nasolabial angle, all of which create facial premature
aging.aging.
Inadvertent maxillary retraction occurs with isolatedInadvertent maxillary retraction occurs with isolated
LeFort surgery when the VTO x-ray film is taken with theLeFort surgery when the VTO x-ray film is taken with the
condyles on the eminence rather than seated in thecondyles on the eminence rather than seated in the
fossa.fossa.

58. 1.} is gently curved15 and gives1.} is gently curved15 and gives
information regarding upper lipinformation regarding upper lip
tension .tension .
2.} Tense lip ------ the sulcus contour2.} Tense lip ------ the sulcus contour
flattens.flattens.
3.} Flaccid lips ---------accentuated3.} Flaccid lips ---------accentuated
curve with the vermilion lip areacurve with the vermilion lip area
showing an accentuation of .showing an accentuation of .
The maxilla should not be retractedThe maxilla should not be retracted
significantly when a deeply curved,significantly when a deeply curved,
thick lip is present since thisthick lip is present since this
produces poor lip support andproduces poor lip support and
cosmetics.cosmetics.

59. With lip tension, the sulcus contour
flattens.
Flaccid lips form an accentuated curve
with the vermilion lip area showing an
accentuation of curve.

60. Gently curved and canGently curved and can
indicate lip tension.indicate lip tension.

61. When deeply curved,------When deeply curved,------
maxillary incisor impingementmaxillary incisor impingement
in the case of deep bite Class IIin the case of deep bite Class II
and vertical maxillaryand vertical maxillary
deficiency.deficiency.
When flattened, the lowerWhen flattened, the lower
lip demonstrates tension oflip demonstrates tension of
tissues (Class III).tissues (Class III).

62. Orbital rim projection is measured from
the anterior most globe (Gb) to the
orbital rim point (OR).
The globe normally is positioned 2 to 4The globe normally is positioned 2 to 4
mm anterior to the orbital rimmm anterior to the orbital rim
is an anteroposterior indicator ofis an anteroposterior indicator of
maxillary position.maxillary position.
Deficient orbital rims may correlateDeficient orbital rims may correlate
positionally with a retruded maxillarypositionally with a retruded maxillary
position.position.
Deficient orbital rims dictate maxillaryDeficient orbital rims dictate maxillary
advancement, all other factors beingadvancement, all other factors being
equal.equal.

63. Requires frontal and profile examination simultaneously .Requires frontal and profile examination simultaneously .
Cheekbone contour (CC) correlates with maxillary anteroposterior position,Cheekbone contour (CC) correlates with maxillary anteroposterior position,
Cheekbone contour is used as one of the main indicators of maxillaryCheekbone contour is used as one of the main indicators of maxillary
retrusion.retrusion.

64. Cheekbone contour is anteriorly facing, curved line that starts just anterior to ear,
extending forward through cheekbone point (CP), then extending anterior-inferiorly
ending at maxilla point (MxP) adjacent to alar base of nose. For descriptive purposes
the cheekbone contour is divided into three areas: (1) zygomatic arch, (2) middle
contour area, and (3) subpupil areas. The CP is located 20 to 25 mm inferior and 5 to
10 mm anterior to the outer canthus (OC) of the eye when viewed in profile . When
viewed frontally the CP is 20 to 25 mm inferior and 5 to 10 mm lateral to the OC

65. The nasal base-lip contour (Nb-LC) extends inferiorly from
the maxilla point (MxP) as a gentle, anteriorly facing curve,
ending just below and lateral to the mouth commissure. In
normoskeletal patients the cheekbone-nasal base-lip contour
complex is a smooth continuation, anteriorly facing, curved
line.

66.  This area is an indicator of maxillary andThis area is an indicator of maxillary and
mandibular skeletal anteroposteriormandibular skeletal anteroposterior
position. The MxP is the most anteriorposition. The MxP is the most anterior
point on the continuum of the cheekbone-point on the continuum of the cheekbone-
nasal-lip contour and is an indication ofnasal-lip contour and is an indication of
maxillary anteroposterior position.maxillary anteroposterior position.

67. Maxillary retrusion is indicated
by a straight or concave
contour at MxP
Mandibular protrusion
interrupts the nasal base-lip
line in the length of the upper
lip

69. Nasal projection (NP) is measured from subnasale (Sn) to nasal
tip (NT). The lines through Sn and NT are perpendicular to the
floor when the head is in a natural postural position

70. Nasal projectionNasal projection
 The nasal projection (NP)The nasal projection (NP)
measured 16 to 20 mm .measured 16 to 20 mm .
 Nasal projection is an indicator ofNasal projection is an indicator of
maxillary anteroposterior position.maxillary anteroposterior position.
 This length becomes particularlyThis length becomes particularly
important when contemplatingimportant when contemplating
anterior movement of the maxilla.anterior movement of the maxilla.
 Decreased nasal projectionDecreased nasal projection
contraindicates maxillarycontraindicates maxillary
advancement.advancement.

71. Throat length (TL) is assessed from
neck-throat point (NTP) to soft tissue
menton (Me'). This distance is
subjectively described as either
normal, long or short length, and with
or without sag.
A patient with a short, sagging throatA patient with a short, sagging throat
length is not a good candidate forlength is not a good candidate for
mandibular setback.mandibular setback.
Chin augmentation to balance lips withChin augmentation to balance lips with
chin and maintain throat length.chin and maintain throat length.
Suction lipectomy.Suction lipectomy.

72.  Upper lip ---------3.5 mm ± 1.4Upper lip ---------3.5 mm ± 1.4
mm,mm,
 Lower lip -----------2.2 mm ± 1.6Lower lip -----------2.2 mm ± 1.6
mm.16mm.16
 Tooth movement changes theTooth movement changes the
relationship of the lips to the Sn-relationship of the lips to the Sn-
Pg' line and therefore thePg' line and therefore the
esthetic result.esthetic result.

73. The relationship of the lips to this line is affected by theThe relationship of the lips to this line is affected by the
following factors:following factors:
1.1. Skeletal relationshipSkeletal relationship: When anterior or posterior skeletal: When anterior or posterior skeletal
disharmony exists, producing overjet abnormalitiesdisharmony exists, producing overjet abnormalities
(positive or negative), the Sn-Pg' has no validity .(positive or negative), the Sn-Pg' has no validity .mustmust
be in used in skeletal class i cases onlybe in used in skeletal class i cases only
2.2. Incisor inclinationsIncisor inclinations: proper overjet and axial inclination to: proper overjet and axial inclination to
produce proper protrusion of the lips relative to the Sn-produce proper protrusion of the lips relative to the Sn-
Pg' line.Pg' line.
3.3. Lip thickness: The lip relationship to the Sn-Pg' line is
true only if the lips are the same thickness, all other
factors being ideal.

74.  With the 19 facial keys, 8 pure skeletalWith the 19 facial keys, 8 pure skeletal
deformities with predictable soft tissuedeformities with predictable soft tissue
appearances can be defined.appearances can be defined.
 Skeletal deformities may occur inSkeletal deformities may occur in
combination (i.e., vertical maxillary excesscombination (i.e., vertical maxillary excess
with mandibular prognathism) and facialwith mandibular prognathism) and facial
traits are therefore blended.traits are therefore blended.
 In all cases, facial traits are helpful inIn all cases, facial traits are helpful in
diagnosing skeletal problems. The eightdiagnosing skeletal problems. The eight
uncombined or pure or unmixeduncombined or pure or unmixed
anteroposterior facial-skeletal types are asanteroposterior facial-skeletal types are as
follows:follows:

75. Class I facial and dental (facialClass I facial and dental (facial
angle Class I)angle Class I)

78. Class II facial and dental (facialClass II facial and dental (facial
angle Class II)angle Class II)

81. Class III facial and dental (facialClass III facial and dental (facial
angle Class III)angle Class III)

85. ConclusionConclusion