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American Journal of ORTHODONTICS
and DENTOFACIAL ORTHOPEDICS
Founded in 1915
Volume 103 Number 5
May 1993
Copyright 9 1993 by the American Association of Orthodontists
SPECIAL ARTICLE
Facial keys to orthodontic diagnosis and treatment
planning--part H
G . William Arnett, DDS, ~ and Robert T. Bergman, DDS, MS b
Santa Barbara, Calif.
This isPart II of a two-part article. Part I was published in the AMERICANJOURNALOF ORTHODONTICS
AND DENTOFACIALORTHOPEDICS,"VoI. 103, No. 4. Part I discussed the problem of accurate orthodontic
diagnosis. Part I1 discusses the solution to the orthodontic diagnostic problem. (AM J ORTHOD
DENTOFAC ORTHOP 1993;103:395-411 .)
N i n e t e e n facial traits were selected for this
examination (Table I). Two views o f the patient are
used for identification of problems in three planes of
space:
I. Frontal
A. Relaxed lip
B. Functional analysis
1. Closed lip
2. Smile
II. Profile
A. Relaxed lip
FRONTAL VIEW
Natural head posture, centric relation, and relaxed
lip posture are used to accurately assess the frontal view.
Outline form and symmetry (Fig. 1)
General outline form and asymmetries are noted.'
The widest dimension o f the face is the zygomatic width
'Private Practice, Orthognathic Surgery; lecturer, orthognathic surgery at University of California at Los Angeles and Loma Linda University; clinical instructor, Orthognathic Surgery at University of California at Los Angeles and
Valley Medical Center; attending staff at St. Francis llospital and Cottage
Hospital, Santa Barbara.
bln private orthodontic practice.
Copyright 9 1993 by the American Association of Orthodontists.
0889-5406/93/Sl.00 + 0.10 811142808
Table I. Frontal and profile facial examination:
the 19 facial traits included in the facial
examination are listed
1. Frontal view
A. Outline form
B. Facial level
C. Midline alignments
D. Facial one-thirds
E. Lower one-third evaluation
I. Upper and lower lip lengths
2. Incisor to relaxed upper lip
3. Interlabial gap
4. Closed lip position
5. Smile-lip level
II. Profile view
A. Profile angle
B. Nasolabial angle
C. Maxillary sulcus contour
D. Mandibular sulcus contour
E. Orbital rim
F. Cheekbone contour
G. Nasal base-lip contour
H. Nasal projection
I. Throat length
J. Subnasale-pogonionline
(Fig. 1). The bigonial width is approximately 30% less
than the bizygomatie dimension. Farkas ''2 has established normal values for height and width. Tile height
to width proportion is 1.3:1 for females and 1.35:1 for
395
396
Arnett and Bergman
American Journal of Orthodontics and Dentofacial Orthopedics
May 1993
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Fig. 1. Facial height: Hairline (H) to soft tissue menton (Me')..
Facial widths: Zygomatic arch (ZA) to zygomatic arch (ZA),.
Gonion (Go') to gonion (Go').
males. An alternative to measuring height and widtiJ is
to artistically describe the face. Faces are wide or narrow, short or long, round or oval, square or rectangular.
The important question when assessing these dimensions is: Will orthodontic and/or surgical care necessary for bite correction correct or accentuate existing
height and width imbalance? An example of orthodontic
correction of height-width imbalance is the use of bite
opening mechanics to lengthen the face during bite corr e c t i o ~ An example of surgical correction is maxillary
impaction to shorten the long face.
The extremes of disproportion are short and wide
or long and narrow. Short, square facial outlines are
indicative of deep bite Class II malocclusion, vertical
maxillary deficiency, and in some cases, masseteric
hyperplasia. Long, narrow faces are associated with
vertical maxillary excess or mandibular protrusion with
dental interferences leading to open bite. The bizygomatic dimension is often deficient (cheekbone deficiency) in combination with maxillary retrusion. The
bigonial dimension may be deficient in combination
with mandibular retrusion.
Height and width disproportion is corrected in two
ways:
1. Maxillary or mandibular surgery is used simultaneously to correct the bite and to lengthen or
shorten the facial height.
"'. Augmentation or reduction of the facial height
or width.
Fig. 2. Pupil plane (PP) is horizontal line drawn through pupils.
This line is usually parallel to the horizon and is referred to as
frontal postural horizontal. Upper dental arch (UDA) level is a
line formed through the left and right maxillarycanine tips. Lower
dental arch (LDA) level is a line formed through the left and
right mandibular canine tips. Chin-jaw line (CJL) is assessed
by a line drawn on the under surface of the chin at maximum
iissue contact. All four lines should be parallel to each ether.
Examples of the latter are chin lengthening to increase facial height (H to Me'), cheekbone augmentation to increase the bizygomatic width (Zy to Zy), or
augmentation of the mandibular angles to increase the
bigonial dimension (Go' to Go'). Buccal lipectomies
can help reduce excessive width in the submalar cheek
areas.
As a general rule, the maxilla should rarely be
moved up and back. This movement decreases lip support, increases the nasolabial folds, decreases incisor
exposure, and can make the facial outline appear short
and wide. These changes give the appearance of premature facial aging.
The most common to least common sites of facial
asymmetry are chin, mandibular angles, and cheek~
bones. The maxilla is rarely in skeletal asymmetry.
Asymmetries can occur with any growth abnormality
but are strongly associated with unilateral condylar hyperplasia.
Correction of asymmetries are accomplished with
(1) cant correction or midline movement of the maxilla
and mandible simultaneous with occlusal correction or
(2) augmentation dr reduction of the skeletal surfaces.
Examples of the latter include unilateral cheekbone,
Arnelt and Berg/nan
American Journal of Orthodontics and Dentofacial Orthopedics
Volume 103. No. 5
397
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Fig. 3. Constructed horizontal reference line is formed by drawing line through pupil area parallel to floor. This line is used
when the pupil plane is not parallel to the floor (eyes are not
level) when the head is in frontal postural horizontal.
angle, or body augmentation. A common asymmetry
correction is chin shifting to the right or left to center
the chin on the facial midline.
Fig. 4. Important midline structures are assessed. Nasal bridge
(NB), nasal tip (NT), filtrurrt (F), upper incisor midline (UIM),
lower incisor midline (LIM), and chin midline point (Me') should
be on a line that is perpendicular to the frontal postural horizontal. Filtrum is usually the least asymmetric of these points
and is therefore generally used as a starting point for midline
structure assessment. All midline points may not line up. The
dental midlines and chin should be placed to integrate with other
midlines (most importantly the filtrum center).
Facial level (Fig. 2)
To examine facial levels a reliable horizontal landmark line is necessary. With the patient in natural head
posture, 3 the pupils are assessed for level with the horizon. If the pupils are level, they are used as the horizontal reference line and adjacent structures are measured relative to this line (Fig. 2). Structures compared
with the pupil line are (1) upper canine level, (2) lower
canine level, and (3) chin and jaw level.
Mandibular deviations commonly have upper and
lower occlusal cants with chin and jaw line canting
associated. Deviations from level should be noted and
correction integrated into the overall bite treatment
plan. If bimaxillary surgery is contemplated, occlusal
cant is corrected routinely at surgery. If one jaw surgery
is contemplated, the occlusal cant can be neglected
unless it is esthetically problematic. When problematic,
either orthodontic tooth movement or bimaxillary surgery must be used to correct the cant.
If the pupils, in natural head posture, are not level
to the horizon, a constructed frontal horizontal reference
line is used (Fig. 3). This line is visualized as follows:
I. Frontal natural head posture.
2. Horizontal line parallel to the horizon through
the pupil area.
3. Assess other structures relative to this line
(Fig. 3).
Midline alignments (Fig. 4)
Midlines are assessed with uppermost condyle position and first tooth contact. If occlusai slides alter
joint position, no reliable midline assessment can be
made. The relative positions of soft tissue landmarks
(nasal bridge, nasal tip, filtrum, chin point) and dental
midline landmarks (upper incisor midline, lower incisor
midline) are noted. Needed changes are incorporated
into the surgical/orthodontic treatment plan to position
these structures on the vertical midline of the face.
Filtrum is usually a reliable midline'structure and can
be used as the basis for midline assessment most often.
When the pupils are level in natural head posture, a
vertical line through filtrum midpoint is used to assess
..other hard and soft tissue midline structures (Fig. 4).
If the pupils are not level, a vertical line through filtrum
midpoint, perpendicular to postural horizontal, is used
to assess midline structures (Fig. 5). With the evalu-
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Arnett a/zd Bergman
American Journal of Orthodontics and Dentofacial Orthopedics
May 1993
1/3
Constructed
Posaa-alHorizontal
Middle 1/3
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Fig. 5. When pupils are not level, constructed horizontal reference line (Fig. 3) is used. A perpendicular to the constructed
horizontal line through filtrum is used to assess other midline
structures.
ation of skeletal or dental midlines, etiologic factors
are assigned.
Dental midline shifts are the result of multiple dental
factors including:
1. Spaces
2. Tooth rotations
3. Missing teeth
4. Buccally or lingually positioned teeth
5. Crowns or fillings which change tooth mass
6. Congenital tooth mass difference from left to
right
Model examination is used to distinguish dental
midline shift etiologic factors (spaces, rotations). Dental midline shifts are treated orthodontically. Asymmetric premolar extractions may be necessary to align
dental and skeletal midlines. Skeletal midline shifts are
not corrected orthodontically, surgery is employed.
When the dental and skeletal midlines deviate together,
the etiologic factor is usually skeletal, and surgery is
used to correct (i.e., chin and lower incisor midline are
3 mm to the left). Stability, periodontal health, and
facial balance are optimized when dental shifts the result of skeletal deviation are treated with surgical, ratherthan orthodontic, tooth movement. Attempts to orth-
Fig. 6. Face is .divided into thirds by drawing lines through
hairline (H), midbrow (Mb), subnasale (Sn), and soft tissue menton (Me').
odontically correct the bite when the etiologic factor is
skeletal can produce buccal plate violation and gingival
recession.4'~
Facial one thirds (Fig. 6)
The face divides vertically into thirds from hairline
to midbrow, midbrow to subnasale, and subnasale to
soft tissue menton (Fig. 6). The thirds are within a
range of 55 to 65 mm, vertically.' The hairline is variable, and the upper third is frequently low range. Increased lower one-third height is frequently found with
vertical maxillary excess and Class III malocclusions
(lack of interdigitation opens vertical height). Decreased lower one-third height is associated with vertical maxillary deficiency and mandibular retrusion
deep bites. Production of correct proportion influences
the choice of surgical procedure used to correct the
occlusion (i.e., maxillary impaction to correct Class II
malocclusion associated with long lower one-third
rather than mandibular advancement). The equality of
the middle and the lower thirds should not be used as
the determining factor in facial height changes. The
appearance of the landmarks (incisor exposure, interlabial gap) within the lower third are more important
in assessing balance than are the equality of the middle
and the lower thirds.
American Journal of Orthodontics and Dentofitcial Orthopedics
Vohtme 103, No. 5
Arnett and Berg/nan
309
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UTTL
Fig. 8. Incisor exposure is measured with lips relaxed from
SQ
Upper Lip Length
F,.
,
i
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Lower Lip Length
Me'
Fig. 7. With lips relaxed, lower third is subdivided by drawing
lines through subnasale (Sn), upper lip inferior (ULI), lower lip
superior (LLS), and soft tissue menton (Me'). The upper lip is
half the length of the lower.
Lower one-third evaluation (Figs. 7 through 9)
This area of facial analysis is extremely important
in surgical orthodontic diagnosis and treatment planning. The importance of relaxed lip position for these
measurements cannot be overemphasized.
Upper and lower lip lengths (Fig. 7). The lips are
measured independently in a relaxed position (Fig. 7).
The normal length from subnasale to upper lip inferior
is 19 to 22 mm. x 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).
The lower lip is measured from lower lip superior
to soft tissue menton and normally measures in a range
of 38 to 44 mm. ~Anatomic short lower lip is sometimes
associated with Class II malocclusion and is verified
by cephalometric measurement of the lower anterior
dental height (lower incisor tip to hard tigsue menton;
women, 40 mm + 2 mm, and men, 44 mm - 2 mm).6
Anatomic short lower lip should not be confused with
a short lower lip secondary to posture (upper incisor
interferences) seen in Class II deep bite cases with normal anterior dental height. Anatomic short lower lip
can be lengthened with a lengthening genioplasty.
upper lip inferior (ULI) to maxillary incisor edge (MxlE). The
upper tooth to lip (UTTL) is the vertical dimension of the incisor
exposed between ULI and MxlE.
Anatomic long lower lip can be associated with
Class III malocclusions. This should be verified with
the cephalometric anterior dental height measurement.
A closed lip position will produce a long lower lip in
combination with increased lower facial height (vertical
maxillary excess and Class II1) as the lip elongates to
close. The closed lip length is misleading and should
not be used for treatment planning. The normal ratio
of upper to lower lip is 1:2. j Proportionate lips harmonize regardless of length; disproportionate lips may
need length modification to appear in balance. Lip measurements identify normal or abnormal soft tissue length
that can be related to dentoskeletal length normalcy,
excess, or deficiency.
Lip redundancy is seen in cases of vertical maxillary
deficiency and mandibular retrusion with deep bite and,
rarely, long lip lengths. To accurately assess lip lengths
with redundant lips, the patient's bite must be opened
until the lips separate (Figs. 7). ~ This is best accomplished with a pink base plate wax bite used to open
the bite on centric relation (no translation), t The face
is examined in that posture, and vertical skeletal increases are planned.
Upper tooth to lip relationship (Fig. 8). The distance from upper lip inferior to maxillary incisal edge
is measured (Fig. 8). The normal range is 1 to 5 mm.t
Women show more within this range. Surgical and
orthodontic vertical changes are based primarily on this
measurement (i.e., postsurgical incisor exposure range
oflto5mm).
Conditions of disharmony are produced by four
variables:
1. Increased or decreased anatomic upper lip length
(infrequently).
2. Increased or decreased maxillary skeletal length
(frequently).
400
Arnett and Bergman
American Journal of Orthodontics and Dentofacial Orthopedics
May 1993
r .}
Interlabial Gap
LI.~
Fig. 9. Interlabial gap is measured in relaxed lip position from
upper lip inferior (ULI) to lower lip superior (LLS).
3. Thick upper lips expose less incisor than thin
upper lips, all other factors being equal.
4. The angle of view changes the amount of incisor
visible to the viewer. The three variables that
contribute to the angle of view are (1) the patient's height, (2) the observer's height, and (3)
the distance from the facial surface of the upper
lip to the incisive edge (increased lip thickness
reveals less relative tooth exposure).
Overimpaction of upper incisor teeth leads to the
appearance of premature aging, especially in conjunction with maxillary retraction. This type of surgical
movement is rarely indicated. Posterior movement of
the maxillary incisors is indicated only for true maxillary protrusion. Orthodontic overretraction, which is
used to occlusally correct mandibular retrusion, produces premature aging of the face.
lnterlabial gap (Fig. 9). With the lips relaxed, a
space of 1 to 5 mm ~ between upper lip inferior and
lower lip superior is present (Fig. 9). Females show a
larger gap within the normal range." This measurement
is also dependent on lip lengths and vertical dentoskeletal height.
Increases in interlabial gap are seen with anatomic
short upper lip, vertical maxillary excess, and mandibular protrusion with open bite secondary to cusp interferences. Decreased interlabial gap is found with vertical maxillary deficiency, anatomically long upper lip
(natural change with aging, especially in males), and
mandibular retrusion with deep bite. Abnormalities
should be considered when planning skeletal changes.
An anatomically short upper lip should be recognized
as a soft tissue problem and should not be treated by
excessively shortening the maxilla. This can lead to a
short, round facial outline.
Closed lip position. Even though an understanding
of relaxed lip position is essential, an understanding of
closed lip position adds support to diagnostic patterns.
The closed lip position also reveals disharmony between
skeletal and soft tissue lengths.
Increased mentalis contraction (mentalis strain), lip
strain, and alar base narrowing are observed in vertical
skeletal excess, anatomic short upper lip and some cases
of mandibular protrusion with open bite.
Lip redundancy is seen with vertical maxillary deficiency and mandibular retrusion with deep bite. With
balanced lip and skeletal lengths, the lips should ideally
close from a relaxed, separated position without lip,
mentalis, or alar base strain. The maxilla should not be
impacted to idealize the short upper lip closure unless
the facial outline will tolerate such a change.
Smile positidn lip level. When examining the smile
posture, different lip elevations are observed in normal
and abnormal skeletal patterns. Ideal exposure with
smile is three-quarters of the crown height to 2 mm of
gingiva, females more than males.~ Variability in gingival exposure is related to (I) lip length, (2) vertical
maxillary length, (3) maxillary anatomic crown length,
and (4) magnitude of lip elevation with smile.
Excess gingival exposure may be caused by a short
upper lip, vertical maxillary excess, short clinical
crown, and/or large lip elevation with smiling. Because
of etiologic variability, surgical shortening of the maxilla is indicated only when excess gingival exposure is
found in combination with increased interlabial gap,
increased tooth exposure, increased lower face height,
and/or mentalis strain.
Deficient exposure etiologic factors include a long
upper lip, vertical maxillary deficiency, and/or minimal
smile lip elevation. Decreased incisor exposure is
treated with maxillary lengthening when found in combination with decreased interlabial gap-lip redundancy,
short lower one-third face height, and normal upper lip
length.
When impacting or lengthening the maxilla on the
basis of reposed incisor exposure, gingival smile exposure should also be considered. For example, if the
patient has normal smile gingival exposure (1 to 2 mm)
and the incisors are lengthened to treat decreased relaxed lip incisor exposure, excessive smile gingival exposure will result.
Particular care should be taken with short clinical
Arnetl and Bergman
American Journal of Orthodontics and Dentofacial Orthopedics
Volume 103, No. 5
401
G,
Sn
Fig. 10. Profile angle is measured by connecting points glabella
(G'), subnasale (Sn), and soft tissue pogonion (Pg'). The angle
is measured on the left hand side with the patient facing right.
crowns. A 3 to 4 mm repose incisor exposure may
expose unacceptable amounts of gingiva when smiling
because of short maxillary incisor crowns. This situation is properly treated by placing normal length crowns
(veneers) on the maxillary incisors and treatment planning from the repose and smile perspective. The "gingival smile" is never treated to ideal at the expense of
underexposing the incisors in the relaxed lip position.
PROFILE VIEW
Natural head posture, centric relation, and relaxed
lips are used to accurately assess profile.'
Profile angle (Fig. 10)
This angle is formed by connecting soft tissue glabelle, subnasale, and soft tissue pogonion'(Fig. 10). 7.8
General harmony of the forehead, midface, and lower
face is appraised with this angle. Maxillary and mandibular basal bone anteroposterior discrepancies are
easily visualized. Class I occlusion presents a total facial angle range of 165 ~ to 175~ ' Class II angles are
less than 165~ and Class III are greater than 175 ~
Skeletal discrepancies producing Class II angulation
Fig. 11. Nasolabial angle is developed by connecting columella
line (inferior nasal septum) (C), subnasaTe (Sn), and upper lip
anterior point (ULA).
include maxillary protrusion (rare), vertical maxillary
excess (common), and mandibular retrusion (common).
Class III skeletal patterns include maxillary retrusion
(common), vertical maxillary deficiency (rare), and
mandibular protrusion (common).
Surgical procedures should generally address the
cosmetic imbalance established with this angle. The
profile angle is the most important key to the need for
anteroposterior surgical correction. When values are
less than 165~ or greater than 175 ~ skeletal malocclusions needing surgery are probably the cause. Angles
at the extreme of normal (greater than 175~ or less than
165~) are usually caused by skeletal disharmony. Soft
tissue thickness differences are not capable of causing
these extreme angle changes.
Nasolablal angle (Fig. 11)
This angle is formed by the intersection of the upper
lip anterior and columella at subnasale (Fig. 11). This
angle can change noticeably with orthodontic and surgical procedures that alter the anteroposterior position
or inclination of the maxillary anterior teeth. 9I' All
procedures should place this angle in the cosmetically
402
A rnetl altd Hergma/z
American Journal of Orthodontics and Dentofacial Orthopedics
May 1993
mass proportion (upper versus lower), posterior rotations, curve of Spee (upper versus
lower), and anchorage (headgear, Class II
elastics).
7. Extraction versus nonextraction.
8. Extraction pattern (first versus second premolars).
MxSC
Fig. 12. Maxillary sulcus contour (MxSC) is subjectively assessed. The contour is described as either accentuated, gentle
curve (normal) or flat. Measurement of this contour is impractical.
If the nasolabial angle is open (approximately,105~
retraction of anterior teeth orthodontically and surgically should be avoided in treatment planning. Likewise, a long nose will become adversely prominent with
lip retraction. Present limited knowledge of how lips
respond to anteroposterior movement of the teeth dictates a conservative approach when large movements
are contemplated. Crowding dictates the need for extraction, facial balance influences which teeth are extracted and how spaces are closed.
Surgical movement of the maxilla also affects the
nasolabial angle. The same factors that affect orthodontic change should be analyzed when considering
maxillary movement. As a general rule, the m a x i l l a
should not be moved posteriorly in treating dentofacial
deformities, especially in combination with superior
repositioning. This creates nasal elongation, alar base
depression, and opening of the nasolabial angle, all of
which create facial premature aging. Inadvertent maxillary retraction occurs with isolated LeFort surgery
when the VTO x-ray film is taken with the condyles
on the eminence rather than seated in the fossa.
Maxillary sulcus contour (Fig. 12)
desirable range of 85 ~ to 105~ I Female patients will
usually be more obtuse within this range. Factors to be
considered in treatment planning to correctly achieve
this angle are as follows:
I. Existing angle.
2. Tilting versus bodily movement of maxillary
teeth (orthodontic and surgical) and predicted
effect on the existing lip position.
3. Estimation of lip tension present. Tense lips may
move more posteriorly with tooth and basal bone
movement and less anteriorly. Flaccid lips may
move less with posterior tooth and basal bone
movement and less with anterior.'-""
4. Anteroposterior lip thickness. Thin lips (6 to 10
ram) 9"12"~3may move more with tooth retraction
movement than thick lips (12 to 20 mm). I-''~4
5. The magnitude of the mandibular retrusion
(overjet). The larger the overjet distance, the
more retraction of the maxillary incisors will be
necessary, thus opening the nasolabial angle..gL'z
6. The following factors affect the anteroposterior
movement of incisor teeth after extractions:
Amount of anterior crowding, spaces, tooth
Normally this sulcus is gently curved 15 and gives
information regarding upper lip tension (Fig. 12). With
lip tension, the sulcus contour flattens. Flaccid lips form
an accentuated curve with the vermilion lip area showing an accentuation of curve. ,2 The flaccid lip generally
is thick (12 to 20 mm from anterior vermilion to labial
incisor) giving the lip (i.e., headgear with Class II elastics or functional appliance treatment) the appearance
of beingtoo far forward relative to the teeth. '2 The
maxilla should not be retracted significantly when a
deeply curved, thick lip is present since this produces
poor lip support and cosmetics. If possible, the maxilla
should be moved forward into a thick, curved lip to
improve lip support.
Mandibular sulcus contour (Fig. 13)
This contour is a gentle curve '~ (Fig. 13) and can
indicate lip tension. When deeply curved, the lower lip
is flaccid in character (Class I1, vertical maxillar3/deficiency). The deep curve is usually secondary to maxillary incisor impingement in the case of deep bite Class
II and vertical maxillary deficiency. When flattened,
the lower lip demonstrates tension of tissues (Class I11).
Arnett and Bergman
American Journal of Orthodontics and Dentofacial Orthopedics
Volume 103, No. 5
403
O~
(.
M~SC
Fig. 13. Mandibular sulcus contour (MdSC) is subjectively assessed. The contour is either accentuated, gentle curve (normal) or flat. Measurement of this contour is impractical.
Fig. 14. Orbital rim projection is measured from the anterior
most globe (Gb)to the orbital rim point (OR).A subjective orbital
rim description is also given: Normal, flat, or protruded.
Surgical procedures that correct the basal bone generally will improve the mandibular sulcus angle (i.e.,
deep contour associated with deep bite Class II malocclusion or flatness associated with mandibular protrusion).
deficient in combination with maxillary retrusion. Deficient cheekbones may correlate positionally with a
retruded maxillary position because the osseous structures are often deficient as groups, rather than in isolation. Cheekbone contour is used as one of the main
indicators of maxillary retrusion. This area should have
an apex at the cheekbone point (CP) and not appear
fiat. 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 (Fig. 15). When viewed frontally the CP is 20 to 25 mm inferior and 5 to 10 mm
lateral to the OC (Fig. 16). It should be noted that true
mandibular prognathism can show mild malar flatness
as a relative observation to the extreme chin protrusion.
True maxillary hypoplasia often is associated with true
malar deficiency.
Orbital rim(Fig. 14)
The orbital rim is an anteroposterior indicator of
maxillary position. Deficient orbital rims may correlate
positionally with a retruded maxillary position because
the osseous structures are often deficient as groups,
rather than in isolation. The globe normally is positioned 2 to 4 mm anterior to the orbital rim (Fig. 14). t
The surgical maxillary versus mandibular decision is
influenced by the orbital rim position. Deficient orbital
rims dictate maxillary advancement, all other factors
being equal.
Nasal base-lip contour (Figs. 15 and 16)
Cheekbone contour (Figs. 15 and 16)
Cheekbone assessment requires frontal and profile
examination simultaneously (Figs. 15 and 16). Cheekbone contour (CC) correlates with maxillary anteroposterior position, frequently the cheekbone contour is
The nasal base-lip contour (Nb-LC) line requires
-'-frontal and profile examination simultaneously (Figs.
15 and 16). The line is the continuation of the cheekbone contour line. This area is an indicator of maxillary
and mandibular skeletal anteroposterior position. Nor-
404
Arlzell atzd Bergman
American Jot*rnal of Orthodontics and Dentofacial Orthopedics
May 1993
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Figs. 15 and 16. Cheekbone contour is anteriorly facing, curved line that starts just anterior to ear,
extending forward through cheekbone point (CP), then extending anteridr-inferiorly ending at maxilla
point (MxP) adjacent to alar base of nose. F.ordescriptive purposes the cheekbone contour is divided
into three areas: (1) zygomatic arch, (2) middle contour area, and (3) subpupil areas. These three
areas, when taken together, constitute the cheekbone contour. Reconstruction of cheekbone contour,
when deficient, should analyze all three parts separately in terms of correction. CP and MxP indicates
osseous cheekbone and maxillary base positions, respectively. 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. This line, when viewed frontally or
from the side, is a definite flowing curve with no interruptions which are apparent with skeletal deformities.
Maxillary Retrusion
h
mal position is indicated by the maxilla point (MxP)
directly behind the alar base. The MxP is the most
anterior point on the continuum of the cheekbone-nasallip contour and is an indication of maxillary anteroposterior position.
Maxillary retrusion is indicated by a straight or concave contour at MxP (Fig. 17). When this anatomic
area is concave or fiat, maxillary advancement is necessary.
Mandibular protrusion interrupts the nasal base-lip
line in the length of the upper lip (Fig. 18). When the
line is interrupted within the height of the upper lip a
mandibular setback may be indicated.
Nasal projection (Fig. 19)
The nasal projection (NP) measured horizontally
from subnasale to nasal tip is normally 16 to 20 mm
Fig. 17. Maxillary retrusion: Cheekbone-nasal base-lip curve is
interrupted at MxP.
American Journal of Orthodontics and Dentofacial Orthopedics
Volume 103, No. 5
Arnelt and Bergnlan
405
Mandibular Protrusion
NP
NT
Fig. 18. Mandibular protrusion: Cheekbone-nasal base-lip curve
is interrupted in upper lip area.
(Fig. 19).' Nasal projection is an indicator of maxillary
anteroposterior position. This length becomes particularly important when contemplating anterior movement
of the maxilla. Decreased nasal projection contraindicates maxillary advancement. With a Class III malocclusion, short nose, and all other factors equal,9 mandibular setback is indicated.
Fig. 19. 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.
Throat length and contour (Fig. 20)
The distance from the neck-throat junction to the
soft tissue menton should be noted (Fig. 20). No millimeter measurement is necessary, but a planned mandibular setback will change this length. The predicted
esthetic result should produce a normal appearing length
without sagging. A patient with a short, sagging throat
length is not a good candidate for mandibular setback.
A long, straight throat length is amenable to mandibular
setback. Often a mandibular setback is necessary with
chin augmentation to balance lips with chin and maintain throat length. Suction lipectomy is a useful adjunct
for controlling submental sag with setbacks or when
isolated fat accumulation is present.
Subnasale-pogonion line (Sn-Pg') (Fig. 21)
Burstone reported that the upper lip is in front of
the Sn-Pg' line by 3.5 mm • 1.4 mm, and the lower
lip is in front of the line by 2.2 mm --- 1.6 mm. 16
The relationship of the lips to the Sn-Pg' line is an
important aid in orthodontic soft tissue analysis and
treatment. Tooth movement changes the relationship of
the lips to the Sn-Pg' line and therefore the esthetic
Fig. 20. 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.
406
Arnett and Bergman
American Journal of Orthodontics and Demofacial Orthopedics
May 1993
lips through subnasale. If Pg' is significantly posterior
to the line, a chin augmentation is indicated. Female
chins are softer relative to this line.
SOFT TISSUE CHARACTERISTICS OF COMMON
SKELETAL DEFORMITIES
Sn
Fig. 21. Subnasale-pogonion reference line is generated
through points subnasale (Sn) and soft tissue pogonion (Pg').
Lip projections are evaluated relative to this line.
result. All tooth movements should be assessed in regard to the anticipated lip change to the Sn-Pg' line.
Extractions should be avoided when they move the teeth
and create retraction of the lips (dished-in) behind this
line (Fig. 22). On the other hand, if unravelling the
crowding with extractions allows for lip balance to the
Sn-Pg' line, the extractions are esthetically acceptable.
The relationship of the lips to this line is affected
by the following factors:
1. Skeletal relationship: When anterior or posterior
skeletal disharmony exists, producing overjet
abnormalities (positive or negative), the Sn-Pg'
has no validity.
2. Incisor inclinations: With a Class I skeletal pattern, the upper and lower incisors must be at
proper overjet and axial inclination to produce
proper protrusion of the lips relative to the SnPg' line.
3. Lip thickness: The lip relationship to the Sn-Pg'
line is dependent on lip thickness. The Burstone
relationship t6 is true only if the lips are the same
thickness, all other factors being ideal. Class I
incisors (upper incisor in front of lower incisor)
produce Class I lips (upper lip in front of lower
lip) only if the lips are of equal thickness.
This line is also used when planning surgery on the
VTO (Fig. 23). The Sn-Pg' line is ideally drawn to the
With the 19 facial keys, 8 pure skeletal deformities
with predictable soft tissue appearances can be defined.
The greater magnitude of the skeletal deformity the
more distinct the soft tissue pattern. Skeletal deformities
may occur hz combination (i.e., vertical maxillary excess with mandibular prognathism) and facial traits are
therefore blended. In all cases, facial traits are helpful
in diagnosing skeletal problems. The eight uncombined
or pure or unmixed anteroposterior facial-skeletal types
are as follows:
A. Class I facial and dental (facial angle Class l)
(Fig. 24)
1. Vertical maxillary excess (Table lI)
2. Vertical maxillary deficiency (Table III)
B. Class II facial and dental (facial angle Class II)
(Fig. 25)
3. Maxillary protrusion (Table IV)
4. Vertical maxillary excess (Table II)
5. Mandibular retrusion (Table V)
C. Class III facial and dental (facial angle Class III)
(Fig. 26)
6. Maxillary retrusion (Table VI)
7. Vertical maxillary deficiency (Table Ill)
8. Mandibular protrusion (Table VII)
Knowing the eight unmixed skeletal patterns is helpful in organizing facial analysis information into a cohesive, meaningful whole. Without facial analysis, distinguishing the skeletal source of the malocclusion can
be difficult. Facial trait identification and categorization
leads to a differential diagnosis of skeletal patterns
(Table VIII Class II, Table IX Class Ill). Cephalometric
analysis has been shown to be ineffective in this regard.
The advantage of a diagnosis based on facial traits is
important. Skeletal malocclusions have profound soft
tissue imbalance that patients expect to be corrected.
Facial based treatment planning ensures that facial
change will be correct, whereas cephalometrics have
been shown to he unreliable.
ORTHODONTIC PREPARATION FOR SURGERY
Facial and dental discrepancies may not be proportionate because of dental compensations to the anteroposterior skeletal malalignment. ~7 Dental compensations are incisor axial inclination changes in response
to increased or decreased overjet. Mandibular retrusion
and, occasionally, vertical maxillary excess are associated with lower incisor flaring and upper incisor up-
American Journal of OrthtMontics and Dente~acial Orthopedics
Volume 103, No. 5
Arnett and Bergman
407
~'~'Sn
'
/
A
:'
Fig. 22. A, Normal lip relationship to Sn-Pg' line. B, Premature aging associated with premolar extractions and incisor retraction. The lips fall on or behind the Sn.~Pg' line giving the "dished-in" orthodontic
appearance. The nasolabial angle may also open to unacceptable ranges.
righting. Mandibular protrusion, maxillary retrusion
and vertical maxillary deficiency are associated ~vith
upper incisor flaring and lower incisor uprighting.
Extraction patterns and mechanics are aimed at removing dental compensations.before surgery. Compensation removal leads to better facial results. An example
of this is a 10 mm skeletal mandibular retrusion. Incisor
dental compensations to the overjet may decrease the
10 mm overjet to 5 ram. If the mandible is advanced
with the compensations present, the chin deficiency is
still 5 mm. In contrast, when dental compensations are
removed, the 10 mm overjet and 10 mm chin retrusion
are simultaneously and totally corrected with surgical
advancement.
Inappropriate orthodontic preparation (e.g., upper
first premolar extractions, headgear and Class II elastics
to treat a skeletal mandibular retrusion) distorts the
equality of the dental and facial problems far more than
dental compensations. In an attempt to correct the bite
without surgery, the dental discrepancy becomes much
less than the facial discrepancy magnitude. Subsequently, if surgery is used for dental correction, the soft
tissue problem is only minimally corrected. This problem leads to the conclusion that surgery should be
planned from the beginning to obtain optimal facial
changes with bite correction.'7"~ Extractions should be
planned around factors including, most importantly,
crowding, periodontal needs, and facial implications.
Generally, extraction patterns decrease dental compensation to the incisor overjet problem.
The most common appropriate extractions for routine facial-skeletal deformities are as follows:
r
Sn
Ideal
t pg'
lk
NeededChl.e
Augmmtatloe
Fig. 23. Sn-Pg' line is frequently used to surgically assess chinlip-nasal base balance. With the v-ro occlusion in Class I, the
line is oriented from Sn through ideal lip position. If Pg' falls on
the chin, balance of chin-lip-nasal base is ideal. If Pg' falls
behind the line, a chin advancement is necessary to obtain
balance.
A. Class 1 facial and dental (chin in balance with
the face)
1. Vertical maxillary excessIvariable
2. Vertical maxillary deficiencyIvariable
408
American Journal of Orthodontics and Dentofaeial Orthopedics
May 1993
Arnett and Bergman
CLASS I's
Oe ien
Fig, 24. Class I occlusion and chin projection can occur in combination with vertical maxillary excess
or vertical maxillary deficiency. The anteropOsterior profile is normal, but the vertical height of the face
is long or short.
4'
Table II. Vertical maxillary excess: c o m m o n
facial characteristics o f vertical maxillary
excess are listed
Vertical maxillary excess
Increased lower one-third
Increased interlabial gap
Increased incisor exposure
Increased gingival smile
Mentalis strain
Decreased total profile angle*
Accentuated mandibular sulcus contour
Decreased throat length
Normal nasal projection
Normal nasotabial angle
Table Ill. Vertical maxillary deficiency: c o m m o n
facial characteristics o f vertical maxillary
deficiency are listed
Vertical maxillary deficiency
Decreased lower one-third
Decreased interlabial gap
Decreased incisor exposure
Decreased incisor exposure with smile
Lip redundancy
Straight to Class Ill profile angle*
Accentuated mandibular sulcus contour
Normal nasal projection
Normal to decreased nasolabial angle
Increased throat length
Normal cheekbones, alar base
*Class I VME can have a normal total facial angle.
*Class I VMD can have a normal total facial angle.
B. Class II facial and dental (chin retruded)
1. Maxillary p r o t r u s i o n - - l o w e r second a n d / o r
upper first premolars, orthodontic correction.
No surgery required.
2. Vertical maxillary e x c e s s - - u p p e r extraction
based on extent and location o f crowding,
lower extraction based on effects on upper lip
support when LeFort I is done to correct vertical maxillary excess.
3. Mandibular r e t r u s i o n - - u p p e r second premolar a n d / o r lower first premolars
.....
C. Class III facial and dental (chin protruded)
1, Maxillary r e t r u s i o n - - u p p e r first and lower
second premolars
2. Vertical maxillary d e f i c i e n c y - - u p p e r first and
lower second premolars
3. Mandibular p r o t r u s i o n - - u p p e r first and lower
second premolars
An additional benefit o f the surgical extraction pattern is that the anticipated surgical relapse becomes the
opposite o f the orthodontic relapse pattern. An example
o f this is mandibular advancement with lower first pre-
Arnell and Bergman
American Journal of Orthtxlontics and Dentofacia/ Orthopedics
Volume 103, No. 5
Class II's
409
Exce~
-<~
/
Fig. 25. Class II bite and chin projection can be produced by entirely different skeletal patterns. Maxillary
protrusion, mandibular retrusion and vertical maxillary excess all can produce identical bites with similar
chin profiles. The a r r o w s indicate the skeletal abnormality responsible for the bite and profile disharmony.
Class III's
V~llary
Deficienc'~
(.
Fig. 26. Class III bite and chin projection can be produced by entirely different skeletal patterns.
Maxillary retrusion, mandibular protrusion, and vertical maxillarydeficiency all can demonstrate identical
Class III bite and similar profile characteristics. The a r r o w s indicate the skeletal abnormality responsible
for bite and facial profile disharmony.
molar extractions that have uprighted the lower incisors.
Surgical relapse is posterior, and orthodontic relapse at
the lower incisors is anterior, in the opposite direction.
The orthodontic relapse is a mechanism to compensate
for surgical relapse.
CONCLUSION
Orthodontists use dental and facial keys to diagnose
and to treat malocclusions. Dental keys include overjet,
c~fiine occlusion, and molar occlusion. The dental keys
are given much weight in the determination of treat-
410
Arnett and Bergman
Table IV. M a x i l l a r y protrusion: c o m m o n facial
characteristics o f maxillary protrusion are listed
Marillary protrusion*
Normal lower one-third
Normal interlabial gap
Normal incisor exposure
Normal smile
Decreased profile angle
Normal mandibular sulcus contour
Normal throat length
Normal to short nasal projection
Decreased nasolabial angle
*Skeletal maxillary protrusion is rare.
American Journal of Orthodontics and Dentofacial Orthopedics
May 1993
Table VI. M a x i l l a r y retrusion: c o m m o n facial
characteristics o f m a x i l l a r y retrusion are listed
Mo.rillary retrusion
Normal lower one-third
Normal interlabial gap
Normal incisor exposure
Normal smile
No mentalis strain
Straight to Class I!I profile angle
Normal mandibular sulcus contour
Increased nasal projection
Nasal base deficiency
Cheekbone/orbital rim deficiency
Normal to increased nasolabial angle
Normal throat length
Table V. M a n d i b u l a r retrusion: c o m m o n facial
characteristics o f m a n d i b u l a r retrusion
are listed
Mandibular retrusion
Decreased or normal lower one-third
Decreased or normal interlabial gap
Normal incisor exposure
Normal smile
Normal-to-lip redundancy
Decreased profile angle
Accentuated mandibular sulcus contour
Decreased throat length
Normal nasolabial angle
Normal nasal projection
merit. Facial keys are not used by s o m e orthodontists
and sparingly by others. Typically, facial keys used by
orthodontists include the relative positions o f the upper
lip, l o w e r lip, and chin. T h e s e g i v e information, but
o n l y limited insight into the c o m p r e h e n s i v e diagnosis.
In contrast, we have presented an o r g a n i z e d , c o m prehensive approach to facial analysis. With this analysis normal facial traits are maintained and abnormal
characteristics are corrected with orthodontics and surgery. Information f r o m facial e x a m i n a t i o n o f the patient
dictates which procedures result in optimal cosmetics
with Class I function. M e r e correction to Class 1 occlusion can g i v e r a n d o m , and often poor, c o s m e t i c resuits. Further, arbitrary correction to Class I occlusion
does not ensure even presurgical c o s m e t i c levels, therefore esthetic guidelines must be f o l l o w e d w h e n determining surgical orthodontic plans: For this purpose 19
key traits have been described.
REFERENCES
I. Amett GW, Bergman RT. Facial Keys to Orthodontic Diagnosis
and Treatment Planning - Part I. AM J ORrHODDEN'I-OFACORTIIOP
1993;103:299-312.
T a b l e VII. M a n d i b u l a r protrusion: c o m m o n
facial characteristics o f mandibular protrusion
are listed
Mandibular protrusion (may have increased vertical
secondary to lack of dental interdigitation)
Normal to increased lower one-third
Normal to increased interlabial gap
Normal inciso~"exposure
Normal tooth exposure with smile
No increased mentalis strain
Straight to Class III profile angle
Normal to flat mandibular sulcus contour
Normal nasal projection, alar base, and cheekbones
Normal nasolabial angle
Increased throat length
2. Farkas LG. Anthropometry of the head and face in medicine.
New York: Elsevier North Holland Inc, 1981.
3. Moorrees CFA, Keen MR. Natural head position, a basic consideration in the interpretation of cephalomctrie radiographs. Am
J Phys Anthropol 1958;16:213-34.
4. Wennstrom JL, Lindhe J, Sinclair F, Thilander B. Some periodontal tissue reactions to orthodontic tooth movement in monkeys. J Clin Periodontol 1987;14:121-9.
5. Sadowsky C, Begole E. Long-tern1 effects of orthodontic treatment on periodontal health. AM J ORmOO 1981;80:156-72.
6. Wolford LM, ltilliard FW, Dugan DJ. Surgical treatment objective. St. Louis: CV Mosby, 1985.
7. Legan HL, Burstone CJ. Soft tissue cephalometric analysis for
orthognathic surgery. J Oral Surg 1980;38:744-51.
8. Burstone CJ. The integumental profile. AM J OR'roOD1958;44:125.
9. Talass MF, Baker RC. Soft tissue profile changes resulting from
retraction of maxillary incisors. AM J ORTttODDEN'I'OFACOR'HIOP
! 987;9 ! (5):385-94.
10. Drobocky OB, Smith RJ. Changes in facial profile during orthodontic treatment with extraction of four first premolars. AM J
ORTIIOD DENTOFACORTIIOP 1989;95(5):220-30.
I I. Lo FD, Hunter WS. Changes in nasolabial angle related to maxillary incisor retraction. Ar,t J OR'roOD 1982;82:384-91.
12. tloldaway RA. A soft-tissue cephalometric analysis and its use
Arnell and Bergtnan
American Journal of Orthodontics and Dentofacial Orthopedics
~?dume 103, No. 5
411
T a b l e VIII. C l a s s II m a l o c c l u s i o n s c a n b e p r o d u c e d b y m a n d i b u l a r r e t r u s i o n ( m o s t c o m m o n ) , m a x i l l a r y
p r o t r u s i o n (rare*), o r vertical m a x i l l a r y e x c e s s ( c o m m o n ) . (Facial traits in the facial a n a l y s i s o f this article
d i s t i n g u i s h a m o n g t h e s e skeletal p r o b l e m s )
Class II profiles
Mandibular retrusion
Lower one-third
lnterlabial gap
Incisor exposure
Smile
Mentalis strain
Profile angle
Mandibular sulcus contour
Nasal projection
Alar base
Cheekbone
Nasolabial angle
Throat length
J
Normal to decreased (1)
Normal to decreased (I)
Normal
Normal
Yes (2)
Decreased
Increased (2)
Normal
Normal
Normal
Normal
Decreased
Maxi'laD"protrusion
I
Normal
Normal
Normal
Normal
Yes (2)
Normal to decreased
Increased (2)
Normal to short
Normal to increased
Normal
Decreased
Normal
Vertical tncL~illaryexcess
Increased
Increased
Increased
Gingiva
Yes
Decreased
Increased
Nornml
Normal
Normal
Normal
Decreased
*Maxillary d~ntal protrusion is common (i.e., thumb sucking), but true maxillary basal bone with dental protrusion is extremely rare.
(1) Decrease d secondary to deep bite.
(2) Upper incisors impinge on lower lip and make lip closure strained.
T a b l e IX. C l a s s III m a l o c c l u s i o n c a n b e p r o d u c e d b y m a n d i b u l a r p r o t r u s i o n ( c o m m o n ) , m a x i l l a r y r e t r u s i o n
( m o s t c o m m o n ) , or vertical m a x i l l a r y d e f i c i e n c y (rare). ( F a c i a l traits in the facial arlalysis o f this article
d i s t i n g u i s h a m o n g t h e s e skeletal pi-oblems)
Class I11 profiles
Mandibular protrusion
J
Ma~illat)"retrusion
I
Lower one-third
Interlabial gap
Incisor exposure
Smile
Mentalis strain
Profile angle
Mandibular sulcus contour
Nasal projection
Alar base
Cheekbones
Nasolabial angle
Throat length
Normal to increased (1)
Normal to increased (I)
Normal
Normal
None to increased
Straight to Class III
Normal to flat
Normal
Normal
Normal
Normal
Increased
J
I
Normal
Normal
Normal
Normal
None
Straight to Class Ill
Normal
Long
Depressed
Flat
Normal to increased
Normal
Vertical maxillary deficiency
Decreased
Decreased
Decreased
Decreased incisor
None, redundant
Straight to Class III
Accentuated
Normal
Normal
Normal
Normal to decreased
Increased
(I) Increased secondary to lack of dental interdigitation.
in orthodontic treatment planning. Part I. AM J ORTIIOD
1983;84(1):1-28.
13. lloldaway RA. A soft-tissue cephalometfic analysis and its use
in orthodontic treatment planning. Part II. AM J ORTIIOD
1984;85:279-93.
14. Oliver BM. The influence of lip thickness and strain on upper
lip response to incisor retraction. Ast J ORTIIOD 1982;82(2):
141-9.
15. Peck H, Peck S. A concept of facial esthetics. Angle Orthod
1970;40:284-317.
16. Burstone CJ. Lip posture and its significance in treatment planning. AM J ORTIIOD 1967;53:262-84.
17. Worms I"W, Spiedel TM, Bevis RR, Waite DE. Posttreatment
stability and esthetics of orthognathic surgery. Angle Orthod
1980;50(4):251-73.
18. Worms FW, Isaacson RJ, Speidel TM. Surgical orthodontic treatment planning: profile analysis and mandibular surgery. Angle
Orthod 1976;46(1):1-25.
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9 E. Pedregosa St.
Santa Barbara, CA 93101