Dynamic evaluation of soft tissues smile /certified fixed orthodontic courses by Indian dental academy

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ESSENTIALS OF A SMILE
It involves the relationship between 3 primary
components:
Teeth
Lip framework
Gingival scaffolding


Anatomy of the Smile
The upper and lower lips frame the display zone of the smile.
Within this framework, the components of the smile are the teeth and
the gingival scaffold
The soft-tissue determinants of the display zone are lip thickness,
intercommissure width,
interlabial gap,
smile index (width/height),
gingival architecture.
Although the commissures of the lips form the lateral borders of the
smile, the eye can perceive inner and outer commissures


A PERFECT SMILE
It is characterized by a medium lip line, an incisal line running against the
upper border of the lower lip, an upper lip presenting an upward curvature.
the mouth corners are symmetrically aligned to the papillary line and leave a
proportional bilateral negative space.


LIP LINES


LIP LINE
The lips define the esthetic zone and frame the smile
The amount of tooth exposure on smile depends on a variety of factors
like degree of contraction of the muscles of expression
soft tissue level ,skeletal peculiarities, tooth shape and tooth wear.
While low lip lines can sometimes be a cover for poor dentistry the high
lip line is more of an esthetic challenge to handle.
The ideal lip line is when smiling the lip elevates to the interdental
gingival margin


NEGATIVE SPACE
It is the dark space that appears between the jaws when laughing and smiling. It
promotes the dental composition by providing contrast. These lateral spaces are
due to the difference in width between the maxillary arch and the breadth of the
smile.


The application of the
divine proportion to
dentistry was attributed to
Lombardi and then
developed by Levin.


Using calipers that open at a constant divine proportion between the
larger and smaller parts, Levin observed that in esthetically pleasing
dentitions viewed from the front the width of the central incisors in the
golden proportion to the lateral incisor which is in golden proportion to
the anterior part of the canine.
He also demonstrated that the width of the negative space is in golden
proportion to one half of the width of the anterior segment.


From these observations he developed a grid to test the validity of this statement,
in the grid the incisors are quoted within a large range of width. The use of this
grid helps the dentist determine what is esthetically wrong with the anterior
proportional dentition.

The buccal corridor is said to be in golden proportion to the anterior smiling
segment.
Adequate restoration of this space permits characterization of the smile.
It is a key factor in the harmony of a smile.


SMILE SYMMETRY:
It refers to the identical placement of the corners of the mouth in the
vertical plane of the face. A coincidence between the commissural
line and the line drawn from one cuspid to another is another
attribute of an esthetic smile. there must be parallelism between
the commissural line, the occlusal line , interpupillary line and the
hypothetical gingival line passing through the zenith of the teeth.


AXIAL ALIGNMENT
It is generally accepted that the anterior dentition when viewed from the front
should possess an inclination to the mesial that becomes more pronounced
when proceeding from central incisor to the canine. Posterior teeth too when
viewed from the premolar to the first or second molar show an increasing axial
inclination to the mesial.


GRADATION
Also known as front back progression. When one similar structures are
aligned one after another they undergo a progressive visual reduction of
size from the nearest to the farthest.


This phenomenon of front back progression is used to give an illusion of
depth to the smile. The buccal corridor helps in achieving this gradation
effect. It reduces perception of details at the back but in turn enhances
depth. This progression is also determined by arch form .


SQUARE DENTAL ARCH

OVOID DENTAL ARCH

TAPERED DENTAL ARCH


CONTACT POINTS


In the anterior view the contact points are situated in a
position that goes from incisal to cervical from the incisors to
the canines and an imaginary line joining these contact points
is a curve emphasizing the curve of the lower lip.


GINGIVAL CONTOURS:
In healthy individuals the gingival tissues blend into the tooth
embrasure which is totally filled and is esthetically ideal. The
development of an unaesthetic black triangle can appear with
recession or due to abnormal tooth morphology and contact.


Health and integrity are not esthetically enough. An irregular gingival margin
detracts from the inherent health it may possess.
It is desirable to establish harmony and continuity of the gingival form of the free
gingival margin.
The gingival margins of the two centrals must mirror each other and the level of
gingival attachment of the laterals incisor must be more incisal yet symmetrical to
the other lateral incisor.
The cuspid’s marginal gingival must be at the same level as that of the central
incisor and the premolar somewhat more coronal.

The most apical point of gingival tissue is located distal to the long axis of
the central incisor and canine. In the mandibular incisors and the maxillary
lateral incisor the zenith is located along the tooth axis


The gingival height in class II div 2 incisors:
The horizontal level of the gingival margin of the lateral incisor is located at a
higher level than the centrals and also tends to overlap the centrals.
Iin a Class I occlusion the gingival margin is symmetric parallel and horizontal
arrangement is esthetically pleasing.The margins of the two central incisors mirror
each other, the lateral gingival margins are lower and symmetric and the canines
are at the same/slightly higher level as the central incisors.

Contemporary orthodontic evaluation attempts to evaluate and examine
static and dynamically the anatomic and physiologic jaw tooth relationships.
Not only is the problem oriented treatment planning being followed, the
orthodontist as an architect of the smile needs to identify and quantify the
elements of the smile that needs correction, enhancement and improvement
as well as identifying the positive elements of the smile that must be saved.
The orthodontist of today must evaluate patients not only in the profile but
also vertically and transversely as well as the fourth dimension of time.
Hence the emphasis on orthodontists to understand the changes that occur
with time.


THE TIME FACTOR:
Growth and maturation as well as aging of the perioral soft tissues have a
profound effect on the appearance of the resting and smiling
presentations.


Changes in lip length and thickness associated with growth
Both upper and lower lips grows more than the skeletal lower face in children
.
In both absolute and proportional terms the lower lip grew more than the upper
lip. (Subtelny)
The upper lip showed rapid increase in length from age 1-3. The rate of growth
was then reduced from age 3-6 when again an upswing occurred till the age of
15.
The growth curve for the upper lip was similar to the growth curve for the
general body growth curve. (Vig and Cohen )

The clinical relevance of this study
•Most children with lip incompetence at age 6 experience self
correction by age 16.
•Lip competence is important not only in terms of esthetics but also
stability of overjet correction.
•In this age group 6-8, when it looks as though that the
incompetancy is due to short lips whereas it is just incomplete soft
tissue growth.


Mamandras
•that males between the ages of 7-17 had a greater increase in
lip length than females in the same period.
•The males experienced little more than 2mm in the vertical
growth of the upper lip whereas in females it was less than an
mm
.
Genecov
•In females vertical lip growth was complete by 14 whereas by
males it leveled off at 18.
•Mandibular lip length increased till 16 in females whereas in
males it was not completed at 18.

LIP THICKNESS DURING GROWTH AND MATURITY:
In Subtelny’s study the upper lip attained a greater thickness in the
vermillion region than over point A.
This increase in thickness at the vermillion border was approximately equal
to the increase in length of the lip.
In both males and females the upper lip increased in thickness from ages 114.
After the age of 14 the lips continued to become thicker in males but not in
females.
Similarly in the lower lip the gain in thickness was greater at vermillion
border than at Pogonion or point B
Lip thickness increase for males form ages 1-18 was around 7mm while for
females it was around 6mm.


Mamandras in his study of lip thickness found that the female lip thickened till the
age of 14 after which it remained the same till the age of 18 beyond which it showed
thinning.
Males attained maximum lip thickness by age of 16 after which they too showed
thinning.
Horizontal thickness of both sexes completed by age15.

Nanda slightly differed from Mamandras. He found that lip thickness increased
uniformly from age 7-18, females attained full lip thickness by age 13 with slight
thinning starting then.In males however the thickness continued till the age of 18.


Clinical applications of this data:
The differential in the two sexes with respect to lip thickness implies
that the treatment result of extraction therapy of the facial profile will
be more noticeable in female than male patients.
Because female lips do not thicken with age , any extraction plan for
females with straight to convex profiles should be cautiously
considered.
Lip fullness in relation to the nose which will continue to grow
should also be noted.


NASAL GROWTH AND ITS CONTRIBUTION TO PROFILE
Class II patients exhibited a more pronounced elevation of the bridge of the nose
than class I. the dorsum of the class II cases also shoed an increased general
convexity. Class I tended to have straighter noses.
Females did not show such a spurt in growth like males but had a more steady
increase in nose growth.
Manera and Subtelny
Subtelny first documented the downward and forward growth of the nose with
maturity.The vertical dimension of the nose experiences more growth than the
anterior posterior projection in both males and females.
There was a spurt in male’s nasal growth from 10-16 with a peak around 13-14
years



This was of importance because an orthodontist treating a class II
girl aged 12 could expect only minimal increases in nasal projection
over the next few years.



However in a male of a similar age any treatment that causes upper
lip retraction in combination with several mm of nose growth might
produce a less than optimal final relationship between the lips and
nose.



The increased prominence of the nasal hump in boys coincides with
pubertal spurt and nasal projection in girls peaks between 9-10.

THE CHIN
Genecov’s study documented that soft tissue chin thickness in females from age
7-9 was greater than males .Females only had a 1.6mm increase upto age 18
whereas the males had a 2.4mm increase in soft tissue drape over the chin. As a
result both sexes had a similar soft tissue thickness at age 17.
In Nanda’s study, the soft issue thickness over the chin. symphysis thickness and
the length of the mandibular corpus, all 3 distances increased with age, the males
showing the largest increments.
Till 7 years the size of the mandibular corpus was the same for both sexes. and
the curves progressed parallel to each other till the age of 15 when the male
sample had larger increases than the female. Increased chin projection seen in the
males is due to the mandibular growth than the increase in soft tissue chin
thickness.

THE MATURE FACE
The reasons why the orthodontist should understand about the aging of the
face is because
•the orthodontist when treating an adolescent is making decisions about how
the individual will look for the rest of his life.
•the increasing demand for adult orthodontics and orthognathic surgery
increases the need to understand the facial aging process.
•an increase in the complexity of treatment plans and the expectations of the
patients is also a factor.
•The age usually having orthognathic surgery includes 28-35 and they soon
move into middle age when aging becomes most apparent. The blame may
be easily placed on orthodontics by the patient.


The general soft tissue changes in males between the ages of 18-42 included
the following finding:
The profile straightened, the lips became more retrusive
The nose increased in size in all dimensions.
There was increased soft tissue thickness at the Pogonion.
There was decreased upper lip thickness and slightly increased lower lip
thickness
In females:
The profile did not become straighter and the lips did not become more
protrusive
The nose increased in size in all dimensions.
There was decreased soft tissue thickness at the Pogonion.
There was upper lip thickness and slightly increased lower lip thickness


THE AGING FACE:
Behrents
In young adulthood, 17-41 subjects tended to be specific to their craniofacial
patterns.
In other words ClassII subjects grew as class II while class III grew as class III.
In later adulthood vertical dimensional changes were common to all subjects. they
became less protrusive with greater facial height increase. the males exhibited
counterclockwise rotation of the mandible. The percentages of change in the
females were less and growth tended to be more vertical.


Nasal changesThere was an increase in nasal projection and the nasal tip moved
more inferiorly.
Lip thickness: the lips became less prominent and were located more inferiorly. that
is the upper lip tended to rotate down and back from the base of the nose. This would
naturally imply that less maxillary incisor would be exposed at rest and smile which
is corroborated clinically.
Nasolabial changes:With the decrease in lip prominence and the lowering of the tip
the nasolabial angle became more acute.
Dental changes:In females the maxillary incisors became more upright and the
lower incisors became more proclined.the lower molar uprighted in males and moved
forward in females. The upper molar tilted forward in the male but uprighted in the
females.


FEATURES ASSOCIATED WITH
AGING:
Lower part of the face appears to lengthen
the interlabial line descends ,
the number of vertical fibers in the upper lip
reduces.
the philtral columns become less prominent
and the vermillion becomes a straight line.
Jowling and increased nasolabial folds are
seen.
the M and W shapes of the lips may become
straight.
the comissures droop giving the look of a
frown.


beauty is not the norm
Proffit states that the basis of the practice of orthodontics is changing
rapidly as a result of 3 major influences:
the biologic revolution,
the recognition that the facial soft tissues are the primary focus of
orthodontic treatment,
and the growing reliance on evidence-based rather than opinion-based
orthodontic research.
Treatment decision making must be determined by what’s esthetically
appealing than what the cephalometric norms may be.

The dynamics of soft tissues involved are twofold:

Examination of the smile in animation and repose which includes
parameters such as gingival display, crown length and lip animation
and other such attributes.

The second factor is that the patient changes with age, the impact of
hard and soft tissue aging cannot be minimized.


RECORDS IN THE TREATMENT OF THE SMILE
Orthodontic records are of three types:
Static records,
dynamic records ,
direct biometric measurements.
Visualization and quantification of the dynamics of the smile is a two stage
process:
The critical first stage is clinical examination with the evaluation of the lip tooth
relationship both statically and dynamically.
Record taking is the second step with digital photography, videography,
radiography and models.
These are taken from a frontal and oblique direction to record a three dimensional
description of the smile characteristics.

The records therefore needed for smile visualization and
quantification are
1)static
the additional photographic images needed are:
profile and oblique smile and oblique and frontal smile
close ups.
2) dynamic


WHY DIGITAL VIDEOGRAPHY ?


Capturing patient smile images with conventional 35mm photography has some
major drawbacks.
Difficult to standardize photographs
Difference in appearance of the smile arc in intraoral and
extraoral views
When several consecutive smile photographs are taken at the
orthodontic records visit, the clinician will often note variations in the
smile. In children, this phenomenon is most likely due to relatively late
maturation of the social smile.
Standardized digital videography allows the clinician to capture a patient’s
speech, oral and pharyngeal function, and smile at the same time.


Digital technology allows the anterior tooth display to be recorded at 30
frames per sec.normally 5 secs of recording is done.

The videos are recorded in a standardized fashion with the camera at a fixed
distance from the subject. One segment is taken in a frontal direction and
another in a oblique direction.

These clips are taken before and after treatment and help to assess the
changes in smile characteristics bought about by orthodontic treatment.

The patient’s head is placed in a cephalometric holder and asked to say,
“Chelsea eats cheesecake in the Chesapeake” and then to smile. The video
clip is reviewed and the frame that represents the patient’ natural unstrained
social smile is selected.

DIGITAL RECORDING OF
THE SMILE


Digital radiography also helps to ascertain the patient’s smile style:
According to Rubin there are three smile styles:
Commissure smile/ Mona Lisa smile:
Cuspid smile
Complex smile


Smile Analysis
first the clinician should assess tongue posture and lip function, particularly during
speech. Immature oral and pharyngeal function with unfavorable tongue posture
can easily be detected.
The frame that best represents the patient’s social smile is selected, saved as a JPEG
file.
The smile image is then opened in a program called SmileMesh, which measures 15
attributes of the smile


This methodology was first used manually by Hulsey and later modified
and computerized by Ackerman
Its most significant advantage is that the orthodontist can quantify such
aspects of the smile as maxillary incisor display, upper lip drape, buccal
corridor ratio, maxillary midline offset, interlabial gap, and
intercommissure width in the frontal plane.
The flaw in traditional smile analysis has been that many of the vertical
and anteroposterior calculations related to anterior tooth display are made
from the tracing of the lateral cephalogram, which is taken in repose. As a
result, incisor position has been determined from a static rather than a
dynamic record.

Direct Biometric measurements:

1.
2.
3.
4.
5.
6.

Philtrum and Commissure height
Interlabial gap
Incisor show at smile& rest
Crown height
Gingival displacement
Smile arc


Smiles can be either posed or
spontaneous.
The posed smile or social
smile is voluntary and need not
be elicited or accompanied by
emotion. A posed smile is static in
the sense that it can be sustained.
The lip animation is fairly
reproducible,
In treating a social smile
represents a repeatable smile,
though it can mature and might
not be consistent over time with
some patients.


The unposed smile is
involuntary and is
induced by joy or mirth.
It is dynamic in the sense
that it bursts forth but is
not sustained. An
unposed smile is natural
in that it expresses
authentic human
emotion. Lip elevation in
the unposed smile is
often more animated, as

seen in the laughing

The social smile is chosen to undergo
examination
in 4 dimensions:
Frontal. Sagittal, oblique and time related.

Frontal.

Sagittal

Smile Index

Over jet

Vertical / Transverse Smile
Characteristics

Incisal Angulations
Transverse effect

Oblique
Palatal Plane
Orientation

Smile Arc

Time
Growth
Maturation
Aging


FRONTAL DIMENSION:
Smile index:
It describes the area framed by the vermillion border during the
social smile.
It is determined by dividing the inter commissural width by the
inter-labial gap during smile. It can be used to compare two
patients or one patient at two different times.
A small smile index would imply a gummy smile.


Vertical dimensions

Vertical parameters:
•Incisal display
•Gingival display
•Relationship between the incisal margins of the upper incisors and the lower
lip
•Gingival margin with the upper lip


CAUSES OF LIP INCOMPETANCE
Vertical maxillary excess with excessive lower facial height
Maxillary impaction via Le Fort I osteotomy
Excessive lower facial height due to excessive chin height
Vertical genioplasty
Short philtrum
V-Y cheiloplasty
Excessive overjet
orthodontics


EXCESSIVE UPPER INCISOR SHOW
AT REST AND ON SMILE
The reasons could include both hard and soft tissue
factors
Short philtrum
V-Y cheiloplasty
Vertical maxillary excess
Maxillary impaction via Le Fort I osteotomy
Long incisor crown height
Crown height reduction
Hyper-mobile smile
Cartilage or spacer technique
Kamer technique
De-torqued incisors
Orthodontic incisor torque

Long philtrum
Not often seen, no procedure
Vertical maxillary deficiency
Maxillary downgraft
Short incisor crown height
Gingival procedures like gingivectomy
Crown lengthening
Flared maxillary incisors
Orthodontic retraction and up righting
Diminished anterior dentoalveolar eruption secondary to chronic digit
habit
Orthodontic leveling
Surgical correction
Inadequate curtain on smile

MAXILLARY INCISOR DISPLAY
The amount of the incisor show at rest is a critical esthetic parameter because a sign of
aging is decreased show of the maxillary incisor.

According to VIG and BRUNDEL
Tooth exposure at rest (in mm)
Male 1.91 mm
Female 3.40 mm

mand incisor- 1.23
mand incisor- .49


Tooth exposure by race
Race
max CI
White
2.43
Black
1.57
Asian
1.86

Tooth exposure by age
Age
max CI
Upto 29
3.37
30-39
1.58
40-49
.95
50-59
.46
60+
-.04

mand CI
.51
.8
1.96
2.44
2.95


mand CI
.98
1.42
1.58

CROWN LENGTH
The vertical height of the maxillary central incisors is between 9 to 12 mm.
The age of the patient plays a role because primary incisors measures only 4-5mm
vertically. Incomplete eruption of the crowns could also present as short clinical
crowns
Thick fibrotic gingival tends to migrate slowly so this must be ruled out.
In an adolescent the periodontal contribution to the gumminess of a smile must be
evaluated. There may be a delay in the apical migration of the gingival tissues.
The treatment also varies depending on whether the lack of clinical crown length
is due to gingival encroachment or loss of tooth structure incisally.

SMILE CURTAIN
A smile curtain is the amount of mobility and elevation of the upper
lip. Patients with an excessive smile curtain simply have and greater
than average range of smile activity than normal. therefore to
attempt to correct a hyper mobile smile through impaction would
adversely affect the incisor lip relation at rest adversely and would
age the patient. The upper lip would also thin and the curvature of
the resting lip would worsen.
Treatment of the hyper mobile smile:
Smile immobilization can be done by inserting a spacer of cartilage or silicone
between the septum and the maxillary alveolar mucosa.
The Kamer technique is simpler than the spacer technique and produces the
same result.
Kamer in his technique excised a horizontal strip of labial mucosa and attached
an inferiorly based mucosal flap from the opposing alveolar mucosa which
effectively decreases the height of the gingival

ALTERED PASSIVE ERUPTION:
Aberration in normal development where a large portion of the anatomic crown
remains covered by gingiva.
Unaesthetic for two reasons:
The normal scalloping is absent, teeth are short and squat.
A potentially medium lip line is converted to a high lip line.
Types of altered passive eruption:
type I : there is an increased amount of gingiva from the margin to the alveolar
mucosa
type II: there is normal amount of attached gingiva from Free gingival margin to
the alveolar mucosa.
Type IA: 1mm present between Cemento enamel junction and osseous level
( treated by gingivectomy)
Type 2A : osseous level close to the Cemento enamel junction (treated by a flap
and osseous resection)

METHODS OF DEVELOPING GINGIVAL HARMONY:
SURGICAL
Additive gingival techniques
Resective gingival techniques

ORTHODONTICS
extrusion
intrusion

The greatest advantage of orthodontic tooth movement is the movement of the
attachment apparatus along with the tooth. Therefore in health while extruding
teeth orthodontically the gingival margin moves the same distance and in the same
direction as the incisal edge.Concomittantly so will the osseous level.
Therefore intrusion or extrusion can be used from an esthetic perspective to
develop gingival margin symmetry without periodontal surgery.


TREATMENT OF A COMBINATION CASE OF VME AND
ALTERED PASSIVE ERUPTION:
1st one should develop the normal silhouette form of the teeth by
removing the altered passive eruption component
next orthognathic surgery – impaction limited by the resting lip to
incisor relation.( 2mm show esthetically desirable)
Finally after surgery according to patient’s desire, further gingival
display can be reduced by a flap and osseous resection.


The smile arc is defined as the relationship of the curvature of
the incisal edges of the maxillary incisors and canines to the
curvature of the lower lip in the posed smile. The ideal smile
arc has the maxillary incisal edge curvature parallel to the
curvature of the lower lip.
The smile arc is more curved for women than men.


Modification of the smile arc:
Growth modification in pre adolescents to treat the occlusal plane
Late adolescents and adults orthognathic surgery is indicated to treat
the occlusal plane
Bracket placement to enhance/ maintain the smile arc
Multi disciplinary approach: periodontal surgery, cosmetic laminates
and esthetic bonding as well as enamel odontoplasty to reshape incisal
edges


Smile arc flattening during orthodontic treatment can occur in
several ways.


Normal orthodontic alignment of the maxillary and mandibular arches may
result in a loss of the curvature of the maxillary incisors relative to the lower lip
curvature
A set formula for bracket placement based on tooth measurements, is not
appropriate for maximum esthetics
Bracket placement may lead to superior repositioning of the incisal edges
relative to the posterior buccal segment heights.
In patients in whom excessive gingival display on smile is noted, maxillary
incisor intrusion may improve the gingival display on smile. However, if the
smile arc relationship has not been noted and evaluated, unwanted flattening of
the smile arc may result.
Maxillary intrusion arches or maxillary archwires with accentuated curve could
result in a flattening of the smile arc

Transverse parameters:
Arch form
Buccal corridor
Transverse cant
Broadening out a narrow arch can have two disadvantages, first the
buccal corridors could be obliterated, and second the broader arch form
could flatten the smile arch.
Smile asymmetry
Could be due to asymmetric smile curtain
Differential eruption of anterior teeth
Skeletal asymmetry


Arch form:
The patient’s archform—and particularly the configuration of
the anterior segment—will greatly influence the degree of
curvature of the smile arc. The broader the archform, the less
curvature of the anterior segment and the greater the likelihood of
a flat smile arc.


OBLIQUE DIMENSIONS:
This view shows smile characteristics not seen with the frontal view, especially
relevant in sagittal skeletal discrepancies. In an esthetically pleasing smile the
cant of the occlusal plane is consonant with the curvature of the lower lip.
The smile arc as defined from the oblique direction:
It is the relation of the incisal edges of the incisors canines’ premolars
and molars to the curvature of the lower lip during a posed social smile. Ideally
the curvature of the incisal edges is consonant with the lower lip and is parallel.
a non consonant smile arc describes a flat incisal curvature.


SAGITTAL DIMENSION
The two characteristic of the smile that are best viewed in this view is the
overjet and incisor angulations .
*Excessive overjet is not perceived in the frontal dimension as well as it is
in the sagittal dimension. In class II and III’s the frontal smile is usually
esthetic.
*Posterior positioning of the maxilla in the sagittal plane can increase the
buccal corridors in the frontal plane.
*Incisor inclination also plays a role in vertical incisor display. Proclined
incisors tend to reduce incisal show while retroclined incisors increase
show.

SMILE ANALYSIS
The diagnostic part of smile analysis begins with the creation of a problem list.
The first set of records analyzed is the extraoral photo gallery
Consideration should be given to the vertical and lateral attributes of the smile
as well as to the cant of the transverse occlusal plane
Next, the cant of the maxillary occlusal plane relative to Frankfort horizontal
should be assessed visually on the lateral cephalogram and measured on the
tracing.
Vertical and anteroposterior skeletal and dental relationships are noted.
Panoramic and supplemental intraoral radiographs are also analyzed.
Finally, the plaster study casts are evaluated for static occlusal relationships
and tooth-size discrepancies.


Clinical Implications for Low and Average Smile Types
In most deep overbite cases, intrusion will tend to hide the maxillary anterior
teeth behind the upper lip in normal conversation. Such a mistake can go
undetected by the orthodontist unless the patient's tooth display and smile are
analyzed from the front.
With increasing age and concomitant drooping of the upper lip, an unaesthetic
anterior tooth display may worsen.
In most orthodontic patients, except those with marked "gummy" smiles, active
intrusion of the maxillary incisors is undesirable.
The best treatment strategy in the majority of deep overbite cases is to actively
intrude the mandibular incisors, using double tubes on the mandibular first
molars and continuous or segmented base arches or utility arches


Another common mistake in orthodontic finishing is to create a straight (or even
reverse) maxillary incisal curve relative to the smile line
Parallelism of the incisal curve and the inner contour of the lower lip in smiling
should be produced .
this appearance can be achieved if the maxillary central incisors are symmetrically
positioned .5-1mm longer than the lateral incisors
If the lower lip shows a marked curvature in smiling, the distoincisal edges of the
maxillary central incisors can be ground slightly without affecting functional
occlusion


Clinical Implications for High Smile Types
Treatment alternatives include various combinations of orthodontic,
periodontal, and surgical therapy.
Intrusion base arches or utility arches may succeed in reducing a gummy
smile orthodontically in some cases Such treatment can produce a
remarkable change in facial appearance.
A different treatment philosophy is needed for patients with high lip
lines than for those with average or low smile types. Active maxillary
incisor intrusion should be the goal in this category of patients.


CONCLUSION:
It is a significant error to attempt to put everyone into the same esthetic
framework and an even greater error to try to do this from hard tissue
relationships alone, taking it for granted that the soft tissues will follow
along in a predictable fashion.

(1) esthetic considerations are paramount in planning appropriate orthodontic
and orthognathic treatment,
(2) rigid rules cannot be applied to this process.


general guidelines for how to optimize dentofacial esthetics
while satisfying other treatment goals.


Dental and facial esthetic relationships must be evaluated in 3 dimensions,
both dynamically and statically
Two-dimensional hard tissue measurements as seen on sagittal or frontal
radiographs are an imperfect reflection of what exists clinically.
Treatment designed around the profile simply ignores the way that others see
our patients and how our patients see themselves.
The three quarter view of the face often reveals dentofacial characteristics,
which although not measurable, yield valuable information in both diagnosis
and treatment planning.
Facial symmetry and vertical canting of the occlusal plane are important.
It is not enough to just correct the teeth.


The upper incisors are the key to esthetic orthodontic treatment
planning. They must be positioned advantageously relative to the
adjacent soft tissues both anteroposteriorly and vertically.
The relative prominence of the nose and chin in relationship to the
lips and overall facial contours is important
Anterior tooth display, as observed in frontal and three-quarter views
of the face, is more important than tooth prominence in profile views


Extending the soft tissue envelope by expanding dental arches to increase hard
tissue support for the lips and cheeks or enlarging the facial skeleton surgically
to increase hard tissue support, usually is more esthetic than the reverse,
especially when the effects of aging are considered. Greater soft tissue fullness
gives a more youthful appearance. This is not an argument for routine
expansion of severely crowded arches,

When possible, computer imaging should be utilized to simulate the soft tissue
facial outcome that would most likely result from the proposed hard tissue
changes. This allows for the patient’s input in the decision-making process.


In summary, the 3 basic requirements for assessing dentofacial esthetics in
orthodontics are:
1.

A dynamic and static 3-dimensional evaluation of the face derived
primarily from the clinical examination of the patient.

2. A determination of lip-tooth relationships and anterior tooth display at rest
and during facial animation.
3. An analysis of the dental and skeletal volume of the face as it effects the
soft tissue facial mask.

When possible this should be an interactive process with the patient and is
best facilitated through the use of graphic images via computer
simulation.

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