Smile analysis

Smile analysis including
dynamic smile relationship

INTRODUCTION
Dale Carnegie said that one of the most important
ways to win friends and influence people is to smile.
“The goal of orthodontic treatment should be the
attainment of the best possible esthetic result, dentally and
facially.” -Wylie
Epker and Fish stated that, “Perhaps the single
most important feature in evaluating facial esthetics is the
relation of the lips to one another and to the teeth”.
Smile analysis and smile design have become key elements of
orthodontic diagnosis and treatment planning . Recent advances
in technology now permit the clinician to measure dynamic lip-
tooth relationships and incorporate that information into the
orthodontic problem list and biomechanical plan.

"Beauty is in the mind of the beholder, each mind perceives a
different beauty." -David Hume,
Although this may be true, the majority of people have fixed ideas
on what is beautiful. Nevertheless,the general geometric
features of the face that give rise to a perception of beauty may
be universal.
Esthetics
Esthetics , which is derived from the Greek word for "perception",
deals with beauty and the beautiful.
It has two dimensions: Objective
Subjective.
1. Objective beauty is based on consideration of the object itself,
implying that the object possesses properties that make it
unmistakably praiseworthy.
2. Subjective beauty is a quality that is value-laden, relative to the
tastes of the person contemplating it.

The Classification of Appearance and Esthetic Analysis is comprised
of three components: Macro-, Mini- and Micro-esthetic divisions.
Sarver&Hills ,Clinical impressions
2005

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.

MUSCULAR BASIS OF THE SMILE
Work by Rubin, Mishriki and Lee has elucidated the anatomic
mechanism producing the open smile. As a result of extensive
cadaver dissections, Rubin and his colleagues have identified the
nasolabial fold as the keystone of the smiling mechanism.
The smile is formed in two stages
The first stage raises the upper lip to the nasolabial fold by
contraction of the levator muscles originating in the fold and
inserting at the upper lip. The medial muscle bundles raise the lip
at the anterior teeth and the lateral muscle groups raise the lip at
the posterior teeth. The lip then meets resistance at the nasolabial
fold because of cheek fat.

The second stage involved further raising superiorly of the lip and the
fold by three muscle groups:
(1) The levator labii superior muscles of the upper lip, originating at
the infraorbital region,
(2) The zygomaticus major muscles
(3) Superior fibers of the buccinator.
Often, the appearance of squinting accompanies the final stage of
smiling. It represents the contraction of the periocular
musculature to support maximum upper-lip elevation through
the fold.

Smile classification
 Posed smile / Unposed smile (Ackerman et al)
 Stage I smile/ Stage II smile (Peck n Peck)
 Social smile/ Enjoyment smile
 Low smile/Average smile/High smile (Tjan)

Ackerman et al designated
stage I smile - the posed smile
stage II smile - the unposed (spontaneous) smile.
The posed 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,similar to the smile that may be rehearsed for
photographs or school pictures.
Rigsbee found that the posed social smile was repeatable
photographically in comparison with the Duchenne smile.
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

Peck and Peck classified smiles as stages I and II.
In the Peck classification, a Stage II smile is a "forced" or strained
posed smile resulting in maximal upper lip elevation.
Thus two types of posed smiles are possible:
Strained
Unstrained.
When a person is asked to pose for a photograph, the smile that is
desired is a voluntary,unstrained, static, yet natural smile.

There are two basic types of smiles:
Social smile
Enjoyment smile.
The social smile, or the smile typically used as a greeting, is a
voluntary, unstrained, static facial expression.The lips part due
to moderate muscular contraction of the lip elevator muscles,
and the teeth and sometimes the gingival scaffold are displayed.
The enjoyment smile, elicited by laughter or great pleasure, is
involuntary. It results from maximal contraction of the upper
and lower lip elevator and depressor muscles, respectively. This
causes full expansion of the lips, with maximum anterior tooth
display and gingival show.

Smile Type – based on Incisor and Gingival Display
Lip coverage of the maxillary incisors in full smiles can
be distinguished into three types:
Low, Average, and High smiles.
The most frequent type (about70%of the youngadult population) is
the average smile that reveals 75-100% of the upper incisors.
The low smile displays <75% of the maxillary incisors in the full
smile and may be found in about 20% of a population,
The high smile ("gummy smile"), revealing the complete
cervicoincisal length of the upper incisors and a contiguous band
of gingiva, occurs in about 10% of the population.

SMILE STYLE
There are three styles
The cuspid smile is characterized by the action of all the elevators of
the upper lip, raising it like a window shade to expose the teeth
and gingival scaffold.
.

The complex smile is characterized by the action of the
elevators of the upper lip and the depressors of the lower lip
acting simultaneously, raising the upper lip like a window shade
and lowering the lower lip like a window.

The Mona Lisa smile is characterized by the action of the
zygomaticus major muscles, drawing the outer commissures
outward and upward, followed by a gradual elevation of the
upper lip. Patients with complex smiles tend to display more
teeth and gingiva than patients with Mona Lisa smiles.

Dynamic smile visualization and quantification:
In the contemporary orthodontic paradigm, we examine patients in
both resting and dynamic relationships in 3 spatial dimensions
and then attempt to harmonize the discrepancy between their
anatomic and physiologic lip–tooth–jaw relationships and their
esthetic and functional desires.
In the art of treating the smile, we are faced with a 2-fold task.
First, in problem-oriented treatment planning, the orthodontist must
establish a diagnosis that identifies and quantifies which elements
of the smile need correction, improvement,and identifying the
positive elements of the smile that should be maintained.
Second, a visualized treatment strategy must be created to address
the patient’s chief concerns. Computer imaging technology has
greatly facilitated recognition of the effect of our orthodontic
treatment plans on facial appearance.

The contemporary orthodontist no longer evaluates patients in terms
of only the profile, but also frontally and vertically, to complete
the 3 spatial dimensions,and statically and dynamically. Sarver
philosophy mandates that the orthodontist now add a fourth
dimension: Time.
The orthodontist must work with 2 dynamics.
The first is that of soft tissue repose and animation assessed at the
patient’s examination and includes how the lips animate on
smile, gingival display, crown length, and other attributes of the
smile.
The second is the facial change throughout a patient’s lifetime
the impact of skeletal and soft tissue maturational and aging
Characteristics.

Orthodontic records fall into 3 separate but interdependent
categories:
Static records.
Dynamic recordings.
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
Static
Dynamic
Static records like plaster models photographs and
cephalometric data for subsequent analysis are simply not
adequate for the excellent co ordination of the hard tissue
planning and esthetic outcome
The additional photographic images needed are:
profile and oblique smile and oblique and frontal smile
close ups.

The first set of records analyzed is the extraoral photo gallery,
consisting of the captured social smile, the full facial portrait at
rest, the three-quarter smiling view, and the profile view.
Consideration should be given to the vertical and lateral attributes
of the smile as well as to the cant of the transverse occlusal plane.
The smile image is a better indication of transverse dental
asymmetry than the frontal intraoral view or even an
anteroposterior cephalogram.
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.

ROLE OF 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.

Smile Analysis
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.
This methodology was first used manually by Hulsey and later
modified and computerized by the Ackerman.
On first viewing of the QuickTime video clip, 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, captured with a program called Screen Snapz, and
saved as a JPEG file. The smile image is then opened in a
program called SmileMesh, which measures 15 attributes of the
smile
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 smile mesh
Ackerman et al. developed a multimedia computer
program, the smile mesh, to analyze photographs of posed smiles
and test the reproducibility and reliability of the smile .
Statistical analysis revealed that a posed smile is indeed
reproducible.
However, because not all patients have individually repeatable
smiles, a good procedure is to take three smile images of the
patient and select the most natural or representative smile for the
application of the smile mesh.
An adjustable grid (the smile mesh) is constructed of three
horizontal lines and four vertical lines, which can be moved with
the cursor and placed on the images of the smile. The smile mesh
measures 11 attributes

Direct Biometric measurements:
 Philtrum and Commissure height
 Interlabial gap
 Incisor show at smile and rest
 Crown height
 Gingival displacement
 Smile arc

PHILTRUM HEIGHT
Measured in mm from subspinale (base of the nose) to most inferior
point of the portion of the upper lip on the vermillion tip of the
cupid bow
COMMISSURE HEIGHT
The height of the Commissure is measured from a line constructed
from the alar bases through subspinale and then from the
commisures perpendicular to this line
In young children and adolescents the philtrum height is shorter than
the commissural heights and can be explained in the differential in
vertical lip growth.

Treatment Solutions for short philtrum
In Adults- Esthetic Lip Surgery
Kamer technique
Correction of the short philtrum can be done by V-Y cheiloplasty in
isolation or in combination with le fort I procedure, rhinoplasty.
V-Y procedure when combined with rhinoplasty dramatically
increases the amount of soft tissue available for modification.
Le fort I usually results in alar base widening and so rhinoplasty is
indicated.
Therefore if a patient needs a maxillary impaction and has a short
philtrum a rhinoplasty is DEFINITELY indicated
Excessive philtrum height is seen only as a result of aging due to
loss of soft tissue elasticity and can be corrected by a direct or
indirect lip lift a soft tissue cosmetic procedure

CAUSES OF LIP INCOMPETENCE
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

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

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
interlabial gap during smile.
A small smile index would imply a gummy smile.

Vertical parameters
Incisal display
Less than 75% of the central incisor crown display is
considered inadequate.
Gingival display
Relationship between the incisal margins of the upper
incisors and the lower lip and the gingival margin with the upper
lip.
The vertical aspects of smile anatomy are the degree of maxillary
anterior tooth display (Morley ratio), upper lip drape, and gingival
display

In a youthful smile, 75-100% of the maxillary central incisors
should be positioned below an imaginary line drawn between
the commissures . Both skeletal and dental relationships
contribute to these smile components.

EXCESSIVE UPPER INCISOR SHOW AT REST AND ON
SMILE
Short philtrum
V-Y cheiloplasty
Vertical maxillary excess
Maxillary impaction via Le Fort I osteotomy
Long incisor crown height
Crown height reduction
Hypermobile smile
Cartilage or spacer technique
Kamer technique
Botulinium toxin injection
Detorqued incisors
Orthodontic incisor torque

Excessive incisal show treatment differs in adults and
adolescents
 In adolescents with moderately excessive incisordisplay
(4-5mm) treatment often is not indicated.
When excessive gingival display (6-8mm) intrusion by
orthodontic intrusion arches or extra orally through J hook
headgear can be considered.
When greater than 8mm, the clinician can consider waiting till
growth ceases for surgical correction the vertical maxillary
excess.
 In adults the treatment options include surgical maxillary
impaction and VY cheiloplasty to lengthen the philtrum as well
as reduction of excessive crown length.

INSUFFICIENT UPPER INCISOR SHOW AT REST AND ON
SMILE
Vertical maxillary deficiency
Maxillary downgraft
Short incisor crown height
Gingival procedures like gingivectomy
Crown lengthening
Flared maxillary incisors
Orthodontic retraction and up righting
Long Philtrum
Direct or Indirect lip lift

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

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

Oblique Characteristics of the Smile
The oblique view of the smile reveals characteristics not
obtainable on the frontal view and certainly not obtainable
through any cephalometric analysis.
The contour of the maxillary occlusal plane from premolar to
premolar should be consonant with the curvature of the
lower lip on smile
The amount of incisor proclination also can have dramatic effects
on incisor display.

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
Subtelny in one of the earliest studies on soft tissue facial growth
measured longitudinal soft tissue growth changes of the upper
and lower lips, the nose and the soft tissue chin.
In a sample from the Bolton Brush study of age 1-18 a general
pattern of change with each increment of age was discovered.
The upper lip showed rapid increase in length from age 1-3. The
rate of growth was as then reduced from age 3-6, again an
upswing at 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 documented that vertical skeletal and
dentoalveolar growth ( LAFH) in adolescents between the ages
of 4-20 generally concluded before the completion of vertical
lip growth. Both upper and lower lips grew more than the
skeletal lower face.
In both absolute and proportional terms the lower lip grew more
than the upper lip.
The clinical relevance of this study
Most children with lip incompetency 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.

Vertical growth of the lips is both age and gender related
Mamandras in his cross sectional study of lip growth mapped the
soft tissue growth of the face as well as some important gender
differences.
He evaluated 32 untreated children from the Burlington Centre
Growth sample and found:
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.
Genecov in his study from the Bolton Brush sample found that
males between the ages of 7-17 had a greater increase in lip
length than females in the same period.

LIP THICKNESS DURING GROWTH AND MATURITY
It was observed in Subtelny’s study that that 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 lip increased in thickness from ages 1-14. 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 from 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 age 15.

Nanda et al in his study 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
staring 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 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.
The differences between chin, lip and nose growth must also be
considered when planning the final esthetic goals.

Facial harmony in orthodontics is determined by the
morphological relationships and proportions of the nose lips
and chin. Because balance between these structures can be
altered by both growth and orthodontics it is clinically
important for the orthodontist to understand the changes that
occurs not only with treatment but also the amount and
direction of growth expected in the facial structures.
The effects of maturation and aging on the soft tissues can be
summarized as (1 ) lengthening of the resting philtrum and
commissure heights. (2) decrease in turgor (or tissue
“fleshiness”), (3) decrease in incisor display at rest, (4) decrease
in incisor display (5) decrease in Gingival display during smile.

THE EIGHT COMPONENTS OF A
BALANCED SMILE.
 LIPLINE
 SMILE ARC
 UPPER LIP CURVATURE
 LATERAL NEGATIVE SPACE
 SMILE SYMMETRY
 FRONTAL OCCLUSAL PLANE
 DENTAL COMPONENTS
 GINGIVAL COMPONENTS
ROY SABRI
JCO- 2005

LIP LINE
The lip line is the amount of vertical tooth exposure in smiling.
The lip line is optimal when the upper lip reaches the gingival
margin, displaying the total cervicoincisal length of the
maxillary central incisors, along with the interproximal
gingiva.
The starting point of a smile is the lip line at rest, with an
average maxillary incisor display of 1 .91 mm in men and
nearly twice that amount. 3.40mm, in women.

Tjan, Miller performed a semi-quantitative study of smile-line
variations; their data suggest evidence of sexual dimorphism of
smile lines in the vertical dimension. Full face photographs of
smiling men and women were analyzed with the intention of
identifying features of lip position for help in designing esthetic
dental restorations.
One part of the study divided the smiles into three categories:
A "low smile" displaying less than 75% of the clinical crown height
of the maxillary anterior teeth,
An "average smile" revealing 75% to 100% of the maxillary anterior
crown height,
A "high smile" exposing a band of contiguous maxillary gingiva.

Among these three categories, there was a sex difference in smile-
line frequency:
Low smile lines were predominantly a male characteristic, 2.5 to 1
High smile lines were predominantly a female characteristic, 2 to 1.
Peck, Peck and Kataja confirmed these findings and identified
quantitatively the smile line dimorphism between male and
female reference samples. At maximum smile, the upper-lip line,
relative to the gingival margin of the maxillary central incisors, is
positioned 1.5mm more superiorly in females than in males, a
statistically significant difference (p<0.01), 1-2mm of gingival
display at maximum smile could be considered normal for
females.

Lip coverage of the maxillary incisors tends to increase with age,
and therefore the percentage of high smiles may be greater
among younger age groups and smaller among older adults.
Normal Age Changes in Lip-Incisor Relationship
Peck and colleagues measured maxillary incisor exposure, at rest
position and full smile, in a sample of 15-year-old males and
females.

Tooth exposure by race
Race max CI mand CI
White 2.43 .98
Black 1.57 1.42
Asian 1.86 1.58
In general ,males show less upper incisor and more lower incisor
at rest,where as females show more upper incisor and less lower
incisor at rest.

Vig and Brundo reported a gradual decrease in maxillary incisor
exposure for each increase in age group from under 30 to over
60.
Age changes in vertical tooth display during normal
conversation, demonstrated by female patients ages 25 and 65.
In rest position , young woman shows only maxillary incisors,
whereas older woman shows only mandibular incisors.
Mean tooth exposure in rest position

Sexual Dimorphism
Females have significantly more maxillary and less mandibular
tooth exposure than males at all ages
In an adult sample, Vig and Brundo found almost twice as much
maxillary anterior tooth display with the lips at rest in women
(3.4mm) as in men (1.9mm). The men displayed much more of
the mandibular incisors (1.2mm to .5mm). As noted above, a
high smile type is twice as prevalent in women.
Dong et all compared the age changes in maxillary and mandibular
inci'sor display at rest and when smiling and confirmed the
observations that the age changes with relaxed lips were
dramatic . Mandibular incisor display shows a corresponding
increase with age. The amount of mandibular incisor display
after age 60 is approximately equal to the amount of maxillary
incisor display before age 30.

This progressive change is caused by the effects of gravity on
upper and lower lip positions. The sagging of the perioral soft
tissue is partly due to the natural flattening, stretching, and
decreasing elasticity of the skin.
Display of the maxillary incisors during normal conversation thus
indicates youth, while display of only the mandibular incisors
indicates age .
The amount of vertical exposure in smiling depends on
 UPPER LIP LENGTH
 LIP ELEVATION
 VERTICAL MAXILLARY HEIGHT
 CROWN HEIGHT
 VERTICAL DENTAL HEIGHT
 INCISOR INCLINATION

LIP LENGTH
The average lip length at rest, as measured from subnasale
to the most inferior portion of the upper lip at midline,
is about 23mm in males and 20mm in females.
Lip length should be roughly equal to the commissure height,
which is the vertical distance between the commissure and a
horizontal line from subnasale .

Lip length and thickness are important elements of the facial
profile. Lip position is affected by the placement and inclination
of the maxillary and mandibular incisors and hence is
responsive to orthodontic treatment.
From age 7 to 18 years- the mean aggregate increase in upper and
lower lip lengths in the male subjects was 6.9 mm, in the female
subjects it was only 2.7 mm.
It is obvious from the small growth changes in the female upper
and lower lip lengths that a protruding dentition at 7 years will
not change much relative to the lips during growth. The
treatment of choice, if so indicated, may require extraction of
first premolars. However, with growth in the lip lengths of the
males,some accommodations are possible.

Small changes in the upper-lip length and prediction equations
suggesting a linear relationship indicate a probability that those
with a short upper lip at 7 years will continue to have a short
upper lip even at age 18 years. The impact of this finding on
treatment planning is significant because the excessive display
of upper gingiva, if present, should be corrected early to
establish a more favorable tooth to lip relationship.
Lip thickness at points A and B increased more than at the
vermilion borders. The increase in lower lip thickness at
vermilion border was very small for the females. These
changes lead to thicker, longer lips for the males. The lips of
males increased approximately 7 mm in length and therefore
accommodate more protrusion of incisors than do
the lips of females.

Upper and lower lips of men decreased in thickness which, taken
with nose changes, sagittal skeletal mandibular changes, and an
increase in chin soft-tissue thickness, resulted in both lips
appearing more retruded with age. The mean trends for men
indicated that the effects of chin growth slightly outweighed
nose changes in the male profile which resulted in a
straightening of the profile.
However, for the women, the upper lip and chin soft-tissue
decreased in thickness, and the lower lip showed a small
increase in thickness. Taken together with the minor mandibular
skeletal changes, the women did not have an effect of
straightening the profile.
Both sexes had increased upper lip length that reduced the incisor
exposure by 1.0mm

In adolescents, a short upper lip relative to commissure height
could be considered normal because of the lip lengthening that
continues even after vertical skeletal growth is complete.
In Adults, a short lip length relative to commissure height results
in an unesthetic, reverse-resting upper lip line.It is not easy to
alter commissure height, but lip lengthening is possible with lip
surgery, either as a single procedure or in combination with a
Le Fort I osteotomy.

Gingival smile line
For some people, the smile at its fullest exposes the gingiva superior
to the maxillary anterior teeth. This anatomical feature defines a
gingival smile line (GSL).
The "gummy" smile, which can be defined as 2mm or more of
maxillary gingival exposure in full smiling..
Peck and Peck pointed out that the capacity to project a gingival
smile was related to: anterior vertical maxillary excess and the
muscular ability to raise the upper lip significantly higher than
average when smiling.

The etiologies of a gummy smile are:
1. Vertical maxillary excess
2. Short philtrum height
3. Excessive smile curtain
4. Short anterior crown height
5. Uprighted or detorqued upper incisors
Its biological mechanism appears to involve the combined effects
of anterior vertical excess, an increased muscular capacity to
raise the upper lip in smiling, and associated factors such as
excessive interlabial gap at rest and excessive overjet and
overbite. The sexual dimorphism in smile types indicates that
females are twice as likely as males to have gummy smiles.
Intrusion base arches or utility arches may succeed in reducing a
gummy smile orthodontically in some cases.

Gingival display can be eliminated by a simple gingivectomy or
surgical crown lengthening with removal of crestal alveolar bone.
Such procedures are particularly indicated in cases with altered
passive eruption, excessive gingival margins, and short clinical
crowns, because they will expose more of the anatomical crowns.
When crestal alveolar bone is removed during surgical crown
lengthening, the gingival margin will stabilize within six months
at about 3mm from the new bone level.
The type of gingival surgery depends on the relationship between the
alveolar bone crest and the cementoenamel junction. At the end of
orthodontic treatment, a labial gingivectomy to the bottom of the
clinical pocket may produce a net gain of 1mm or more in crown
length, or about half the probing length.
The gingivectomy is especially useful in eliminating the
accumulation of hyperplastic gingiva often associated with fixed
appliance therapy.

Gingival smile line and VME
The gingival smile line is often an associated feature of maxillary
alveolar overdevelopment or vertical maxillary excess (VME).
This GSL-VME association was first published in 1974 by Karin
Willmar in her description of the idiopathic long face.
Treatment of the most severe gummy smiles may require maxillary
superior repositioning surgery (LeFort I osteotomy), along with
reduction of the associated vertical maxillary excess.
This approach does have limitations, however, since the upper lip
may be considerably shortened. Because of the gradual drooping
of the lips over time, there is reasonable evidence that a gummy
smile will diminish with age.

Lip Elevation
In smiling, the upper lip is elevated by about 80% of its original
length, displaying 10mm of the maxillary incisors.
Women have 3.5% more lip elevation than men. There is
considerable individual variability in upper-lip elevation from
rest position to the full smile, ranging from 2-12mm, with an
average of 7-8mm.
If a gingival smile is caused by a hypermobile lip, it would be a
mistake to correct it with aggressive incisor intrusion or
maxillary impaction surgery, because that would result in little
or no incisor display at rest and thus make the patient look
older.

The muscular capacity to raise the upper up higher than average
(hyperfunctional muscle) can cause excessive gingival display.
Several surgical procedures have been reported in the literature to
correct a gummy smile caused by hyper functional upper lip
elevator muscles (mostly the levator labii superioris muscles).
Rubinstein described a procedure whereby an elliptical portion of
gingiva and buccal mucosa was excised and the borders
approximated and sutured together.
Miskinyar performed myectomy and partial resection of the
levator labii superioris muscles: I or both of the bellies of
the muscles were amputated 1 .0 to 2.0 cm
at their junction with the orbicularis oris muscle.

Litton and Fournier referred to muscle detachment from the bony
structures above to bring the lip down
Ellenbogen reported that resection of the levator labii superioris is
short lived, with the gummy smile returning within 6 months.
He advocated placing a spacer, either nasal cartilage or
prosthetic material between the stumps to prevent the muscles
from being reunited and again hyperelevating the lip.
Ezquerra et al presented a multidisciplinary approach for treating a
high smile line with excessive gingival display: either LeFort I
osteotomy or gingival and alveolar bone remodeling surgery, or
a modified (intra oral) camouflage procedure or a combination
of the latter 2.

Botulinum toxin type A in the treatment of excessive gingival
display
Mario Polo
Botulinum toxin is produced by the anaerobic bacterium
Clostridium botulinum. Type A (BTX-A) is the most potent and
the most commonly used clinically.
Botox is a purified BTX-A isolated from the fermentation of C
botulinum. It is a stable, sterile, vacuum-dried powder that is
diluted with saline solution without preservatives.
BTX-A weakens skeletal muscles by cleaving the synaptosome
—associated protein SNAP—25, thus blocking the release of
acetylcholine from the motor neuron and enabling the
repolarization of the postsynaptic terminal. As a result, the
muscular contraction is blocked. The production of
acetylcholine is nor affected by this blockade of the
neuromuscular transmission.

5 patients with excessive gingival display due to hyperfunctional
upper elevator muscles were treated with BTX-A injection.
The following measurements (called A, B. and C were recorded:
A: RP 1 to superior border of upper lip vermillion
B RP 1 to inferior border of upper lip vermillion
C: inferior border of upper lip vermilion border to junction of the
gingiva with the maxilIarry central incisor crown along its own
midline

All 5 patients began to show improvement approximately 10 days
after the injections. After 14 days results were definitely
observed. The pre- and postoperative measurements were
recorded and compared. At 2 weeks after injection in phases II
and III . All 5 patients had a mean increase of measurements A
and B of 4.20mm and a mean decrease of measurement C of
4.20 mm
The ideal dosage might be 2.5 U per side at the LLS, 2.5 U per
side at the LLS/ZM sites, and 1.25 U per side at the OO sites.

Vertical Maxillary Height
When upper lip length and mobility are normal, a gingival smile
with excessive incisor display at rest can be attributed to
vertical maxillary excess.
This kind of skeletal gingival smile is generally associated with
excessive lower facial height.
Conversely, a low lip line with no incisor display at rest is
“skeletal” when associated with inadequate lower facial height
due to a vertically deficient maxilla .

The best reference for impacting or lengthening the maxilla is the
incisor display at rest, taking upper lip length and any incisor
attrition into account.
The full smile does not make a good reference, partly because of
the individual variation in lip mobility.
A short upper lip should not be treated by shortening the maxilla
unless the facial outline can accommodate such a change. It
should also be noted that in maxillary impaction, the upper lip
shortens by as much as 50 % of the surgical skeletal intrusion

Crown Height
The average vertical height of the maxillary central incisor is
10.6mm in males and 9.8mm in females.
If there is little or no incisor display at rest, but the lip line is
normal in smiling, the crown height can be increased incisally
with cosmetic dentistry.
A gingivectomy or a crown-lengthening procedure with crestal
bone removal is recommended when short clinical crowns are
associated with a gingival smile and a normal incisor display at
rest.

Vertical dental height
A deep bite should be corrected by maxillary incisor
intrusion in a patient with excessive incisor display at rest, but
posterior extrusion or lower incisor intrusion in a patient with a
normal lipline at rest. In open bite cases with inadequate
incisor display at rest should be corrected by maxillary incisor
extrusion.If the lip line is normal posterior intrusion and lower
incisor extrusion.
Incisor Inclination
Proclined maxillary incisors, whether in a Class II, division I
malocclusion or in a Class III compensation, tend to reduce the
incisor display at rest and in smiling .
On the other hand, uprighted or retroclined maxillary incisors,
as seen in Class II, division 2 malocclusion or after
orthodontic retraction without torque control, tend to increase
the incisor display.

Smile arc
The smile arc is the relationship between a hypothetical curve
drawn along the edges of the maxillary anterior teeth and the
inner contour of the lower lip in the posed smile.
Jco mar 05
The smile arc as defined from the frontal view
The smile arc from the frontal view is 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 social
smile.
Ajo jul 2003
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.

The relationship of the maxillary incisal curve to the inner contour of
the lower lip also can be divided into three types:
parallel, straight, and reverse.
Maxillary Incisal Curve and Lower Lip
The Tjan survey revealed that 85% of the students had a maxillary
incisal curve parallel to the inner contour of the lower lip, 14%
showed a straight rather than a curved line, and 1% had a reverse
smile line . Since parallelism is the "normal" finding in untreated
persons, it would seem to be an optimal goal for objective beauty
In an ideal smile arc, the curvature of the maxillary incisal edge is
parallel to the curvature of the lower lip upon smile.
The term consonant describes this parallel relationship .
In a nonconsonant or flat smile, the maxillary incisal curvature is
flatter than the curvature of the lower lip on smile.

The curvature of the incisal edges appears to be more
pronounced for women than for men, and tend to flatten with
age. The curvature of the lower lip is usually more pronounced
in younger smiles.
Hulsey published the first orthodontic study to quantify lip-tooth
characteristics at smile. By placing a grid over the cropped
smile photograph, he measured a sample of orthodontically
treated patients and compared them with a sample of untreated
orthodontic patients with normal occlusion. The treated group
had significantly poorer smile scores, as judged by a lay and
professional panel, when looking at maxillary incisor–maxillary
lip relationships.
Hulsey concluded that a key component present in an esthetic
smile was a consonance between the arcs formed between the
incisal edges of the maxillary anterior teeth and the curvature of
the lower lip.

The smile arc can be unintentionally flattened during orthodontic
treatment by any or all of the following three techniques.
Overintrusion of Maxillary Incisors
If the maxillary incisors are overintruded to correct an overbite or
a gingival smile without considering or monitoring the incisor-
lip position at rest, the smile arc may be flattened.
Indiscriminate use of utility arches or archwires with accentuated
curves can not only flatten the smile arc, but can also result in a
low lip line at rest and in smiling, which ages the patient.

Bracket Positioning
The same bracket heights should not be used for parallel,
flat, and reverse smile arcs.
If optimal smile arc esthetics are to be achieved., the bracket
positions must take into account the relationship of the incisal
edges to the lower lip curvature for each individual patient.
In a reverse smile arc, for example, the brackets should be
positioned higher than usual on the maxillary central incisors
and progressively lower on the lateral incisors and canines

Cant of the Occlusal Plane
Extraoral forces, intermaxillary elastics, and orthognathic
surgery can affect the cant of the occlusal plane.
If the maxillary occlusal plane is canted upward anteriorly, for
instance,the incisal edges will move away from the lower lip,
resulting in a nonconsonant smile arc .
Conversely, if the occlusal plane has an excessive clockwise tilt,
the upper incisal edges will be covered by the lower lip,
making the smile arc less attractive.
Maxillary incisor inclination affects not only the lip line, but the
smile arc as well, when the curvature of the incisal edges does
not coincide with the border of the lower lip in smiling.

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.

The Correlation of Smile Line with the Vertical
Cephalometric Parameters of Anterior Facial Height
Journal of Dentistry, Tehran University of Medical Sciences
Hosseinzade-Nik et al. 2005
More vertical growth in the posterior maxilla than in the anterior
maxilla could result in a changed relationship between the
occlusal plane and the curvature of the lower lip upon smile.
Growth in the brachyfacial pattern (low mandibular plane angle
and a tendency for parallelism of the sella-nasion line, palatal
plane and occlusal plane) may lead to a flat smile arc.
Patients with this skeletal pattern might, theoretically have a
tendency for the anterior maxilla to lack the clockwise tilt
needed for an ideal smile arc, in some cases, it might even
exhibit a counterclockwise tilt that results in a flat smile arc.

Upper Lip Curvature
The upper lip curvature is assessed from the central position
to the corner of the mouth in smiling.
Upward -when the corner of the mouth is higher than the central
position
Straight - when the corner of the mouth and the central position
are at the same level,
Downward-when the corner of the mouth is lower than the central
positionl.
Upward and straight lip curvatures are considered more esthetic
than downward lip curvatures.A downward lip curvature could
therefore be considered a limiting factor in achieving an
optimal smile .

Lateral Negative Space
Lateral negative space is the buccal corridor
between the posterior teeth and the corner of the mouth in
smiling .
The extent to which the orthodontist is able to
differentiate between the anatomy of the inner and outer
commissures is largely dependent on lighting.

When a video is taken with ambient light only, the buccal corridor
often appears much more pronounced than when supplemental
light is added . Thus, what has been called “negative space”is
often not space at all, but just an illusion.

Buccal corridor
In 1958, Frush and Fisher defined buccal corridors as the spaces
between the facial surfaces of the posterior teeth and the corners of
the lips when the patient is smiling. Their interest in buccal
corridors derived from attempts to fabricate a more realistic
looking denture.
This smile feature has been thought of primarily in terms of
maxillary width, but there is evidence that the buccal corridors
are also heavily influenced by the anteroposterior position of the
maxilla relative to the lip drape.

Smile fullness is calculated as visible maxillary dentition width
divided by inner commissure width.
Buccal corridor is calculated as difference between visible maxillary
dentition width and inner commisure width divided by
innercommissure width.
Smile breadth is defined as percent ratio of outer commissure width
to width of face at vertical level of commissures

A first molar-to-first-molar smile is often advocated in
orthodontics. but is considered evidence of a poorly constructed
denture in prosthodontics.
In studies measuring the number of teeth displayed in the smiles
of young subjects with normal occlusions, those displaying the
first molars were ranked the highest esthetically. A first molar
display was found in only 3.7% of one sample, however, with
most of the subjects (57%) displaying only the second
premolars.
In fact, nonextraction treatment with maxillary expansion does
not necessarily improve the attractiveness of the smile.
Research has shown that premolar extraction does not lead to
arch constriction or a widening of buccal corridors.

Johnson and Smith, defined “ buccal corridor ratio,” as the
maxillary intercanine width divided by the width of the mouth
during a smile, to assess smile esthetics . It was found that the
ratio was the same after both extraction and nonextraction
treatment. Also, the width of the dental arches, at least in the
canine region, is generally not smaller after extraction treatment
than after nonextraction therapy.
Anthony Gianelly, Ajo 2003jan
Archform also affects the transverse dimension of the smile,
A broad arch is more likely to fill the buccal corridors than a
narrow and constricted arch.
In addition, buccal corridors are heavily influenced by the
anteroposterior position of the maxilla relative to the lip drape.
Moving the maxilla forward will reduce the negative space
because a wider portion of the arch will come forward to fill the
intercommissure space

Smile Symmetry
Smile symmetry, 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.

Frontal Occlusal Plane
The frontal occlusal plane is represented by a line
running from the tip of the right canine to the tip of the left
canine.
A transverse cant can be caused by differential eruption of the
maxillary anterior teeth or a skeletal asymmetry of the
mandible. This relationship of the maxilla to the smile cannot
be seen on intraoral images or study casts, and smile
photographs can also be misleading.
Therefore, clinical examination and digital video documentation
are essential in making a differential diagnosis between smile
asymmetry, a canted occlusal plane, and facial asymmetry.

Dental Components
Dental components of the smile include the size, shape, color.
alignment, and crown angulation (tip) of the teeth; the
midline; and arch symmetry.
The ideal maxillary central incisor should be approximately
80% width compared with height, but it has been reported to
vary between 66% and 80%.
A higher width/height ratio means a squarer tooth, and a lower
ratio indicates a longer appearance.

Terminal Tooth on Smiling
Generally speaking, about 90% of people show either the first or
the second premolar as the last tooth when they are,smiling.
To create the illusion of smile fullness, the last premolar displayed
should be positioned relatively upright.It is particularly
important to avoid a lingual inclination of the maxillary
premolars in patients with a relatively small maxillary apical
base and in premolar extraction cases.
When there is crown inclination asymmetry between the right and
left last premolar on smiling, the smile invariably appears
narrower on the side where the premolar has more tilt.

Connector Area Versus Contact Point
Morley and Eubank introduced the term connector area as a useful
tool and a visual goal to optimize smile esthetics in dental
patients.
Contact between anterior teeth is where teeth actually touch,
Connector is where teeth appear to touch.
Connector areas are larger, broader areas than the contact points
between teeth, and can be defined as the zone in which two
adjacent teeth appear to touch.The most esthetic relationship
between the maxillary anterior teeth is referred to as the 50-40-30
rule.

The most important connector area is the one between the two
maxillary central incisors. Since it should be quite long in
orthodontically well-treated cases, it is clinically important to
carefully check the clinical mid axis between the mesial
surfaces of the central incisors before appliance removal.
In pretreatment crowding, it is always necessary to recontour
these mesial surfaces by grinding. This will relocate the contact
point in an apical direction to reduce or avoid interdental
gingival recession (dark triangles between the teeth due to loss
of the gingival papillae)and result in an optimally long and
vertical connector area.

Number of Teeth Displayed in the Smile
The Los Angeles survey revealed that in a typical or average
smile in young adults, the six maxillary anterior teeth and the
first or second premolars are displayed. The number of teeth
displayed in the full smiles of 454 students were: six anteriors
only, 7%; six anteriors and first premolars, 48.5%; six anteriors
and first and second premolars, 40.5%; six anteriors, first and
second premolars,and first molars, 4%.

The satisfactory division of a surface into parts that are different in
shape and size yet are related to each other is called repeated
ratio. The most significant repeated ratio in history is the
"Golden Proportion (Golden Rules)".
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

Apical Base Size and Crown Inclination Variations
It appears to be a general rule for obtaining optimal esthetics that
the smaller the maxillary apical base, the more labial tilt may be
given to the canines and premolars to allow a broader smile .
For most patients, optimal esthetics will be achieved with upright
canines or a very mild lingual crown inclination .
Too much lingual crown inclination of the canines will generally
disrupt the harmony of the front-to-back tooth display curve .

The dental midline is an important focal point in an esthetic
smile. A practical and reliable method of locating the facial
midline, which normally coincides with the dental midline, is
to use two anatomical landmarks: nasion and the base of the
philtrum, known as the “cupid’s bow”, in the center of the
upper lip. A line drawnbetween these two landmarks not only
locates the facial midline, but also determines its direction. The
parallelism between the maxillary central incisor midline and
the facial midline is more important than the coincidence
between the dental and facial midlines

Gingival Components
The gingival components of the smile are the color, contour,
texture, and height of the gingiva.
Inflammation, blunted papillae, open gingival embrasures, and
uneven gingival margins detract from the esthetic quality of the
smile. The space created by a missing papilla above the central
incisor contact point, referred to as a “black triangle”, may be
caused by root divergence, triangular teeth, or advanced
periodontal disease.
Orthodontic root paralleling and flattening of the mesial surfaces
of the central incisors, followed by space closure, will lengthen
this contact area and move it apically toward the papilla.
The gingival margins of the central incisors are normally at the
same level or slightly lower than those of the canines, while the
gingival margins of the lateral incisors are lower than those of
the central incisors.

Gingival shape refers curvature of the gingival margin of the
tooth.The gingival zenith of the maxillary lateral incisors and
the mandibular incisors should coincide with their longitudinal
axis.
Gingival contour, as compared with gingival shape refers to a
more 3—dimensional description of gingival topography. Ideal
gingival Contour is characterized by sharp interdental papillae
and equally tapered gingival margins at the cervical margin of
the teeth.

The most frequent applications of lasers in dentistry include
Gingivectomy,frenectomy, removal of mucocutaneous lesions, and
gingival sculpting associated with implants and mucogingival
surgery.
THREE BASIC TYPES OF LASERS
Three types lasers are available for use in dentistry:
The CO2 laser, The erbium laser, and The diode laser.
INDICATIONS FOR SOFT TISSUE LASER TREATMENT
-cosmetic gingival contouring ,
-In solving tooth eruption and soft tissue problems that
impede efficient orthodontic finishing.

Concepts that are important in cosmetic dentistry
Crown heights, tooth proportionality, and gingival shape and
contours therefore, the uses of soft tissue lasers in orthodontic
practice broadly fall into following categories:
Improving gingival shape, contour,
Lengthening crowns.
Idealizing proportionality
Resolving crown /height -asymmetries.

CLINICAL GUIDELINES
VERTICAL DIMENSION
Study the patient's dentition directly from the front to make a
reliable esthetic evaluation.
In the dentist's chair, move the patient's head to the side of the
head rest, which allows an "eye-to-eye" perspective.
A short video with the patient speaking is very helpful.
Provide a curve of the maxillary incisors that is parallel to the
inner contour of the lower lip on smiling. This is generally
achieved by making the maxillary central incisors 0.5-1.5 mm
longer than the lateral incisors.
Be careful not to actively intrude the maxillary incisors when their
pretreatment vertical position is normal for the patient's age.
Do not overintrude and hide away the maxillary incisors behind
the upper lip . Establish an age-appropriate vertical incisor
display in the rest position and normal conversation for each
patient

Midlines
A vertical line from the nasion to the base of the philtrum may be
the most practical guide to locate the facial midline.
A precise dental midline coincident with the facial midline is not
necessary for optimal esthetics.
Moderate maxillary midline deviation is acceptable to most
individuals, as long as the central incisor crown angulation is
not significantly canted .
Securing optimal connector areas between the maxillary anterior
teeth according to the 50-40-30 rule is useful for esthetic smile
design.
The connector area between the two maxillary central incisors
should be long (approximately half their clinical crown
lengths), vertical, and parallel to the facial midline. The
mandibular midline is less important for esthetics.

Transverse Dimension
Provide an individualized,esthetic, symmetric labiolingual crown
inclination of canines and premolars for each patient.
Crown inclination asymmetries between contralateral canines and
premolars in the right and left side of the mouth are common.
They must be (1) recognized early in treatment by studying the
dentition from the front; and (2) intentionally corrected by
archwire torquing (or possibly by custom-made bracket torque
prescriptions). Otherwise, the finished result will be asymmetric
with regard to clinical crown inclination.
The terminal teeth shown on smiling should be straight to provide
smile fullness. In about 90% of cases, this will be the maxillary
first or second premolar.
A smooth, gradual front-to-back tooth display curve laterally
provides harmony and beauty to the treatment result. Any
disruption will reduce the esthetic outcome.
Avoid tipping the mandibular canines, premolars, and molars
lingually during the orthodontic treatment.

Conclusion
Thus the smile management of a patient starts right from
understanding the patients perceptions,concepts and needs of a
beautiful smile and integrate it with our diagnosis,treatment
plan,and biomechanics so that at the end of day when treatment
finishes both the clinician and the patient has a reason to smile.
SMILE IS A CURVE
WHICH MAKES THINGS STRAIGHT.

Smile analysis

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