Esthetics: a comparison of dentists` and patients` concepts

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When male and female patients, dental students, and dentists evaluated
drawings and photographs of maxillary central incisors of varying
shape, symmetry, and proportion, it was found that the preferences of
dentists and patients differed significantly.
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Esthetics: a comparison of dentists' and patients' concepts
Arthur S. Brisman, DDS
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ental esthetics is a science based on the general
taste of society. Certain shapes and arrangements of
teeth may be considered esthetically pleasing when
many patients agree that they are. Investigators may
take surveys to discover what forms, shapes, colors,
and other sensory impressions are generally preferred.
The dentist creates an illusion. He learns concepts
of perception l and tries to achieve the patient's desires for an esthetic appearance. Unfortunately, dentists may develop concepts of anesthetic appearance that differ from patients'. This can create communication problems and unanticipated difficulties.
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should be given round, soft, and delicate teeth
(tapering/ovoid). Men are thought of as square, angular, and rugged and should be given teeth that
harmonize with this image. 6 Developing this idea to
its natural conclusion, we must assume that old patients prefer old and defective teeth to match their
age and physical condition, and unpleasant patients
are to be given unpleasant teeth to match their personality.
Attempts to create an individualized dental composition for each patienp·7 conflict with the hypothesis that there are standard concepts of beauty in society that develop from social, cultural, and psychological considerations and that each person wants
teeth that conform to these concepts.
Tooth shape and harmony
IESI
In 1914, Williams concluded that human teeth
could be classified into three principal shapes: rectangular, triangular, and ovoid. 2 Williams claimed
that the most pleasing appearance is one in which
the outline form of the individual's face turned upside down and the outline form of the individual's
maxillary central incisor are identical. Williams's
method of harmonizing the face with teeth has been
popular for more than 60 years. 3 This is remarkable
because the outline forms of the face and the maxillary central incisor coincide in only a small percentage of cases, and it has never been proved that this
occurrence results in an ideal esthetic appearance. 4
Perhaps the only major addition to Williams's
concept of esthetics was the attempt by Frush and
FisherS to harmonize the teeth with a patient's sex,
personality, and age (SPA factor). According to this
concept, women are considered to be round, soft,
and delicate and, for proper harmony and esthetics,
Symmetry
Any concept of esthetics must consider symmetry.s
In another field, Furtwangler9 wrote: "Symmetry refers to the regularity or balance in the arrangement
of forms and objects. There are two kinds of symmetry, horizontal or running symmetry, and radiating or bilateral symmetry." Horizontal symmetry
occurs when the design shows similar elements
from left to right in a regular sequence. This type of
symmetry is psychologically predictable and comfortable but tends to be monotonous. l The dentition
approaches horizontal symmetry when all the teeth
have the same shape; that is, when they look like
central incisors. Radiating symmetry results when'.
the design extends from a central point and the left
and right sides are mirror images. Elongating the
central incisors and narrowing the lateral incisors
will exaggerate the effect of radiating symmetry.
According to the Academy of Denture Prosthe'ADA. Vol.l00•.Man:h 1980 • 345
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tics,10 "anterior crowns should maintain some of the
irregularities observed in natural teeth to be esthetically acceptable." But, according to psychologists,l1
"forms and designs which are repetitive and regular
(symmetrical) are usually found to be more pleasing." Teeth are seldom symmetrical, although patients think they are. There must be some irregularities if teeth are to appear natural; however, this
does not mean they are esthetically pleasing to the
patient. Patients may prefer teeth that look artificial
or unnatural but are closer to their concept of the
ideal esthetic appearance .
Proportion
Proportion is another important concept of esthetics. We will consider the relationship between the
length and width of.the tooth. The average maxillary
central incisor has a length-to-width ratio of 10:9.
Yet, the recommended proportion in dental
anatomy and for dental laboratory technici~s is
10.5:8.5. 12.13 This discrepancy can only be explained by the empirically derived impression that
elongating the central incisor will result in a more
esthetically pleasing arrangement. It has also been
suggested that the cervical mesial-to-distal dimension be widened from 6.5 to 7 mm. This reduces the
taper of the tooth; a squarer incisor is created.
When the central incisor is elongated, it approaches an interesting length-to-width proportion,
3:5. Artists, architects. and psychologists have
found that people prefer lines and areas that can be
divided approximately in the ratio of 1 to 0.618, or
approximately 3 to 5. The Greeks may have used this
proportion in art and architecture. It was studied by
Fibonacci, a 13th century Italian mathematician,
and is currently used in designs by commercial artists. I 4-16 Dentists have also written about the golden
proportion. t.17 Levin even developed a grid that relates central incisors, lateral incisors, canines, and
premolars in a 3:5 proportion. IS
Study objectives
The evaluations described in this paper have tried to
answer, with respect to symmetry. proportion, and
shape of teeth, these questions:
-Is there a shape of teeth (square, tapered, or
ovoid) that is preferred?
-Is symmetry preferred?
-Is radiating symmetry preferred to horizontal
symmetry?
-Are elongated teeth with a length-to-width ratio
of 3:5 (the golden mean) preferred?
-Are dentists and dental students' concepts of
esthetic appearance similar to those of patients?
-Are square teeth considered masculine. are tapered ovoid teeth considered feminine, and do
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348 • JADA, Vol. 100, March 1980
women pref~r a different and presumably Illore
feminine type of teeth?
Methods
Preferences of patients, dentists, and dental students with respect to shape, proportion, and sYmmetry of maxillary incisors were investigated by
analyzing their choices in a series of studies. The patients were white, middle-class men and WOIllen
who lived in the greater New York area. Ages ranged
from 20 to 70 years; none of the patients wore dentures. The dental practitioners and students were
men. The dentists had a minimum of three years'
experience. The students were seniors at New York
University College of Dentistry. Totals of 112 dentists, 215 dental students, 695 female patients, and
399 male patients were used for the different
studies. No participant answered more than three of
the nine surveys.
Studies 1 and 2 evaluated the preferences of the
four groups to variations in drawings of basic shapes
and photographs of variously shaped maxillary
teeth. Study 3 evaluated preferences to photographs
of two set-ups of so-called masculine or feminine
teeth. Studies 4, 5, and 6 evaluated preferences to
drawings and photographs of teeth of the same
shape but with different length-to-width proportions. Studies 7 and 8 evaluated preferences to draw- .
ings and photographs of teeth of different symmetry
but which had the same shape and proportion.
Study 9 evaluated preferences to teeth of varying
combinations of shapes and symmetry but with the
same proportions.
Data and illustrations for the nine studies are
found on the following five :oages. Discussion follows Study 9.
Participants were asked to list their choices as:
best, second best, third. and so forth. A weighted
score for each reply was obtained by totaling the
scores of the respondents in each group (dentists,
dental students, and male and female patients). First
choice was given a weight of 1, second choice was
weighted as 2, third choice was weighted as 3, and
so forth. The lower the total score, the more favorable the response.
By ranking the weighted replies, we attempted to
test the consistency of the replies among the four
groups. The closer the weighted score was to 1, 2, or
3. the more consistent were the replies to the test
within the group. Complete consistency rarely occurred within each group; often, the weighted
scores for two of the choices were close.
Differences in weighted totals for the four groupS
in each study were tested for statistical significance
by the chi-square test. This tests whether the differences in weighted rank scores among groups of
subjects were statistically significant or could have
occurred by chance.
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Table 1 • Mean scores and rankings of preferences of four groups of respondents (male
and female patients, dental students and practitioners) for basic shapes of teeth as seen in
Study 1 (Fig 1).
Group
MalePatieots (0 = 80)
Ovoid
Squar"
Triangle
Female patients (n = 118)
Ovoid
Square
Triangle
Students (n = 68)
Ovoid
Square
Triangle
Dentists (n = 27)
Ovoid
Square
Triangle
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First
choice
Second
choice
Third
choice
Mean
score
Rank
41
37
2
36
35
9
3
8
69
1.52
1.64
2,84
1
2
3
40
56
22
10
12
96
1.51
1,68
2.Bl
1
2
3
14
42
12
1
13
54
1,24
2,00
2,76
1
2
3
4
20
3
a
1.15
1,96
2.89
1
2
3
68
50
a
53
13
2
23
4
a
3
24
. Study 1: Basic shapes, drawings.
Three shapes-square, ovoid, and
triangular-were shown to participants who were asked to give their
preferences (Fig 1). They were not
told the shapes represented teeth although this was inferred by most participants because of the test situation.
Table 1 shows the preferences of each
of the four groups, the mean scores,
and the ranks of the mean scores. All
groups chose the ovoid as their first
choice, the square as second choice,
and the triangle as third choice.
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Note: x' = 8.41; df = 6; P> ,OS,
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Fig 1 • Basic square, ovoid, and triangular
forms that were shown to participants. All
dentists chose ovoid fonn as first preference.
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A
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Table 2 • Mean scores and rankings of preferences of four groups for basic shapes of teeth as seen in photographs of maxillary central
incisors in Study 2 (Fig 2).
Shape
of tooth
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j
A.
B.
C.
Note: x'
Male patients
(n = 80)
Square
ovoid
Ovoid
Tapered
ovoid
= 7.15;
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Mean
score
Rank
1.80
Second
1.63
First
1.65
2.55
First
Third
1.66
2.71
Second
Third
Mean
Rank
score
Dentists
(n = 27)
Students
(n = 68)
Mean
1.93
Rank
Second
Mean
score
2.11
Rank
Second
1.43
2.64
First
Third
1.37
2.52
First
Third
scor~
df - 8; P> .05.
A
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Female patients
(n = 118)
B
Fig 2 • Photographs of maxillary central incisors that were closely associated in form with
drawings shown in Figure 1. A, square ovoid;
B, ovoid; and C, tapered ovoid. Ovoid was first
choice, especially of dentists.
Study 2: Basic shapes, photographs.
This study was designed to determine if the participants' preferences '
in Study 1 carried over to photographs of maxillary central incisors.
For this study, the triangular shape
was softened to make a tapered
ovoid, and the square was made a
square ovoid (Fig 2). Table 2 shows
that the choices followed a pattern
similar to that in Study 1. Ovoid was •
first choice in three of the four groups
and virtually tied for first choice of
female patients. Differences in .
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weighted "ore' were not 't.ti,t
cally significant.
Brisman: ESTIlETICS • 347
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Table 3 • Percentages of respondents preferring masculine (Fig 3, A) or feminine (Fig 3,
B) teeth as seen in photographs in Study 3.
Male
patients
(n = 60)
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Which do you prefer?'
Masculine teeth (A)
Feminine teeth (B)
Which would you prefer for
yourself?t
Masculine teeth (A)
Feminine teeth ~)
Which do you t ink is more
masculine?:!:
Masculine teeth (A)
Feminine teeth (B)
No opinion
Female
patients
(n = 100)
Study 3: Masculine and feminine
teeth. In Study 3, we investigated the
concept that square central inCisors
are masculine and tapered ovoid central incisors are feminine (Fig 3). AU
groups preferred masculine teeth
(the square ovoid shape) to the
feminine teeth (the tapered OVoid
shape), and the differences were not
statistically significant. When asked
"Which would you prefer for Yourself?", a similar percentage of Participants (including female patients)
preferred the masculine teeth. Again,
differences in responses were not
statistically significant. In reply to
"Which do you think is more masculine 1", 24 of the 2 5 dentists termed
the square ovoid masculine. Although most of the patients considered the square ovoid more masculine, many did not, and some
could not decide. Differences in percentages were not statistically significant (Table 3).
Male
dentists
(n = 25)
Male
students
(n = 40)
%
%
%
%.
60
40
69
31
68
32
64
58
42
65
35
68
32
60
40
78
12
10
74
10
80
20
96
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36
16
·x' = 1.41; df =
tx'
tx'
3; P> .05 .
= 1.18; df = 3; P > .05.
- 3.66; df = 3; P > .05.
lOne dentist thought set-up B was more masculine because it looked uneven and irreglliar.
B
A
Fig 3 • Photographs used to evaluate concept that square ovoid central incisors (A) are masculine
and tapered ovoid central incisors (B) are feminine. Female patients preferred square ovoid shape (A).
Lengthto-width
proportion
A. 3;2
B. 5:4
C.9:10
D.2:1
E. 4:3
Male patients
(n = 70)
Mean
score
Rank
1.69
2.87
4.29
4.61
1.54
Second
Third
Fourth
Fifth
First
Note: X' - 13.01; df = 12: P
Female patients
(n - 1(0)
Mean
score
Rank
1.98
2.74
3.99
4.64
1.65
Students
(n = 55)
Second
Third
Fourth
Fifth
First
Dentists
(n = 25)
Mean
score
Rank
Mean
score
1.84
2.82
4.67
4:32
1.35
Second
Third
Fifth
Fourth
First
1.92
2.80
4.88
4:04
1.36
Rank
Second
Third
Fifth
Fourth
First
> .05.
Study 4: Proportions, drawings. This
study evaluated the length-to-width
proportion of teeth. The drawings of
the five shapes in this study are
square ovoids (Fig 4). They have the
same widths but different lengths. In
shape E, the length to width was 4:3;
this was first choice of all groups. In
shape A, the length to width was 3:2;
this was second choice, and shape B,
in which the length to width was 5:4,
was third choice. Patients selected
shape C, in which the length to width
was 9:10, as fourth choice to the most
elongated shape, shape D. Dentists
and students, however, preferred
A
B
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D
E
Fig 4 • Drawings used to evaluate length.to-width proportion of teeth. Drawings A to E are square
ovoids with same widths but different lengths. Shape E, with iength-to-width ratio of 4:3, was first
choice of all groups, but dentists preferred teeth that were more elongated.
shape D, in which the length to width
was 2:1, to shapeC (Table 4). Dentists
were more consistent in their prefer-
ences than other groups. Differences
in choices among the four groupS
were not statistically significant.
,
348 • JADA, Vol. 100, March 1980
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Table 5
(Fig 5) in Study 5.
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Male patients
(n = 75)
Lengthto-width
proportion
Female patients
(n = 125)
Students
(n = 50)
Dentists
(n = 29)
Mean
score
Rank
Mean
score
Rank
Mean
score
Rank
3.80
1.63
2.07
2.50
Fourth
First
Second
Third
3.66
1.58
2.16
2.60
Fourth
First
Second
Third
3.88
1.54
2.26
2.32
Fourth
First
Second
Third
A. 9:10
B.5:4
C. 10:9
D.4:3
Mean
score
4.00
1.58
2.21
2.21
Rank
Fourth"
First
Second (tied)
Second (tied)
"Unanimous preference.
Nole: X'
= 3.852; df = 9:
P > .05.
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Fig 5 • Drawings of pairs of central incisors used to evaluate preferences in length-ta-width proportions. Drawing B-with length-ta-width proportion of5:4 (proportion presented in manuals for dental
laboratory technicians)-was most favored. Drawing A was unanimously rejected by dentists although highly favored by patients.
Study 5: Proportions in pairs, drawings. Study 5 compares four drawings of pairs of central incisors (Fig
5). Drawing A represents central incisors with a length-to-width ratio of
9:10. This is the average proportion
of deciduous central incisors 19 and
corresponds with shape C in Study 4.
Drawing B, in which the length to
width, 5:4, corresponds to shape B in
Study 4, represents the ideal proportion presented in manuals for dental
laboratory technicians and is
suggested for waxing-up of teeth in
dental anatomy.13.20 Drawing C, in
which the length to width is 10:9, is
the average dimension of the central
incisor.19 Drawing D, in which the
length to width is 4:3, corresponds to
shape E, the preferred proportion in
Study 4 (Fig 4).
Table 5 shows that drawing B was
the most favored of all four groups,
although this proportion (5:4) ranked
third in the drawings of individual
teeth in Study 4. Drawing D ranked as
third choice of patients and students
but tied for second choice for dentists. Differences between groups
were not statistically significant.
Table 6 • Mean scores and rankings of preferences of four groups for various proportions of maxillary teeth as seen in photographs of
set-ups (Fig 6) in Study 6.
Male patients
(n = 70)
Lengthto-width
proportions
Mean
A. 10:9
B. 5:4
C. 3:2
Female patients
(n = 110)
Students
(n - 85)
Dentists
(n = 54)
score
Rank
Mean
score
Rank
Mean
score
Rank
Mean
score
Rank
2.64
1.46
Third
First
Second
2.47
1.39
2.14
Third
First
Second
2.68
1.59
1.53
Third
Second"
First"
2.97
1.64
1.39
Third
Second
First
1.90
"Preference was tied for second choice.
Note: X' - 20,005;
dt -
6; and P
< .02.
B
Fig 6 • Photographs of three set-up. used to
evaluate preferlBlcas in length-ta-width proportions of clBltral incisors. Patients favored B (5:4
ratio) first and C (3:2 ratio) second; dentists and
dental students favored C, then B.
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Study 6: Proportions of set-ups, photographs. In the photographs of three
set-ups in Study 6, shape and symmetry are constant, and only lengthto-width proportion of the central incisors is changed (Fig 6). Photograph
A has a length-to-width ratio of 10:9;
B has a proportion of 5:4 which was
favored in Study 5; and C is elongated to a proportion of 3:2, the ratio
favored second in Study 4. Table 6
shows that patients first chose Band
then chose C, whereas dentists and
students first chose C and then chose
B. Photograph A was third choice in
all groups. Differences in choice!>
among groups were statistically significant.
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C
B
A
Fig 7 • Drawings ofteeth used to evaluate preferences ofvarious forms of symmetry: A. horizontal symmetry; B.
asymmetry; and C. radiating symmetry. Dentists and dental students preferred radiating symmetry and rejected
horizontal symmetry. Patients found horizontal symmetry pleasing.
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Study 7: Symmetry, drawings. This
study elicited preferences to drawings of teeth of different symmetry.
Figure 7 shows drawings of horizontal symmetry (the effect was exaggerated by drawing the lateral incisors
and canines approximately the same
size and shape as the central incisors), asymmetry, and radiating
symmetry.
Table 7 shows a different pattern of
choices for patients, students, and
dentists. Dentists were most consistent in their preferences. They preferred radiating symmetry, showed
interest in asymmetry. and disliked
the drawing of horizontal symmetry.
Students ranked radiating symmetry
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Table 7 • Mean scores and rankings of preferences of four groups for varying symmetry
of maxillary teeth as seen in drawings (Fig 7) in Study 7.
Variants
A. Horizontal
symmetry
B. Asymmetry
C. Radiating
symmetry
Male patients
(n = 80)
Mean
score
Rank
1.56
Second
2.98
1.46
Female patients
(n = 130)
Mean
score
Rank
First*
1.57
Third
First
2.86
1.57
Third
First'
Students
(n = 80)
Mean
score
2.41
2.44
1.15
Rank
Secondt
Thirdt
First
Dentists
(n = 40)
Mean
score
Rank
2.90
Third
1.83
1.27
Second
First
·Preference was tied.
tPreference was virtually tied.
Note: X' = 67.24; df = 6; P < .001.
first and ranked horizontal symmetry
and asymmetry virtually the same.
Male and female patients almost
unanimously rejected asymmetry
(third choice), and equally preferred
the radiating and horizontal symmetries. Differences in group preferences
were statistically significant.
prefher(eF~ces)
~f fsourdgroups for various degrees of radiating and horizontal symmetry as seim in
.g 8 on lu y 8.
T 8ble 8 • hMeafnfscores and rafnkings. of
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Male patients
(n = 126)
Symmetry
Radiating symmetry, degree 1 (B)
Radiating symmetry, degree 2 (C)
Horizontal symmetry (A)
Radiating symmetry, degree 3 (0)
Note: X' = 146.742;
df -
9; P
Mean
score
1.70
2.18
2.74
3.38
Rank
First
Second
Third
Fourth
Female patients
(n = 169)
Mean
score
Rank
1.56
First
2.18
Second
2.93
Third
3.33
Fourth
Students
(n = 94)
Mean
score
2.28
1.37
3.90
2.45
Dentists
(n = 44)
Mean
score
2.75
1.59
3.98
1.68
Rank
Second
First
Fourth
Third
Rank
Third
First
Fourth
Second
< .001.
Study 8: Symmetry, photographs. In
Study 8, photographs of four set-ups
of anterior teeth in which the arch of
radiating symmetry was varied were
shown to participants (Fig 8). Set-up
A shows horizontal symmetry. the
central incisors are even, and the lateral incisors approximate the size
and shape of the central incisors.
Set-up B shows radiating symmetry,
degree 1 (1 to 2 mm); set-up C shows
radiating symmetry, degree 2 (2 to 4
mm); and set-up D shows radiating
symmetry, degree 3 (more than 4
mm). Set-ups B, C, and D have identical lateral incisors and canines. The
central incisors are square ovoids
that are identical except for their positions; the length-to-width ratios are
the same.
Table 8 shows the mean scores and
ranks. Both groups of patients preferred teeth arranged in radiating
symmetry, degree 1 (B). followed by
degree 2 (C). They preferred horizontal symmetry (A) to radiating symmetry, degree 3 (D). Dentists, how-
A
C
D
Fig 8 • Photographs of four set-ups in which arch of radiating symmetry is varied. A, horizontal
symmetry; B, radiating symmetry, degree 1 (1,t03 mm); C, radiating symmetry, degree 3, (3 to4 mm);
and D, radiating symmetry, degree 3, (m.ore than 4 mm). Patients preferred B, foll_ed by C; dentists
preferred C, followed by D, then B.
ever, rated degree 2 (C) as first choice,
degree 3 (D) as second choice. and
degree 1 (B) as third choice. Horizontal symmetry (A) was last choice; it
was almost a unanimous last place
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choice with a mean score of 3.98.
Dental students' choices tended to
resemble those of dentists. Differences in the preferences among
groups were statistically significant.
_______________________
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;able 9 • Mean scores and rankings of preferences of four groups. for teeth with
shape and symmetry as seen in photographs of anterior maxillary teeth (Fig 9)
Study 9.
.
Variations
of shape and
symmetry
Set-up
Set-up
Set-up
Set-up
Set-up
A
B
C
0
E
Mean
score
Rank
Second'
Fifth
Second'
First
Fourth
2.15
4.88
2.15
1.90
3.92
Mean
score
1.88
4.92
2.54
1.67
3.99
Rank
Second
Fifth
Third
First
Fourth
Mean
score
Rank
3.65
3.84
1.96
2.43
3.12
Fourth
Fifth
First
Second
Third
Mean
score
4.71
2.97
1.55
3.28
2.49
III
Rank
Fifth
Third
First
Fourth
Second
"Preferences were tied.
Note: X' = 484.29: df = 12: P < .001.
Study 9: Shape and symmetry, photographs. Study 9 used photographs
of five set-ups of teeth of varying
shape and symmetry (Fig 9). Set-up A
has square ovoid teeth arranged with
horizontal symmetry; set-up B has
tapered ovoid teeth with radiating
symmetry. degree 3; set-up C has,
square ovoid teeth with radiating .1
symmetry. degree 3; set-up D hasj
square ovoid teeth with horizontal :1
symmetry; and set-up E has square .i
ovoid teeth with an asymmetrical ar-J
rangement. Set-ups C and E are 1
nearly identical; the slight asymmet-,1
rical change in E is the only variant. ~l
Study 9 may be considered a com- '
posite of Study 7-in which drawing
A resembles set-up D, drawing B resembles set-up E, and drawing C re- j
sembles set-up C-and Study 3-in 1
which photograph A corresponds to ~
set-up A, and photograph B corre- ),•. j
sponds to set-up B.
:1
Table 9 discloses results of Study 9
that are consistent with the results of
Studies 3 and 7. All the patients preferred the horizontal symmetry in 1
set-ups A and D and disliked the ta- ,.I,
pered ovoid feminine teeth in set-up
B. The asymmetrical natural-looking ;1
teeth (set-up EJ, although only '.,1
slightly different from set-up C, were 1
consistently rejected. Dentists. how- 'j
ever, although preferring C, liked the
asymmetrical arrangment. Positive
interest was shown in the tapered
ovoid teeth, although that shape was
picked third. Dentists gave the lowest preference to the horizontal
symmetry of A and D; set-up A was
almost unanimously picked as last
choice. Mean scores for the students
were closer than in the other groups;
this indicated a lack of unanimous
opinion. Differences in preferences
were highly statistically significant.
,11'
A
D
".',1.'
c
E
D
Fig 9 • Photographs of five set-ups in which
both shape and symmetry are varied: A, square
ovoid teeth, horizontal symmetry; D, tapered
ovoid teeth, radiating symmetry (degree 3); C,
square ovoid teeth, radiating symmetry; D,
square ovoid teeth with horizontal symmetry; E,
square ovoid teeth, asymmetriw arrangement.
Patients preferred set-ups A and D; dentists preferred C but also liked asymmetrical arrangement shown in E.
Discussion
Our studies dealt with only a few of the factors that
can affect esthetic appearance. Other variables include shade, size, arch form, and shape of the lips.
The arrangement of teeth is important and different
effects can be created from only one mold of
teeth 21.22; yet our surveys show that dentists' and patients' concepts of esthetic appearance may differ.
Although dentists and patients have the same preferences for the shape of maxillary anterior teeth, the
preferences differed for proportions of length and
width; there is a particularly large difference in the
preferences with respect to symmetry of maxillary
anterior teeth. Dental students seem to have preferences that are between those of patients and dentists. Both groups of patients had similar patterns of
preferences.
The studies indicate that, when patients and dentists observe individual teeth, they prefer an elongated tooth that approximates the ideal, 3:5, proportion (Study 4). However, when pairs of central inDrisman : ESTHI!TICS a 351
I
!
cisors are evaluated, a less elongated tooth is preferred (Studies 5, 6).
Most dentists dislike the piano key or picket fence
composition; however, patients may prefer this
look. In making dentures, it is easy to break up a
mold, rotate teeth, and create a more natural look.
When dentists believe it is necessary to soften the
symmetry of this composition, they do so with
timidity. Perhaps the canines are made slightly
darker, and the incisors are slightly rotated. Symmetry, p-owever, is not really destroyed, and the results are virtually the same. Seldom will a lateral incisor differ significantly from the other, and never
will the central incisors. This is not surprising, and
dentists should not be criticized. Patients must be
given dental compositions that conform with their
concept of esthetic appearance and not necessarily
with the dentist's concepts.
The dentist is challenged to take varied physiological conditions and limitations, and, with inadequate materials and techniques, arrive at a relatively standard result for each patient.
Summary
Drawings and photographs of shape, symmetry, and
proportion of maxillary central incisors were evaluated by 112 dentists, 215 dental students, 399 male
patients, and 695 female patients. A significant difference was found between the evaluations of patients and dentists; the preferences of dental students were between those of patients and dentists.
Male and female patients had similar opinions.
The author thanks Dr. Larry Garfinkle. associate professor, department
of removable prosthodontics, New York University College of Dentistry,
for statistical evaluation and organization of the paper, Dr. Elias Karnoff,
assistant professor, department of dental materials, New York University
College of Dentistry, for the photographs; and Dr. Timothy Wong, instructor, department of operative dentistry, for the artwork.
352 • JADA, Vol. 100, Marcla 1980
"
Dr. Brisman is an associa~e cl~nical professor, ~epartment of fbted
prnsthodontics, New York Uruverslty College of Dentistry, New York. Address requests for reprints to the author. 31 Washington Sq, New York,
10011.
1. Lombardi. R.E. The principles of visual perception and th.ek clinical
application to denture aesthetics. J Prosthet Dent 29:358-382. 1973.
2. Williams. J.L. A new classification of human tooth forms With special
reference to a new system of artificial teeth. Dent Cosmos 56:627-628.1914.
3. Pound, E. Applying harmony in selecting and arranging teeth. Dent
Clin North Am 241-258.1962.
4. Bell, R.A. The geometric theory of selection of artificial teeth: is it
valid? JADA 97(4):637-640, 1978.
5. Frush. J.P .• and Fisher, R.D. Introduction to dentogeDic restorations. J
Prosthet Dent 5:586-595. 1955.
.
6. Shelby. D.S. Anterior restoration. fixed bridgework. and aesthetics.
Springfield. III. Charles C Thomas. 1976, p 204.
7. House. M.M .• and Loop. J.L. Form and color harmony in the dental
art. Privately printed. 1939.
8. Gerber. A. Creative and artistic tasks in complete prosthodontlta.
Quintessence Int 6(2):45-50. 1975.
9. Furtwangler, A. Masterpieces of Greek sculpture. Chicago. Argonaut,
1964. p 227.
10. Vincent. J.A. History of art. New York. Barnes and Noble, Inc., 1955,
p 30.
11. Garrett. H.E. Psychology. New York. American Book Co., 1950. P
121.
12. Academy of Denture Prosthetics. Principles. concepts. and practices
in prosthodontics-1976. J Prosthet Dent 37:212,1977.
13. Arrangement and articulation of Trubyte teeth: asymmetry and its
influence on tooth arrangement. York. Pa. Dentsply International Inc.,
1976. P 11.
14. Wheeler. R.C. Dental anatomy and physiology. PhiladelphIa. W. B;
Saunders Co .• 1940, P 127.
15. Sowter. J.B. Dental laboratory technology, dental anatomy. UnIversity of North Carolina. p 98. 1972.
.
16. Borissavlievitch. M. The golden number. London. Alec ·Tirantl,
1958.
17. Huntley. H.E. The divine proportion. New York. Dover Publications, 1970.
18. Hambridge. J. Dynamic symmetry. Sci Am 4:23, 1921.
.
19. Mclean. J.W. Full mouth reconstruction. Quintessence Int 11:41/
1978.
'
20. Levin. E.I. Dental aesthetics and the golden proportion. J Proathet
Dent 40:244. 1978.
21. Hardy. I.R. Problem-solving in denture aesthetics. Dent Clin North
Am 305-320, 1960.
22. Krajicek. E. Dental art in prosthodontics. J Prosthet Dent 21:i23-131.
1969.