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Assessment of Tooth Proportions in an Aesthetically Acceptable Smile

Authors:

Abstract

Introduction: Aesthetic facial animation is mostly reported to be due to a close relationship between soft and hard tissue i.e. dynamic smile with appropriate tooth proportions. But variations in tooth size have been seen among various ethnic populations globally. Aim: To evaluate the size and morphology of maxillary anterior teeth, the tooth with maximum variation both mesiodistally and cervicoincisally. Also, the tooth to tooth ratio in percentage of the mean tooth sizes in both genders in patients with aesthetically acceptable smile decided by a panel in North Indian population. Materials and Methods: A total of 100 subjects (50 males and 50 females) were taken and a video clip of their dynamic smile was captured .The smiles were analyzed by a panel and the tooth proportions of the selected attractive smiles were evaluated in both males and females separately. Statistical analysis: Data obtained was subjected to statistical analysis using Microsoft Excel 2007 software; test used was Unpaired t-test and also Mean ± S.D., Variance, Ratio of W/L and its ranges were calculated. Significance is assessed at 5% level of significance. Results: The mesiodistal width and cervicoincisal length of maxillary central incisor was greater compared to lateral incisor and canine in both males and females. There was a statistically significant difference between the width/length ratio of maxillary anterior teeth between males and females.Canine and Lateral incisor showed maximum variation mesio-distally and cervico-incisally. Conclusion: A smile is more pleasing if the visible teeth are in proper morphological proportions. Thus, it relates that teeth play a vital role in increasing the attractiveness of a smile. The mean coronal width/length ratio displayed a more square like tooth form for both males and females.
Journal of Clinical and Diagnostic Research. 2015 Apr, Vol-9(4): ZC01-ZC04 11
DOI: 10.7860/JCDR/2015/11338.5771 Original Article
INTRODUCTION
Smile plays an important role in self-perception of an individual and is
an important element of facial expression and physical attractiveness.
A bright smile is associated with intelligence, empathy, extroversion
and creates its own perception towards facial attractiveness [1].
There has been a paradigm shift in analysis of smile from static
to dynamic. Ackerman et al., [2] and Tarantili et al., [3] advocated
the use of video recording due its distinct advantage over clinically
posed photographs for accurately capturing a true representation
of the smile.
Nowadays, treatment methodology has shifted the focus on soft
tissue–hard tissue relationships. So, the relationship between smile
and tooth proportions is important, as the anterior tooth display
during dynamic facial animation has entered clinical evaluation [4].
Tooth size variations have been reported among various ethnic
populations, like North American Caucasians [5], Negroes [6] etc.
So, the knowledge of racial norms of tooth proportion may help
to specify certain aesthetic modifications to the treatment for that
particular population [7]. Therefore, owing to human variability and
gender differences in tooth size proportions, a study was taken
up on North Indian population with the aims of selecting a sample
with aesthetically acceptable smile and evaluating its width/length
ratio, tooth to tooth ratio in percentage and the tooth with maximum
variation in maxillary anterior teeth region for both genders.
MATERIALS AND METHODS
A sample of 100 subjects (50 males and 50 females) from dental
college in Meerut, Uttar Pradesh, India, were solicited by a written
consent as prescribed and approved by ethical committee of
University, Meerut, Uttar Pradesh to participate in the study. The
inclusion criteria were (1) Age group between 18 to 26 y. (2) No
previous history of orthodontic treatment. (3) No significant skeletal
/dental asymmetry. (4) No missing or malformed teeth causing a
tooth-size discrepancy. (5) No interdental spacing and crowding.
(6) No retained primary or supernumerary teeth. (7) All subjects
presented a complete permanent dentition with the exception of
third molars. (8) No gingival alteration like gingival inflammation,
hyperplasia and periodontal surgery. (9) There should be no incisal
edge/proximal tooth alteration in the form of restoration, fracture,
caries and attrition. The only exclusion Criteria was: Poor video clip
quality (out of focus, not viewable).
Each sample was positioned in the customized cephalostat in
natural head position to stabilize the head and to avoid excess
motion [Table/Fig-1]. The digital video camera (Sony DHX-7V) was
mounted on the adjustable tripod stand and was set at a fixed
distance of 36 inches from the subject. The lens was positioned
parallel to the true perpendicular of the face in natural head position,
and the camera was raised to the level of the patient’s lower facial
third. Then, the patient was made to smile [8].
While capturing the dynamic smile, 5 sec video clip was recorded
with video camera capturing at 30 frames/sec. The raw video clip
was downloaded to a computer and imported to video editing
software (Free studio video to JPG converter, V.5.0.29 build 925) for
converting streaming video into individual 150 photographic frames.
It was seen that every 16th frames showed a change in smile, so every
16th frame out of 150 frames were selected. Out of the selected 10
Keywords: Cervico-incisal length, Dynamic smile, Mesio-distal width
Dentistry Section
Assessment of Tooth Proportions in
an Aesthetically Acceptable Smile
SAMBHAV JAIN1, MUNISH REDDY2, PRADEEP RAGHAV3, SHALU JAIN4, ARBAB ANJUM5, VAIBHAV MISRA6, RAGINI SURI7
ABSTRACT
Introduction: Aesthetic facial animation is mostly reported to
be due to a close relationship between soft and hard tissue i.e.
dynamic smile with appropriate tooth proportions. But variations
in tooth size have been seen among various ethnic populations
globally.
Aim: To evaluate the size and morphology of maxillary anterior
teeth, the tooth with maximum variation both mesiodistally and
cervicoincisally. Also, the tooth to tooth ratio in percentage
of the mean tooth sizes in both genders in patients with
aesthetically acceptable smile decided by a panel in North
Indian population.
Materials and Methods: A total of 100 subjects (50 males
and 50 females) were taken and a video clip of their dynamic
smile was captured .The smiles were analyzed by a panel and
the tooth proportions of the selected attractive smiles were
evaluated in both males and females separately.
Statistical analysis: Data obtained was subjected to statistical
analysis using Microsoft Excel 2007 software; test used was
Unpaired t-test and also Mean ± S.D., Variance, Ratio of W/L
and its ranges were calculated. Significance is assessed at 5%
level of significance.
Results: The mesiodistal width and cervicoincisal length of maxillary
central incisor was greater compared to lateral incisor and canine
in both males and females. There was a statistically significant
difference between the width/length ratio of maxillary anterior teeth
between males and females.Canine and Lateral incisor showed
maximum variation mesio-distally and cervico-incisally.
Conclusion: A smile is more pleasing if the visible teeth are
in proper morphological proportions. Thus, it relates that teeth
play a vital role in increasing the attractiveness of a smile. The
mean coronal width/length ratio displayed a more square like
tooth form for both males and females.
[Table/Fig-1]: Customized cephalostat to standardize photographic conditions
Sambhav Jain et al., Assessment of Tooth Proportions in an Esthetically Acceptable Smile www.jcdr.net
Journal of Clinical and Diagnostic Research. 2015 Apr, Vol-9(4): ZC01-ZC04
22
frames of each sample, the frame representing the subject’s posed
unstrained social smile was selected and identified as “held smile
[2]. The chosen frame was imported into Picasa 3.9.0(Build 136.20,
0) to eliminate any rotations due to head positioning. In addition, the
images were cropped to eliminate most of the nose, cheeks, and
chin to minimize the influence of background facial attractiveness
[9].
The resolution settings and computer monitor sizes affect the
quality of photographs, and it causes variation in rating among the
raters [10]. Therefore, to minimize the bias and to standardize the
response, the photographs were edited and printed in dimensions
of 4 x 6 inches, were number coded (for females it was F1, F2, F3…
to F50 and for males it was M1, M2, M3…to M50), each subject’s
photograph was centred on a single page and finally placed in an
8.5 x 11-inch survey binder [Table/Fig-2] [11].
The judgment for aesthetically acceptable smile was given by a
panel comprising of 2 general dentists, 2 teachers and 2 artists.
Serial numbers were given to the raters as R1, R2, and R3 ….to R6.
The raters were instructed to evaluate the smile for aesthetic value
of teeth and lip appearance and to disregard the facial blemishes as
well as any variations in teeth shade, or picture quality. It was made
sure that the binder was evaluated individually by each panelist to
eliminate the bias. Each sample in the binder was shown for 20
seconds without being able to re-evaluate the previously seen
photographs [12]. Raters gave scores to the closest aesthetically
acceptable smile and categorized them as:
Score 1- Average
Score 2- Good
Score 3 - Excellent
After evaluation of the scores given by the panelist, a sample could
achieve a maximum score of 18 and minimum of 6. The sample that
attained a score of 9 and above were selected as a sample having
the most attractive smiles.
In the selected subjects, the irreversible hydrocolloid (alginate)
impression of maxillary arch were made in stock tray and poured in
dental stone (Type III). To estimate the mesiodistal width and cervico-
incisal length of the maxillary anterior teeth measurements were
made on the casts. All measurements were recorded in millimetres
on the facial surface of tooth with the help of digital verniercalliper
(Aerospace) with least count of 0.01mm [5] and to evaluate the
mean tooth sizes of each tooth (central incisor, lateral incisors and
canine) in percentage and to compare these among each other, a
formula was used which was given by Richardson [6]: X1/X x 100
Where X1 is the mesiodistal width/cervico-incisal length of the
smaller tooth and; X is the mesiodistal width/cervico-incisal length
of the larger tooth. Thus, for example the ratio between the maxillary
incisors is computed as follows:
Mean mesiodistal crown dimension of maxillary lateral incisor
–––––––––––––––––––––––––––––––––––––––––––––––––––– ×100
Mean mesiodistal crown dimension of maxillary central incisor
STATISTICAL ANALYSIS
Data obtained was subjected to statistical analysis using Microsoft
Excel 2007 software; test used was Unpaired t-test and also
Mean+S.D., Variance, Ratio of W/L and its ranges were calculated.
Significance is assessed at 5% level of significance.
RESULTS
The comparison between the right and left side for three maxillary
anterior teeth mesiodistally and cervicoincisally in both males and
females showed no significant difference using unpaired t-test. So,
the single mean values were taken and used further in the study for
both males and females. [Table/Fig-3] shows that when the mean
mesiodistal widths of three teeth were compared for the differences
between the genders, the data revealed that the maximum
mesiodistal width is for central incisor in both males and females.
Further unpaired t-test revealed that significant difference was
present for central incisor and canine between males and females
at 0.05 level of significance.
It was observed in [Table/Fig-4] that maximum cervico-incisal length
was for central incisor in both males and females. Further unpaired
t-test revealed that significant difference was present for central
incisor, lateral incisor and canine between males and females at
0.05 level of significance.
[Table/Fig-5] expresses mean width/length of central incisor, lateral
incisor and canine in ratio for males and females.
[Table/Fig-6] shows the width/length ratio in percentage for both
genders and on comparison between them a statistically significant
difference was seen for all the three teeth.
[Table/Fig-2]: 4 x 6 inches print of photographs in a 8 x 11 inch ring binder
[Table/Fig-3]: Mean, standard deviation and probability of unpaired t-test of mean
values of central incisor, lateral incisor and canine between males and females
for mesiodistal width *indicates values are statistically significant (p < 0.05), * All
measurements are in millimetre
S.No Tooth Male Female Probability of
unpaired t-test
1Central incisor 8.55±0.01 8.26±0.01 < 0.05*
2 Lateral incisor 6.70±0.00 6.62±0.01 0.3233
3 Canine 7.76±0.06 7.45±0.02 < 0.05*
[Table/Fig-6]: Width/length ratios in percentage and the mean coronal tooth width /
length ratios for both the genders. A comparison between male and female of the rating
of central incisor, lateral incisor and canine showed significant difference*indicates
values are statistically significant (p < 0.05), * All measurements are in millimeter
S.
No
Tooth Males
Width/
length
% Females
Width/length
(mm)
% Probability
of unpaired
t-test
1 Central incisor 8.55/10.00 85.55 8.26/9.03 91.47 0.0009*
2 Lateral incisor 6.70/8.34 80.33 6.62/7.54 87.79 0.0001*
3 Canine 7.76/9.26 83.80 7.45/8.24 90.41 0.0009*
S.No Tooth Male Female Probability of
unpaired t-test
1 Central incisor 10.00±0.00 9.03±0.04 < 0.05*
2 Lateral incisor 8.34±0.02 7.54±0.10 < 0.05*
3 Canine 9.26±0.00 8.24±0.00 < 0.05*
[Table/Fig-4]: Mean, standard deviation and probability of unpaired t-test of mean
values of central incisor, lateral incisor and canine between males and females for
cervicoincisal length *indicates values are statistically significant. (p < 0.05), * All
measurements are in millimetre
[Table/Fig-5]: Mean width/length ratios of central incisor, lateral incisor and canine
for males and females
S.No Tooth MALES Ratio FEMALES Ratio
1 Central incisor 1.06:1.25 1.03:1.13
2 Lateral incisor 0.83:1.04 1.65:1.88
3 Canine 0.86:1.03 0.93:1.03
www.jcdr.net Sambhav Jain et al., Assessment of Tooth Proportions in an Esthetically Acceptable Smile
Journal of Clinical and Diagnostic Research. 2015 Apr, Vol-9(4): ZC01-ZC04 33
[Table/Fig-7] reveals that 81.87%, 88.42%, 92.58% difference
was present between LI: CI, LI: canine, canine: CI respectively for
cervicoincisal length; and 78.29%, 86.28%, 90.73% difference
was present between LI: CI, LI: canine, canine: CI respectively for
mesiodistal width in males.
[Table/Fig-8] reveals that 83.54%, 91.45%, 91.34% difference
was present between LI: CI, LI: canine, canine: CI respectively for
cervicoincisal length; and 80.12%, 88.85%, 90.17% difference
was present between LI: CI, LI: canine, canine: CI respectively for
mesiodistal width in females.
Using statistical variance it was seen that tooth with maximum
variation in mesiodistal width was canine between males and
females as shown in [Table/Fig-9].
Using statistical Variance it was seen that tooth with maximum
variation in cervico-incisal length was lateral incisor between males
and females as shown in [Table/Fig-10].
DISCUSSION
There has been a pattern shift in capturing the maximum extent
of smile from a single photographic image to its video recording
depicting its dynamic nature. Also, clinician strongly preferred
videography over photography [13].Therefore, in the current study
a five second clip of dynamic smile was video recorded. The raw
video clip was downloaded to a computer for converting streaming
video into individual 150 photographic frames. Out of these, frame
representing the subject’s posed unstrained social smile was
selected and then presented before the selected panel so as to
evaluate the best smiling photographs that were further used in the
study for evaluation of tooth proportions.
Many studies [14] have reported a direct relationship between
an aesthetic smile and correct tooth proportions. Aesthetic is
assessed by viewing the patient from the front in dynamic states,
like conversation, facial expressions and smiling [15]. Also, a genetic
diversity is seen in various populations due to its geographical
location and historical background, giving rise to many dental and
facial variations. Therefore, information regarding tooth norms in this
group may prove useful to clinicians since the 7th key to occlusion is
important while finishing an orthodontic case.
Therefore, the present study was taken up on Western Uttar Pradesh
population to evaluate the size and morphology of the maxillary
anterior teeth in aesthetically acceptable smile by a panel.
In this study, firstly the width/length ratio of maxillary anterior teeth
was established for which mesiodistal width and cervico-incisal
length of maxillary anterior teeth was evaluated separately as shown
in [Table/Fig-3,4] respectively for both males and females.
In mesiodistal width [Table/Fig-3] showed that the mean values
of males central incisor, lateral incisors and canine were 8.55 ±
0.01mm, 6.7 ± 0.01 mm and 7.76 ± 0.06 mm whereas in females
the mean values were 8.26 ± 0.01mm, 6.62 ± 0.01mm and 7.45 ±
0.02 mm respectively. Therefore, it was inferred that in both males
and females central incisor was the widest tooth mesiodistally
followed by canine and then lateral incisor. It was also seen that
males had wider teeth than females, akin to the findings of Sashi B
Ekka [16], Fernandes et al., [17] and Srivastava R [18].
A statistically significant difference was observed in mesiodistal
width of each tooth in both genders; Sashi B Ekka [16] conducted a
study on different populations and found similar results in the African
group whereas Japanese group showed contrasting results. Nikola
et al., [19] stated that there was no statistical difference between
men and women which was also not in agreement with our results
and this disparity might be due to the racial differences between the
various populations assessed.
Secondly, in Cervico-incisal length the mean values of males for
central incisor, lateral incisor and canine as shown in [Table/Fig-4]
were 10.00 ± 0.00mm, 8.34 ± 0.02mm and 9.26 ± 0.00mm
respectively.Whereas in females the mean values were 9.03 ±
0.04mm, 7.54 ± 0.10mm and 8.24 ± 0.00mm of central incisor,
lateral incisor and canine respectively. Therefore it was inferred
that the central incisor was the lengthiest tooth in both males and
Females cervico-incisally, followed by canine and the lateral incisor
and it was also observed that males had cervico-incisally lengthier
teeth than females. Both these results are in accordance with the
study done by Sterret et al., [5], Ufuk Hasanreisoglu et al., [7] and in
an In-Vitro study done by Eduardo et al., [20] on Asian population.
A statistically significant difference was observed among maxillary
anterior teeth i.e. central incisor, lateral incisor and canine (p<0.05)
while comparing between males and females. This result was in
contrast to the study done by UfukHasanreisoglu et al., [7] where
he reported that there was no significant difference between males
and females for lateral incisors.
Thirdly, Width/length ratio was expressed in percentage it was seen
that the mean coronal tooth width/length ratios for males vs. females
were central incisor (85.55% versus 91.47%), lateral incisor (80.33%
versus 87.79%) and canine (83.80% versus 90.41%) as shown in
[Table/Fig-6]. The crown to width /length ratio was accepted to be
most stable reference, as it showed minimal variation between the
genders or between teeth [21,22]. In the present study, ratios ranging
[Table/Fig-9]: Variance of central incisor, lateral incisor and canine in mesiodistal
width between males and females
S.No Tooth Male Mesiodistal
Width (VARIANCE)
Female Mesiodistal
Width (VARIANCE)
1 Central incisor 0.0003 0.0002
2 Lateral incisor 0.0001 0.0003
3 Canine 0.0039 0.0005
[Table/Fig-10]: Variance of central incisor, lateral incisor and canine in cervico-incisal
length between males and females
S.No Tooth Male Cervico-incisal
Length (VARIANCE)
Female Cervico-incisal
Length (VARIANCE)
1 Central incisor 0.0000 0.0017
2 Lateral incisor 0.0009 0.0112
3 Canine 0.0001 0.0000
[Table/Fig-7]: Ratio of mean tooth sizes expressed as % in males
[Table/Fig-8]: Ratio of mean tooth sizes expressed as % in females
Sambhav Jain et al., Assessment of Tooth Proportions in an Esthetically Acceptable Smile www.jcdr.net
Journal of Clinical and Diagnostic Research. 2015 Apr, Vol-9(4): ZC01-ZC04
44
PARTICULARS OF CONTRIBUTORS:
1. Senior Lecturer, Department of Orthodontics,Guru Nanak Dev Dental College and Research Institute, Sunam, Punjab, India.
2. Professor, Department of Orthodontics, Subharti Dental College, Meerut, India.
3. Professor and Head, Department of Orthodontics,Subharti Dental College, Meerut, India.
4. Senior Lecturer, Department of Orthodontics, Subharti Dental College, Meerut, India.
5. Assistant Professor, Department of Orthodontics, Dr.Z.A.Dental College, A.M.U., Aligarh, India.
6. Reader, Department of Orthodontics, Subharti Dental College, Meerut, India.
7. Post Graduate Student, Department of Orthodontics, Subharti Dental College, Meerut, India.
NAME, ADDRESS, E-MAIL ID OF THE CORRESPONDING AUTHOR:
Dr. Sambhav Jain,
#2, Railway Road, Near Octroi Post,Sangrur-148001, Punjab, India.
Email: drsambhav@yahoo.co.in
FINANCIAL OR OTHER COMPETING INTERESTS: None.
Date of Submission: Sep 28, 2014
Date of Peer Review: Jan 28, 2015
Date of Acceptance: Mar 02, 2015
Date of Publishing: Apr 01, 2015
from 70.35% to 108.23% were recorded, compared to ratios ranging
from 76% to 86% noted in the dental literature [5,23-25]. That is, the
width /length ratios of maxillary anterior teeth in both genders were
found to be greater than those suggested in previous studies [5].
So, it appears that maxillary anterior teeth of north Indian population
group studied display a more square like form due to the teeth
having shorter height and/or greater width than those of the other
population. Also, the results of current studies revealed significant
gender differences in width /height proportion of all three maxillary
anterior teeth, contrasting to the findings of previous studies [5,26].
In the current study according to best of our knowledge for the
first time we evaluated the width/length Ratio of each tooth in both
males and females, respectively in our population which were as
follows: for males: CI :: 1.06 : 1.25, LI :: 0.83 : 1.04 and Canine ::
0.86 :1.03 and females CI :: 1.03 : 1.13, LI :: 1.65 : 1.88 and Canine
:: 0.93 : 1.03 as shown in [Table/Fig-5].
Fourthly, tooth to tooth ratio of mean tooth size in percentage for
cervico-incisal length and mesiodistal width in both genders were
also evaluated. For males, the difference between the two teeth
in percentage for lateral incisor to central incisor was 81.87% and
78.29%, lateral incisor to canine 88.42% and 86.28% and canine
to central incisor was 92.58% and 90.73% respectively as shown
in [Table/Fig-7]. Whereas in females, on comparing lateral incisor to
central incisor, lateral incisor to canine and canine to central incisor,
the difference between the two teeth in percentage were found to be
83.54% and 80.12%, 91.45% and 88.85%, 91.34% and 90.17%
respectively as shown in [Table/Fig-8]. No study had evaluated the
tooth to tooth ratio in percentage for cervico-incisal length to the
best of our knowledge. So, these results can help us in evaluating
the tooth to tooth ratios not only mesiodistally and cervico-incisally
but also separately in males and females in our population and can
act as a guide for comparing with other populations too.
Finally, the tooth with maximum variance in mesiodistal dimension
and cervico-incisal length in males and females was evaluated. It
was found that the tooth with maximum variation in mesiodistal
width was canine in both genders as shown in [Table/Fig-9].
This result was in disagreement with the study done by Sashi B Ekka et
al., [16] in which mesiodistal width of lateral incisor was most variable
in both genders. Whereas, in cervico-incisal length lateral incisor
showed maximum variation in both males and females as shown in
[Table/Fig-10], which was in contrast to study done by K Sridhar [27]
in which canine showed maximum variation cervico-incisally.
CONCLUSION
It was seen that mesio-distally and cervico-incisally central incisor
is the widest and lengthiest tooth in both males and females. Males
had wider and lengthier tooth than females. The mean coronal tooth
width/length ratio for males and females revealed a more square
like form due to teeth having shorter height and/or greater width.
Canine showed maximum variation in mesiodistal width whereas
cervico-incisally lateral incisor showed maximum variation.
REFERENCES
Van der Geld P, Oosterveld P, Van Waas M, Kuijpers-Jagtman AM. Digital [1]
videographic measurement of tooth display and lip position in smiling and
speech: Reliability and clinical application. Am J Orthod Dentofacial Orthop.
2007;131:301.e1-301.e8.
Ackerman JL, Ackerman MB, Brensinger CM, Landis JR. A morphometric [2]
analysis of the posed smile. Clin Orthod Res.1998;1:2-11.
Tarantili VV, Halazonetis DJ, Spyropoulos MN. The spontaneous smile in dynamic [3]
motion. Am J Orthod Dentofacial Orthop. 2005;128:8-15.
Hulsey CM. An aesthetic evaluation of lip-teeth relationships present in the smile. [4]
Am J Orthod.1970;57:132-44.
Sterrett JD, Oliver T, Robinson F, Fortson W, Knaak B, Russell CM.Width/Length [5]
ratios of normal clinical crowns of the maxillary anterior dentition in man. J Clin
Periodontol. 1999;26:153–57.
Richardson ER, Malhotra SK. Mesiodistal crown dimension of the permanent [6]
dentition of American Negroes. Am J Orthod. 1975;68(2):157-64.
Ufuk H, Semih B, Kerem A, Ilker A. An analysis of maxillary anterior teeth: Facial [7]
and dental proportions.J Prosthet Dent. 2005;94:530-38.
Ackerman MB, Ackerman JL. Smile analysis and design in the digital era. [8] J
ClinOrthod. 2002;36:221-36.
Kokich VO, Kokich VG, Kiyak HA. Perceptions of dental professionals and [9]
laypersons to altered dental aesthetics: Asymmetric and symmetric situations.
Am J Orthod Dentofacial Orthop. 2006;130:141-51.
Parekh SM, Fields HW, Beck M, Rosenstiel S. Attractiveness of Variations in the [10]
Smile Arc and Buccal Corridor Space as Judged by Orthodontists and Laymen.
Angle Orthod. 2006;76:557–63.
DR Johnson, R Gallerano, J English. The effects of buccal corridor spaces and arch [11]
form on smile aesthetics. Am J Orthod Dentofacial Orthop. 2005;127:343-50.
MC Flores, E Silva, MI Barriga, MO Lagravere, PW Major. Lay person’s [12]
perception of smile aaesthetics in dental and facial view. Journal of Orthodontics.
2004;31:204–09.
Walder JF, Freeman K, Lipp MJ, Nicolay OF, Cisneros GJ. Photographic [13]
and videographic assessment of smile:objective and subjective evaluations
of posed and spontaneous smiles. Am J Orthod Dentofacial Orthop.
2013;144(6):793-801.
Wolfart S, Thormann H, Freitag S, Kern M. Assessment of dental appearance [14]
following changes in incisor proportions. Eur J Oral Sci. 2005;113:159–65.
Ku JE, Yang HS, Yun KD. A morphometric analysis of maxillary central incisor on [15]
the basis of facial appearance in Korea. J Adv Prosthodont. 2012;4:13-17.
Sashi B Ekka, Koshi Philip, Rajesh K Balani, Chandresh Shukla, Sahil Agrawal, [16]
Amit Prakash. Mesiodistal Crown Dimensions for Kerala Population – A Cross
Sectional Survey. J Res Adv Dent. 2014;3:3S:62-67.
Fernandes TMF, Sathler R, Natalício GL, Henriques JFC, Pinzan A. Comparison [17]
of mesiodistal tooth widths in Caucasian, African and Japanese individuals
with Brazilian ancestry and normal occlusion. Dental Press J Orthod.
2013;18(3):130-35.
Srivastava R, Jyoti B, Jha P, Gupta M, Devi P, Jayaram R. Gender determination [18]
from the mesiodistal dimension of permanent maxillary incisors and canines: An
odontometric study. J Indian Acad Oral Med Radiol. 2014;26:287-92.
Petricevici N, Celebic A, Ibrahimagic SL, Kovacic I. Appropriate proportion [19]
as guidelines in selection of anterior denture teeth. Medicinski Glasnik.
2008;5:103-08.
E Marcushamer, T Tsukiyama, TJ Griffin, E Arguello, GO Gallucci, P Magne. [20]
Anatomical Crown Width/Length Ratios of Worn and Unworn Maxillary Teeth in
Asian Subjects. Int J Periodontics Restorative Dent. 2011;31:495–503.
Chiche GJ, Pinault A. Aesthetics of anterior fixed prosthodontics. [21]
Chicago:Quintessence; 1994. Pp. 61-65.
Magne P, Belser U. Bonded porcelain restorations in the anterior dentition:a [22]
biomimetic approach. Chicago: Quintessence; 2002. Pp. 64-70.
Magne Pascal. Anatomic crown width/length ratios of unworn and worn maxillary [23]
teeth in white subjects. J Prosthet Dent. 2003;89:453-61.
Moorrees CFA, Reed RB. Biometrics of crowding and spacing of the teeth in the [24]
mandible. Am J Phys Anthropol. 1954;12:77-88.
Qualtrough AJ, Burke FJ. A look at dental aesthetics. [25] Quintessence
Int.1994;25:7-14.
Sherfudhin H, Abdullah MA, Khan N. A cross-sectional study of canine [26]
dimorphism in establishing sex identity: comparison of two statistical methods. J
Oral Rehabil. 1996;23:627-31.
K Sridhar, AV Arun, Karthikswamy, P Kiran Kumar, CH Sudheer Kumar, KVV [27]
PratapVerma. Morphometrics of Permanent Dentition in Chennai Population. J
Ind Orthod Soc. 2011;45(3):110-18.
... "Композицията на усмивката" се определя от взаимоотношението между горната устна и видимостта на гингивалните тъкани и зъбите (8). ...
... Линията на усмивката, която разкрива цялата дължина на зъбите и част от гингивалните тъкани, се асоциира с по-млада възраст. С напредване на възрастта линията на усмивката разкрива само част от зъбните коронки, като се стеснява на височина, а трансверзално става по-широка, тъй като с възрастта способността на мускулите да разтегнат устните в усмивка намалява (8). ...
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Smile line has a decisive meaning for the assessment of the aesthetic risk of dental periodontal and implant therapy, especially in the aesthetic zone of the maxilla. The position and outline of marginal gingival tissues are very important for the aesthetics of the smile, as well as the morphological characteristics of hard dental tissues. Generally, the smile line is classified as low, medium and high. Мost gingival tisuues are visible in the case of a high smile line. The smile line was assessed in 219 participants (79 males and 140 females) according to the Tyan’s classification (1984). The descriptive statistical analysis was performed by IBM SPSS Statistic version 19 softwаre. When it comes to the smile line, sex and age are important factors in assessing the aesthetic risk of periodontal and implant therapy.
... This technique following the method used by other authors. Hasanreisoglu et al. 2005, (10) used a specially designed stabilizer device resembling a face bow, whereas Jain et al. 2015, (13) used a customized cephalostat. The results of current study indicate that anterior teeth dimensions vary by gender. ...
... These results are in agreement with many other authors who confirmed gender variations in the dimensions of the anterior teeth, with men exhibiting wider anterior teeth than women. (9,13) The results in the present study for W/L ratio of anterior teeth in a sample of Egyptian population were 86% for the CI, 78% for the LI and 82% for the C. These results were in agreement with Sterrett et al. 1999, (7) and Orozco-Varo et al. 2015, except for W/L of canine was of lesser value (79%) than this study. ...
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To observe the presence of sexual dimorphism and compare the mesiodistal width of the teeth in Caucasian, African and Japanese individuals with Brazilian ancestry not orthodontically treated and with normal occlusion. One hundred pairs of dental casts were used. It was measured, from first molar to first molar in both arches, the teeth's mesiodistal widths, using a digital caliper. For the statistical analysis of results Kolmogorov-Smirnov, t test, ANOVA and Tukey's test (p < 0.05) were used. Sexual dimorphism occurred on the three evaluated groups, and the highest mesiodistal widths were found in males. There was statistically significant difference between racial groups in all evaluated teeth in males. However, in females, this same difference was found only on upper lateral incisor and first molar; and lower lateral incisor, canine, first premolar and first molar. Most of mesiodistal measures present particular characteristics in relation to gender, with higher values for males, and to race, with a tendency for African to present greater mesiodistal distance of the teeth, followed by Japanese and Caucasians, respectively, important for the correct diagnosis and orthodontic planning.
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We aimed to identify a more esthetic width-to-length ratio by analyzing maxillary central incisor of Korean adult population. Information regarding tooth ratio in the Korean population may be useful to clinicians when restoring anterior teeth. A total of 40 men and 40 women were included in this study. The NON-MEDIA group included 40 non-celebrities, who were healthy and 25 to 39 years old, with normal dentofacial appearance. The MEDIA group consisted of 40 celebrities selected only on the basis of their soft-tissue facial appearance. The facial photographs of 40 celebrities were collected from the Internet websites. The width and length of the maxillary central incisor were measured using Adobe Photoshop® 7.0, a software for analysis, measurement and edition of photographs. Data were analyzed statistically using the Independent t-test at 5% statistical significance level. The mean ratio for the MEDIA group was 0.77, whereas that of the NON-MEDIA group was 0.88. The difference between the two groups was statistically significant. No significant gender differences were found in the width-to-length ratio in MEDIA group. In NON-MEDIA group, however, there were significant differences between female and male. After analyzing maxillary anterior teeth of Korean adults, our results were in accordance with the general Western standards of esthetics. A dentist restoring the natural look and beauty of teeth will have to consider those standards.
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Crown width/length ratios have been considered an important aspect in the esthetic zone. Because previous investigations focused on Caucasian populations, limited information is available on other ethnic groups to propose a comprehensive approach to anterior maxillary teeth. The purpose of this study was to analyze the dimensions of anatomical crowns of maxillary anterior tooth groups with respect to width, length, and width/length ratios among an Asian population. The tooth dimensions presented in this investigation may serve as guidelines for treatment planning in restorative dentistry and periodontal surgery for this particular ethnic group.
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Esthetic considerations play an increasingly important role in patient care, and clinicians need a methodology that includes imaging techniques to capture the dynamic nature of the smile. Photographs of the posed smile are routinely used to guide diagnosis and treatment, but there is no standardized and validated method for recording the dynamic smile. The purposes of this study were to (1) determine whether a posed smile is reproducible, (2) compare visual and verbal cues in eliciting a smile, and (3) compare the diagnostic value of videography and photography in evaluating a patient's smile. The smiles of 22 subjects were simultaneously photographed and videotaped on 2 separate occasions. For objective comparisons, measurements of the smile were obtained from 8 × 10 color still photographs and selected digitized video images. A panel consisting of a layperson, an oral surgeon, an orthodontist, and a prosthodontist subjectively assessed the reproducibility of the smile, posed vs spontaneous smiles, and the diagnostic value of video vs still images. Objective measurements showed that the posed smile can be reliably reproduced, whether captured by videography or still photography. However, subjectively, the panel members detected differences between the posed smiles taken on different days 80% of the time. The clinician panel members expressed a strong preference for videography over photography and for the spontaneous over the posed smiles. This study emphasizes the need to continue to investigate and standardize the methods of eliciting and recording a smile of diagnostic quality.
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Various aspects of anatomic tooth dimensions have been examined in a number of studies where data are primarily based on the measurements obtained from white subjects. Additional factors such as ethnicity should be considered to produce a more comprehensive analysis. The purpose of this study is to compare the anatomic crown dimensions of extracted maxillary teeth in Asian and white populations. The width/length ratio (%) was calculated with standardized digital images of extracted maxillary anterior teeth from 157 Asian and 142 white subjects. Statistical analysis was performed to compare the 4 tooth groups (central incisiors, lateral incisiors, canines, and premolars) of the 2 ethnicities. The distribution of the outcome variables were examined for normality with the Kolmigorov-Smirnov test. Independent sample t tests were used to examine differences in outcomes in Asian and white subjects. There was a significant difference (P<.05) in the width/length ratios of all maxillary anterior teeth in Asian and white subjects. In addition, there was a significant difference in the width of unworn central incisors and the length of worn lateral incisors and canines. Ethnicity influences width/length ratios for all 4 anterior maxillary teeth. Anterior maxillary teeth in Asian subjects appear to be more slender when compared with those in white subjects.
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A study of the mesiodistal crown dimension was conducted on the teeth of 162 American Negroes, equally divided between males and females. A total of 3,980 teeth were measured. Teeth were measured from the plaster casts by means of Boley gauges. The sample was drawn from a growth study, private practice, and a dental clinic. The mean width of the teeth of males and females was reported. The teeth of males were larger than those of females for each type of tooth in both arches, although they exhibited a similar pattern of tooth size. The maxillary first premolars were larger than the second premolars, while the mandibular second premolars were larger than the first premolars. The first molars were larger than the second molars in both the maxillary and mandibular arches in both sexes. The ratio of the mandibular dentition ot the maxillary dentition was 94 per cent in both sexes. The ratio of the sum of the widths of the canines and incisors of the mandibular dentition to those of the maxillary dentition was 77 per cent. Also, the ratio of the mandibular incisors to the maxillary incisors was 71 per cent in both sexes.