Common Facial Proportionsd1ue90e5sp4tcv.cloudfront.net/2855/images/Asset270057_v1.pdf · 5 Tall...

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Common Facial Proportions

•Used in many other specialties-plastic surgery, orthodontics

Common FacialProportions


•Average head to body ratio is 1:7

Common Facial Proportions


•Average head to body ratio is 1:7

•Desired professional model head to body ratio is 1:8

•Divide face into equal fifths

•Each fifth is an eye width

Rule of Fifths

•Attributed to Pythagoras.•Explains the beauty in

nature to the harmony of mathematics

Golden Proportion

•Used by da Vinci

Golden Proportion

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Golden Proportion

62%

Golden Proportion

•Width of Anterior Teeth in Golden Proportion to the Inter-commissural Width

Proportion of Anterior Teeth to the Face

Anterior 6 too wide

Anterior 6 too narrow

•Central Incisor is 1/16th the Width of Inter-Zygomatic Width

“House” Proportion

House MM, Loop JL –Monograph 1937“Form and Color Harmony in the Dental Art”

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•Central Incisor is 1/16th the Length from Ideal Hairline to Chin

“House” Proportion

House MM, Loop JL –Monograph 1937“Form and Color Harmony in the Dental Art”

•Use Trubyte indicator to determine proportions

Trubyte Proportion Guide

1/16 Inter-zygomatic width

•Use Trubyte indicator to determine proportions

Trubyte Proportion Guide

Rule of Thirds combined with

1/16 Trichion-Menton Length

Using Inter-pupillary width for width of central incisor

•Width of central incisor is 1/7 inter-pupillary width

Isa ZM, Tawfiq OF, Noor NM. Shamsudheen MI, Rijal OM. Regression methods to investigate the

relationship between facial measurements and widths of the maxillary anterior teeth. J Prosthet Dent 2010;

103:182-188.

Ideal Width to Height ratio = 78%

Central IncisorWidth to Height ratio

Sterrett et al – J ClinPeriodontol 1999

“Width/length ratios of normal clinical crowns of the maxillary anterior dentition in man”

> 78%

< 78%

Central IncisorWidth to Height ratio

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Width to Height ratio of Central Incisor=78%

Chu’s Aesthetic Gauges

Levin - JPD 1978“Dental Esthetics and the

Golden Proportion”

“The widths of the maxillary central incisors are in golden proportion to the lateral incisors as seen from the frontal”

Golden Proportion(Tooth-to-Tooth Width)

1.618 X 62%=1

1 X 62%=0.618

Snow - JED 1999“Esthetic Smile Analysis of

Anterior Tooth Width: The Golden Percentage”

“The widths of the maxillary central incisors, lateral incisors, & canines should be 25%, 15%, & 10% of the total frontal view width of the anterior 6 teeth ”

Golden Mean(Tooth-to-Tooth Width)

CI=25% ICW

LI=15% ICW

C=10% ICW

Repeated Ratio(Tooth-to-Tooth Width)

Lombardi - JPD 1973“The principles of visual

perception and their clinical application to denture esthetics”

“The existing proportion between the width of the maxillary central incisor and lateral incisor should be consistent as you progress distally”

Preston Proportion(Tooth-to-Tooth Width)

Preston - JED 1993“The golden proportion

revisited”

“The golden proportion was found in the relationship between the perceived width of the maxillary central and lateral incisors in only 17% of observed images”

LI=CI * 66%

C=LI * 84%

Tooth to ToothWidth Proportions

Problem is none relate tooth width proportions with

tooth height

Golden

ProportionGoldenMeanPreston

ProportionRepeated Ratio……

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RED Proportion

Ward DH. Proportional smile design using the RED

proportion. Dent Clin North Am 2001;45:143-154.

“The proportion between the successive widths of the teeth as viewed from the frontal should remain

constant as you move distally”

RED Proportion



Without pre-existing constraints

Sample RED Proportions



x 0.8x 0.64x

x 0.7x 0.49x

x 0.62x 0.38x

Same size Central Incisors

Sample RED Proportions



Same Inter-Canine Width

Same Tooth Heights

DifferentCentral

Incisor W/H Ratios

Selecting RED Proportions

What is the effect of relative tooth height when selecting the appropriate RED Proportion?

How is the RED Proportion affected by is the Central Incisor Width/Height Ratio?

Rosenstiel SF, Ward DH, Rashid RG. Dentists’ Preferences of Anterior

Tooth Proportion-A Web-based Study. J Prosthodont 2000;9:123-136.

Purpose of Preliminary Study

…to determine how dentists rate anterior tooth arrangements with different tooth-to-tooth width proportions and whether the best-ranked tooth proportions are affected by inciso-gingival tooth length.

Relative tooth height

Preferred RED Proportion



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Materials and Methods

Ideal Imaged Retracted Natural Smile

Tooth to ToothWidth Proportions

Problem is none relate tooth widthproportions with

tooth height

Golden

ProportionGoldenMeanPreston

ProportionRepeated Ratio……


70% RED Proportion

Normal80% RED Proportion

Golden Proportion

Tall(110% Height)

Normal80% RED Proportion

Golden Proportion

70% RED Proportion

Short(90% Height)

Golden

Proportion

70% RED Proportion

80% RED

Proportion

NormalVery Short

(80% Height)

70% RED Proportion

80% RED Proportion

Golden Proportion

NormalNormal

(100% Height)

70% RED Proportion

Normal80% RED

Proportion

Golden Proportion

Very Tall(120% Height)

DCBASurvey Set


3342 emails sent to dentists in 38 countries

Results

549 dentists responded from 38 countries (470 from US or Canada counted)

Summary Preferred

62% RED Proportion

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Summary Preferred

70% RED Proportion

Summary Preferred

80% RED Proportion

“The majority (of dentists surveyed) chose central incisors that were as close to 0.75-0.78 width/height ratio as possible.”



Preferred RED Proportions

86% W/L Ratio 78% W/L Ratio

Width/Length Ratio of Central Incisors

Naturally Observed Dentist Preferred

Sterrett JD, Oliver T, Robinson F, et al. Width/length ratios of normal clinical crowns of the maxillary anterior dentition in man. J ClinPeriodontol 1999;26:153-157.


Naylor CK. Esthetic Treatment Planning: The Grid Analysis System. J Esthet Restor Dent 2002;14:76-84. Wolfart S. Thormann H, Freitag S, Kern M. Assessment of dental appearance following changes in incisor proportions. J Oral Rehabil 2006;33:489-495.


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Width/Length Ratio of Central Incisors Summary Natural

Preston Proportion 86% W/L CI

Summary Preferred

70% RED Proportion 78% W/L CI

Preferred RED Proportions

78% w/hratio

78% w/hratio

78% w/hratio

Very Short

Normal

Very Tall

Same Inter-canine tooth width

Relative Tooth heights

Individual Tooth % of ICW

Ward DH. Using the RED Proportion to Engineer

the Perfect Smile. Dent Today 2008;27(8):112-117.



Summary

•The taller the tooth the smaller the preferred RED Proportion

•The shorter the tooth the larger the preferred RED Proportion

•The 78% w/h ratio of the central incisor should be maintained

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Validity of the RED Proportion

Is the RED Proportion found in nature?

If not is the RED Proportion preferred to Proportions found in nature?

Observed Proportions

Ali Fayyad MA, Jamani KD, Aqrabawi J. Geometric and Mathematical Proportions and their Relations to Maxillary Anterior Teeth. J Contemp Dent Pract 2006;5:62-70.

“The Golden Proportion and Recurring Esthetic Dental (RED) Proportion were not found to exist between the maxillary anterior teeth of the natural dentition.”

(Photos of 376 Jordanian dental students)

Mahsid M, Khoshvaghti A, Varshosaz M, Vallaei N. Evaluation of “golden proportion” in

individuals with esthetic smile. J Esthet Restor Dent 2004;16:185-192.

“The Golden Proportion was not found to exist between perceived maxillary anterior teeth widths of individuals with an esthetic smile.”

(157 dental students)

Observed Proportions

“a majority of dentists surveyed considered smiles with a width proportion greater than 69.9% between the maxillary central incisor and lateral incisor, to be esthetically acceptable”The authors suggested consideration for the use of the 70% RED proportion.

Preferred Proportions

Basting RT, Trindale RS, Flório FM. Comparative Study of Smile Analysis by Subjective and Computerized Methods. Oper Dent 2006;31:652-659.

Purpose of this Study

…to determine if North American dentists surveyed prefer the Recurring Esthetic Dental (RED) proportion, other mathematical-defined proportions or naturally occurring tooth-to-tooth width proportions

Ward DH. A Study of Dentists’ Preferred Anterior Tooth Proportions:Comparing the RED Proportion to

other mathematical and naturally occurring proportions. J Esthet Restor Dent 2007;19:323-336.

NatureScience


Ideal Smile:78% w/h ratio CI, 70% RED

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Only anterior 6 teeth modified

Set View A View B

1 Golden Proportion Golden Mean(same length maxillary anterior (same length maxillary anterior teeth teeth as Preston Proportion) teeth as Preston Proportion)

2 Preston Proportion Golden Proportion(78% w/h ratio central incisor) (same length maxillary anterior teeth

teeth as Preston Proportion)

3 Golden Proportion 70% RED Proportion(same length maxillary anterior teeth (78% w/h ratio central incisor)teeth as Preston Proportion)

4 Preston Proportion 70% RED Proportion(78%w/h ratio central incisor) (78%w/h ratio central incisor)

5 Tall Preston Proportion Tall Golden Proportion(same length maxillary anterior) (78%w/h ratio central incisor)teeth as tall Golden proportion)

301 NA dentists from 36 states & provinces

12 groups throughout US-prior to lecture

Golden Proportion

#1a

Golden Mean

#1b

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Golden MeanNo Statistical Preference

#1b

Preston Proportion

#2a

Golden Proportion

#2b

Preston Proportion70% Preference

#2a

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Golden Proportion

#3a

70% RED Proportion

#3b

70% RED Proportion75% Preference

#3b

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Preston Proportion

#4a

70% RED Proportion

#4b

70% RED Proportion57% Preference

#4b

Preston Proportion

Tall#5a

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Golden (62% RED) Proportion

Tall#5b

Tall

Golden (62% RED) Proportion58% Preference

#5b

Primary Factor Influencing Decision

62%

23%19%

36%

Conclusions

nSmiles created using the principles of the RED Proportion where preferred by a majority of North American dentists surveyed.

nOverall balance was the primary deciding factor

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Clinical Significance

n The RED Proportion may be useful in creating smiles preferred by North American dentists.


n 75% of NA dentists preferred the RED Proportion when designing smiles with normal length teeth over the GP


n Applying the GP universally should be reconsidered since it was found to be the least pleasing and accepted for normal length teeth

62% RED Proportion used with Tall Teeth

78%w/h CI ratio

78%w/h CI ratio

70% RED Proportion used with Normal Teeth

78%w/h CI ratio

80% RED Proportion used with Short Teeth

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•Central Incisor should maintain 78% width/height ratio

•The taller the central incisor the wider it should be

•The taller the central incisor the smaller the RED Proportion used

•The taller the central incisor the more dominant it becomes in the arch

•The wider the central incisor the narrower the resulting lateral incisor and canine

RED Proportion Principles

•The shorter the central incisor the narrower it should be

•The shorter the central incisor the larger the RED Proportion used

•The shorter the central incisor the more similar the relative individual tooth widths

•The narrower the central incisor the wider the resulting lateral incisor and canine

•Clinical judgment is paramount

RED Proportion Principles

Average Length Face

70% RED

Short Length Face

80% RED

Tall Length Face

62% RED

Short Average Tall

80% RED 70% RED 62% RED

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Short Average Tall

80% RED 70% RED 62% RED

Correlation exists between “beauty, nature and mathematics”

Proportional Smile DesignPrinciples

Objective Smile Design must include the analysis of tooth proportions

Proportional Smile Design Principles

Perspective for analysis is frontal view

Proportional Smile Design Principles

Facial Image View EvaluationFIVE STEPS

STEP1

Obtain Image

one

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STEP2

Measurement Worksheet

two

COMPLETE PHOTOGRAPHIC

MEASUREMENTS

CALCULATECONVERSION FACTOR

Cast Length Central Incisor __9.0__mm

Photo Length Central Incisor _ 25.0_mm

Conversion factor = 9/25 = 0.36

MULTIPLY PHOTO MEASUREMENTS X

CONVERSION FACTOR

Conversion factor = 9/25 = 0.36

Conversion factor X Photographic Widths=“FIVE Widths”

EFFECTS OF CAMERA ANGLE

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RESULTS:

Central Incisor accurate +/- 15o

Lateral incisors within 5% +/- 10o

Cuspids within 10% +/- 5o

RESULTS:

Ideal camera angle within 5o of parallel

CONCLUSION:

Lateral incisors within 5% +/- 10o

Cuspids within 10% +/- 5o

Central Incisor accurate +/- 15o

Ideal camera angle within 5o

of parallel

CONCLUSION: CALCULATE W/H RATIO

OF CENTRAL INCISORS

7.4 / 8.1 = 0.91 or 91%

CALCULATE

RED PROPORTIONS

1.0 / 4.5 = 0.22 or 22%

Completed Measurement Worksheet

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STEP3

Determine Incisal Edge

three • Esthetics

• Phonetics

• Anterior guidance / Occlusion

DESIRED INCISAL EDGE POSITION

STEP4

Evaluate REDproportions

four

EVALUATE REDPROPORTIONS

FIVE

EVALUATE REDPROPORTIONS

STEP5

Treatment & Blueprint

five

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Imaged without Perio Surgery


Imaged with Perio Surgery


1 Month Post Perio Surgery


2 Weeks post-treatment

AfterBefore AfterBefore

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Total intercuspid width Width of

-------------------------------- = Central

2(1+RED+RED2) Incisor

TOO COMPLICATED

Using RED to determine tooth widths

Total intercuspid width Width of

-------------------------------- = Central

2(1+RED+RED2) Incisor

Simplified Clinical Application

Substitute values and pre-solve the equation

Simplified RED Proportion Application

METHOD 1

Using ICW and Simple Tooth Height to determine the sizes of the Maxillary Anterior Six Teeth

Use Inter-Canine Width to Determine Ideal Central Incisor

Simplified Clinical Application



SHORT

NORMAL

TALL

STEP 1-Determine Tooth Height

STEP 2-Measure Inter-Canine Width

www.erskinedental.com

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70% RED

If normal length Canine-Canine Width

4.4

STEP 3a-Divide Inter-Canine Width by factor for CIW

Lateral Incisor Width

STEP 3b-Multiply CIW* 70% for Lateral Incisor Width

If normal length

70% RED

*0.7

Canine Width

STEP 3c-Multiply LIW * 70% for CW

70% RED

If normal length *0.7

Canine-Canine Width

4.0

STEP 3a-Divide Inter-Canine Width by factor

62% RED

If very tall length

Lateral Incisor Width

STEP 3b-Multiply CIW* 62% for Lateral Incisor Width

62% RED

If very tall length *0.62

Canine Width

STEP 3c-Multiply LIW* 62% for Canine Width

62% RED

If very tall length *0.62

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Canine-Canine Width

4.8

STEP 3a-Divide Inter-Canine Width by factor

80% RED

If very short length Lateral Incisor Width

STEP 3b-Multiply CIW * 80% for Lateral Incisor Width

80% RED

If very short length *0.80

Canine Width

STEP 3c-Multiply LIW * 80% for Canine Width

80% RED

If very short length *0.80

Using RED to determine individual tooth widths









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Summary

(with interpolations)



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Hands-On Exercise One

Obtain Image

Fill Out Full Face Evaluation Form-Page 1

v

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Fill Out Full Smile Evaluation Form-Page 2

Fill Out Proportional Smile Design

Hands-On Exercise 1

Cast CIL=8.5mm

Patient is tall

Fill Out Proportional Smile Design

Hands-On Exercise 1

Cast CIL=8.5mm

Patient is tall

Measurement Worksheet

Incisal Edge Determinants

• Esthetics

• Phonetics

• Anterior guidance / Occlusion

Lengthen incisal edge #9 -0.5mm

Imaging

Imaged with Perio Surgery

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AfterPost Perio Surgery AfterBefore

n Total intercuspid width Width of

n ------------------------------ = Central

n 2(1+RED+RED2) Incisor

Using Inter-Cuspid Width & Central Incisor Height for RED

(solve for RED substituting desired 78% w/h ratio of central incisor) (solve for RED substituting desired 78% w/h ratio of central incisor)

n Total intercuspid width

n ------------------------------ = 2(1+RED+RED2)

n Width of Central Incisor

Using Inter-Cuspid Width & Central Incisor Height for RED

Determining RED for 78%w/h ratio central incisor

TOO COMPLICATED


METHOD 2

Using ICW and Central Incisor Tooth Height to determine the sizes of the Maxillary Anterior Six Teeth

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ICW

Simplified use of RED to determine individual tooth widths

•Measure Frontal View Inter-Canine Width



CIH




•Measure Central Incisor Height

ICW

CIH

ICW/CIH



•Divide ICW by CIH to give Quotient


ICW/CIH



•Lookup Quotient for RED & Tooth Sizes


Divide inter-canine width by central incisor length to give a quotient

ICW

C

I

H

ICW/CIH=3.4 ICW/CIH=3.4

LOOKUP QUOTIENT IN CHART FOR RED & TOOTH SIZES

•Central Incisor =ICW/4.38

•Lateral Incisor=ICW/6.26

•Canine=ICW/8.94

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Graphic Summary Graphic Summary

Graphic SummarySimplified RED Proportion Application

METHOD 3

Using ICW and Relative Tooth Height to determine the width and height of the Maxillary Central Incisor

ICW

Using relative central incisor length to determine RED proportion and central incisor length and width


Ward DH. Proportional Smile Design: Using the Recurring Esthetic Dental Proportion to Correlate the Widths and Lengths of the Maxillary Anterior Teeth with the Size of the Face. Dent Clin North Am. 2015; 59(3):623-38.

Very Short

Short

Normal

Tall

Very Tall

Tooth Height

•Choose desired relative Central Incisor Height



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Lookup associated quotient and divisors



ICW/3.8ICW/4.880% RED Very Short

ICW/3.6ICW/4.675% REDShort

ICW/3.4ICW/4.470% REDNormal

ICW/3.25ICW/4.266% REDTall

ICW/3.1ICW/462% REDVery Tall

Central Incisor LengthCentral Incisor WidthRED ProportionTooth Height

CIW CILDesired RED proportion

•Divide ICW by divisors for CIW and CIL






ICW/4.4=CIW







ICW/4.4=CIW

ICW/3.4=CIL


METHOD 4

Using ICW and Desired Tooth Height to determine the width and height of the Maxillary Central Incisor

ICW



Using desired central incisor length to determine RED proportion and central incisor length and width

DCIH

•Choose desired Central Incisor Height (DCIH)

•7-13mm



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ICW

DCIH

ICW/DCIH=Quotient

•Divide ICW by DCIH to give quotient



ICW/CIH



•Lookup Quotient for RED & Divisors

ICW/3.880% REDVery Short3.8

ICW/3.675% REDShort3.6

ICW/3.470% REDAverage3.4

ICW/3.2566% REDTall3.25

ICW/3.162% REDVery Tall3.1

Central Incisor WidthRED ProportionTooth HeightQuotient


ICW/CIH •Lookup Quotient for RED & Divisors

ICW/3.470% REDAverage3.4

Central Incisor WidthRED ProportionTooth HeightQuotient



ICW/3.4=CIL


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