Macro-esthetic in dentistry

Esthetic formula

There should be a harmony between;
i)Basal bone of jaws (mandible and maxilla)
ii)Musculature (lips and cheeks)
iii) Teeth (color, size, form, alignment, position)

Macro-esthetic

It is the relationship between a group of teeth and surrounding soft tissue and facial design

1)Midline

 It is the line dividing the face vertically into 2 equal halves
 The philtrum of the lip is the most accurate anatomical landmarks to detect shifting of the midline
as it is always in the center of the face therefore it
should match the papilla between 2 centrals
 other refrences are the nose and the median palatine raphe
 Slight shift of midline up to 4 mm will be acceptable

2) Inter-pupillary line

● Should be parallel to the incisal plane.

3) Phonetics- incisal edge position relationship

●During pronouncing letter “ F “ OR “ V “ the incisale dge of maxillary centrals should be located at the wet-dry line

 During pronouncing letter “ S” the incisal edge of lower anterior should be 1mm lingual to the upper anteriors.

●During pronouncing letter “ E” the incisal edge of maxillary centrals should be midway or slightly lower than midway line between upper and lower lip

●Therefore in case of esthetic crown lengthening

 the incisal edge position should be considered otherwise phonatics may be affected

 ( gingival crown lengthening can be done)

4)Lip displayed incisal edge relationship:

● It is the amount of teeth that displayed by the lip at the rest position

 and it is changed with age.

● at 20y

 the displayed part of maxillary anterior teeth is more than that of the mandibular anterior teeth

● by aging

the displayed part of maxillary anterior teeth decrease

 The displayed part of mandibular anterior teeth increase

Due to muscle relaxation and dropping of lips

● at 60 y

 maxillary anterior teeth are not displayed

But only mandibular anterior teeth are

displayed about 2-3 mm

5) Smile line

●It is hypothetical curved line drawn along the incisal

edge of maxillary anterior teeth which should be run

parallel with the curvature of inner border of the lower lip

●Reverse smile line  unattractive smile approach

6) Lip line:

It refers to the position of inferior border of upper lip

during smile formation

a)Low lip line: 15% of population

the cervical margin of the anterior teeth doesn’t displayed

by smiling  i.e ↑ esthetic

b)High lip line: 30% of population

●The cervical margin of the anterior teeth is displayed

during smiling  therefore restoration margin appear as

grayish line through the translucent gingival tissues

i.e all ceramic or PFM with shoulder porcelain is indicated.

c) Normal lip line : nearly 55-60% of population

7) Balance and symmetry:

•Midline is the vertical contact between the 2 maxillary

centrals  it should be // to the long axis of the face and perpendicular to the incisal plane ( i.e dividing the face

into 2 equal halves)

●Balance and symmetry include the location of the

midline which is important in prosthodontics →because

the observer expects the left & right sides of the mouth to

be balanced out.

●For best esthetic  fixed restoration should locate

midline in its ideal position as possible  a maximum of

1mm mesial or distal deviation is accepted.

8)Proportion:

•An object is considered beautiful if it is properly

proportioned.

• →Golden proportion → in frontal view for better

esthetic → the apparent size of teeth decrease gradually

from midline→ distally by a ratio of 0.619.

●limitation of golden proportion;

1- The apparent width versus the real width ( what

about side view??)  so it neglects the side view

2-It does not address the tooth height  only

proportions in teeth width

3-Based on architecture concept  teeth are not

building

Therefore the golden proportion should be

considered as a clinical guidline  as only 17% in

population have the golden proportion.

The Golden Percentage is a simplified version of the

Golden Proportion. It described by [Snow],& suggests that

each maxillary anterior tooth should occupy a certain

percentage of the anterior segment from facial view. Ideally,

each central should occupy 25% of this space

Tooth-to tooth proportion; Dr Stephen Chu shows that if

the central incisor’s mesiodistal width is Xmm, then the

lateral should measure X−2mm and the canine should be

X−1mm .Note that X−1 should account for the entire

mesiodistal width of the canine, versus the traditional

golden proportion approach that only accounted for the

mesial half of this tooth.

Chu’s esthetic gauges:

Approximate length of the central should be 10–11 mm

and the width is calculated accordingly so that the ratio

falls between 75 and 80%

Recurring esthetic dental proportion: The successive

width proportion when viewed from the facial aspect should

remain constant as we move posteriorly from midline. This offers great flexibility to match tooth properties with facial

proportions

9) Axial tooth inclination :

 From central to canine  There should be natural

increase in the mesial inclination of anterior teeth.

10) Interdental contact areas and points:

 Interdental contact point moves apically as we move

from middline  posteriorly

 Interdental contact area between upper 2 central

represent 50% while between central and lateral 40

% while between lateral and canine 30%

11) Sex/ Age/ Personality: ( SPA factor)

 Age; upper central ( young versus old ) see cultural

biase

 Sex : upper lateral ( male versus female) see

cultural biase

 Personality: upper canine

soft personality: short/rounded cusp tip

aggressive personality: pointed/sharp cusp tip

12) Buccal corridor:

 It is the negative dark space visible during smile

between mouth corners and buccal surface of

maxillary teeth

 It is affected by:

a) Position of the buccal surface of upper premoalrs

b) Prominence of the canine ( especially disto-labial

line angle)

c) Tone of facial muscle

d) Width of the smile and maxillary arch.