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.