Download - Facial Analysis for Dental Restorations
Facial AnalysisParag R. Kachalia, DDS
Elements of facial composition
• Position of the
• Eyes
• Nose
• Chin
• Lips
Elements of facial composition
• Measurable landmarks
• Horizontal reference points
• Vertical reference points
Why examine facial composition
• Objective
• Restore adequate parallelism between occlusal plane and the horizontal reference lines
• Re-establish ideal height of the lower third of the face
• Recreate proper anterior positioning in alignment with patient’s profile and lips
Examination process
• Frontal View
• Reference Lines
• Interpupillary line
• Midline
Horizontal Reference
• Interpupillary line
• A line that passes through the center of the eyes and is ideally parallel to the horizontal plane
• Other references can include
• Ophriac line
• Commisural line
• Interalar line
Horizontal Reference
• Clinical significance
• Orienting the incisal plane
• Occlusal plane
• Gingival contour
Horizontal Disharmony
• Disharmony
• Commissural line slants in relation to the interpupillary line which is horizontal
• Commissural line and interpupillary line slant in opposite directions
• Commissural line and interpupillary line slant together - still parallel to one another
Complete disharmony
• Decide on reference points
• May need to use the horizon to determine incisal plane
• Face bow mounting is critical in this situation
Vertical Reference
• Midline
• Line through the glabella, the tip of the nose, the philtrum, and the tip of the chin
• If these reference points do not line up the center of the upper lip can be used as a reference point
• Vertical disharmony
• Tip of the nose and the tip of the chin may not always be aligned
• May have to use the center of the upper lip as landmark
Symmetry
• Organized framework
• Vertical and horizontal references allow the practitioner to identify presence of asymmetry
• We can only tolerate an asymmetry of 3% before our eyes can detect it
Left ½ of face doubled Right ½ of face
doubled
Facial Proportions
• Well proportioned face
• Upper 1/3 - hairline and ophriac line
• Middle 1/3 - ophriac to the interalar line
• Lower 1/3 - interalar to the tip of the chin
Lower third
• Upper 1/3 of this space is occupied by the upper lip
• Lower 2/3 of this space is occupied by the bottom lip and the cin
Facial proportions
• Prosthetic considerations
• Lost vertical dimension the variation in height of the lower 1/3 of the face is noticeable
• Edges of the lips tend to fold inward
• Deepening of the chin concavity
• Facial Proportions
• Prosthetic Consideration
• Re-establish a correct vertical dimension to re-create an adequate height of the lower 1/3 of the face
Lateral View
• Natural Head Posture
• Frankfort horizontal plane
• Lowest point of the orbit to portion (external auditory meatus)
• Esthetic plane
• about 8 degrees lower than Frankfort when patient is looking at the horizon
Esthetic plane
Frankfort horizontal – external auditory meatus
and the lowest point on the orbit
About eight degrees lower than the Frankfort
horizontal – Arbitrary horizontal plane
Profile
• Normal (Glabella, subnasale, tip of the chin)
• Angle of approximately 170 dgrees
• Convex
• Marked posterior divergence
• Concave
• Greater than 180 degrees
Horizontal Reference
Glabella
Subnasale
Pogonion (tip of the chin)
Normal profile lip is about 4mm posterior to the E-line, while the lower lip is
about 2mm posterior.
Approximately 90-95 degrees in men and
100-105 degrees in women
E-Line
Nasolabial angle
• E-Line / Nasolabial angle
• Prosthetic Consideration
• Modify dental arrangement w/o interfering with the active muscular area
E - line
Thin
Average
Thick
• Height of the upper lip as rule should be half the height
of the lower lip
• Shape and size are sometimes associated w/
psychological traits
• Thick lips – Extroversion, Subjectivity,
and sometimes materialsim
• Thin lips – introversion, objectivity, and self
control
• Concave Profile – Thick lips
• Prosthetic Consideration
• Re-establish a marked dominance of the anterior teeth
• Convex Profile – Thin lips
• Prosthetic Consideration
• Re-establish a moderate dominance of the anterior teeth – getting to aggressive will make the lips incompetent
• Chief Complaint:
Thinks teeth make
her look too young, does
not like space between
teeth.
Notice exact tight occlusal contacts and average Curve of Spee
Design the case in your mind before you touch a wax adder
• Snow (1999) suggests Golden Percentages
10 15 25 25 15 10
50
30
20
Crest of the tissue around each tooth has specific contour and
relationship to one another
Incisal edges must contain an appropriate amount of color and
translucency creating a natural appearance
Facial depressions are essential to refract light in such a way that hue and value (brightness) are controlled
Small Medium Large
Fill in wax between central incisors creating a “uni” tooth. This will allow for the proper placement of midline.
T-reference
Note anterior
teeth converge at the navel
Add wax across the incisal edge to establish the T-reference. Note: this would normally follow our facial landmark
registration
Carve in facial embrasure to establish midline and maintain T-reference
Incisal embrasures have specific relationships to each other. Maintain these at Small-Medium-Large
SmallMedium
Large
Most critical component of the process is constant assessment
Stop---Look---Assess---Modify
Add wax on both lateral incisors establishing the proper width to length ratio
Carve the lateral incisors a little at a time to establish bilateral symmetry
Precise wax-ups can be measured down to the 10th of a millimeter
Wax is added to the canines to establish 1) Anterior Guidance2) Facial contours (note the apparent asymmetry at this stage)
Carve the facial embrasure between lateral and canine to lessen the width issues apparent on this slide
Use a flat surface to check the length relationships of the anterior teeth to one another
Carve canine to establish the proper reveal and contours emphasizing the heights of contour
Check the position of the proximal contact areas so they move apically as they move distally
Make sure you’ve created axial inclinations which decrease in severity with each distal tooth
Establish right and left canine guidance using wax on the lingual
surface of the cuspids
Establish protrusive guidance of the anterior teeth. This can be
significantly impacted by the slopes of the articular eminence.
Blend and smooth all remaining surface on the palatal aspect to
create a smooth transition from stone to wax
Carve facial embrasures to establish proper surface reflection and accentuate long axis of each tooth
Add age appropriate incisal characteristics. These may or may not include mammelons.
Completed Case
Check the wax-up in the patient for proper lip positioning and
confirm the incisal edge to lip relationship
• Confirm T reference
Simulated Smile Design
Before Simulation After Simulation
Midline is on, but interpupillary line very difficult to follow