Facial Analysis For Dental Restorations

Facial Analysis Parag 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

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Vertical disharmony

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Tip of the nose and the tip of the chin may not always be aligned

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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

Frankfort horizontal – external auditory meatus and the lowest point on the orbit Esthetic plane 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 Horizontal Reference • Marked posterior divergence • Concave • Greater than 180 degrees

Glabella Subnasale Pogonion (tip of the chin)

Normal profile lip is about 4mm posterior to the Eline, while the lower lip is about 2mm posterior.

E-Line

Approximately 90-95 degrees in men and 100-105 degrees in women

Nasolabial angle

E - line •

E-Line / Nasolabial angle

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Prosthetic Consideration

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Modify dental arrangement w/o interfering with the active muscular area

• Height of the upper lip as rule should be half the height of the lower lip •

Thin

Shape and size are sometimes associated w/ psychological traits • Thick lips – Extroversion, Subjectivity, and sometimes materialsim

Average

• Thin lips – introversion, objectivity, and self control

Thick

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Concave Profile – Thick lips

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Prosthetic Consideration

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Re-establish a marked dominance of the anterior teeth

Convex Profile – Thin lips

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Prosthetic Consideration

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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

10 15

25

25

15

10

50 30 20

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Snow (1999) suggests Golden Percentages

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

Small Medium Large Facial depressions are essential to refract light in such a way that hue and value (brightness) are controlled

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

Small Medium Large Incisal embrasures have specific relationships to each other. Maintain these at Small-Medium-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 Guidance 2) 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

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Confirm T reference

Simulated Smile Design

Before Simulation

After Simulation

Midline is on, but interpupillary line very difficult to follow