Dr Muhammad Rizwan Memon FCPS

Assistant Professor

Anterior Tooth Selection “ATS”

Purpose For The Selection Of Artificial Teeth

1. Function

2. Speech

3. Esthetic

4. Not abuse the tissues over Residual Ridges

Psychology of Acceptance:

“Give patients what they want”

STEPS IN ANTERIOR TEETH SELECTION

Listen to the patient. What the patient wants is the reason that she or he came to your office

Listen much & talk little, we can’t hear when we are talking

Ask the patient for his or her opinion about the teeth, patient may take the help from a spouse, relative or a close friends

Let the decision maker choose the teeth

FIRST STEP

Patient may wish to have teeth that look whiter and less restored than what would normally be expected in persons their age

The dentist’s task is to assist a patient in making the best decision

STEP-2 Get record of the existing and the previous teeth and

find out the patient’s opinion of them

Ask the patient to bring any models, old dentures & photographs that show them happy & smiling

If your patients are happy with the appearance of his teeth, use these records to provide a denture service that has similar teeth, but a better vertical dimension & adaptation to the tissues

This has been identified as “confirmative approach”

If teeth are of wrong color, size, shape & position or excessively worn and if the patient is not satisfied with previous teeth, plan on improvements, consider a “reorganized approach”

STEP-3

Arrange your practice for ATS

Good light

Hand mirror

To describe colors in the simplest terms, we need three definitions:

Hue - the shade, or the blend

of red, blue and green that make up the colour.

Chroma- the saturation of

the colour. For example, chroma is what makes a colour photograph different from a black and white photograph.

Value- the brilliance or

brightness of a color

STEP-4 (COLOR)

FACTORS EFFECTS THE COLOR OF NATURAL TEETH

AGE: Teeth become more opaque with increasing age.

WEAR: Teeth looks more glossy, smooth & prone to stain.

GENDER: Females have more whiter teeth.

DEMINERALIZATION: Teeth gets more prone to staining.

STAINS: Both extrinsic & intrinsic stains effects the actual shade of the natural standing teeth.

PRE_EXTRACTION GUIDES:

Not particularly helpful for shade selection

1. Photographs

2. Extracted teeth

POST-EXTRACTION GUIDES: 1. COLOUR OF THE EYES & HAIRS Little correlation exist (Hallarman). Hair color is unreliable. Black eye individuals have darker teeth shade

2. SKIN COLOUR:

The color of skin may change from a reddish complexion in health to pallor in sickness, the same teeth remain harmony with both conditions

Fair skinned individuals can be given with lighter shades. Lighter shades on Darker skinned individual look more noticeable

Three dominant colors are; Yellow Grey Opal

Each found in a wide variety of shades and intensity

1. Yellow is dominant with fair hair, blue eyes and fresh

complexion

2. Grey some time touched with blue, is dominant with dark hair, brown eyes and dark complexion

3. Opal is dominant with a clear, pale complexion, irrespective of the color of hair and eyes

3. DENTOGENIC CONCEPT: • Concept proposed by FRUSH & FISHER. • Has got the great impact on selection of teeth. • Teeth selected according to this concept consider the following factors in

the given order.

A. GENDER:

B. PERSONALITY: Patient can have VIGOROUS or DELICATE personality Vigorous look can be given by, Selecting the darker shade Delicate personality can be created by, Selecting More paler teeth

C. AGE:

Aged appearance can be given by, Select darker shade Age characterized molds are also available

Facilitate Patient:

Allow the patient to select the color of teeth he/she prefer, Color is easiest thing for a patient to decide about teeth

Show the patient a complete shade guide and select the two tabs that are lightest and darkest (Method of Pair comparison)

Hold them against patient lips and ask him to point to the one that he/she prefers

Delete the rejected colour

Select another shade in the preferred half of the shade guide and repeat the pair comparison

After two selection by patient, you wil probably have a pair of shades that are very close to what the patient want.

STEP-5 (SIZE)

SELECTION OF THE SIZE INCLUDES

1. Width (Mesio-Distal)

2. Length (Occluso-gingival)

3. Thickness (Labio-lingual)

1.Width (Mesio-Distal)

PRE-EXTRACTION GUIDES: 1. Diagnostic casts: Most reliable guide Helps to duplicate pt: original teeth shape, size &

positional arrangement . Especially useful in immediate dentures.

2. Photographs: Provide information on width & form of teeth (rarely on

color). Usefulness depends on the extent of teeth visibility Human size photographs are more valuable Digitization of images make computer assisted vision

possible.

3. RADIOGRAPHS:

Helps in size & form selection

Need compensation for magnification

Distortion of radiographic image is an inherent problem.

4. EXTRACTED TEETH:

Excellent guide for tooth size & form selection.

Not a good guide to select shade of teeth.

5. Previous Dentures:

POST EXTRACTION GUIDES:

a) Size of the face:

b) Anthropometric Measurements

a) Bi-zygomatic width

b) Cranial circumference

Ratio of cranial circumference to the combined upper anterior width is 10:1.

c) Corners of Mouth: Line drops over the maxillary rim from

corners of the mouth at rest, corresponds to the distal surface of the canine.

d) Ala of the Nose: A vertical line dropping from

the ala of the nose usually passes along through middle of canine.

2.Length (Occluso-gingival height)

The necks of the teeth will overlap the anterior ridge by 2-3mm cervically and the incisal edges of the centrals will show below the relaxed lip, about 3mm in a young patient and less than half of that in elderly person

This is not a hard and fast rule

Wide Variations Found

1. Length of Upper Lip

Some people have long lip, which cover all their natural teeth

whiles other have short lips which even In the relaxed position show half of the length of teeth

2. Mobility of the upper lip

During smile, some of patients expose all of their teeth and considerable amount of gum, while others merely stretch the lip

3. Vertical height of occlusion

Reduction in vertical height will cause the lips to bunch up and cover the teeth, while an increase will cause an excessive amount of the teeth to show

4. Vertical overlap

A deep vertical overlap result in the exposure of a much greater length of the tooth than an edge to edge incisal relationship

3.Thickness (Labio-lingual)

Labio-Lingual thickness has considerable bearing on Phonetics, though it is of less esthetic importance

Thicker teeth should be given preference, they can be rotated & space out to give more realistic appearance

Facilitate Patient:

Jointly with the actual measurements, use the Method of Pair Comparison to assist patient to decide what size of tooth they prefer

Set two different sizes of teeth on a piece of wax rope or a tooth selector rim

Place this under the upper lip and find out which one the patient prefer

STEP-6 (MOLD)

Teeth of similar size can have a different appearance because of difference in the crown taper and labial curvature

3D Shape of Denture Teeth Facial Form

Lateral/Proximal Form

Incisal Form

Pre-Extraction Guides

1. Diagnostic Casts

2. Photographs

3. Radiographs

4. Extracted teeth

5. Old Dentures

Post-Extraction Guides:

1. Matching Tooth Form to Face Form:

LEON WILLIAM’S THEORY:

Face can be categorized into three primary forms; Square form

Tapering form

Ovoid form

According to LEON WILLIAM’S theory if one of the central incisor enlarged, and the incisal edge placed above the brows with the neck of the tooth on the chin, then the outline of the tooth would nearly coincide with that of the face

2. Matching Tooth Form to Arch Form

It has been realized that there is some relationship between the shape of the edentulous upper arch and the upper teeth

V shaped arch is associated with the incisors which are much narrower at the neck than at the inisal edge

A round arch, with ovoid teeth

A squarish arch, with almost parallel sided incisors

3. Dentogenic Concept (SPA Factor):

Proposed by Frush & Fisher

a) Sex:

The out line of female form tend to be a series of curves and the basic tooth form should be of the curved or ovoid type

The out line of male figure is more straight lined and angular on contrast to the female form and the basic tooth form should be tapering or square

b) Personality: Patient can have VIGOROUS or DELICATE personality

Vigorous look can be given by,

Selecting wider centrals Wearing the centrals & canine Sharp line & point angles

Delicate personality can be created by,

More paler teeth Rounded contours

c) Age:

Aged appearance can be given by,

Wearing the incisal edges

Proximal wear can also be incorporated

More of the cervical portion visible to give gingival recession appearance

Additional Clinical & Technical Considerations

Patient Preference

Patients may want teeth to be porcelain or acrylic, depending on various reasons they have heard

Listen and respond with your knowledge of dental materials

Highly Visible Gingiva

Select squarer teeth with a long contact point rather than highly tapered teeth, this will minimize interproximal display of pink Gingiva

Limited Interocclusal Space

Use acrylic teeth, these can be ground thin, yet they make chemical bond with acrylic base, Porcelain teeth loose their mechanical retention, if the palatal pins are ground off.

Opposing Natural Teeth

Use acrylic teeth because porcelain teeth can be very abrasive

We can use teeth with Gold Occlusal

Overdentures

The tooth positioned just over a retained root or implant abutment has to be ”hollow-ground”, and a little extra tooth volume is needed for strength