Classification of patients1. Patients with remaining natural

teeth2. Patients who have old denture3. Patients without remaining

natural teeth and without old denture

Objectives:1. Esthetics2. Masticatory function3. Correction of speech defects4. Preservation of the remaining

tissue and muscle tone

- Primary selection of the teeth must be carried out at the first appointment.

Guides for the anterior teeth selection1. Pre-extraction guidesa. Study castb. Photographsc. Radiographsd. Extracted teeth

2. Post extraction guides

- Selection of size (width and length)a. Size of the face and headb. Size of the contour of the maxillary archc. Maxillomandibular relations

i. In class I – Normal relationship, the teeth in one arch are compatible with the teeth in the other arch.

ii. In class II – The mandible is retruded and the mandibular teeth are frequently smaller

iii. In class III – The mandibular teeth are frequently larger than normal

- Width of the anterior teeth

a. Bizygomatic width – The average width of the maxillary central incisor is estimated to be 1-16 of the bizygomatic width that is, the distance between the cheek bones measured just in front of the ears. Some simple devices are available from tooth manufacturers for making this determination or caliper may be used to measure this distance. A face bow maybe used as caliper to make this determination. The combined width of the six maxillary anteriors is slightly less than one third the bizygomatic width.

b.The width of the nose – An estimation of the position of the apex of the upper natural canine can be found by extending parallel lines from the lateral surface of the ala of the nose onto the labial surface of the upper occlusion rim.

c. Corners of the mouth – The distance measured between the two commisures (angles of the mouth ) will represent the width of the upper six anteriors from the distal surface of the canine to the distal surface of the other canine.

d.Canine eminence

e.Cranial circumference

f. Incisine papilla – It has been found that a transverse line bisecting the incisive papilla will pass through the middle of the upper canines. The necks of the upper anterior teeth overlap the anterior ridge by 1-2 mm cervically, and the incisive edges of the centrals must show below the relaxed lip by 1-2 mm in a young person and less than half that amount in an elderly patient.

1. The vertical distance between the ridges – Is determined by the available space between the existing ridges.2. The lips3. Vertical overlap

4. The length width ration of the patient’s face.

Length of faceWidth of face

=Length of toothWidth of tooth

Selection of the form- Guides for selecting the form of

anterior teeth.- Shape of the arch.

Tooth form in relation to arch form- Shape of the face

Selection of shade- Color and shade of tooth

N.B. The shade consist of:a. Hue i.e specific colorb. Saturation i.e. amount of color per

unit area.c. Translucency i.e ability of color to

permit light to pas through it.

Patients age – With age, darker, while lighter teeth are suitable for young patients.

Patients complexion—light teeth for fair skin, blue eyes, dark teeth usually for dark skin and black eyes.

The following facts are true for nearly all natural teeth:

a. The neck of the tooth has a more pronounced color than the incisive edge.

b. The incisive edge if not worn, is more transluscent that the body of the tooth and is usually of a bluish shade (composed entirely of enamel)

c. The upper central incisors are lightest teeth in the mouth followed by the laterals and canines. Posterior teeth are usually uniform in color.

d. Teeth darken slightly with age.- Aid for selecting the shadeShade guides – The shade guide tooth should be

moistened and selection made in the normal light.

a. Outside the mouth along the side of the nose.

b. Under the lip with the incisal edge exposedc. Under the lip with only the cervical end

covered and the mouth open.

The color should be matched with the skin of the cheeks.

General consideration for selection of anterior teeth

1. Sexa. Females – All teeth are more curved,

rounded line and point angles, the teeth more ovoid or tapeing than square.

b. Male – The teeth are larger with sharp line and point angles, the teeth more square than ovoid or tapeing.

2. Age3. Personality

Posterior teeth selection – Posterior teeth should have a small bucco-lingual width to keep forces on the supporting structure to a minimum.

The mesiodistal measurements of the upper posterior teeth is taken from the distal surface of the canine to the prominence of the tuberosity. The total mesiodistal width of the four posterior teeth is often used as a mould number. The lower posterior teeth should not extend posterior to the mesial border of the retromolar pad.

It is advisable to select upper posterior teeth as long as possible so that the premolars will be esthically in harmony with the canine. Actually there are long, medium and short posterior teeth.

Anatomic teeth- Balanced occlusion- Young healthy patients- Good ridges

Non anatomic form or monoplane teeth- Flat occlusal surfaces (without cusp)- Not function efficiently- Balanced occlusion- Less destructive force to the tissues- Old patients having poor ridges with

poor neuromuscular control.

Advantages of anatomic teeth.1. Esthetically acceptable2. More efficient in cutting of food,

thereby reducing forces that are directed to the supporting

structures during masticatory movement.

3. They can be arranged in balances occlusion

Disadvantages of anatomic teeth.

1. It is mandatory to use an adjustable articulator.

2. Eccentric records must be done for articulator adjustments

3. Clinical remount is essential to adjust the occlusion after denture settling.

4. Balanced occlusion lost when settling occurs.

5. More horizontal forces during functions.6. Frequent relining, Fast bone resorption

Advantages of non anatomic teeth1. Comfortable2. The allow greater range of movements

which is necessary in patients with mal-related jaws (as those with Para functional jaw habits or wide mandibular movement)

3. Non anatomic teeth exerts less horizontal or torquing forces, so they are used with flat ridge cases.

4. Centric record only is needed5. When the neuromuscular control are so

uncoordinated, the jaw records are not repeatable

Disadvantages of non anatomic teeth.

1. They are of unnatural look2. Less cutting efficiency3. The flat teeth occlude in two

dimensions only, but the mandible has 3 dimension movements.

Porcelain teeth- Wear is clinically insignificant over a long period

of time- No significant loss vertical dimension- Allow for the total rebasing procedures- Maintain communicating efficiency- Difficult to grind and fit into a close inter-ridge

space- Cause dangerous abrasion to opposing gold

crown and natural teeth.- Have a sharp impact sound- Will not bond to the base material except with

mechanical means. The anterior porcelain teeth have pins at the back, while the posteriors have holes.

Acrylic resin teeth.- Wear is clinically significant- Loss of occlusal vertical dimension due to

wear.- Occlusal surface is altered by wear.- Do not chip, and have softer impact sounds- Easy to adjust and polish- Easy to grind into close inter ridge space- Will bond to base material by chemical union.- Minimal wear to opposing natural teeth and

gold crowns. This is a definite indication for their use

Acrylic teeth are used in the following situations

1. Limited inter-arch distance2. Maxillary single denture against

natural dentition.3. Maxillary single denture

opposing partial denture4. Opposing natural teeth with gold

occlusal surfaces

Upper and lower posterior teeth can be- Both porcelain- Both acrylic- A combination of porcelain and acrylic resin

teeth on opposing dentures can be used. It softens the impact sounds, reduces friction and eliminates chipping.

- Upper posterior porcelain anatomic teeth with non anatomic lower resin teeth

- Upper and lower posterior acrylic teeth with upper anterior porcelain teeth is contraindicated because the resin teeth will wear rapidly resulting in occlusal destruction of the underlying tissues.