ARRANGEMENT OF ARTIFICIAL TEETH

Aims of Arrangement

1. Preservation of alveolar bone2. Esthetics3. Masticatory efficiency4. Retention and stability during function5. Health and comfort of the TMJ

Factors Affecting Position of Teeth

1. Esthetics• Lip support• Tooth visibility• Buccal corridor

2. Function • Speech and mastication

3. Stability• Neutral zone

Guides to Positioning Anterior Teeth

Payne stated,“Set the teeth where they grew.”

However,• patient may not want the original tooth

position and arrangement• an esthetically correct position may be

functionally unstable

Preextraction Guide

• Photographs• Cast

Postextraction Guides

Anteroposterior position Supeoinferior position

Visibility of upper incisors Mediolateral position

- Midline of face- Ala of nose

Inclination or slant

Anteroposterior Position

• Distance from the incisive papilla– 8-10mm

• Relation to the residual ridge– Anterior to the ridge

• Fullness of lips (esthetics as guide)• Phonetics as guide

Phonetics

• Labial sounds• Labiodental sounds• Dental and alveolar sounds• Palatal and velar sounds

Labial Sounds

• b, p, m• Insufficient lip support can cause these sounds

to be defective

Labiodental Sounds

• f, v• If the upper anterior teeth are too short, the v

sound will be more like an f• If they are too long, the f will sound more like

a v

Dental Sounds

• th• Tip of tongue extends slightly between the

upper and lower teeth• About 3mm of the tongue should be visible

Alveolar Sounds

• t, d, n, s, z• Contact between the tip of the tongue and

the alveolus or the lingual side of the anterior teeth

• If teeth are too lingual, t will sound like d• If too anterior, d will sound like t

Sibilants

• S, z, sh, zh, ch, and j• Upper and lower teeth should approach but

not touch

Inclination of the anterior teeth.

• Relationship to the labial plate – The roots of anterior teeth are parallel to and

close to the labial surface of the bone.– The cervical third of teeth appear to be

continuous with the labial plate of bone.

• Relationship to the facial profile– Teeth are inclined parallel to the lower third of

the face.

Relationship to the labial plate

Relationship to the facial profile

Arrangement of Posterior Teeth

Guides to Positioning Posterior Teeth

Both upper and lower posterior teeth are centered over the crest of the ridge whenever possible. This improves the balance and stability of the denture.

Guides to Positioning Posterior Teeth

Don’t place teeth too far buccally as it can cause:

1. Cheek biting2. Denture instability3. Esthetic problems

Guides to Positioning Posterior Teeth

Placing the teeth too lingually can cause:1. Crowding of the tongue2. Tongue biting3. Imbalance due to tongue function

Approaches to Posterior Setting

1. Setting all the maxillary teeth first2. Setting all the mandibular teeth first3. Setting the mandibular teeth before the

corresponding maxillary teeth

Maxillary should not be placed over the maxillary tuberosity as it can cause lever imbalance.

Mandibular teeth should not be placed over the retromolar pad or on the slope as it can result in denture sliding and instability.

Occlusal Schemes in CD

A. Balanced OcclusionB. Non-balanced OcclusionC. Lingualized OcclusionD. Functionally generated occlusal scheme

Christensen’s Phenomenon

• Separation of the posterior teeth caused by the downward movement of the condyle during mandibular protrusion and lateral movement (balancing side)

Balanced Occlusion

• Bilateral, simultaneous, anterior and posterior occlusal contact of teeth in centric and eccentric positions

Balanced Occlusion

• Ideal occlusal scheme for CD• Achieved by incorporating compensating

curves into the posterior setting

Compensating Curves

• are artificial curves introduced into the CD occlusion in order to achieve a balanced occlusion

Compensating Curves

Curve of Spee - an anteroposterior curve along the cusp tips and incisal edges of teeth

Curve of Wilson - a mediolateral or side-to-side curve contacting the cusp tips of posterior teeth

Advantages of Balanced Occlusion

1. Improves stability and retention of the denture bases

2. Reduces soreness and resorption caused by the denture base movement

3. More comfortable to the px

Non-balanced Occlusion

• No attempt is made to create balanced occlusion. Creating multiple uniform contact in centric relation was sufficient

Lingualized Occlusion

• Forces are directed towards the lingual side• It was claimed that this improved the stability

of the lower denture