Shortened Dental Arch

Question 1

What is the definition of occlusal stability?

Answer 1

Stability of tooth positioning relative to its spatial relationship in the occluding dental arches

Question 2

What is occlusal stability defined as?

Answer 2

Periodontal support
Number of teeth in the dental arches
Interdental spacing
Occlusal contacts
Absence of pathology- tooth wear, periodontal disease
Mandibular stability

Question 3

What are the 5 requirements of occlusal stability?

Answer 3

1. Stable contacts on all teeth of equal intensity in centric relation
2. Anterior guidance in harmony with posselts’ envelope of function
3. Disclusion of all posterior teeth during mandibular protrusive movement
4. Disclusion of posterior teeth on the non-working side during mandibular lateral movement
5. Disclusion of posterior teeth on the working side during mandibular movement

Question 4

What can the loss of molars be associated with?

Answer 4

Reduced masticatory efficiency
Mandibular displacement
Alterations in food selection
Aesthetic issues
Loss of occlusal stability
TMJ problems

Question 5

What are the indications for a shortened dental arch?

Answer 5

Missing posterior teeth with 3-5 OU remaining
Sufficient occlusal contacts to provide large enough occlusal table
Favourable prognosis for remaining anterior and premolar teeth
Patient not motivated to pursue complex Tx plan
Limited financial resources for dental care

Question 6

What are the contraindications for a shortened dental arch?

Answer 6

Poor prognosis for the remaining dentition
Untreated or advanced periodontal disease
Pre-existing TMJ dysfunction
Signs of pathological toothwear
Patient has a significant malocclusion

Question 7

How many teeth are involved in a shortened dental arch?

Answer 7

20-24 teeth ( 10-12 occluding pairs )

Question 8

What kind of tooth migration occurs in a shortened dental arch?

Answer 8

Distal tooth migration

Question 9

What effects can distal tooth migration have on shortened dental arches?

Answer 9

Increases anterior load
Increases number and intensity of anterior occlusal contacts
Increases interdental spacing
Exacerbated by inadequate perio support

Question 10

What is a shortened dental arch?

Answer 10

Posteriors missing, with at least 2 premolars in each quadrant with a minimum of 20 teeth. 3-5 functioning units minimum.

Question 11

Why is a shortened dental arch considered acceptable?

Answer 11

This provides patient with suitable aesthetics, function, occlusal stability and ability to perform oral hygiene