Shortened dental arch Flashcards
What is a ‘unit’
A pair of occluding premolars = 1 unit
A pair of occluding molars = 2 units
How many units are needed for a SDA?
3 - 5 units
What were the main outcomes of a study with SDA?
SDA’s provide sufficient oral function and oral comfort in terms of chewing function, aesthetics and signs and symptoms of TMJD
Provide sufficient mandibular stability and not a risk factor for TMJ disorders
Provides a stable occlusion
Alveolar bone height tend to decrease same rate as full dental arches
What are indications for SDA?
Missing posteriors but 3-5 units remain
Sufficient occlusal contacts for large enough occlusal table
Favourable prognosis of remaining teeth
Patient not motivated for complex treatment plan
Limited financial resources
Contraindications for SDA?
Poor prognosis remaining posterior teeth
Untreated or advanced perio
Pre existing TMJ disorder
Pathological toothwear
Significant malocclusion
Cosmetic concerns from pt
Discomfort from remaining teeth
What extra oral considerations should be made when considering SDA?
Signs for TMJ dysfunction
- click, crepitus, deviation, pain
- hypertrophy or tenderness of MOM
What intra oral considerations should be made when considering SDA?
Signs of bruxism
- buccal keratosis, scalloping, wear, trauma etc
Periodontal disease
Occlusal assessment
Prognosis of teeth?
what issues would a patient with unstable perio present in SDA?
Drifting of periodontally compromised teeth under occlusal load
Loss of alveolar bone, compromised denture bearing area
Distal migration increasing anterior load
Define occlusal stability
The stability of tooth positioning relative to its special relationship in the occluding dental arches
What are the 5 requirements of occlusal stability?
Stable contacts on all teeth of equal intensity in centric relation
Anterior guidance in harmony with envelope of function
Disclusion of all posterior teeth during mandibular Protrusive movement
Disclusion of posterior teeth on the non working side during mandibular lateral movement
Disclusion of posterior teeth on the working side during mandibular lateral movement
what are some manifestation of traumatic occluson
Fractured tooth / restorations
Widened lamina dura
Tooth mobility
Fremitus
Dental pain not related to infection
Toothwear
TMJ disorder
Why is a someone with TMD contraindicated for SDA?
Loss of posterior support may be contributing to the TMD
Replacement of these teeth can help to solve TMD
How can extension of the SDA be done?
Distal cantilever max of one unit, with light contact on cantilever contacts
Single tooth implants or bridge implants
RPD in bilateral free end saddle with RPI Design
