L4.Anatomy of the Edentulous Mandible

Question 0

Where would you find the pear shaped pad in relation to the retromolar pad on the mandibular arch?

Answer 0

Anterior border

Question 1

Give the 2 primary denture support areas and 2 secondary support areas for the mandible.

Answer 1

Primary:
1. Buccal Shelf
2. Retromolar pad and pear shaped pad
Secondary:
1. Ridge crest area
2. Genial tubercle area

Question 2

How is the masseteric notch (groove) formed?

Answer 2

The masseter muscle reflects the buccinator muscle in a superior and medial direction

Question 3

What part of the denture must be countoured to allow for the masseteric notch movement in order to avoid denture displacement and tissue irritability?

Answer 3

The distobuccal flange

Question 4

The lateral border of, and access to the, buccal shelf is determined by what factor?

Answer 4

Lateral border of the buccal shelf is determined by the buccinator muscle and access is determined specifically by the attachment of the buccinator

Question 5

Upon resorption what happens to the buccal shelf?

Answer 5

It becomes thinner. Note, however, that the buccal shelf is made mainly of dense cortical bone that is resistant to resorption. The loss of width is generally on the medial side with alveolar ridge resorption

Question 6

Compare the # of labial frena typically found in the maxillary vs the mandibular

Answer 6

Maxillary = 1
Mandibular = 3

Question 7

Why is the alveolar ridge of the mandibular only a secondary support area?

Answer 7

B/c the mandibular alveolar ridge resorbs rapidly (4X rate of maxillary) and the compressive forces from the denture only hasten the resorption. Also, as the ridge resorbs it becomes thinner and more rough.

Question 8

The coronoid process of the mandible affects what space in the maxillary?

Answer 8

Retrozygomatic space