lec 8

Question 1

The seal area at the posterior border of a maxillary removable dental prosthesis.

Answer 1

POSTPALATAL SEAL / POST-DAM

Question 2

FUNCTIONS (5)

Answer 2

• Retention (primary function)
• Acts as a barrier and prevents food accumulation beneath the denture.
• Maintains contact with the moving soft palate, thereby, reducing the gag reflex by reducing the patient’s awareness of the denture.
• Compensates for curing shrinkage.
• Reduces tongue irritation as posterior border merges better with palate.

Question 3

COMPONENTS (2)

Answer 3

A. Posterior palatal seal
B. Pterygomaxillary seal – located immediately behind the maxillary tuberosity.

Question 4

BOUNDARIES OF POSTPALATAL SEAL (3)

Answer 4

 Anteriorly - Anterior vibrating line
 Posteriorly - Posterior vibrating line
 Laterally - Pterygomaxillary notch

Question 5

Anterior Vibrating Line

Answer 5

• An imaginary line located at the junction of the attached tissues of the hard palate and the moveable tissues of the immediately adjacent soft palate.

Question 6

• Bow shape – “Cupid’s Bow” due to the projection of the ______.

Answer 6

posterior nasal spine

Question 7

• Located by: (2)

Answer 7

o ▪ Valsalva maneuver – both the nostrils are held firmly while the patient blows gently through the nose.
o Patient is asked to say “Ah” with short vigorous bursts.

Question 8

Posterior Vibrating Line

Answer 8

• An imaginary line at the junction of the aponeurosis of the tensor veli palatini and the muscular portion of the soft palate.

Question 9

• It represents the demarcation between that part of the soft palate that has shallow movement (quivers) during function and the remainder that is markedly displaced.

Answer 9

Posterior Vibrating Line

Question 10

Posterior Vibrating Line
* Located by: (1)

Answer 10

o It can be visualized when the patient says “Ah” in a normal, unexaggerated fashion.

Question 11

TECHNIQUES OF RECORDING THE POSTERIOR PALATAL SEAL

Answer 11

A. Arbitrary techniques
a. Conventional technique
b. Boucher’s technique

B. Physiologic techniques
a. Fluid wax technique
b. Stick compound technique
c. Extended palatal technique

Question 12

CONVENTIONAL TECHNIQUE
 Stage of recording: ________________

BOUCHERS TECHNIQUE
 Stage of recording: _______________

Answer 12

At the start of jaw relations.

During jaw relation

Question 13

FLUID WAX TECHNIQUE
 Stage of recording: ___________

STICK COMPOUND TECHNIQUE
 Stage of recording: ________________________

EXTENDED PALATAL TECHNIQUE (SILVERMAN)
 ___________________

Answer 13

After making final impression.

During border moulding of the special tray, before the final impression is made

Denture border is extended 8.2 mm beyond the anterior vibrating line.

Question 14

• Occurs when the distal border of the denture extends onto the active portion of the soft palate.

Answer 14

OVEREXTENDED

Question 15

OVEREXTENDED
* Symptoms:

Answer 15

o Patient complains that swallowing is difficult or painful.
o Areas of redness or ulcerations maybe seen.
o Patient may experience sharp pain specially during function.

Question 16

OVEREXTENDED
* Correction: _____

Answer 16

the exact area of redness is marked with an indelible pencil and transferred to the denture. The denture is then shortened with a bur and repolished.

Question 17

• Common cause of failure of the posterior palatal seal.
• Results in the loss of retention.

Answer 17

Underextension

Question 18

Underextension
* Reason:

Answer 18

o Failure of the dentist to identify the posterior vibrating line.
o In the gagging patient, the dentist might have kept the impression tray underextended to reduce the gagging sensation.

Question 19

• Failure to effectively place the tissues of the posterior palatal seal area results in poor seal and reduced retention.

Answer 19

UNDERPOSTDAMMING

Question 20

UNDERPOSTDAMMING
* Diagnosed by:

Answer 20

o The trial denture base is wet and placed in the mouth. Using a finger in the palatal region, it is slowly pressed into position. With a mirror, the distal border is examined for scaping air bubbles. Escaping air bubbles indicate an underpostdammed area.

Question 21

UNDERPOSTDAMMING
Correction:

Answer 21

o Further scrape the cast and readapt the trial base.

Question 22

• Over scraping of the cast can result in

Answer 22

OVERPOSTDAMMING

Question 23

can result in pressure symptoms on the tissues. An area of redness or tissue irritation may be seen.

Answer 23

o Moderate postdamming

Question 24

causes downward displacement of the denture.

Answer 24

o Severe postdamming

Question 25

OVERPOSTDAMMING
Prevention

Answer 25

o Reduction of the denture with carbide bur, followed by lightly pumicing the area while maintaining its convexity.