The document discusses the posterior palatal seal area of maxillary dentures. It defines the posterior palatal seal area as the soft tissue junction between the hard and soft palates that can withstand pressure from a denture to aid retention. It describes techniques for establishing the posterior palatal seal area during impression making and processing a denture to optimize denture fit and retention.

1. DR MUAIYED BUZAYAN Dr. Muaiyed. Mahmoud. Buzayan, BDS
MClinDent Malaysia
AF AAMP USA

2. Posterior Palatal Seal area
It is defined as a soft tissue along the junction of the hard
and soft palates on which pressure within the physiologic
limits of the tissues can be applied by a denture to aid in the
retention of the denture.
DR MUAIYED BUZAYAN

3.  The seal area at the posterior border of a maxillary removable dental
prosthesis
 It is a slight elevation at the posterior border of the maxillary denture
 PPS area of the upper denture is the area that should be placed on non-movable
tissues of the soft palate just behind the hard palate.
 The posterior palatal seal is formed through both hamular notches &
DR across the MUAIYED palate over the vibrating line.
BUZAYAN


4. 1. Compensates for polymerization shrinkage away from palate
2. Enhances the retention. The main function of PPS is to
maintain contact with the anterior portion of the soft palate (the
tissue undergo shallow displacement) during functional movement
of the somatognathic system (that is mastication, deglutination &
phonation) DR MUAIYED therefore the main purpose BUZAYAN
of PPS is the retention of
maxillary denture
3. It also reduces food accumulation beneath the posterior
aspect of denture owing to proper utilization of tissue
compressibility.

5. 4. It also reduces gag reflex as there is no separation between denture
base & soft palate during normal functional movement
5. Inconspicuous with the tongue: Reduce patient discomfort contact
occur between dorsum of the tongue & posterior end of denture base
DR MUAIYED BUZAYAN

6. Posterior palatal seal requirement:
1- Lies on easily displaced tissue
2- Should be in continuous contact with soft palate in the rest
and function
ANATOMIC & PHYSIOLOGIC CONCIDERATION
The PPS is divided in two anatomic separate boundaries-
1. Post palatal seal
1.
2. Pterygomaxillary seal
DR MUAIYED BUZAYAN
A B C B A
A- Pterygomaxillary seal
B- Post palatal seal extends from
hamular notch to hamular notch
C- Post palatal seal lies between
anterior and posterior vibrating lines

7.  The post palatal seal is extending from one tuberosity to other.
Pterygomaxillary seal extend through pterygomaxillary notch
continuing for 3-4 mm anterolaterally approximation the
mucogingival junction.
 It also occupies the entire width of pterygomaxillary notch. This
pterygomaxillary notch is covered by pterygomandibular fold
DR which extend MUAIYED from the posterior BUZAYAN
aspect of the tuberosity
posterio-inferiorly to insert into the retromolar pad.
 This fold of tissue can influence the posterior border seal during
the mouth wide opening.

8. The imaginary line across the posterior part of the palate
marking the division between the movable & immovable
tissue of the soft palate which can be identified when the
movable tissue are moving.
1. Anterior vibrating line
2. Posterior vibrating line
1.
DR MUAIYED BUZAYAN

9.  It is an imaginary line lying at the junction between the
immovable tissues over the hard palate & the slightly
movable tissue of the soft palate
 Instructing the patient to say “AH” with short vigorous
bursts
 The anterior vibrating line is not a straight line, due to the
projection of the posterior nasal spine..
DR 
MUAIYED BUZAYAN

10.  It is an imaginary line at the junction of the aponeurosis of
tensor vili palatini muscles in the muscular portion of the
soft palate. It separates the movable and the immovable
portions of the soft palate.
 It represents demarcation between the part of soft palate
that has limited or shallow movement during function
(quivers) & the remainder of the soft palate that is
mark edly displaced during functional movement.
DR MUAIYED BUZAYAN

11. It is classified in-
CLASS I
It indicates soft palate that is rather horizontal or as an
extension posteriorly with minimum muscular activity.
The separation between anterior and posterior vibrating
line does having wide PPS area yielding more retentive
denture base
CLASS DR II
MUAIYED BUZAYAN
The soft palate that has a medium curvature and allow
for a medium width of the posterior palatal seal area.
Palatal contour lie between class I & class III
CLASS III
It is seen in conjugation with high V shape palatal vault. There is few
millimeters of separation between the anterior and posterior vibrating lines
thus the PPS area would be small and the retention is less.

12.  1- The post dam extends from the hamular notch on one side to the
other hamular notch of the other side. It should be wide enough to
avoid cutting or irritating the soft tissues, but not so wide to
compress too large an area and thus prevent the denture from sealing
properly.
 2- The post dam is usually narrow in its central part, wider as it
extends laterally on each side, and narrow again as it approaches the
hamular notch to fade out behind the tuberosity. It is sometimes
called butterfly (Cupid's bow) post dam
DR MUAIYED BUZAYAN
 3- The post dam should be about 4-6mm wide in its widest part. The
depth or thickness of the post dam should vary in different
individuals, according to compressibility and softness of the tissue. Its
depth should also vary (0.5 – 1mm) in different parts of the same
mouth in exactly the same manner as its width. The average depth is
1mm.

13. DR MUAIYED BUZAYAN

14. 1- Impression making: To establish positive contact
posteriorly to prevent the final impression materials from
sliding down the pharynx. And to serve as a guide for
positioning the impression tray, especially if a shim (wax
spacer) has been used within the tray to establish the
borders.
DR MUAIYED BUZAYAN
2- Jaw relation: To stabilize the trial denture base and to
determine if adequate retention & seal of the potential
denture border is present.

15. 3- Finished denture: to gain all the benefit of the
posterior palatal seal. Existing denture may have poor
length and depth of PPS. Properly examine existing
dentures. If there are other problems in the dentures
(vertical dimension, centric, esthetics etc.) then new
dentures are to be made. If only PPS is short then correction
should be undertaken.
Different materials and techniques can be used.
1) Heat cure material.
2) Self cure acrylic resin.
3) Light cure resin.
DR MUAIYED BUZAYAN

16. There are several established for the placement of the posterior palatal
seal:
1- Conventional method
2- Scraping of master cast (arbitrary post-damming)
3- Fluid wax technique
4- Post damming during try-in stage
1- Conventional method
DR MUAIYED BUZAYAN
PROCEDURE
1. The posterior vibrating line. A line is placed with an indelible
pencil, through the pterygomaxillary notch & extended 3-4 mm antero-laterally
the tuberosity approximating the mucogingival junction
(intraorally).

17. 2. The custom tray inserted into the mouth & seated firmly. Upon
removal from the mouth, the indelible lines will be transferred to the tray.
The tray in return to master cast to complete the transfer of the complete
posterior border.
3. The tray is trimmed to the posterior determines DR the MUAIYED post extent denture border.
BUZAYAN
vibration line so that it
4. To get the anterior vibrating line, the soft palate is palpated with the
‘T’ burnisher or mouth mirror to determine their compressibility in width &
depth. The termination of glandular tissue usually coincides with the
anterior vibrating line. The anterior vibrating line now marked and
transferred to master cast.

18. 5. The visual outline is in the shape of cupid bow the area between the
anterior posterior vibrating lines is usually narrowest in the mid palatal
region because of the projection of the posterior nasal spine.
6. DR Kingsley MUAIYED scraper used to score the cast. BUZAYAN
The deepest area is located
on either side of midline. It is usually scraped to a depth of approximately
1-1.5 mm. The tissue covering the medial palatal raphe is not scrapped (or
minimally scraped).

19. 2- Scraping of master cast
This technique is the least accurate and leaves the most to chance of tissue
compressibility of the insertion of the denture.
The anterior and posterior vibrating lines are visualized by examining the
patient and then they are approximately marked on the cast. The technician will
scrap the 0.5 to 1mm depth of the stone in the posterior palatal seal area.
This technique is almost as non-physiologically correct as the technician's
attempt to place the posterior palatal seal arbitrarily.
DR MUAIYED BUZAYAN

20. 3- Fluid wax technique
 It starts with locating and transfer of anterior and posterior vibrating line similar to
conventional approach. Then with the marks made, final impression is made using
ZOE/impression plaster (not with elastomeric impression material as they are resilient, non-adherent
to wax, and distort wax when reseated into oral cavity).
 Impression waxes used to get seal. These waxes have specific characteristics like low-melting
point to permit their use intraorally without discomfort or trauma, high flow rate at
mouth temperature.
 The melted wax is painted into the impression surface (within the outline of the proposed
seal area). The impression is carried to the mouth and held in place under gentle pressure
for DR 4-6 min and MUAIYED allow time for the material to flow. BUZAYAN
Take care for head position (30° to
Frankfort Horizontal plane). In this position the soft palate is impression in its most
functionally depressed position.
 After 4 min remove the impression tray and trim any
excess (or) if no tissue contact is established then add and
redo the procedure

21. 4- Post damming during try-in stage
The trial denture base is inserted so the indelible pencil line marked on
vibrating line of the soft palate will be transferred from the soft palate to
the trial denture base. And the excess base plate is reduced to this line.
The trial denture base is placed on the cast and a knife or pencil is used
to mark a line following the posterior limits of the base plate.
DR MUAIYED BUZAYAN

22. DR MUAIYED BUZAYAN