The posterior palatal seal (PPS) area provides denture retention through application of light pressure on the soft palate. It is located between the anterior and posterior vibrating lines in the soft palate. The most accurate technique for determining the PPS area is the fluid wax technique, which records the vibrating line markings made by the patient directly into the final impression with wax at a 30 degree head tilt. Errors in processing the PPS area can result in inadequate or excessive damming, detected by air bubbles when inserting the wet denture or gagging respectively.

1. Seal Max Contact , elimination of passage of air or moisture which can dislodge denture  No Retention
PPS To achieve retention  Pressure within physiologic limit on soft tissue is applied along junction of
hard palate and immovable part of soft palate (palatile aponeurosis)
 In maxilla only – PPS is area not line
 Pressure should be with physiologic limit otherwise  ulceration and inflammation will occur
 If thickness of acryl in hamular notch (>0.5ml) high pressure  severe pain during function
Anatomy and physiology
Palatile aponeurosis Immovable part of soft palate that include PPS
Fovea palatinin anterior to anterior vibrating line by (1.3 ml) .. not included in PPS otherwise no retention
Med palatine raph End in hard palate … not included in PPS
Need relief otherwise  midline fracture of denture or mid palatal fissure
Torus palatinus If large and extended to PPS  surgical removal
Narrow cord like band of tissue Extend between post nasal spine and aponeurosis of tensor veli palatine muscle
Need relief
Saliva Thick ropy saliva create hydrostatic pressure create  dislodging forces  no retention
Classification of soft palate
Class 1 5 mm or more of movable tissue available  wide area for PPS  ideal for retention
Class 2 Less than 5 mm movable tissue available  moderate area for PPS
Class 3 2mm movable tissue available associated with high V shaped palate  narrow area for PPS  the worst
PPS area  area between anterior and posterior vibrating line  cupid bow (butterfly shape)
Ant vibrating line  Imaginary line run from hamular notch in one side to hamular notch in the other side  in
junction between hard palate and immovable part of soft palate
 Most of line in soft palate and some of it in hard palate
 Cupid bow  due to presence of posterior nasal spine
 Techniques :
1. Valsalva maneuver  close nostrils with skipping of air from nose , draw line
2. Ah technique  short vigorous (exaggerated) burst or motion
Post vibrating line  Imaginary line run from hamular notch in one side to hamular notch in the other side  in soft
palate from tensor veli palatine muscle to movable part of soft palate
 All of line in soft palate
 Techniques :
1. Ah technique  normal non-vigorous (unexaggerated) burst or motion
Functions of PPS 1. Retention 2- determine posterior extension 3- reduce gag reflex 4- provide patient comfort
Techniques of post daming  for placement of posterior palatal seal
Conventional technique 1) Mouth mirror or T-burnisher  is used to locate hamular notch by palpating posteriorly to
maxillary tuberosity on both sides , then marking hamular notch by indelible pencil
2) Post vibrating line is marked by asking patient to say “Ah” in normal non-vigorous manner
3) Ant vibrating line is marked by asking patient to say “Ah” in short vigorous manner
4) The markings are transferred to the master cast , the visual outline is in shape of cupid bow
 area between ant & post vibrating line is usually narrowest in the mid palatal region
because of the projection of posterior nasal spine
5) Kingsley scraper or burs with low speed hand  scraping in master cast to depth of :
 0.5 ml in region of hamular notch
 1 ml in region of mid palatine raphe
 1.5 ml on either side of mid palatine raphe
Fluid wax technique
(mouth temp technique)
functional technique  The most accurate technique – done in presence of patient
1) As above in conventional method 1,2,3 without scraping
2) The markings are recorded in final impression by one of the four type of fluid wax :
Iowa wax korecta wax - no.4 adaptol wax H-L physiologic paste
3) Patient head is tilted downward by keeping frank-fort plane(canthus tragus) 30 degree
using protractor … why 30 degree ?  it provide the most favorable flexion of soft palate
Arbitrary technique Unphysiologically correct  the least accurate
Extended palatal technique
Erors in processing Post
Palatal Seal area
Under post daming  need addition Over post daming  need subtraction
Detected by  air bubble on inserting wet denture Detected by  gag reflex – asphyxia
POSTERIOR PALATAL SEAL
PROSTHEASY