POSTERIOR PALATAL SEAL

Preeti Kalia

Ist year PG student

Department of Prosthodontics

A.E.C.S Maaruti Dental College

Posterior palatal seal

Defnition

Purpose

Functions

Anatomic considerations

Physiologic consideration

Anterior and posterior vibrating

lines

Soft palate

Techniques

Trouble shooting

Definition

According to GPT “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."

Functions

Retention

Reduce patient awareness

Reduce food accumulation

Reduce patient discomfort

Compensate for volumetric shrinkage

Anatomic considerations

Anatomic considerations

Posterior palatal seal divided according to anatomic boundaries into

1) Pterygomaxillary seal

2) Post palatal seal

Anatomic consideration

Hamular process

Anatomical considerations

Maxillary tuberosity

Anatomic Considerations

Hamular notch

Anatomical considerations

Pterygomandibular raphe

Anatomic Considerations

Fovea palatini

Anatomic Considerations

Median palatal raphe

Anatomic considerations

Torus palatinus

Physiologic consideration

SalivaPresence of thick ropy saliva can create hydrostatic pressure in the area anterior to the posterior palatal seal , resulting in a downward dislodging forces

Anterior vibrating line

Posterior vibrating lines

Classification of soft palate

Rationale of recording posterior palatal seal

1) To establish positive contact

2) To serve as a guide for

positioning the impression tray

3) To create slight displacement

of the soft palate

4) To obtain adequate

retention and seal.

Techniques

Functional

Semi functional

Empirical

Conventional technique

Conventional technique

Conventional technique

Conventional technique

Scraping of the cast

Vid4.mov

Conventional technique

Advantages

Trial base is more retentive

Psychologic security to the patient

Practitioner can determine the retentive qualities in the finished denture

Patient realizes the posterior extent which may ease the adjustment period

Conventional technique

Disadvantages

Not a physiologic technique

Potential for overcompression of tissues

Fluid wax technique

Fluid wax technique

Fluid wax technique

Advantages

Physiologic technique

Over compression of tissues is avoided

Posterior palatal seal is incorporated into the

trial denture base for added retention

Mechanical scraping of the cast is avoided

Fluid wax technique

Disadvantages

More time is necessary during the impression appointment

Difficulty in handling materials

Arbitrary scraping of the master cast

Extended palatal technique

Proposed by Silvermann

Posterior border of the denture can be extended by 8mm for patients with Class I soft palate

Not accepted now

Establishing the posterior palatal seal during the final impression stage

Ansari.I.H , JProsthet Dent 1997;78:324-6.

Selective pressure technique

Adding a posterior palatal seal to the existing denture

Adding a posterior palatal seal to the existing denture

Posterior palatal seal configuration

Troubleshooting

1) Underextension

2) Underpostdamming

3) Overpostdamming

4) Overextension

Review of literature

JacobJ, Shetty.S , Shetty.M , A semifunctional impression technique to develop PPS and a method to visualize and confirm it by addition of heat polymerized clear acrylic resin at the posterior border of the denture base.JIPS 2007:7;184-187

Review of literature

JacobJ, Shetty.S , Shetty.M , A semifunctional impression technique to develop PPS and a method to visualize and confirm it by addition of heat polymerized clear acrylic resin at the posterior border of the denture base.JIPS 2007:7;184-187

Review of literature

Fernendes.V, Chitre.V., Aras.M, A study to determine whether the anterior and posterior vibrating lines can be distinguished as two separate lines of flexion by unbiased observers: A pilot study ,Indian Journal of Dental Research 2008:19;4,335-340

References

Sheldon Winkler,Essentials of Complete Denture Prosthodontics,2nd edition,2009,A.I.B.T.S publishers and distributors, India, pp-107-122

Charles.L.Bolender,Prosthodontic treatment for edentulous patients,12th edition,2003,Mosby publications,St.Louis,pp-331-3

Deepak Nallaswamy,Textbook of Prosthodontics, Ist edition,2003,Jaypee publishers,New Delhi,pp-51-53,84-88

References

Irving R Hardy, Krishan K Kapur,Posterior border seal-Its Rationale and Importance. J Prosthet Dent 1958:8;3,386-397

Winland, RD and Young JM.Maxillary complete denture posterior palatal seal: variation in size shape and form. J Prosthet Dent 29:256-261, 1973.

Ettinger:, R.l., Scandrett, F.R.The posterior palatal seal. A review. Aust Dent J 25: 197-200, 1980.

References Jacobson, T. E. and Krol, A. J, A

contemporary review of the factors involved in complete retention , stability, and support.Part I.J Prosthet Dent1983 49:5-15,

Jacobson, T. E. and. A contemporary review of the factors involved in complete retention , stability, and support Part II J Prosthet Dent 1983 ;49, 165-172, .

Jacobson, T. E. and. A contemporary review of the factors involved in complete retention , stability, and support PartI III J Prosthet Dent 1983;49:306-313, .

References

Ansari.I.H, Establishing the posterior palatal seal during the final impression stage, JProsthet Dent 1997;78:324-6

Jacob.J, Shetty.S , Shetty.M ,A semifunctional impression technique to develop PPS and a method to visualize and confirm it by addition of heat polymerized clear acrylic resin at the posterior border of the denture base ,JIPS 2007:7;184-187

References

Fernendes.V, Chitre.V, Aras.M, A study to determine whether the anterior and posterior vibrating lines can be distinguished as two separate lines of flexion by unbiased observers: A pilot study ,Indian J Dent Res 2008:19;4,335-340

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