The Posterior Palatal Seal - Its Forms and Functions

By Dr.Swathi Pai on Tuesday, January 6, 2009 with 0 comments

The posterior palatal seal (PPS) is generally regarded as an important contributor to maxillary complete denture retention. A well designed and properly placed PPS serves several functions.

1. Helps maintain the peripheral seal.
2. Prevents the ingress of air and food which could dislodge the denture.
3. Helps compensate for dimensional changes that occur during the curing of the acrylic resin.
4. May reduce gagging by maintaining firm contact with the tissues of the soft palate.
5. Increases the thickness of the acrylic resin at the posterior border and strengthens the denture.
6. May make the distal border of the denture less noticeable to the tongue by applying pressure to the tissues of the palate.

The development of an appropriate design for the PPS requires an assessment of the palatal throat form, tissue displaceability, and the role of individual anatomic landmarks in establishing a denture seal. The following steps can act as a guide to diagnose the PPS design.

1. Determine the palatal throat form. House Class 1, 2 or 3.
2. Assess and note any unusual anatomical features.
3. Evaluate the status of key anatomical features, i.e. hamular notches, fovea palatine, etc.

Posterior palatal seal preparation is an integral part of the maxillary complete denture fabrication requiring assessment of physiological and technical parameters. In the case of patients with either a House Class 1 or 2 throat form, the clinician may have a choice for the placement of the area of greatest depth. A patient with a House Class 3 has limited options because it is the least favourable of the three classes because of limited space for the placement of the PPS.

It is important to point out that there is no single PPS design for all patients.

Category: Prosthodontics Notes



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