An article by Sabine von Sinner (translated from the French original text)

In the case of a removable full denture, it is recommended to determine the posterior palatal seal to ensure better adhesion of the upper denture in the mouth.

To better understand what it is, here is a definition:* It is a thickening of the posterior border of a maxillary full denture that corresponds to a compressive registration of the soft palate at its limit with the hard palate and establishes a permanent and firm contact with the palatal mucosa.

This refers to a raised edge on the back and inside of the palate of the prosthesis, which ensures the continuity of the functional edge and seals it.

This helps to ensure that no air and/or food can get between the prosthesis and the mucous membrane.

As this area is individual for each patient and varies depending on the inclination of the velum and the thickness of the tissue layer in the Schroeder area, it must be determined by the dentist. At the dental chair, he can visualize the posterior dam and transfer it to the alginate of the primary impression.

The model made in the laboratory enables the dental technician to prepare his customized impression tray, which should be slightly longer than the drawn border. The aim is to support the impression material so that this area is captured during the functional impression. After the functional impression is taken, the final model is made and the dentist carves the area of the so-called posterior dam. It is important to check this area during the aesthetic try-in.

Since the aniline pen is no longer permitted, a surgical marker can be used or a small amount of water/zinc oxide mixture can be applied with a disposable brush at the border of the velums bendig zone.

The try-in is brought back into the mouth and the length of the base of the set-up is checked. If the carving has been made successfully, the mucosa should be in constant contact with the set-up base during every load of the set-up. Static position, swallowing, phonation, pronounced ‘A’, …

At the front, the anterior line of the post dam corresponds to the limit between the hard and soft palate. In the mouth, it can be recognized by its different color: the attached mucosa is pinker and the mobile mucosa is more red. It is often contoured like a ‘moustache’ and can be extended to the Schroeder zones if these allow it. The dentist should assess their contour and layer thickness.

To achieve a perfect carving, use an instrument like a ‘LeCron’ and scrape the dorsal, deeper area without crossing the border.

The central area is then scraped/carved, decreasing in depth, up to the anterior line, where it ends in the form of a cupid’s bow. If it is possible and requested by the dentist, the carved area is extended in the predetermined Schroeders zones.

On the left and right, the carving ends at the small protrusion caused by the pterygoid hamulus.

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