A contribution from Sabine von Sinner

In the case of a removable full denture, it is recommended to determine the palatal alveolar ridge 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 edge of a maxillary full denture that corresponds to a registration under pressure of the soft palate at the border with the hard palate and establishes a permanent and firm contact with the palatal mucosa.

This refers to a raised rim on the back and inside of the palate of the prosthesis, which ensures the continuity of the functional rim 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 soft palate and the thickness of the tissue layer in the area of the fatty tissue zones, it must be determined by the dentist. At the chairside, he can visualize the soft palate and transfer it to the alginate of the primary impression.

The model made in the laboratory allows the dental technician to prepare his customized impression tray, which should be slightly longer than the drawn border. The purpose is to support the impression material so that this area is captured during the functional impression. After the functional impression, the final model is made and the dentist erases the area of the so-called palatal ridge. It is important to check this area during the esthetic 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 soft palate's descending zone.

The try-in is brought back into the mouth and the length of the base of the setup is checked. If the etching has been successful, the mucosa should be in constant contact with the base of the set-up during all stresses. Static position, swallowing, phonation, pronounced "A", ...

At the front, the anterior line of the palatine periosteum corresponds to the border between the hard and soft palate. In the mouth, it can be recognized by its different color: the attached mucosa is more pink and the mobile mucosa is more red. It is often contoured like a "moustache" and can be extended to the fatty tissue zones if these allow it. The dentist should assess its contour and thickness.

To achieve perfect erasing, use an instrument similar to a "LeCron" and erase the dorsal, deeper area without crossing the border.

The central area is then etched, decreasing in depth, up to the anterior line, where it ends in the form of a cupid's bow. If it is possible and desired by the dentist, the etching is extended in the predetermined fat tissue zones.

On the left and right, the erasing ends at the small protrusion caused by the hamulus pterygoideus.

Sources and notes:

• • Prothèse complète Clinique et Laboratoire. Michel Pompignoli Didier Raux Jean-Yves Doukhan

• • Stratégie Prothétique vol 18 N°2 mise au point. Christophe Rignon Bret

• • lexique des termes de prothèse dentaire. Eveline Batarec

• • Prothèse complète réalité clinique solutions thérapeutique. Olivier Hüe, Marie-Violaine Berteretche.