An investigation of the anatomic position of the posterior palatal seal by ultrasound.

The posterior palatal seal contributes significantly to the retention of a maxillary complete denture. It is commonly considered to lie on the tissue covering the soft palate. However, no references are available to substantiate this correlation between the clinical and anatomic placement. This research used ultrasound instrumentation as a noninvasive procedure to locate the anatomic structures in the posterior palatal seal region of 15 maxillary edentulous patients. The posterior border was determined to lie on the tissue covering the soft palate.