Complete dentures may suffer from a lack of proper border extension, but most important of all is the posterior palatal extension on maxillary complete dentures. The posterior border terminates on a surface that is movable in varying degrees and not at a turn of tissue as are the other denture borders. Locating and designing of posterior palatal seal after thorough understanding of the anatomic and physiological boundaries of this dynamic region greatly enhances border seal and increases maxillary complete denture retention.   The diagnostic evaluation and placement of posterior seal are often given only minor attention in complete denture construction. This article reviews the importance of the posterior palatal seal with regard to its anatomy, location, design and placement.

Restricted mouth opening of a patient presents a great challenge in prosthodontic rehabilitation, especially with complete dentures. Making an adequate border molded secondary impression is crucial in the success of such prostheses. Numerous techniques exist for making impressions in cases of microstomia. All of them involve sectional impressions and extraoral reorientation of the segments. Peripheral seal is compromised in these procedures. This article is laid out to explain how preserving border seal by using single-stage impression is by far the best technique found in the Prosthodontic literature to eliminate the cumbersome sectional impression method. A new method of preserving the seal by means of an impression recorded at a single stage is proposed.