POSTERIOR PALATAL SEAL PPS IN COMPLETE DENTURE POSTERIOR

POSTERIOR PALATAL SEAL (PPS) IN COMPLETE DENTURE

POSTERIOR PALATAL SEAL � Is landmark for the maxillary impression (Frenal area, Buccal vestibular area and Posterior palatal seal) � It is a favorable landmark for placing the posterior border, which is the most important part of retention of the upper denture. (Hayakawa, 2001)

POSTERIOR PALATAL SEAL � Situated between the maxillary tuberosity and the hamulus of the medial pterygoid plate. � Must be sited at the junction of fixed and mobile tissue of the palate. (Plummer, K. D. , et al. 2009)

SIGNIFICANCE OF PPS � Functional depth and width of the sulci in order to restrict access of air and saliva to fitting surface of appliance and thereby improve retentive forces. � prevent food and debris from entering, � reducing the gagging tendency � compensating for the volumetric shrinkage of the acrylic resin in this area � Resulting in increased strength

ANATOMY LANDMARKS http: //bookdome. com/health/anatomy/Anatomy-Human-Skeleton/Cranial-Bones-Part-2. html

ANATOMY LANDMARKS Hamular process � The hamular process is a bony projection of the medial plate of the pterygoid bone and is located distal to maxillary tuberosity. (Plummer, K. D. , et al. 2009)

ANATOMY LANDMARKS Hamular notch � Hamular notch is a groove lying between the maxillary tuberosity and the hamular process. (Plummer, K. D. , et al. 2009)

ANATOMY LANDMARKS Fovea palatine The fovea palatini are two depressions that lie bilateral to the midline of the palate, at the approximate junction between the soft and hard palate. They generally occur within 2 mm of the vibrating line. (Plummer, K. D. , et al. 2009)

ANATOMY LANDMARKS Vibrating line The vibrating line can be considered as the junction between the hard and soft palates , this line runs from about 2 mm buccal to the center of the hamular notch on one side of the arch. (Plummer, K. D. , et al. 2009)

PROCEDURE � Step final impression � Step try-in occlusion rim to try-in teeth

PROCEDURE Determine and mark anterior and posterior vibrating lines on the soft palate with an indelible marking stick. (J Prosthet Dent, 2006)

ANTERIOR VIBRATING LINE � Imaginary line lying at the junction between fixed and mobile tissue of the palate. shaped depend on projection of posterior nasal spine � Can be located by asking the patient to perform the Valsalva maneuver �

POSTERIOR VIBRATING LINE � Imaginary line at the junction of the aponeurosis of tensor veli palatini muscles and muscular portion of soft palate � This line is usually straight � Recorded by asking patient to say “ah” in short

PROCEDURE � Step final impression (J Prosthet Dent, 1997)

PROCEDURE � Step final impression (J Prosthet Dent, 1997)

PROCEDURE � Step final impression (J Prosthet Dent, 1997)

PROCEDURE � Step final impression (J Prosthet Dent, 1997)

ADVANTAGES � Physiologic technique � Over compression of tissue are less � No need for scrapping the master cast

DISADVANTAGE � Handling of the material is very difficult � Increased chair side time

PROCEDURE � Step final impression � Step try-in occlusion rim to try-in teeth

PROCEDURE • Insert the trial denture intraorally and allow it to remain in place for 1 minute. • Confirm that the ink is transferred from the soft palate to the base of thewax trial denture. (J Prosthet Dent, 2006)

PROCEDURE • Trim the trial denture base to the posterior vibrating line of the PPS area • Draw the posterior vibrating line of the PPS area on the cast (J Prosthet Dent, 2006)

PROCEDURE • Trim the trial denture base to the anterior vibrating line of the PPS area • Draw the anterior vibrating line of the PPS area on the cast (J Prosthet Dent, 2006)

ADVANTAGES � Its easier to retain the base plate during jaw relation � The patient can experience the retentive qualities of denture at an earlier stage

DISADVANTAGES � Technique sensitive � Excessive scrapping of the cast can lead to tissue compression

LAB PROCEDURE

REFERENCE � Hayakawa, I. (2001). Principles and practices of complete dentures creating the mental image of a denture, Quintessence publishing, tokyo. � Rahn AO. , Ivanhoe JR. , Plummer KD. (2009). Textbook of complete dentures (6 th ed. ). People’s Medical Publishing House, CT. � Ansari, I. H. (1997). Establishing the posterior palatal seal during the final impression stage, The Journal Prosthetic Dentistry. 78, 324 -326. � Chang, B. M. W. , Wright, R. F. (2006). Accurate location of postpalatal seal area on the maxillary complete denture cast, The Journal Prosthetic Dentistry. 96(6), 454 -455.