The document discusses the posterior palatal seal, which enhances retention and maintains the peripheral seal of a maxillary denture base. It compensates for polymerization shrinkage and minor denture base movements. The posterior palatal seal is determined by identifying the vibrating area or line between the mobile and non-mobile portions of the soft palate. The extent of displaceable glandular tissue behind this line is marked and transferred to the denture cast to process a positive "bead seal" onto the palatal portion of the denture base.

1. 26. Posterior Palatal Seal Michael Hamada, DDS Lecturer Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry UCLA School of Dentistry This program of instruction is protected by copyright ©. No portion of this program of instruction may be reproduced, recorded or transferred by any means electronic, digital, photographic, mechanical etc., or by any information storage or retrieval system, without prior permission.

2. Posterior Palatal Seal Introduction Purpose Palatal and Velar Anatomy House Classification Clinical Determination

3. The Peripheral Seal Tongue function Cheek and labial function

4. The Peripheral Seal Tongue function Cheek and labial function Seal is rarely achieved with the mandibular denture. Retention is more dependent on tongue position, floor of mouth posture and neuromuscular control.

5. The Peripheral Seal Cheek and labial function Palatal function Gravity

6. The Peripheral Seal Cheek and labial function Palatal function Gravity Posterior Palatal Seal

7. Purpose To enhance retention & maintain the peripheral seal of the maxillary denture base by compensating for : 1) polymerization shrinkage 2) minor denture base functional movements Posterior Palatal Seal

8. Palatal and Velar Anatomy Posterior Palatal Seal

9. Palatal and Velar Anatomy Posterior Palatal Seal

10. Palatal and Velar Anatomy Posterior Nasal Spine Nasopalatine Canal Velum

11. Palatal and Velar Anatomy Posterior Nasal Spine Velum Glandular tissue

12. Palatal and Velar Anatomy Posterior Nasal Spine Glandular tissue Velum

13. Palatal and Velar Anatomy Posterior Nasal Spine Velum Glandular tissue

14. Palatal and Velar Anatomy Posterior Nasal Spine Velum Glandular tissue

15. Palatal and Velar Anatomy Posterior Palatal Seal Velum Glandular tissue

16. Palatal and Velar Anatomy Posterior Palatal Seal Velum Glandular tissue

17. Palatal and Velar Anatomy Posterior Palatal Seal Velum Glandular tissue

18. Palatal and Velar Anatomy The Vibrating Area or Line The junction between the mobile and non-mobile portions of the soft palate

19. Palatal and Velar Anatomy The Vibrating Area or Line

20. The House Palatal Classification The greater the functional movement of the soft palate the less favorable the House Classification The Vibrating Area or Line

21. Clinical Determination of the PPS Identify the Vibrating Area or Line Junction of the mobile and non-mobile palate “ Ah-Ah” sound Glandular tissue

22. Clinical Determination of the PPS Identify the Vibrating Area or Line Glandular tissue Posterior extent of maxillary denture base ends at or just anterior to the Vibrating Line

23. Clinical Determination of the PPS Use a blunt instrument to palpate the extent of the displaceable glandular tissue Mark with indelible marking stick Glandular tissue

24. Clinical Determination of the PPS Transfer extent of displaceable glandular tissues to impression . . . Glandular tissue

25. Clinical Determination of the PPS Transfer extent of displaceable glandular tissues to impression . . . Glandular tissue . . . and transfer to master cast in preparation for cast modification

26. Clinical Determination of the PPS Develop “bead seal” by modifying cast with small rounded instrument . . . Glandular tissue . . .taking into account location and thickness of displaceable tissues

27. Clinical Determination of the PPS Posterior palatal seal will be processed as a positive “bead seal” onto the palatal portion of the denture base Glandular tissue

28. Clinical Determination of the PPS Posterior palatal seal will be processed as a positive “bead seal” onto the palatal portion of the denture base Glandular tissue

29. Clinical Variants

30. Clinical Variants

31. Clinical Variants

32. Clinical Variants