Landmarks of maxilla

Landmarks of maxilla, its relief supporting and limiting structures

1. Landmarks of Maxilla Dr. Yumna Lecturer Dental Hygiene and Technology

2. Introduction Aim of a prosthodontist is not only the meticulous replacement of what is missing, but also preservation of what is present Complete denture must function in harmony with the remaining natural tissues. So for the success thorough knowledge of the anatomical structures is must

3. Maxilla

4. Intra oral Landmarks of Maxilla Limiting structures Supporting structures Primary Stress bearing area Secondary Stress bearing area Relief area

5. 1. Limiting Structures

6. 1. Limiting Structures These are the sites that will guide us in having optimum extension of the denture so as to engage maximum surface area without encroaching upon the muscle actions

7. 1. Limiting Structures Encroaching on these structures will result in the D islodgment of the dentures Soreness of the area Decreased retention, stability and support

8. 1. Limiting Structures Labial frenum Labial vestibule Buccal frenum Buccal vestibule Hamular notch Posterior seal area

9. Frenum and Vestibule Fold of mucous membrane at the midline Contains no muscles Properly relieved Vestibule is the area bounded between cheek and alveolar ridge

10. Hamular Notch Also called pterygomaxillary notch Distal extension of denture Identify the palatal seal area

11. Posterior Seal Area An imaginary line drawn across the palate that marks the beginning of the soft palate when the patient says ‘ aaah ’ It extends from one hamular notch to the other Lie usually 2mm in front of fovea palatine

12. Posterior Seal area

13. 2. Supporting Structures

14. 2. Supporting Structures Masticatory forces produce quite a pressure on the underlying structures Every structure beneath the denture cannot take such stress hence we need to know about the areas which can bear the stress

15. 2. Supporting Structures They are divided into Primary stress bearing area Secondary stress bearing area

16. Primary Stress bearing area These are the areas which are most capable of taking the masticatory load providing a proper support to the denture Some desired properties of these areas are Sufficient fibrous connective tissue Presence of cortical bone Absence of structures which can get harm due top stress

17. Primary Stress bearing area Horizontal portion of the hard palate, lateral to the midline Slopes of the residual alveolar ridge

18. Secondary Stress bearing area Areas that resist the lateral forces of occlusion and can aid the resistance to the vertical forces They have increased vascularity These areas are Rugae Maxillary Tuberosity

19. Secondary Stress bearing area

20. 3. Relief Areas

21. Relief Areas Areas which have fragile structures They can resorb easily They should be relieved to avoid trauma

22. Relief Areas They include Incisive papilla Median palatine raphe Fovea palatine

23. Incisive papilla Projection on the palate near the incisors

24. Median palatine raphe

25. Fovea palatine Area of compressible tissue located anteriorly to the vibrating line Tissue in this area is very thin