This document reviews factors influencing complete denture stability, including the relationships between the denture base, supporting tissues, and oro-facial musculature. It emphasizes the importance of correct anatomical design, occlusal relationships, and the role of muscle action in achieving optimal stability and comfort. The content encompasses theories of occlusion, denture design implications, and considerations for patient-specific variations.

1. A
A CONTEMPORARY REVIEW OF THE
CONTEMPORARY REVIEW OF THE
FACTORS INVOLVED IN COMPLETE
FACTORS INVOLVED IN COMPLETE
DENTURES. PART II: STABILITY
DENTURES. PART II: STABILITY
T.E. JACOBSON, D.D.S.
T.E. JACOBSON, D.D.S.
A.J. KROL, D.D.S.
A.J. KROL, D.D.S.
JPD 1983, 49(2):165-172
JPD 1983, 49(2):165-172

3. RETENTION
RETENTION-
- is the resistance to
is the resistance to
displacement of the denture base away from
displacement of the denture base away from
the ridge.
the ridge.
Psychological comfort
Psychological comfort
Easy acceptance of prosthesis
Easy acceptance of prosthesis

4. STABILITY
STABILITY-
- Resistance to horizontal and
Resistance to horizontal and
rotational forces
rotational forces.
.
 Physiological comfort
Physiological comfort

5. SUPPORT
SUPPORT-
- resistance to vertical movement of
resistance to vertical movement of
the denture base towards the ridge.
the denture base towards the ridge.
Longevity of prosthesis
Longevity of prosthesis

6. STABILITY
STABILITY

7. Factors Affecting Stability
Factors Affecting Stability
►Relationship of the denture base to the
Relationship of the denture base to the
underlying tissues.
underlying tissues.
►Relationship of the external surface and
Relationship of the external surface and
border to the surrounding oro-facial
border to the surrounding oro-facial
musculature.
musculature.
►Relationship of the opposing occlusal
Relationship of the opposing occlusal
surfaces.
surfaces.

8. Relationship of the Denture Base
Relationship of the Denture Base
to Tissues
to Tissues
►Accuracy of the impression procedures.
Accuracy of the impression procedures.
►Adequate extension of the denture base as
Adequate extension of the denture base as
limited by the movable tissues.
limited by the movable tissues.
►Nature of the underlying soft tissues.
Nature of the underlying soft tissues.
►Ridges should be at right angle to the occlusal
Ridges should be at right angle to the occlusal
plane.
plane.

9. Mandibular Lingual Flange
Mandibular Lingual Flange
►At 90° to the
At 90° to the
occlusal plane.
occlusal plane.
►Effectively resists
Effectively resists
horizontal forces
horizontal forces.
.

14.  RESIDUAL RIDGE ANATOMY
RESIDUAL RIDGE ANATOMY
ARCH FORM
ARCH FORM
SHAPE OF PALATAL VAULT
SHAPE OF PALATAL VAULT

15. Relationship of the External Surface
Relationship of the External Surface
and Periphery to Surrounding Oro-
and Periphery to Surrounding Oro-
facial Structures
facial Structures
►Non-interference with muscle action.
Non-interference with muscle action.
►Utilizing muscle action.
Utilizing muscle action.
Fish (1933):
Fish (1933): “ it is not so widely understood that
“ it is not so widely understood that
the actual shape of the whole of the buccal,
the actual shape of the whole of the buccal,
labial and lingual surfaces can wreck the
labial and lingual surfaces can wreck the
stability of a denture just as completely as a
stability of a denture just as completely as a
bad impression or wrong bite.”
bad impression or wrong bite.”

16. Influence of Oro-facial
Influence of Oro-facial
Musculature
Musculature
►Basic geometric
Basic geometric
design –
design – Triangular
Triangular

17. ►Design
Design –
– to guide
to guide
the tongue to
the tongue to
exert seating
exert seating
forces
forces.
.

18. ►Design
Design –
– concave contours for positive
concave contours for positive
seating.
seating.

19. THE MODIOLUS
THE MODIOLUS

20. Importance of the Modiolus and
Importance of the Modiolus and
Other Structures
Other Structures
►Facial muscles fix modiolus.
Facial muscles fix modiolus.
►Permits buccinator to control food bolus.
Permits buccinator to control food bolus.

21. ►Premolar region
Premolar region:
: shortened and
shortened and
narrowed flange for modiolus action.
narrowed flange for modiolus action.

22. THE BUCCINATOR
THE BUCCINATOR

23. Relationship of Opposing Occlusal
Relationship of Opposing Occlusal
Surfaces
Surfaces
►Free of interferences within range of
Free of interferences within range of
functional movements.
functional movements.
►Bilateral simultaneous posterior tooth
Bilateral simultaneous posterior tooth
contact in centric relation.
contact in centric relation.

24. Theories of Occlusion
Theories of Occlusion
►Balanced occlusion
Balanced occlusion
►Monoplane occlusion
Monoplane occlusion
►Lingualized occlusion
Lingualized occlusion

25. Selection of Teeth
Selection of Teeth
►Chosen occlusal scheme.
Chosen occlusal scheme.
►Quality of residual ridge – height and
Quality of residual ridge – height and
contours.
contours.

26. Tooth Position and Occlusal
Tooth Position and Occlusal
Plane
Plane
►Teeth arranged as close as possible to
Teeth arranged as close as possible to
natural tooth position.
natural tooth position.
►Superior-inferior position of the occlusal
Superior-inferior position of the occlusal
plane
plane.
.

27. Disadvantages of high occlusal
Disadvantages of high occlusal
plane
plane
 Magnification of lateral tilting forces
Magnification of lateral tilting forces
►Loss of control of food bolus by tongue
Loss of control of food bolus by tongue

28. Ridge Relationships
Ridge Relationships
►Offset ridge relations in prognathic and
Offset ridge relations in prognathic and
retrognathic patients.
retrognathic patients.

29. The factor of stability involve
The factor of stability involve
the tissue, occlusal and
the tissue, occlusal and
polished surfaces of the
polished surfaces of the
denture. Care must be taken
denture. Care must be taken
in the development of all
in the development of all
three of these surfaces to
three of these surfaces to
ensure optimal stability of
ensure optimal stability of
the final prosthesis
the final prosthesis.
IN CONCLUSION

30. References
References
►Zarb, Bolender, Carlsson. Prosthodontic
Zarb, Bolender, Carlsson. Prosthodontic
treatment for edentulous patients, 11 ed.
treatment for edentulous patients, 11 ed.
►S. Winkler. Essentials of complete denture
S. Winkler. Essentials of complete denture
prosthodontics, 2 ed.
prosthodontics, 2 ed.
►F. Lott, B Levin. Flange technique: An
F. Lott, B Levin. Flange technique: An
anatomic and physiologic approach to
anatomic and physiologic approach to
increased retention, function, comfort
increased retention, function, comfort
and appearance of dentures. J Prosth
and appearance of dentures. J Prosth
Dent 1966, 16(3):394-413.
Dent 1966, 16(3):394-413.

31. ►C. R. Wright. Evaluation of the factors
C. R. Wright. Evaluation of the factors
necessary to develop stability in
necessary to develop stability in
mandibular dentures. J Prosth Dent 1966,
mandibular dentures. J Prosth Dent 1966,
16(3):414-430.
16(3):414-430.
►T. E. Jacobson, A. J. Krol. A contemporary
T. E. Jacobson, A. J. Krol. A contemporary
of factors involved in complete dentures.
of factors involved in complete dentures.
Part I: Retention; Part III: Support. J Prosth
Part I: Retention; Part III: Support. J Prosth
Dent 1983, 49(2):5-15; 306-313.
Dent 1983, 49(2):5-15; 306-313.
►F. J. Schiesser. The neutral zone and
F. J. Schiesser. The neutral zone and
polished surfaces in complete dentures. J
polished surfaces in complete dentures. J
Prosth Dent 1964, 14(5):854-865.
Prosth Dent 1964, 14(5):854-865.

32. ►C. M. Becker. Lingualized occlusion for
C. M. Becker. Lingualized occlusion for
removable prosthodontics. J Prosth Dent
removable prosthodontics. J Prosth Dent
1977, 38(6):601-608
1977, 38(6):601-608.
.

33. THANK YOU