1. Flat Ridge
MINYA University
Faculty of dentistry
Prosthodontics department
Internship seminar
Topic name :
A Presentation Submitted to
Prosthodontics deparment factulty of dentistry minya university
In Partial Fulfillment of the Requirements for the Practical Training of internship Round
2. Editors :
Hussein Fathy Abou el-khier
Under the supervision of
Stuff members of Prosthodontics department
Seminar team
Presenters :
Mustafa Mohammad abbas
omar saad el-araby
Mohammad ahmed Mohammed
5. After tooth extraction, a cascade of inflammatory
reactions is immediately activated, and the extraction
socket is temporarily closed by the blood clot. Epithelial
tissue begins its proliferation and migration within the
first week and the disrupted tissue integrity is quickly
restored.
Introduction
Flat ridge , Hussein Fathy 5
6. The most striking feature of the extraction wound healing is that even after the healing of
wounds, the residual alveolar ridge bone undergoes a life-long catabolic remodeling. The
size of the residual ridge is reduced most rapidly in the first 6 months, but the bone
resorption activity continues throughout life at a slower rate, resulting in removal of a
large amount of jaw structure.
This unique phenomena has been described as Residual Ridge Resorption (RRR).
Introduction
Flat ridge , Hussein Fathy 6
8. S W
O T
Introduction
Flat RIDGE, HUSSEIN FATHY 8
Residual ridge is a term used to describe the shape of the
clinical alveolar ridge after healing of bone and soft tissues
after tooth extractions.
WHAT IS RESIDUAL RIDGE ?
9. S W
O T
Introduction to Solar Power
Flat RIDGE, HUSSEIN FATHY 9
Flat Ridge is a clinical term used to describe severly
resorbed and atrophic ridges
WHAT IS FLAT RIDGE
11. It is postulated that residual ridge
resorption is a multifactorial,
biomechanical disease that results from a
combination of:
• Anatomic factors
• Metabolic factors
• Mechanical factors
• Prosthodontic factors
Etiology
FLAT RIDGE , HUSSEIN FATHY 11
12. Ridge resorption varies with-
Quantity and Quality of the bone.
Shape& Form of the ridges (Large, well-rounded
ridges and broad palates would seem to be
favorable anatomic factors)
Density of the ridge (density at any given
moment does not signify the current, metabolic
activity of the bone and bone can be resorbed by
osteoclastic activity regardless of its degree of
calcification)
Etiology - A. Anatomic factors:-
FLAT RIDGE , HUSSEIN FATHY 12
13. RRR α bone resorption factors
bone formation factors
In equilibrium the two antagonistic actions
(of osteoblasts and osteoclasts) are in
balance.
The normal equilibrium may be upset and
pathologic bone loss may occur if either
bone resorption is increased or bone
formation is decreased, or if both occur.
Etiology - B. Metabolic factors:-
FLAT RIDGE , HUSSEIN FATHY 13
14. • Some local biochemical factors in
relation to periodontal disease which
affects the ridge resorption-
Endotoxins from dental plaque on unclear
dentures.
Osteoclast activating factor (OAF).
Prostaglandins.
Human gingival bone resorption stimulating
factors.
Heparin acts as a cofactor in bone
resorption which is produced from mast
cells
Etiology - B. Metabolic factors:-
FLAT RIDGE , HUSSEIN FATHY 14
15. • Systemic factors influence the balance between
the normal bone formation and bone
resorption. These factors create a natural
resistance to unfavorable local factors. They are-
Estrogen.
Thyroxin.
Growth hormone.
Androgens.
Calcium.
Phosphorus.
Vitamin D.
Protein.
Fluoride.
Etiology - B. Metabolic factors:-
FLAT RIDGE , HUSSEIN FATHY 15
16. Functional Factors-
RRR directly proportional to Force:-
• Amount, frequency, duration, direction, area
over which force is distributed (force/unit
area) and damping effect of the underlying
tissue.
• Some postulate that it is because of disuse
atrophy and others as abuse of bone.
• There is increased tendency for mandibular
ridge to undergo resorption compared to
maxilla.
Etiology - C. Mechanical factors:-
FLAT RIDGE , HUSSEIN FATHY 16
17. Damping Effect/ Energy Absorption-
Resorbing residual ridge is indirectly
proportional to damping effect.
Dampening effect takes place in the
mucoperiosteum, which is a viscoelastic
material. Maxillary bone (RR) is
frequently broader, flatter and more
cancellous than its mandibular
counterpart.
So it is ideally constructed for the
absorption and dissipation of energy.
Frost pointed out that the trabaculae in
cancellous bone are arranged parallel to
direction of compression deformation.
Etiology - C. Mechanical factors:-
FLAT RIDGE , HUSSEIN FATHY 17
18. resorption can be caused by physiologically
intolerable forces produced by functioning
complete dentures.
The inherent denture factors which
may affect the supporting structures
include:
• The occlusal forms of the teeth.
• The alignment of the denture teeth / occlusal
pattern.
• Deformation of the denture bases.
• Materials with which denture teeth are made
and
• The effects of the loss of proper occlusal vertical
dimension (over closure).
Etiology - D. Prosthodontic factors:-
FLAT RIDGE , HUSSEIN FATHY 18
20. Classification
Flat RIDGE , HUSSEIN FATHY 20
•Atwood (1963)
Order I – Pre extraction.
Order II – Post extraction.
Order III – High well rounded.
Order IV – Knife edge.
Order V – Low, well rounded.
Order VII – Depressed.
22. Classification
Flat RIDGE , HUSSEIN FATHY 22
• Wical and Swoope :
• Class I : Upto one third of the original
vertical height lost.
• Class II : From one third to two thirds of
the vertical height lost.
• Class III : Two third or more of the
mandibular height lost.
23. Classification
Flat RIDGE , HUSSEIN FATHY 23
• the American college of prosthodontists classification
Based on Bone Height (Mandible only)
• Type I : Residual bone height of 21 mm or greater
measured at the least vertical height of the mandible.
• Type II : Residual bone height of 16 - 20 mm measured
at least vertical height of the mandible.
•
• Type III : Residual alveolar bone height of 11 - 15 mm
measured at the least vertical height of the mandible.
• Type IV : Residual vertical bone height of 10 mm or less
measured at the least vertical height of the mandible.
25. Problems
Flat RIDGE , HUSSEIN FATHY 25
1- Extensive resorption leads to:
a. Narrower ridge
b. decreased supporting tissues
C. increase inter-ridge space
So NO RETENTION AND STABILITY
2- Esthetic problem due to decrease
vertical dimensions
3 – Neuromuscular Disorder due to
decrease vertical dimensions
27. Prevention:
Flat RIDGE , HUSSEIN FATHY 27
1- Best of all is to prevent the loss of teeth.
2- Prevention and/or the correct diagnosis and
management of all of the etiologic factors of
the disease.
3-Any systemic illness that is contributing to
the degenerated bone condition must be
corrected or stabilized. Any dental treatment
should follow only after the condition is under
control and the patient is fit for treatment. In
cases where limited help can be given, the
patient should be counseled about its effect on
dental health.
28. Prevention:
Flat RIDGE , HUSSEIN FATHY 28
4- Diet is one of the most neglected facets of
treatment in degenerate denture ridge
patients. These patients need a diet high in
protein, vitamin, and mineral content. So the
dietary problems should be corrected.
5- Correcting deficiency of various hormone,
vitamin, mineral etc.
6- Tissue treatment therapy to rejuvenate the
tissue bearing area by the use of soft
conditioning material.
7- Muscle strengthening exercises.
31. Management : 1- Prosthetic management :-
Flat RIDGE , HUSSEIN FATHY 31
A. IMPRESSION MAKING-
main aim of the impression is to gain
maximum area of coverage to decreases the
force experienced per unit area.
in resorbed ridge the extension of the base is
critical to avoid interferences with the
movement of border structure
Special techniques, to determine accurately the
denture border extension have been evolved-
32. Management:
Flat RIDGE , HUSSEIN FATHY 32
CLOSED mouth technique
- It requires :-
1 – well-fitting recording base
2- accurate occlusal rim
3- acceptable vertical diminsions
- Procedures
1- 1ry impression with stock tray
2- special tray with occlusal rims
3- usual border molding
4- 2ry with ZOE or light body silicon
while pt. close his mout
5- pt. do functional movements as
blowing , puffing and smiling
33. Management:
Flat RIDGE , HUSSEIN FATHY 33
Sublingual crescent technique ( butterfly)
- indications :-
1 – advanced resoprtion with projecting
subblingual gland
- Procedures :-
1- trim any overextension of special tray
2- molding with low fusing compound
remove excess in pre-mylohyoid area
3- record sublingual crescent area by adding
compound in layers
4- spanning entire anterior border with
compound
5- insert tray in the mouth , pt. gently place
tongue against lingual side of tray handle.
34. Management:
Flat RIDGE , HUSSEIN FATHY 34
Sublingual crescent technique ( butterfly)
- Procedures :-
6- recorded sublingual crescent will bulges, its half-
spindle shape bilateral
7- 2ry impression with ZOE or light body silicon , make
lip and cheek movements while tongue positioned as
mentioned berfore
36. Management:
Flat RIDGE , HUSSEIN FATHY 36
Neutral zone impression technique
- Procedures :-
- 1- 1ry impression with impression compound
- 2- wash of ZOE
- 3-make A lower acrylic special tray with metal spurs
”fins” to aid retention of the impression material
- 4-JAW RELATION registration
- 5- Occlusal pillars built in green stick to establish
the occlusal height
6 - Tissue conditioner being molded with
the mouth movements
7-The tray now kept on the cast
8- Form plaster index around neutral zone
9- Wax rim formed
10-Teeth set up in neutral zone