The document discusses preprosthetic surgery procedures for modifying the oral anatomy to facilitate denture retention. It describes various ridge correction techniques like alveoloplasty and mylohyoid reduction. It also discusses ridge augmentation procedures for both the maxilla and mandible using autogenous bone grafts harvested from different sites or alloplastic grafts like hydroxyapatite. Complications of these surgical techniques are also outlined. The goal of these preprosthetic surgeries is to establish an optimal bony foundation with adequate height, width, and contour of the residual alveolar ridges to support dentures.

1. - Dr. Dona Bhattacharya

2. 1. Introduction
2. Objectives
3. Alveolar atrophy
4. Diagnosis & treatment planning
5. Ridge correction procedures
a) Alveoloplasty
b) Mylohyoid reduction
c) Tuberosity reduction
d) Genial tubercles reduction
e) Removal of tori
f) Removal of exostoses
g) Removal of undercuts
6. Ridge augmentation
7. Conclusion
8. References

3. ∆ Preprosthetic surgery refers to the surgical procedures that can modify the
oral anatomy to facilitate the retention of conventional dentures.
∆ According to the Glossary of Prosthodontic Terms (7), preprosthetic
surgery is defined as surgical procedures designed to facilitate fabrication
or to improve the prognosis of prosthodontic care.
∆ According to Bruce Donoff, preprosthetic surgery is that part of the
oral and maxillofacial surgery designed to establish the best hard and
soft tissue bases for prosthetic appliances.

4. ∆ Elimination of disease
∆ Conservation of oral structures
∆ Provide residual tissue to withstand masticatory forces
∆ Maintain function
∆ Esthetics

5. ∆ The term alveolar atrophy refers to the regression of the
teeth-supporting, crescent-shaped osseous part of the upper and
lower jaw.

6. Causes:
∆ Periodontal diseases
∆ Trauma
∆ Pt factors (age, gender, skeletal morphology)
∆ Endocrine & metabolic disorders (hyperparathyrodism,Ca defeciency)
∆ Dietary considerations
∆ Mechanical factors (extractions,removable denture wearers,
combination syndrome)

7. Patterns of bone loss
∆ The results of Talgren’ s studies indicate that changes under the
denture base more often occur in the mandible.(4:1)
∆ The difference in resorption of the jaws increases within the first year
of denture wearing, which proves that the mandible cannot resist the
strong bite forces under the denture base.
∆ According to Klemetti initially resorption starts on the alveolar part of
the mandible, and the rest of the mandible remains unchanged.
∆ Resorption is faster in the labial and buccal parts of the alveolar ridge.
(Resorptive Changes of Maxillary and Mandibular Bone Structures; Dubravka Knezovi et al, Acta
Stomat Croat 2002; 261-265)

8. Class Characteristics Treatment
I Alveolar ridge (AR) adequate in height but Hydroxyapatite (HA) alone
inadequate in width, usually with lateral
deficiency or undercut areas
II AR deficient in both height & width and has a HA alone
knife edge appearance
III AR resorbed to level of the basilar bone, HA alone or mixed with
producing concave form on posterior areas of the autogenous cancellous bone
mandible and sharp bony ridge form with mobile
soft tissue in the maxilla
IV Resorption of the basilar bone, producing pencil- HA mixed with autogenous
thin, flat mandible or flat maxilla cancellous bone
(Mercier,1995)

9. Modifications:
Class II-no wall
defect/buccal
wall/multiwall
defect
Class VI-
marginal
resection
/continuity
defect
Atrophy of the Residual Alveolar Ridge Following Tooth Loss in a Historical Population; Reich,
Karoline et al;"Oral Diseases 17, 1 (2010)

10. Functional effects of edentulism:
∆ The maxillomandibular relationship is altered in all spatial dimensions.
∆ Progression toward decreased overall lower facial height, leading to the
typical overclosed appearance.
∆ Progressive instability of conventional soft tissue

11. Ideal denture base has following characteristics:
a) Adequate bony support
b) Soft tissue coverage
c) No undercuts or protuberances
d) No sharp ridges
e) Adequate sulci
f) Absence of peripheral scar bands
g) no muscle fibres to mobilize prosthesis
h) No soft tissue folds/hypertrophies
i) No neoplastic lesions
j) Proper maxillomandibular arch relationships
k) Adequate palatal vault/tuberosity notching

12. 1. History
∆ Chief complaint
∆ Medical history
2. Physical examination
 Soft tissues
a) Presence of mass
b) Tenderness
c) Frena
d) Mucous membrane
e) Muscle movements
f) Relation of oral mucosa to gingiva

13.  Hard tissues
a) Undercuts
b) Bony prominences
c) Sharp ridges
d) Ridge form
e) Ridge parallelism
f) Tuberosity notching
 Maxillo-mandibular relation
 Dentition
3. Investigations
 Radiographic
a) Gen condition of dentition
b) Bone resorption
c) Proximity to imp structures
d) Maxillo-mandibular relation
 Lab investigations

14. Patient selection:
∆ General physical status
∆ Age
∆ Anatomic factors

15. Preprosthetic procedures
Ridge correction
• Alveoloplasty
• Mylohyoid reduction
• Tuberosity reduction
• Genial tubercles reduction
• Removal of tori
• Removal of exostoses
• Removal of undercuts
Ridge extension
• vestibuloplasty
Ridge augmentation
• Maxillary
• Mandibular

16. Defined as surgical recontouring of alveolar process
History:
∆ Willard(1853) –removal of interdental papilla ,permitting edge to edge closure
∆ Beers(1876): radical alveolectomy
∆ De van(1930): trend towards conservatism had begun
∆ Molt(1923):use of study casts in planning alveolectomy
∆ Dean(1936):interseptal alveoloplasty
∆ Obwegesser(1966):modification of dean’s technique
∆ Michael & Barsoum(1976): study on post operative resorption

17. Principles:
1. Optimal ridge contour
2. Permit early construction of dentures
3. Preservation of alveolar bone
4. Broad alveolar ridges
5. Reduction of irregularities
6. Rounding off sharp ridges
7. Preserve cortical bone as much as possible
8. Defer surgery 4-6 weeks in case of severe periodontitis

18. Types
Alveolar Simple Labial & Dean’s Obwegesser’s
compression alveoloplasty buccal cortical intraseptal technique

19. ∆ Easiest & quickest method
∆ Involves compression of cortical plates with fingers
∆ Reduction in socket width

20. Indications:
∆ Reduction of buccal/labial plate
∆ Extraction of single/multiple teeth
Technique:
∆ Single tooth extraction
∆ Multiple teeth extraction
∆ Over erupted teeth

22. Principles:
a) Reduction of labial/alveolar prominences
b) Muscle attachments are undisturbed
c) Intact periosteum
d) Preserve cortical bone
e) Less post-op resorption

23. Indications:
∆ immediate dentures
∆ quadrant extraction
Technique:
Mac Kay’s modification(1964)

24. 1966
Indication
-premaxillary protrusion
Technique
Advantages

25. Extreme resorption results
in sharp, pointed ridge that
cuts into mucoperiosteum
on pressure application.
Pain occurs on wearing
dentures.

26. Technique

27. Gillies(1956): Mylohyoid ridge should be
reduced if found at same or higher level
than alveolar process
Roberts(1977): Reduction of mylohyoid
ridge & extension of posterior lingual
denture flange into retromylohyoid fossa
Howe(1964): Mylohyoid ridge reduction
is the most useful single operation

28. Technique (Trauner)

29. Obwegesser modification

30. Excess tissue in the region of the
maxillary tuberosity may become so
large that it:
∆ Impinge upon the mandible during
mastication.
∆ Interfere with denture construction,
insertion and seating
Complication of tuberosity reduction
-expanded tuberosity in proximity to
sinus

31. 3 techniques:
Removal of tubercle followed by
allowing genial muscle to reattach
on its own.
Removal of tubercle followed by
repositioning of muscle with
sutures fastened to chin.
Removal of tubercle followed by
transposition of muscle to inferior
border.

33. ∆ Torus mandibular is an exostosis
found on the lingual surface of the
mandible opposite the canine and
premolars region.
∆ Present in 8% of the population,
with equal frequency in males and
females
∆ Usually bilateral, (80% of affected
patients), may be single, multiple
or lobulated.
∆ Etiology: unknown, functional
reaction to masticatory forces.

34. Indications for removal:
∆ Tori causing lingual undercuts and interfering with lingual flange
extension of the planned prosthesis.
∆ When the mucosal covering is ulcerated.
∆ Large tori interfering with speech and deglutition
Technique
Complications

36. ∆ Torus palatinus present itself as an
outgrowth in the midline of the palate.
∆ Shapes (single dome shaped, spindle
shaped, nodular, lobular or multiple).
∆ Present in approximately 25% of all
females
∆ Etiology unknown
∆ Composed of cortical bone; may have a
cancellous component

37. Indications for removal:
∆ An extremely large torus filling the palatal
vault.
∆ A torus that extend beyond the posterior dam
area.
∆ Traumatized mucosa over the torus.
∆ Deep bony undercuts interfering with
denture insertion and stability.
∆ Interference with function (speech,
deglutition).
∆ Psychological considerations (malignancy
phobia).

38. Technique
Position: head tilted
backward

39. Complications:
∆ Haemorrhage
∆ Hematoma formation.
∆ Nasal or antral perforation.
∆ Sloughing and necrosis of palatal tissues.
∆ Fracture of palatine bone.

40. Found in maxillary molar
region.
Preservation of vascular
supply: main concern during
surgery

42. Caused by resorption in
apical areas.
Treatment:
∆ Excision
∆ Filling of undercut

43. Technique

45. Indications for Ridge Augmentation
Progressive loss of denture stability and retention.
Loss of alveolar ridge height, width and decreased vestibular depth
and denture bearing area.
Considerable basal bone resorption in the mandible, resulting in
neurosensory disturbances.
Increased susceptibility to fracture of the atrophic jaws.
Replacement of necessary supportive bone.
Altered interarch relationship

46. Ridge Augmentation
Maxillary augmentation Mandibular augmentation
Superior
border Inferior border Onlay
Onlay bone
Interpositio augmentati augmentation grafting:
grafting – Alloplastic Sinus Interpositional Visor
nal / on (Iliac (Autogenous or Autogenou
Autogenou onlay lift procedu / sandwich osteoto
grafting sandwich crest, rib allogenic freeze s, allograft
s / allogenic re bone grafts my
grafts graft, dried cadaveric and
grafts
hydroxyapa mandible) alloplastic
tite)

47. Graft:
portion of a tissue or organ that after removal from its origin or donor site is
positioned or inserted at a different place with the objective of reinforcing the
existing tissues &/or correcting a structural defect.

48. Classification
According to
According to According to
embryologic
structure source
origin
Cortical Autograft Membranous
Cancellous Allograft Endochondral
Cortico-
Xenograft
cancellous
Alloplast

49. Autogenous Grafts
Distant sites Local sites
•Rib •Chin
•Iliac crest •Body and ramus
•Calvarium •ZM buttress
•Fibula •Coronoid
•Tibia

51. AUGMENTATION OF SUPERIOR
BORDER OF MANDIBLE (Davis,
1970)
Indications:
Remaining bone < 10 mm
Ability of patient to tolerate procedure
Donor considerations
Recipient site

52. Kerfing of rib graft

54. Augmentation of inferior border of
mandible
Indications:
∆ Remaining bone < 10 mm
∆ Risk of pathologic #
∆ Management of malunion or non
union of #
Donor considerations
Recipient site

55. ADVANTAGES
No vestibule obliteration
No dehiscence
Less pain
Better # stabilization
2o sulculoplasty not required
Less bone resorption
Indicated for pencil thin ridges
Easier to perform skin graft vestibuloplasty
DISADVANTAGES
Scarring
Presence of loose submandibular tissue
Does not correct superior irregularities

56. AUGMENTATION OF MANDIBLE BY PEDICLED FLAPS
Horizontal Vertical
osteotomy/sandwich osteotomy/visor
technique technique

57. Horizontal osteotomy (Danielson and
Nemarich)/sandwich technique
Indication
∆ reasonable amt of bone above
mandibular canal
∆ b/l dimension<12-15mm

58. Technique
Donor site
Recipient site
Lekkas modification

59. Vertical osteotomy (Harle,1975)/visor
osteotomy
Indications
∆ little bone above mandibular canal
Technique

61. Combined vertical and horizontal osteotomy (Koomen et al)
Advantages:
∆ Less risk of #
∆ Better sup & post repositioning of segment
∆ Correction of mild-moderate AP discrepancies
∆ Increase in amt of augmentation
Technique
Stoelinga modification

63. Bell & mc bride(1977)

64. Augmentation with synthetic graft materials:
Hydroxyapatite is the prototype of the nonresorbable ceramic bone
substitutes. It is a calcium phosphate material having physical and chemical
characteristic nearly identical to dental enamel and cortical bone.

65. Technique

66. Advantages:
∆ Simple surgical technique suitable as an office procedure.
∆ No donor site is required to obtain autogenous bone graft
material unless a composite graft is being accomplished.
∆ HA is totally biocompatible and nonresorbable
∆ Composite grafting can easily be accomplished as in severe class
III and IV cases.
∆ Vestibular extension after alveolar augmentation is possible after
3 months of primary healing.
∆ Local augmentation is possible such as in bridge pontic areas.
∆ Metallic implant systems through HA augmented ridges are
possible.

67. Complications:
∆ Dehiscence with extrusion of particles
∆ Abrasion through the mucosa with extrusion of the HA implant
∆ Infection
∆ Abnormal color is noted under the mucosa
∆ Mental nerve neuropathy

68. The use of particulate bone with membrane
coverage allows for both horizontal and vertical
augmentation of the mandible. The membrane
is designed to prevent infiltration of the
particulate graft with connective tissue and
allow bone to infiltrate into the particulate
graft mass rather than connective tissue, with
the formation of sufficient bone.
Disadvantage:
∆ premature exposure of the membrane
through the mucosa.
∆ infection
Used for ant maxillary combination syndrome

69. Grafting bone on the superior surface of the residual alveolar cortical bone
is accomplished by first gaining access to the cortical bone, placing and
securing a bone graft to the region to be augmented, and closing the soft
tissue.
Indication: class V
Advantage:
1. avoidance of direct damage to the IAN
2. ease of placement of the graft
3. immediate postoperative vertical augmentation.
Disadvantage:
incision breakdown over the graft can result in a reduction of the long-
term augmentation

70. Mandibular Tori as a Source for Onlay Bone Graft Augmentation: A Surgical
Procedure; Scott D. Ganz JPPA;2007

71. After alveolar bone osteotomy,distractor device is placed in
transport segment, which remains vascularized via periosteum
Latency
period(5-
7 days)
Bony segment subjected to traction
Distraction
period(0.5-
1mm/day
1-4 times Activation of tissue growth & regeneration
Consolidation
period(8-12
weeks)
Formation of distraction callus, matures into bone

72. Indications:
∆ Moderate-severe alveolar bone defects
∆ Segmental deficiencies
∆ Adjuvant to other grafts
∆ Less b/l width of ridges

73. Simple, less resorption, include teeth,
implants in transport segment, less time

74. Accurate diagnosis of the problem areas during denture
construction and determination of the necessity of surgery is
accomplished by careful evaluation of the information
systematically obtained from the patient.
As conservation is the philosophy of surgical patient
management. therefore every attempt should be made to preserve
as much as oral structures as possible.
Proper knowledge of the available surgical procedures helps in
achieving the best results.

75. 1. Preprosthetic oral & maxillofacial surgery-Starshak &
Sanders
2. Textbook of oral & maxillofacial surgery- Laskin vol II
3. Principles of oral & maxillofacial surgery-Peterson
4. Textbook of oral & maxillofacial surgery- Fonseca vol 7
5. Textbook of oral & maxillofacial surgery- Kruger
6. Textbook of oral & maxillofacial Surgery – Archer
7. Textbook of oral & maxillofacial surgery- Killey And Kay
8. Bone grafting in oral implantology: Alfaro

76. 9. Alveolar bone grafting techniques for dental implant preparation-
OMFS,Aug 2010
10. Sugar,Hopkins et al:A sandwich mandibular osteotomy, BJOMS, 1982,
20:168
11. Interpositional Osteotomy for Posterior Mandible Ridge
Augmentation Michael S. Block, DMD,* Christopher J. Haggerty.JOMS
67:31-39, 2009, Suppl 3
12. Distraction implants: a new operative technique for alveolar ridge
augmentation Alexander Gaggl, Gfinter Schultes, Hans
K~ircherJournal of Cranio-Maxilloj'acial Surge , (1999) 27, 214-221
13. Reconstruction of the severely atrophic mandible with iliac crest
grafts and endosteal implants: a report of two cases; O’Connell J.E.
,Galvin M, Journal of the Irish Dental Association 2009; 55 (5): 237-241.
14. Mandibular Tori as a Source for Onlay Bone Graft Augmentation:A
Surgical Procedure Scott D. Ganz,JPPAD