Preprosthetic Surgery

Question 1

Definition

Answer 1

According to the Glossary of Prosthodontic Terms (10), preprosthetic surgery is defined as surgical procedures designed to facilitate fabrication or to improve the prognosis of prosthodontic care.

Question 2

Objectives of pre prosthetic surgery

Answer 2

• Elimination of disease
• Conservation of oral structures
• Provide residual tissue to withstard masticatory forces
• Maintain function
• Esthetics

Question 3

Goals of preprosthetic surgery

Answer 3

• To modify the oral environment to render it free of disease

• Provide a broad and flat ridge form with vertical height (minimum 5 mm)

• Provide a firm resilient mucosal covering

• Provide ideal interarch distance

• Provide post tuberosity (hamular) notching to enhance the posterior border seal and resistance of the denture to anterior dislodging forces.

Question 4

The best denture support has the following characteristics:

Answer 4

1. No evidence of intraoral or extraoral pathologic conditions
2. Proper interarch jaw relationship in the anteroposterior, transverse, and vertical dimensions
3. Alveolar processes that are as large as possible and of the proper configuration (The ideal shape of the alveolar process is a broad U- shaped ridge, with the vertical components as parallel as possible)
4. No bony or soft tissue protuberances or undercuts
5. Adequate palatal vault form

Question 5

PRE-PROSTHETIC SURGICAL PROCEDURES CAN BE CLASSIFIED AS

Answer 5

a) Basic procedures: can be carried out under local anaesthesia on a day care basis.

b) Advanced surgery procedures: require hospitalization and general anaesthesia.

Question 6

1. Alveolar ridge correction

Answer 6

Bony surgeries

i. Alveolectomy

ii. Alveoloplasty

iii. Elimination of unfavourable undercuts
- Reduction of genial tubercles
- Reduction of mylohyoid ridge iv.

iv. Excision of tori

v. Maxillary tuberosity reduction and exostosis removal

Question 7

Soft tissue surgeries

Answer 7

i. Removal of redundant crestal soft tissues
ii. Frenectomy
iii. Excision of epulis fissurata
iv. Excision of palatal papillary hyperplasia.

Question 8

Alveolectomy

Answer 8

• Surgical removal or trimming of the alveolar process is termed as alveolectomy

• After extraction whenever there is presence of sharp margins at interdental, interseptal or labiobuccal alveolar crest, they should be trimmed with bone rounger or round bur and smoothened with bone file.

Question 9

Alveoloplasty

Answer 9

• Alveoloplasty defined as surgical recontouring of the alveolar process.

• Conservation is the key factor in this procedure.

Types:
a) Simple alveoloplasty
b) Interseptal alveoloplasty:
1) Dean’s alveoloplasty
2) Obwegeser’s modification
c) Post-extraction alveoloplasty

Labial & Buccaneers cortical alveoloplasty

Question 10

Dean’s interseptal alveoloplasty

Answer 10

Using bone cutter/bone to cut off interseptal bone and bring everything together

• Only done in maxillary anterior region to reduce gross maxillary over jet.
• Mostly done immediately after extraction of anterior teeth.
• This technique is best used in an area where the ridge is of relative regular contour and adequate height but presents an undercut to the depth of the labial vestibule.

Question 11

Obwegeser’s modification

Answer 11

• In this both the labial and palatal cortices are repositioned .
• This is done when the anterior over jet is too gross that can not be reduced by labial plate repositioning.
• Procedure - Procedure is same as dean’s alveoloplasty but the only addition is that, here palatal plate is fractured too at its base and repositioned with labial plate in palatal direction.

Question 12

Soft tissue surgeries

Answer 12

• The presence of the fibrous, hyperplasic tissue gives rise to flabby ridge form.
• These flabby ridges results in unstable base for dentures.
• Bone augmentation should be considered before any surgery.
• If adequate alveolar height remains after reduction of hypermobile soft tissue, the excision maybe indicated

Question 13

Frenectomy

Answer 13

• Many times there is high frenum attached near to the crest of the ridge which may be too broad which interfere in getting proper peripheral seal in denture.
• Lingual frenum may be too short and attached till the tip of the tongue which interfere with normal tongue movements and causes speech problem to the patient, so surgical correction is advocated in these cases.

Question 14

VESTIBULOPLASTY**

Answer 14

• Labial vestibuloplasty :
> For mandibular ridge: Kazanjian technique (1924).
Godwin’s modification (1947)
Clark’s technique
Obwegeser’s modification (1959)
> For maxillary ridge: Maxillary pocket inlay vestibuloplasty
• Lingual vestibuloplasty: Trauner’s technique
Caldwell’s technique
• Mental nerve transposition

Question 15

Kazanjian’s technique

Answer 15

Cutting and brining down the tissue cut so that the vestibule is deeper

Question 16

Godwin’s modification

Answer 16

Less scaring of the lip mucosa

Question 17

Clarks technique

Answer 17

Flap reflected and mucosa is