SEMINAR PRESENTATION ON PREPROSTHETIC SURGERYDR. SEENA SAM2ND YEAR P.G. STUDENTDEPT. OF PROSTHODONTICS AND CROWN AND BRIDGE

29.01.2014

INTRODUCTIONA significant number of patients can never be made to use dentures effectively because of :bone atrophysoft tissue hypertrophylocalized soft and hard tissue problems all of them

Various treatment methods to improve patients denture foundation and ridge relations are:NonsurgicalSurgicalCombination of both

Nonsurgical methodsRest for denture supporting tissues

Occlusal correction of the old prosthesis

Good nutrition

Conditioning of the patients musculature

Adequate bone support.

Adequate firm soft tissue coverage.

No bony or soft tissue undercut or prominences.

No sharp ridges.

No high muscle or frenal attachments.

Characteristic of ideal denture bearing area

No presence of peripheral fibrous tissue bands to prevent proper seating

No soft tissue hypertrophies on the ridges or in the sulci

No intraoral or extraoral pathology

Proper alveolar ridge relationship in all three planes

DEFINITION PREPROSTHETIC SURGERYSurgical procedures designed to facilitate the fabrication of a prosthesis or to improve the prognosis of prosthodontic care [GPT- 8]

Preprosthetic surgery is carried out to reform/redesign soft / hard tissues by eliminating biological hinderness to receive comfortable & stable prosthesis.

Aims of preprosthetic surgery

To provide adequate bony tissue support for the placement of prosthesis

Provide adequate soft tissue support ,optimum vestibular depth

Elimination of the pre-existing bony deformities eg. Tori, promoinent mylohyoid ridge, genial tubercle

Correction of mandibular and maxillary ridge relationship

Elimination of preexisting deformities. eg. epulis, flabby ridges, hyperplastic tissues

Relocation of frenal or muscle attachments

Relocation of mental nerve

Establishment of correct vestibular depth

Specific indications for preprosthetic surgery include1. Complete or partial edentulism secondary to early tooth loss.2. Naturally occurring reduction of the residual bony ridge.a) Jaw atrophy b) Mucosal atrophyc) Interarch changes (vertical, anti post, transverse) d) Reduction of denture bearing area e) Muscle hypotonia f) Facial changes

3. Pain (not remedial by conventional prosthetic measures) due to:a) Mucositis (a burning discomfort of the mucous membrane)

b) Neuropathy (alteration of sensation of the lips varying from objective/ subjective paraesthesia to anesthesia or pain arising from traumatized nerve trunks.)

c) Local recurrent ulceration

d) Temporomandibular joint pain

4. Dysfunction (not remediable by conventional prosthetic means) of:a) Mastication b) Speech c) Deglutitiond) Temporomandibular joint dysfunction due to deficient dental occlusion

5. Replacement of lost tissue following disease/traumaa) Orbital prosthesis.b) Obturator which replaces the missing jaw or orbit. c) Craniofacial prosthesis.d) Enhanced gag reflex / excessive palatal sensitivity.e) Allergy to conventional prosthetic materials.f) Phobia to normal prosthetic appliances.

CONTRAINDICATIONS1. Underlying systemic diseases, e.g. cardiovascular, metabolic/haematological 2. Insufficient quantity of bone

3. Inadequate quality of bone (sclerotic/ osteoporotic)

4. Unfavourable inter arch relations (vertical, horizontal, transverse)

5. Adverse mucosal conditions (quality/quantity)

6. Adverse skin conditions and congenital remnants

7. Pre-existing pathology

8. Adjacent dentition

9. Local anatomy (inferior alveolar nerve, maxillary sinus, floor of nose, tongue size)

10. Psychological/ psychiatric disorders

11. Parafunctional habits

12. Opposing dentition/jaw

13. Additional bone grafting

14. Previous radiotherapy

15. Poor oral hygiene

16. Poor patient co-operation/compliance

17. Heavy tobacco smoking

Common conditions that require surgical correction prior to CD construction

Soft-tissue abnormalities:hypermobile ridge tissue, soft-tissue interferences, hypertrophic labial and lingual frenum,prominent buccal frenum,papillary hyperplasia, epulis fissuratum

Osseous abnormalities: ridge undercuts, prominent mylohyoid and internal oblique ridges, bony tuberosity interference, sharp spiny residual ridge, tori and exostoses

Retained dentition: unerupted teeth, retained roots

Preprosthetic surgical procedures

ALVEOLAR RIDGE CORRECTION

Bone surgeries

Labial alveolectomyPrimary alveoplastySecondary alveoloplasty Excision of toriReduction of genial tubercleReduction of mylohyoid ridgesMaxillary tuberosity reduction

Soft tissue surgeries:

Removal of redundant crestal soft tissue

Frenectomy labial & lingual

Excision of epulis fissuratum & palatal hyperplasia

ALVEOLECTOMY

Surgical removal or trimming of the alveolar process

Trimming done with roungeur or round bur and smoothened with bone file

Use in the presence of sharp margins at interseptal or labiobuccal alveolar ridge

Too much bone loss will result in poor denture base retention

Single tooth alveolectomy

Simple Alveoloplasty

Refers to surgical recontouring of the alveolar process.

Primary alveoloplasty always done at the time of multiple extraction or single extraction.

Minimum amount of alveolar bone resorption occurs if after simple extraction ,digital compression of the alveolar cortices done immediately.

Intraseptal alveoloplasty deans alveoloplasty with repositioning of labial cortical bone.

Used in maxilla

Used to reduce gross maxillary overjet

To reduce the volume of cancellous bone , maintaining stress bearing cortical bone intact

Not require for raising mucoperiosteal flap

Carried following extraction of anterior teeth immediately.

Maintain periosteal attachment to the labial plate of bone.

It will reduce buccal undercut or labial prominence without reducing the height of residual alveolar ridge.

Best long time result

Indicated in cases , in which the adequate bone height exists.

Indications

1.Multiple extraction

2.Early initial post extraction period.

Steps

1.removal of bone followed by

2.repositioning of the labial cortical bone

Technique

Teeth should be extracted avoiding trauma to the labial cortex.

Interdental septal bone is cut from canine to canine region with the straight fissure bur attached to surgical handpiece or with rongeur.

With the same bur ,vertical cuts are made only in the labial cortex at distal end of the canine extraction sockets bilaterally without perforation of the labial mucosa in the deans technique.

With periosteal elevator /osteotome placed in the base of the canine socket bilaterally, labial cortex is fractured.

Digital pressure is used to compress the fractured labial cortex into the palatal direction.

Labial and palatal plate will come into approximation with each other

Interrupted continous suturing is carried out.

Obwegessers modification for interseptal alveoloplastyIndicationGross max.overjet.( when compression of the labial cortex is not sufficient)

After cutting the interseptal bone ,an inverted cone vulcanite bur is used to widen the socket.

With small bur ,horizontal cuts are made at the base of the extraction socket in the labial and palatal cortices.

Vertical cuts then made bilaterally in both the labial and palatal cortices in the area distal to the canine socket.

With digital pressure,both the labial and palatal cortices are compressed together and sutures are given.

Immediate denture delivery is planned ,used as a template to check for any pressure points.

Alveoloplasty with post extraction healingCrestal incision is taken not to tear the mucoperiosteal flap, but the reflection

Side ways separation with the periosteal elevator will help the smooth reflection

Sharp areas or large undercuts should be trimmed with rongeur and suturing done.

Elimination of unfavourable undercutUsually done in the mandibular lingual aspect (genial tubercle , sharp mylohyoid ridge prominence.)

Seen in patients wearing old dentures, due to resorption over the years, the denture become unstable

Reduction /resection of the genial tubercleAre bony attachments of genioglossus muscle.

Are seen on the crestal level on the lingual aspect.

TechniqueCrestal incision is made from the lower canine to canine region , after infilteration of the LA

No reflection of flap done on the labial side

Full thickness flap is reflected to expose the genial tubercle

Excision of tubercle is done by rotary instruments

Smoothening can be done by a bone file

Irrigation should be done before suturing

Reduction of mylohyoid ridgesDone with IFAN block.

Crestal incision taken in the posterior ridge region.

Mucoperiosteal flap reflected on the lingual side to expose the medial surface of the mandible at the mylohyoid ridge region.

Tissue from the floor of the mouth and lingual mucoperiostium are protected by inserting the flat blade of the tongue depressor

The reduction of the mylohyoid ridge is carried with osteotome or round bur ,after dissecting mylohyoid fibres away.

Bone is smoothened with bone file.

Soft tissue flap is returned back and the complete lingual vestibule checked with digital pressure for any sharp areas.

After complete smoothening sutures are given.

Excision of toriIndicationsLarge torus ,filling the palatal vault.

Large torus extending beyond the postdam area.

Ulceration or traumatisation or hyperkeratinisation of the overlying mucosa.

Deep bony undercut.

Interference with function.

Psychological consideration.

Food lodgement

Under LA ( bilateral grater palatine and incisive nerve block)

A-P linear incision in the midline of the palate.

Y shaped releasing incision at one or both the ends of the incision.Technique

Two mucoperiosteal flaps raised with periosteal elevator from the midline sideways.

Retraction sutures placed on both the flaps to minimize the exposure.

Division of the torus into the multiple segments should be done with the bur.

Small pieces removed with chisel and mallet.

Continous over and under type suturing using fine absorbable suture material.

Prefabricated acrylic stent or splint or iodoform pack can be given to prevent heamatoma.

Mandibular tori removal TechniqueIFAN block is given.

Incision over alveolar ridge in lower premolar region.

Mucoperiostial flap is raised

Make a purchase point or groove with bur on medial aspect of the torus.

Cleavage taken with a osteotome.

Smoothen with round bur or bone file.

Irrigate band suture.

Maxillary tuberosity reduction and exostosis removalTechniqueUnder infilteration or PSA nerve & GPN block

Crestal elliptical incisions from tuberosity to premolar area.

Periostium is reflected and tissue present b/w the crestal incision removed with chisel mallet or bur.

Flap is sutured and stent is placed.

Soft tissue surgeriesRemoval of redundant crestal soft tissue - eg . enlarged tuberosity, enlarged retromolar pad.

Denture granuloma or hyperplasia.

To reduce this elliptical incision taken on either sides of the tissue .

Excision of epulis fissuratum.

Sharp excision

Electro-cauterisation

Cryosurgery

Laser excision

Palatal papillary hyperplasia.

Supra-periosteal excision.

FrenectomyIndicationsHigh attachment of frenum.

Ulceration at the frenal attachment a due to overuse of the denture

TECHNIQUECrosss-diamond excision.

Base of the frenum at the alveolar crest is grasped with the hemostat and incision is taken below and above the hemostat.

Surgical defect created by excision of fibrous bands.

Z plasty procedure can be done.

Lingual frenectomyIndication: Tongue tie

TechniqueBilateral lingual nerve blockSubmucosal dissection done on either side .Dissection of genioglossus muscle and suture it.

RIDGE EXTENSION PROCEDURE

Vestibuloplasty or sulcoplasty It is a deepening procedure of vestibule.

labial vestibular procedure transpositional flap vestibuloplasty or lip switch procedure

Indications Used when patient has a bone ht of 15mm or more in the ant region

TechniquesKazanjian technique (1924) oldest technique

use mucosal flap from the inner aspect of lower lip.

Carried out in premolar to premolar region.

Proceduresubmucosal dissection is done and directed inferiorly to remove muscle and connective tissue attachments

Raised mucosal flap is adapted to the new vestibule and

Suture is done

Godwin s modification (1947)Mucosal incision in inner aspect of lip is longer than the proposed vestibular depth

Labial periosteal margin is sutured to the incised lip mucosa.

Stent is placed.

Clarks technique

Supraperiosteal flap on the inner aspect of lip leaves a raw surface on the bone covering the inner lips surface

Incision started labial to the crest

Supraperiosteal dissection is done along the labial surface till the vestibular depth

Edge of the mobilized flap is pushed into the new vestibular area and held in position by sutures

Alveolar bone is covered by periosteal layer

Similar to clarks method except the area of alveolar bone with its periosteal attachment covered with split thickness graft.

AdvantagesCovers the bone and ensures fast healingLess bone loss and scarring .Obwegessers modification

Lingual vestibuloplastyIndication

In case where mylohyoid and genioglossus close to the alveolar ridge.

Trauners techniqueIncision is done from 2nd molar to 2nd premolar region

Supraperiosteal dissection is done

Instrument passed below mylohyoid muscle and separate it from bony attachment

Fixation of mylohyoid muscle to new desired vestibular depth by sutures.

Here mylohyoid muscle superficial - fibres of genioglossus muscle pushed inferiorly.

Rubber tubing placed in the lingual vestibule and flap is held in position by suturesCaldwells technique

Obwegessers technique

Lingual vestibuloplasty + buccal vestibuloplastyEdges of buccal and lingual flaps are raised and sutured below the inferior border of the mandible.

Skin graft is placed over the entire alveolar ridge.

Acrylic stent or denture placed and fixed to mandible with circum mandibular wiring.

Submucosal vestibuloplasty techniqueIndicationShallow vestibular depth with good underlying bone height and contour.

TechniqueVertical midline incision is made in the labial vestibule.Supraperiosteal tunnel from one premolar to other .Intervening submucosal tissue excised or repositioned superiorly.

Procedure involves surgically creating pockets in the max,mattress and pyriform aperture region helps in the denture extension into the pockets

Intraoral incision is taken just above the attached gingiva from one maxillary buttress to the other buttress

Supraperiosteal dissection is performed to create two pockets on either side of pyriform apertureMax. pocket inlay vestibuloplasty (obwegesser)

Dissection is extended superiorly to the level of attachment of the levator anguli oris

Also continued in the midline upto the base of the pyriform aperture

Impression is taken with the impression compound

Labial flanges of the dentures then covered with split thickness skin graft

Bilateral circumzygomatic wires and pyriform margin wires used to stabilize the denture.

Patients with severe mandibular atrophic ridges - Complain of pain after wearing denture because of superior position of the mental neurovascular bundle - Repositioning of the mental nerve should be done.Mental nerve transposition

A crestal incision is taken with buccal releasing incision in the region of premolars

Mucoperiosteal flap is reflected inferiorly to locate the nerve

Dissection below the foramen till the inferior border of the mandible should be done and the nerve is freed lightly and held with hook upward.

Bony groove is cut below the mental foramen,only in the buccal cortex.

Nerve is positioned inferiorly and secured in place with the gelfoam and flaps is sutured.

RIDGE AUGMENTATION PROCEDURES

When alveolar ridge resorption is so extreme - vestibuloplasty is not done. Two options are availableAugmentation of alveolar bone.Place the implants.

Procedures

Mandibular augmentation

1. Superior border augmentationBone grafts

cartilage graft

alloplastic grafts

2.inferior border augmentationbone grafts

cartilage grafts

3.interpositional or sand witch bone graftsBone grafts

Cartilage grafts

hydroxyapatite blocks

4. visor osteotomy

5.onlay graftingautogenous allogenousalloplastic

B. Maxillary augmentation.Onlay grafting

Onlay grafting of alloplastic material

Interpositional or sandwitch grafts

Sinus lift procedure

Augmentation in combination with orthognathic surgerymandibular osteotomy procedure

maxillary osteotomy procedure

Combination

Materials for augmentation of alveolar ridgeautogenous graftsiliac crest rib graftallogenic bonefreeze dried cadaver bone.Alloplastic materialHydroxyapatite

Mandibular augmentationSuperior border grafting or augmentation

Use 15 cm rib graft

Fixed to mandible with trans osseous wiring or circum mandibular wiring.

DisadvantageDonor site morbidityContinued resorption of grafted sites.Soft tissue dehiscence or limitation

Inferior border graftingIt is indicated when the arch less than 5- 8 mm in height.

ProcedureSupraclavicular incision followed by subplatysmal incision till the inferior border of the mandible.

Freeze dried allogenic cadaver mandible is hollowed out and multiple perforations made into it and it is used as a tray.

It is then filled with autogenous cancellous graft particles fixed to the inferior border with 2-0 vicryl sutures by circum-mandibular fixation

Interpositional bone grafting ( sandwitch bone grafting)

Horizontal osteotomy is performed

Splitting is done and bone graft is grafted into this gap

In mandible , autogenic or allogenic bone or hydroxyapatite grafts can be used.

Delivery of appliance is delayed for 3-5 months.

Onlay graftingUsed in case of inadequate width but adequate height for the maxilla or mandible

Oldest technique

Onlay augmentation with hydroxyapatite is advocated by obwegessor via submucosal vestibuloplasty technique.

After creating a tunnel via a midline a putty is formed of hydroxyapatite crystals mixed with saline or blood and is injected via syringe into the submucosal tunnel.

Solid or porous blocks of hydroxyl apatite is used.

Split thickness ribgraft or iliac crest can be used.

TechniqueHigh vestibular incision is taken , mucoperiostial flap is reflected to expose the defect.

Small perforations made in this external cortex by using small round bur.

Grafting material is placed or mounted over the external cortex.

Visor osteotomy

To increase the height of mandibular ridge for denture support.

Consists of central splitting of the mandible in buccolingual dimension and the superior positioning of the lingual section of mandible wired in position

Cancellous bone grafting material placed at the outer cortex over the superior labial junction for improving the contour.

Modified visor osteotomyConsists of splitting of the mandible buccolingually by vertical osteotomy only in the posterior region and a horizontal osteotomy in the anterior region.

Posterior lingual segments are then pushed superiorly on both sides.

Anterior fragment is also pushed superiorly and fixed with wires.

Cortico-cancellous bone graft particles with hydroxyapatite granules placed in the gap between the superior , inferior and anterior segments.

Sinus lift procedure or sinus graftingSinus lining at the floor of the mouth is lifted up surgically and the bone graft is placed between the sinus lining and the inner aspect of the alveolar crest or floor of the maxillary sinus in the posterior maxilla.

Totum was the first surgeon who used this method.

Materials used are autogenous boneallogenic bone.tricalcium phosphatehydroxyapatite.calcium phosphate.ceramicscalcium deficient carbonate apatite from bovine bone.

TechniqueIntraoral incision is taken on maxillary crest or slightly on the palatal aspect with vertical incision from canine to tuberosity area

Antrolateral wall of maxilla is exposed by reflecting the mucoperiosteal flap

Bony windows made with trap door type osteotomy , lateral and posterior to the canine fossa.

15 20 mm long inferior osteotomy cut placed 3mm above the sinus floor

Anterior vertical cut parallel to the lateral nasal wall and perpendicular to the horizontal osteotomy.

Posterior vertical cut is at the maxillary tuberosity.

Vertical cuts are joined superiorly by placing the small bur holes placed at small intervals without completing the superior cut.

Trap door type of bony window is lifted up superiorly to expose the schineiderian membrane.

Gap between lifted sinus membrane and the floor is filled with graft material.

One stage implant

Coticocancellous iliac crest bone block

Otherwise 6-9 months before implant placement

Augmentation in combination with orthognathic surgery

1.anterior maxillary osteotomy.

2.total lefort osteotomy used along with interpositioning of grafts.

Limitation of augmentation technique1.inadequate soft tissue coverage.

2.rejection of autografts.

3.dehiscence of overlying mucosa.

4.migration of graft material.

5.resorption of graft.

Review of the literatureTwo studies (19811990 retrospective, and 19891993 prospective) were performed to determine the optimal methods in preprosthetic surgery.

[The optimal vestibuloplasty in preprosthetic surgery of the mandible. T. Frschl,A. Kerscher. Journal of Cranio-Maxillofacial Surgery Volume 25, Issue 2, April 1997, Pages 8590]

The first study deals with four different types of grafts (split thickness skin, mucosal, mesh mucosal, palatal) in combination with vestibuloplasties and lowering of the floor of the mouth.

Keratinized grafts (split-thickness skin and palatal) showed advantages.

On the basis of a high rate of complications at the site of harvesting of palatal mucosa and the limited amount of palatal mucosa available for grafting, prefer a split-thickness skin graft.

A second prospective study to compare the Edlan- and Kazanjian-plasty showed the disadvantages of both methods.

The Edlan-plasty, in combination with implants, showed a small amount of bone resorption; the Kazanjian-plasty showed a significant loss of attached mucosa.

For cases with insufficient width of attached mucosa, recommend a vestibuloplasty secondarily, with keratinized grafts. If there is a deep palatal vault and the need for a large amount of graft material, a split-thickness skin graft should be harvested. In cases of limited need and flat palatal vault, the graft can be harvested from the palate.

The surgical carbon dioxide laser has the ability to vaporize soft tissues with little bleeding, pain, swelling, or wound contraction. evaluation.

[The carbon dioxide laser in soft tissue preprosthetic surgery. M. A. Pogrel, (J PROSTHET DENT 1989;61:203-8.)]

The laser was evaluated on 27 patients requiring soft tissue preprosthetic surgery, including frenectomies, tuberosity reduction, hyperplasia removal, and sulcus deepening.

Surgery was performed on an ambulatory basis with no bleeding or infection. Swelling was minimal and pain, as measured on a linear pain scale, was moderate. One third of the patients required no analgesics.

Wound contraction did occur but was less than is historically quoted for scalpel wounds.

The carbon dioxide laser would appear to have advantages for soft tissue preprosthetic surgery that warrant further

Hillerup concluded in his article:Preprothetic surgery is still a relevant treatment option for elderly patients.

Well-defined prosthodontic needs of ridge improvement may be satisfied in a simple and cost-effective manner with the aid of preprosthetic surgery.

The combination of preprosthetic surgery and implants may solve problems that neither of the two can alone do.

Interdisciplinary cooperation is a prerequisite for optimal service.

[Preprosthetic surgery in the elderly. Soren Hillerup. J PROSTHET DENT 1994, 72 : 551-8]

The objective of the study was to compare denture satisfaction and chewing ability of edentulous patients treated with dental implant-retained overdentures or with full dentures with or without previous preprosthetic surgery.

[E.M Boerrigter.Patient satisfaction and chewing ability with implant-retained mandibular overdentures: A comparison with new complete dentures with or without preprosthetic surgery. Journal of Oral and Maxillofacial Surgery Volume 53, Issue 10, October 1995, Pages 11671173]

Based on the baseline data from the denture complaints and chewing ability questionnaires, nine interpretable factors could be extracted.

Two factors did not vary following treatment and were excluded from the outcome analysis.

At the 1-year evaluation five of seven factors showed significantly better scores for the two surgical groups than for the control group. The same was found for the overall denture satisfaction rate.

Overdentures retained by dental implants or complete dentures made after a vestibuloplasty and deepening of the floor of the mouth provide a more satisfactory solution for denture-related problems than complete dentures alone.

Conclusion

Preprosthetic surgery offers a sigificant contribution in patients with bone atrophy,soft tissue hypertrophy or localized soft and hard tissue problems or all of them.

Pre existing structures like frenal attachments, exostosis,tori are insignificant while teeth are present in the oral cavity.

But these non significant structures cause hindrances for denture stability and resultant reduced masticatory function after tooth loss.

Preprosthetic surgery plays an important role in providing a better anatomic environment and to create proper supporting structures for denture construction.

REFERENCESHopkins R. Color atlas of preprosthetic surgery. Philadelphia, Lea and Febiger, 1987;The Academy of Prosthodontics Foundation. The Glossary of Prosthodontics Terms, 8th ed, GPT-8. St. Louis: CV Mosby ; 2005.Rahn AO, Heartwell CM. Textbook of complete dentures, 5th ed, Philadelphia, Lea and Febiger, 1993; 59-110.Winkler S. Essentials of complete denture prosthodontics. 2nd ed. Delhi: AITBS Publishers; 2000. 142-182.Sharry J J. Complete denture prosthodontics. 3rd ed. London: McGraw Hill Book Company; 15-27.

Zarb GA, Bolender CL. Prosthodontic treatment for edentulous patients: Complete dentures and implant-supported prostheses. 12th ed. St. Louis: CV Mosby; 2004; 34-50.Fonseca RJ, Davis W. Reconstructive prepeostrhetic oral and maxillofacial surgery, Philadephia, WB Saunders, 1985.Peterson LJ, Ellis E, Hupp JR, Tucker MR. Contemporary oral and maxillofacial surgery, 2nd ed., St, Louis, Mosby publication, 1993.Michael CG, Barsoum WM. Comparing ridge resorption with various surgical techniques on immediate dentures. J Prosthet Dent 1976; 35: 142-145.

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