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7/31/2019 Abhi Prostho

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Presented by,Abhi AIV BDS (Part II)

Annoor dental college


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INTRODUCTION

A significant number of prtients can neverbe made to use dentures effectivelybecause of bone atrophy,soft tissuehypertrophy or localized soft and hard

tissue problems or all of them.various treatment methods to improvepatients denture foundation and ridgerelations are:

NonsurgicalSurgical

Combination of both


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Nonsurgical methods

Rest for denture supporting tissues

Occlusal correction of the old

prosthesis Good nutrition

Conditioning of the patientsmusculature


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1. Adequate bone support.2. Adequate firm soft tissue coverage.3. No bony or soft tissue undercut or prominences.4. No sharp ridges.

5. No high muscle or frenal attachments.6. No presence of peripheral fibrous tissue bands to

prevent proper seating.7. No soft tissue hypertrophies on the ridges or in

the sulci.

8. No intraoral or extraoral pathology.9. Proper alveolar ridge relationship in all threeplanes.

Characteristic of idealdenture bearing area


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Preprosthetic surgery.

Preprosthetic surgery is carriedout to reform/redesign soft /hard tissues by eliminating

biological hinderness to receivecomfortable & stable prosthesis.


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Aims of preprosthetic surgery

1.To provide adequate bony tissue support forthe placement of rpd /cd.

2. Provide adequate soft tissue support,optimum vestibular depth.

3. Elimination of the pre-existing bonydeformities eg. Tori, promoinent mylohyoidridge,genial tubercle.

4. Correction of mandibular and maxillary ridgerelationship.

5. Elimination of preexisting deformities.eg.epulis,flabby ridges, hyperplastic tissues.6. Relocation of frenal or muscle attachments.7. Relocation of mental nerve.8. Establishment of correct vestibular depth.


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Preprosthetic surgical procedures .

Alveolar ridge correction

Alveolar ridge extension

Alveolar ridgeaugmentation.


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Alveolar ridge correction

Bony surgeries.

Labial alveolectomy.

Primary alveoplasty. Secondary alveoloplasty.

Excision of tori.

Reduction of genial tubercle.

Reduction of mylohyoid ridges.

Maxillary tuberosity reduction


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Soft tissue surgeries:

Removal of redundant crestal softtissue.

Frenectomy labial & lingual.

Excision of epulis fissuratum &

palatal hyperplasia.


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ALVEOLECTOMY.

Surgical removal or trimming of thealveolar process.

Trimming done with roungeur or round

bur and smoothened with bone file.

Use in the presence of sharp margins atinterseptal or labiobuccal alveolar ridge.

Too much bone loss will result in poordenture base.


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Single tooth alveolectomy


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Simple Alveoloplasty

Refers to surgical recontouring of thealveolar process.

Primary alveoloplasty always done at the

time of multiple extraction or singleextraction.

Minimum amount of alveolar boneresorption occurs if after simple

extraction ,digital compression of theaqlveolar cortices done immediately.


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Intraseptal alveoloplastydeansalveloplasty with repositioning oflabial 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 ofresidual alveolar ridge. Best long time result. Indicated in cases , in which the adequate bone

height exists.


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Indications 1.Multiple extraction 2.Early initial post extraction period. Steps 1.removal of bone followed by

2.repositioning of the labial corttical 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 canineextraction sockets bilaterally without perforation ofthe labial mucosa in the deans technique.


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With periosteal elevator /osteotome placedin the base of the canine socketbilaterally, labial cortex is fractured.

Digital pressure is used to compress the

fractured labial cortex into the palataldirection.

Labial and palatal plate will come intoapproximation with each other.

Interrupted continous suturing is carried

out.


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Obwegessers modification for

interseptal alveoloplasty

Indication Gross 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 andpalatal cortices.

Vertical cuts then made bilaterally in both thelabial 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 aregiven.

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


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Alveoloplasty with post extractionhealing

Crestal incision is taken not to tearthe mucoperiosteal flap, but thereflection

Side ways separation with theperiosteal elevator will help thesmooth reflection.

Sharp areas or large undercutsshould be trimmed with rongeur.And suturing done.


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Elimination of unfavourableundercut

Usually done in the mandibularlingual aspect (genial tubercle ,sharp mylohyoid ridge prominence.)

Seen in patients wearing olddentures, due to resorption over theyears,the denture become unstable


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Reduction /resection of the genialtubercle

Are bony attachments of genioglossus muscle.

Are seen on the crestal level on the lingualaspect.


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Technique

Crestal incision is made from the lowercanine to canine region , after infilterationof 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.


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Reduction of mylohyoid ridges

Done 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 themylohyoid ridge region.

Tissue from the floor of the mouth and lingualmucoperiostium are protected by inserting the flatblade of the tongue depressor .

The reduction of the mylohyoid ridge is carried withosteotome or round bur ,after dissecting mylohyoidfibres away.

Bone is smoothened with bone file. Soft tissue flap is returned back and the complete

lingual vestibule checked with digital pressure for anysharp areas.

After complete smoothening sutures are given.


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Excision of tori

Indications Large torus ,filling the palatal vault. Large torus extending beyond the

postdam area. Ulceration or traumatisation or

hyperkeratinisation of the overlyingmucosa.

Deep bony undercut.

Interference with function. Psychological consideration. Food lodgement.


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Under LA ( bilateral grater palatine and incisivenerve block)

A-P linear incision in the midline of the palate. Y shaped releasing incision at one or both the ends

of the incision.

Two mucoperiosteal flaps raised with periostealelevator from th 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. Conyinous over and under type suturing using fine

absorbable suture material. Prefabricated acrylic stent or splint or iodoform pack

can be given to prevent heamatoma.

Technique


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Mandibular tori removal.

Technique

IFAN block is given.

Incision over alveolar ridge in lower

premolar region. Mucoperiostral flap is raised

Make a purchase point or groove with buron medial aspect of the tporus.

Cleavage taken with a osteotome. Smoothen with roud bur or bone file.

Irrigatre band suture.


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Maxillary tuberosity reduction andexostosis removal

Technique

Under infilteration or PSA nerve &GPN block.

Crestal elliptical incisions fromtuberosity to premolar area.

Periostium is reflected and tissue

present b/w the crestal incisionremoved with chisel mallet or bur.

Flap is sutured and stent is placed.


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Soft tissue surgeries

Removal 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 Electrocauterisation Cryosurgery

Laser excision Palatal papillary hyperplasia. Supraperiosteal excision.


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Frenectomy

Indications

High attachment of frenum.

Ulceration at the frenal attachment a due to overuseof the denture

TECHNIQUE

Crosssdiamond 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.


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Lingual frenectomy

Indication

Tongue tie

Technique

Bilateral lingual nerve blockSubmucosal dissection done oneither side .Dissection of genioglossus muscle

and suture it.


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Ridge extension procedure

Vestibuloblasty or sulcoplastyIt is a deepening procedure of vestibule.

Mandibular techniques

done on labial side done on lingual side labial vestibular procedure

transpositional flap vestibuloplasty orlip switch procedure

IndicationsUsed when patient has a bone ht of 15mm

or more in the ant region


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Techniques

kazanjian technique (1924) oldest technique

use mucosal flap from the inner aspect of lowerlip.

Carried out in premolar to premolar region.

Procedure

submucosal dissection is done anddirected inferiorly to remove muscle andconnective tissue attachments.

Raised mucosal flap is adapted to thenew vestibule and

Suture is done


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Godwin s modification (1947)

Mucosal incision in inner aspect of lip islonger than the proposed vestibular depth .

Labial periosteal margin is sutured to theincised lip mucosa.

Stent is placed.


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Supraperiosteal flap on the inner aspect oflip leaves a raw surface on the bonecovering the inner lips surface .

Incision started labial to the crest

Supraperiosteal dissection is done along thelabial surface till the vestibular depth.

Edge of the mobilized flap is pushed intothe new vestibular area and held in positionby sutures .

Alveolar bone is covered by periosteallayer.


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Similar to clarks method except the area ofalveolar bone with its periosteal attachment

covered with split thickness graft. Advantages

Covers the bone and ensures fast healing

Less bone loss and scarring .

Obwegessers modification


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Lingual vestibuloplasty

Indication

In case where mylohyoid and genioglossus closeto the alveolar ridge.

Trauners technique

Incision is done from 2nd molar to 2nd premolarregion

Supraperiosteal dissection is done

Instrument paseed below mylohyoid muscle andseparate it from bony attachment.

Fixation of mylohyoid muscle to new desiredvestibular depth by sutures.


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Here mylohyoid muscle superficaial fibreesof genioglossus muscle pushed inferiorly.

Rubbertubing placed in the lingual vestibuleand flap is held in position by sutures

Caldwells technique


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Obwegessers technique

Lingual vestibuloplasty + buccalvestibuloplasty

Edges of buccal and lingual flaps areraised and sutured below the inferiorborder of the mandible.

Skin graft is placed over the entirealveolar ridge.

Acrylic stent or denture placed and fixedto mandible with circummandibularwiring.


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Submucosal vestibuloplasty techniqueIndication Shallow vestibular depth with good

underlying bone height and contour.Technique Vertical midline incision is made in the

labial vestibule. Supraperiosteal tunnel from one premolar

to other . Intervening submucosal tissue excised or

repositioned superiorly.


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Procedure involves surgical creating pockets in themax,mattress and pyriform aperture region helps inthe denture extension into the pockets.

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

buttress. Supraperiosteal dissection is performed to create two

pockets on either side of pyriform aperture. 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.

Max.pocket inlay vestibuloplasty (obwegesser)


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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.

A crestal incision is taken with buccal releasing incision inthe 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 freedlightly and held with hook upward.

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

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

Mental nerve transposition


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Ridge augmentation procedures

Alveolar ridge resorption is soextreme that the alveolar bone iscompletely disappeared., in this

case vestibuloplasty is not done.

Two appointments are available

Augmentation of alveolar bone.

Place the implants.


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Procedures

Mandibular augmentation

1. Superior border augmentation

Bone grafts

cartilage graft

alloplastic grafts


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2.inferior border augmentation

bone grafts .cartilage grafts


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3.interpositional or sand witch bonegrafts

Bone grafts

cartilage grafts

hydroxyapatite blocks


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4. visor osteotomy5.onlay grafting autogenous

allogenous alloplasticB. maxillary augmentation. Onlay grafting Onlay grafting of alloplastic material Interpositional or sandwitch grafs Sinus lift procedure


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Augmentation in combination withorthognathic surgery

mandibular osteotomy procedure maxillary osteotomy procedure

CombinationMaterials for augmentation of alveolar ridge autogenous grafts iliac crest rib graft

allogenic bone freeze dried cadaver bone. Alloplastic material Hydroxyapatite


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Mandibular augmentation

Superior border grafting oraugmentation

Use 15 cm rib graft . Fixed to mandibvle with trans osseous

wiring of circum mandibular wiring.

Disadvantage

Donor site morbidity Continued resorption of grafted sites.

Soft tissue dehiscence or limitation.


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Inferior border grafting It is indicated when the arch less than 5-

8 mm in height.Procedure Supraclavicular incision followed by

subplatysmal incision till the inferiorboredr of the mandible.

Freeze dried alloogenic cadaver mandible

is hollowed out and multiple perforationsmade into it and it is used as atray. It is then filled with autogenous

cancellous graft particles fixed to theinferior border with 2-0 vicryl sutures by

cicummandibular fixation


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Interpositional bone grafting (sandwitch bone grafting)

Horizontal osteotomy is performed

Splitting is done and bone graft is graftedinto this gap

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

Delivery of aplliance is delayed for 3-5months.


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Onlay grafting

Used in case of inadequate width but adequateheight for the maxilla or mandible

Oldest technique

Onlay augmentation with hydroxyapatite isadvocated by obwegessor via submucosalvetibuloplasty technique.

After creating a tunnel via a midline a putty isformed of hydroxyapatite crystals is mixed withsaline 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.


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Technique High vestibular incision is taken , mucoperiosteal 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 externalcortex.

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 thelingual section of mandible wired in position

Cancellous bone grafting material placed at the outercortex over the superior labial junction for improving thecontour.


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Modified visor osteotomy Consists of splitting of the mandible

buccolingually by vertical osteotomy only in theposterior region and a horizontal osteotomy inthe anterior region.

Posterior lingual segments are then pushedsuperiorly on both sides. Anterior fragment is also pushed superiorly and

fixed with wires. Corticocancellous bone graft particles with

hydroxyapatite granules placed in the gap

between the superior , inferior and anteriorsegments.


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Sinus lift procedure or sinus grafting Sinus lining at the floor of the mouth is lifted up

surgically and the bone graft is placed between thesinus lining and the inner aspect of the alveolarcrest or floor of the maxillary sinus in the posterior

maxilla.Totum was the first surgeon who used this

method.Materials used are autogenous bone allogenic bone. tricalcium phosphate hydroxyapatite. calcium phosphate. ceramics calcium deficient carbonate apatite from bovine

bone.


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Technique Intraoral incision is taken on maxillary crest or

slightly on the palatal aspect with vertical incisionfrom 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 caine fossa. 15 20 mm lomg 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 withoutcompleting the superior cut.


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Trap door type of bony window is lifted upsuperiorly o expose the schineiderianmembrane.

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


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Augmentation in combination withorthognathic surgery

1.anterior maxillary osteotomy. 2.total lefort osteotomy used along with

interpositioning of grafts. Limitation of augmentation technique 1.inadequate soft tissue coverage. 2.rejection of autografts.

3.dehiscence of overlying mucosa. 4. migration of graft material. 5..resorption of graft.


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conclusion

Preprosthetic surgery offers a sigificant contributionin patients with bone atrophy,soft tissuehypertrophy or localized soft and hard tissueproblems or all of them.

Pre existing stuctures like frenal

attachments,exostosis,tori are insignificant whileteeth are present in the oral cavity. But these nonsignificant structures cause hindrences fordenture stability and resultant reducedmasticatory function after tooth loss.

Preprosthetic surgery plays an important role in

providing a better anatomic environment and tocreate proper supporting structures for dentureconstruction.

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