Management of Odontogenic Tumors / orthodontic courses by Indian dental academy

INDIAN DENTAL ACADEMY

Leader in continuing dental education www.indiandentalacademy.com

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CONTENTSIntroductionObjectives of managementGuidelines of managementTreatment methods

Enucleation & Curettage-Carnoys solution-CryosurgeryMarginal ResectionSegmental Resection

Reconstruction


INTRODUCTIONTreatment of odontogenic tumors is designed

to eradicate the lesion and restore aesthetic form and optimal function.

Because of these needs and the benign nature of these lesions, a variety of surgical techniques that preserve vital structures and facial aesthetics have been developed for the treatment of odontogenic tumors.


Objectives of management:Eradication of the lesionPreservation of normal tissue to the extent

possibleRestoration of significant tissue loss, form &

functionWell-planned & executed resection &

reconstruction serves the patient physically & emotionally better than repeated surgical procedure


GUIDELINESSIZE & LOCATION OF TUMOR: Small – Excisional biopsyIncreased size – more radicalLocation – important role in post – operative

morbidityInaccessibility – responsible for inadequate

surgical clearance


DURATION: When the tumor was 1st noticedFast growing in short duration – immediate

treatmentPrognosis depends on rate of growth of

tumorSlow growing – more elective treatmentFast growing – indicate malignant


BENIGN Vs MALIGNANT :Benign tumor – treat conservativelySome benign tumors behave aggressively –

radical treatmentBenign & small – enucleationLesion involves full thickness – segmental

resectionLesion is extensive – radical resection


Factors governing the choice of treatment methodAge and health of the patientClinical type of ameloblastomaSite of the lesionSize of the lesionChances of recurrencePatient preference


Treatment methodsEnucleation & curettage - Thermal cauterization

- Carnoys solution - Cryosurgery

Resection without continuity defectResection with continuity defect


ENUCLEATION:Allows the cystic cavity to be covered by a

mucoperiosteal flap & the space fills with the blood clot which will eventually organize and form normal bone.

INDICATIONS:Surgical excision of tumor which tend to

grow by expansion, rather than by infiltration of surrounding tissues.

Lesions occurring in the bone with a distinct separation b/w the lesion & the surrounding bone.

Often there is a cortical margin of bone that delineates the tumor from the bone.


Indicated in:OdontomaAmeloblastic fibromaAmeloblastic fibroodontomaAdenmatoid odontogenic tumorCementoblastomaSquamous odontogenic tumor


Enucleation - procedure


ADVANTAGES:Primary closure of the woundHealing is rapidPost operative care is reducedDISADVANTAGES:After primary closure, it is not possible to

directly observe the healing of the cavityRemoval of unerupted teeth with the lesionWeakening of mandible making it prone to

jaw fractureDamage to adjacent vital structures


Curettage

Curettage - removal of the tumour by scrapping it from the surrounding normal tissue

Currently - least desirable form of therapy Sehdev et al (1974) - cure rate of only 10%. Taylor (1968) - 63% recurrence rateRankow and Hickey (1954) - 91% recurrence rate.Failure - nests of tumour cells extend beyond the

clinical and radiographic margins of the lesionChemical and electrical cauterisation have been

used by surgeons in conjunction with curettage but they have reported only a slight improvement in cure rate.


INDICATIONSUnicystic ameloblastoma Small tumour - a child or a young adultPatient can be followed up for 10 years or

more.Small tumour in the body of the mandible in

an elderly patient, as ameloblastoma takes several years to recur


Operative procedureIntra-oral approachMucoperiosteal flap is reflected Mandible - buccal aspectLingual access - injury to lingual nerve &

mandibular neurovascular bundle Maxilla - palatal or buccal / labial approach Rongeur or surgical bur - remove sufficient

bone - expose the underlying tumorAngular / straight curettes - convex surface of

the curette placed against the bony wall.


Ameloblastoma – Enucleation & Curettage


Adenomatoid Odontogenic tumor:


Ameloblastic fibro odontoma


Ameloblastic fibroma


Compound odontoma:


After lesion is removed - largest curette - a margin of apparently normal bone should be removed by aggressive scrapping.

After thus removing 1 to 3 mm of surrounding bone, all margins are smoothened with a rongeur or a large round bur.

Adjunctive treatment like cauterisation may be employed at this stage.

Irrigation with normal salineSmall wounds - closed primarilyLarge wounds - packed with gauze

impregnated with compound tincture of benzoin, balsam of Peru or Whitehead’s varnish


Topical antibiotic - gauze pack.The pack is removed approximately 2 to 3

inches everyday until the surgical defect is filled with granulation tissue.

Oral hygiene is maintained.ComplicationsNumerous complications - particularly

extensions to vital structuresCurettage procedure breaks the cortical

barrier, thus paving the way for residual tumour to grow into the soft tissues, which then becomes more difficult to treat.


Cautery (desiccation) Various types - primarily as an adjuvant to

curettage, but in some cases as a primary mode of therapy.

Chemical agents: -Carnoy’s solution -Electrocautery -Cryotherapy Cauterisation is basically an attempt to eradicate

the tumour that has infiltrated beyond the clinical and radiographic margins of the tumour


Cautery is empirical :(i) how far the tumour in each case has

extended into the cancellous bone

(ii) how far the caustic agent (heat / chemicals) penetrates into the cancellous bone

(iii) how effective is the agent in eradicating the tumour cells and

(iv) the possible harmful effects to normal tissue


Electrocoagulation (thermal cautery)Mehlisch et al (1972) - 50% recurrence rateMore effective therapy than curettage Secondary ischaemia & necrosis - may

destroy the invading tumour cells. Cautery frequently been employed as an

adjuvant to other methods of therapy to give a better result (Gardner and Pecak – 1980)

Mehlisch et al - no recurrences


Chemical cauterisationCarnoy’s solution - a fixing agent

absolute alcohol chloroform glacial acetic acid ferric chloride (modification)Stoelinga and Bronkhorst (1988) - unicystic

ameloblastoma and reported no recurrencesDepth of penetration - cancellous bone up to 1.5 mm

after 5 minutes and up to 1.8 mm after 1 hour (Voorsmit et al – 1981)

Use of Carnoy’s solution appears to be harmless and has the potential of reducing recurrences after curettage.


Technique:Teeth – extractedEnucleation and curretageBony cavity is examinedCarnoys solution is appliedCotton applicator / ribbon guaze – 3 minutesCopious irrigation with salineBIPP inserted & wound kept openBIPP replaced periodicallyRecurrence – 10%


CRYOSURGERY:Alternative treatment modalityExcellent results in maxillo-facial regionAIM: eliminate invasive bone lesion without

necessarily involving the problems of conventional anatomic radical surgery

Advantage of cryotherapy is that it is possible to devitalise the tissue with liquid nitrogen to a depth of 1.5 cm

The jaw can be frozen through its entire thickness if necessary.


TECHNIQUE:After curettageSurrounding soft tissues are retracted &

protected away with gauze and flap retractorsEntire bony cavity – frozen with liquid nitrogen

spraySolid frost is observed3 freezing cyclesEach cycle - 1 minuteGap b/w each cycle – 5 minutesMucoperiosteal flap were sutured


Complications - sequestration, pathological fracture, transient anaesthesia of mandibular nerve

More extensive the freezing, the greater the risk

Another method which has been described (Weaver and Smith-1963, Bradley-1978) in which the affected segment of bone is excised, frozen in liquid nitrogen to devitalise the tissue, and then reimplanted as an autogenous graft.


MARGINAL RESECTION / RESECTION WITHOUT CONTINUITY DEFECT / PERIPHERAL OSTEOTOMY / EN BLOC RESECTIONIndicated in lesions which are known for

recurrenceLesions that tend to grow beyond their surgically

apparent capsuleTreatment - when the lesion does not extent closer

than 1 cm to the inferior border of the mandible. Margin of 1 to 2 cm - minimum acceptable margin. Various authors - good results with en bloc

resectionLesions of the maxilla - en bloc resection is not as

successful and recommend segmental resection


INDICATIONS:AmeloblastomaCalcifying epithelial odontogenic tumorMyxomaAmeloblastic odontomaSquamous odontogenic tumor


Procedure allows complete excision of the tumor but at the same time a continuity f the jaw bone is retained thus deformity, disfigurement & need for secondary cosmetic surgery & prosthetic rehabilitation are avoided.

ADVANTAGE:Not violating the tumor margins during

resection which might provide the possibility of tumor seeding in the surgical site.

DISADVANTAGE:Does not discriminate b/w tumor tissue &

vital structures in close approximation such as inferior alveolar nerve.


Operative procedure

Intra-oral / extra-oral approachIntra-oral - good access and when the lesion

is anterior to third molar regionExtra-oral approach - lesion involves the

ramus of the mandible or when immediate reconstruction is planned


Surgical approaches to maxilla:


Surgical approaches to mandible:


Intra-oral approachLarge mandibular lesions - a midline lip-splitting

incisionConnecting vertical incisions are made on the

buccal and lingualIncisions - extend deep into buccal and lingual

folds. The teeth bordering the surgical margin should

be extractedHorizontal incisions connecting the lower ends of

vertical incisions are made. The buccal and lingual mucoperiosteal flaps are then developed, but not reflected superiorly over the region of bone to be removed.


Marginal Resection


On exposure of the mandible, the bony segment is sectioned with an air-driven saw or bur, at least 1 to 1.5 cm from the radiographic margin of the lesion

Haemorrhage - controlled by crushing the bone over small blood vessels with a blunt instrument or by using bone wax

The mucoperiosteum is then undermined both lingually and facially to relieve tension.

They are approximated with interrupted silk sutures.


Segmental (partial) mandibular resection / hemimandibulectomySegmental resection - maxillectomy and

hemimandibulectomyLeast number of recurrences.Indications:Infiltrative lesions Lesions – posterior/ inferior border of

mandibleLesions with high recurrence rate


Segmental resection:


Operative procedureDepending on the size - a lip-splitting incision

may or may not be necessaryA submandibular incision - join the vertical lip

incisionIntra-orally - horizontal incision is made through

the mucoperiosteum The facial and lingual flaps are advanced below

the horizontal incision using a periosteal elevator.

The lingual flap is raised as deep as to expose the mylohyoid attachment.

A vertical mucoperiosteal incision is made 0.5 cm proximal to the anticipated anterior bony cut.


Expose the mental neurovascular bundle, which is ligated and sectioned.

Preservation of the marginal mandibular branch of the facial nerve

Using an air-driven saw, bur or a Gigli saw, a vertical cut is made through the mandible anterior to the lesion.

Using bone forceps, the proximal part of the mandible is rotated laterally, exposing the inferior alveolar nerve and vessels, at the lingula of the mandible. They are ligated and cut adjacent to the mandibular foramen.

The capsule is cut with a scalpel and the segment of mandible is disarticulated and removed using bone-holding forceps.

Bleeding - controlled by digital pressure, coagulation or ligation, depending on the size of the bleeding vessel.


Resection with disarticulation:


Odontogenic myxoma


The patient should be fed through a naso-gastric tube for a week and scrupulous oral hygiene should be maintained.

Dressings should be changed daily. Removal of drain depends on the amount of

drainage. Alternate skin sutures are removed after 4

days and the remaining ones, after 6 days. After that, the naso-gastric tube may be

removed and oral feeding may be begun.


Classification of Maxillectomies

1. Partial Maxillectomy(Alveolectomy): Removal of lower half of the Maxilla.

2. Subtotal Maxillectomy:: lesions which extend beyond the confines of Antrum

3. Medial Maxillectomy: Medial wall of antrum, inferior & middle Turbinates, ethmoidal air cells, Lamina papyracea (one side)

4. Total Maxillectomy: complete removal of Maxilla.


Marginal (partial) maxillectomyThe marginal maxillectomy is the surgical

procedure most often used for tumors of maxilla when the maxillary sinus is not involved.

Operative procedureIntra-oral approachMucoperiosteal incision - 1 to 2 cm in all

directions from the underlying tumour.It may be necessary to extract one or more

teeth to complete these incisions. www.indiandentalacademy.com

Partial Maxillectomy (Alveolectomy)


Calcifying epithelial odontogenic tumor:


Extra oral procedure


Total maxillectomy


British Journal of Oral and Maxillofacial Surgery 45 (2007) 306–310www.indiandentalacademy.com

RECONSTRUCTIONRadical surgeries like segmental resection,

hemimandibulectomy and maxillectomy leave the patient with a thoroughly incapacitating aesthetic and functional deficit


Goals of mandibular reconstruction

Re-establishment of mandibular continuity and an osseus-alveolar base

Maintenance of oral functions and proper occlusion with maxillary arch.

To achieve minimal impairment of function Correction of soft-tissue defectsTo achieve good aesthetic results.


Goals of maxillary reconstruction

Obliteration of the defect Restoration of essential function of mid

face Provision of adequate structural

support. Aesthetic reconstruction of external

features.


Immediate Vs delayed reconstructionIMMEDIATEADVANTAGESSingle stage surgeryEarly retain of

functionMinimal compromise

of estheticsDISADVANTAGESRecurrenceTime consumingInfection

DELAYED ADVANTAGESGood resultLess recurrenceGood planning

DISADVATAGESFibrosisWound contraction2nd surgery


Ideal Graft:Restoration of ability to masticateAcceptable esthetic appearanceWithstand physiologic forcesNon-reactive in tissuesSterileReadily available


CLASSIFICATIONDepending on nature of boneDepending on donorDepending on the preparation Depending on the vascularity Depending on donor site:Depending on function


Depending on nature of boneCancellous bone graftCortical bone graftCorticocancellous grafts

. Blocks

. Chips

. PowderMarrow graftDepending on donorAutogenous bone graft – from same individualIsogenic bone graft – from genetically related

individualAllogenic – allograft – from another individual of same

speciesXenografts from different species


Depending on the preparation allografts and xenografts can be again divided into:

a. Freezed bone graftsb. Freezed driedc. Demineralisedd. Antigen extracted autolysed

Depending on the vascularity autografts can be divided into:

Non vascularisedVascularised bone transfer attached on soft

tissue, pedicle, microvascular free transfer.


Depending on donor site:Iliac crest graft -

anterior ileumposterior ileumtrephine grafts

Rib graftFull thicknessSplit rib graft

Calvarial graftFullSplit

Fibulawww.indiandentalacademy.com

Depending on functionBridging graft or inlay graftReconstruction graftContour graft – onlay graft.Bone substitutes


Maxillary reconstruction

ProsthesisObturator and splintsLocal soft tissue flapsBuccal and palatal advancement flapsCheek flapsBuccal pad of fat


Regional flapsTemporalis – myofascial / myo-osseousTrapezius – muscle / myo-cutaneous / osseo-

myo-cutaneousFree flapsRectus abdominusRadial forearmIliac crestOmentum


Mandibular reconstruction

Autogenous vascularised bone by pedicled flaps

Clavicle pedicled on sternocleidomastoidRib pedicled on pectoralis majorScapula pedicled on trapeziusCalvarium pedicled on temporalisRib pedicled on latissimus dorsi


Autogenous vascularised bone by free flapsiliac crest based on deep circumflex iliac arteryfibula based on peroneal arteryscapula based on circumflex scapular arteryradial forearm based on radial arteryrib based on intercostal arterysecond metatarsalcalvarium based on superficial temporal artery


Autogenous non-vascularised bonecalvariumiliac crestribFibulaAllograftsXenograftsAlloplastic materialsstainless steel reconstruction platehydroxyapatite


Fibula Free Flap


Mandible Reconstruction


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Management of Odontogenic Tumors / orthodontic courses by Indian dental academy

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