Presented by – Dr. Dwij Kothari

Darshan Dental College and Hospital

Contents Introduction

Classification of mandibular defects

Factors affecting treatment of mandibulectomy

patients

Immediate vs Delayed reconstruction

Relating surgical considerations in mandibulectomy

patients

Prosthetic rehabilitation of mandibulectomy patients

Mandibular guidance

Intermaxillary fixation

Resection guidance restoration

Guidance prosthesis

Speech aids and speech therapy

Tongue prosthesis

Prosthetic rehabilitation of dentulous patient

Lateral discontinuity defect (class 2 & 3)

Defects with mandibular continuity anterior defect(class 5)

Defects with mandibular continuity lateral defect(class 1 & 4)

Prosthetic rehabilitation of edentulous patient

Management of discontinuity defect

Factors determining prosthetic program for CD

Impression

Centric registration

Occlusal schemes and lateral registration

Anterior border defects

Review of literature

Summery and conclusion

References

Introduction

Mandible is a single bone that creates:

Peripheral boundaries of the floor of the mouth

Facial form

Speech

Swallowing

Mastication

Respiration

Disruption of the mandible has the potential todisrupt any of these.

Rehabilitation of mandibulectomy patients shouldtherefore consider both form and function.

Surgical resection of tumor often includes a partialmandibulectomy resection, a partial glossectomy , apartial resection of the floor of the mouth and aradical neck dissection.

The extent of surgery and effect of radiation therapyand chemotherapy determine the amount ofrehabilitation needed to a patient.

Classification of mandibular defects

According to Laney(1979)

Based on etiology

1. Acquired: - Marginal- Segmental :- a) Lateral to midline

- Body only

- Ramus- Body with disarticulationb) Anterior body

- Subtotal- Total

2. Congenital

- Incomplete formation

- Incomplete ossification

i.e. hypoplasias, mandibulofacial dysostosis,etc

3. Developmental

as a result of postnatal insults

i.e. trauma during birth, surgery,etc

Based on amount of resection (Laney)

Continuity defect

(marginal resection)

- Inferior border and its continuity preserved

- No deviation

- Less facial disfigurement

- Occlusion rarely changed

- Can be :- anterior defect

posterior defect

Discontinuity defect

(segmental resection)

- Complete segment - from alveolar crest to inferior border removed

- Mandible deviates to resected side

- Marked facial disfigurement

- Occlusion altered

- Can be :- lateral discontinuity

defect

midline discontinuity

defect

According to Cantor and Curtis (1971)

Class 1 : Radical alveolectomy with preservation of

mandibular continuity

Tissues resected : Portion of alveolar process and body

of mandible

Lingual and buccal sulcus mucosa

Portion of base of tongue andmylohyoid muscle

Lingual and inferior alveolar nerves

Sublingual and Submaxillarysalivary glands

Sometimes anterior part of digastricmuscle

FEATURES:-1. Least debilitating.

2. Sometimes resection of part of mylohyoid muscle and resultant scarringcan raise the floor of the mouth causing reduction in tongue mobility.

3. Ability to shape and control the tongue form may be lost due to loss ofsome intrinsic muscles.

4. Resection of lingual and inf. alveolar nerves results in a loss of sensationin the mucosa of cheek, alveolar process, lower lip and loss of taste onanterior 2/3rd of the tongue.

Class 2 : Lateral resection of mandible distal to cuspid

Tissues resected: Condyle, ramus and body of mandible

distal to cuspid

Mylohyoid, hypoglossal

Pterygoid, masseter, external pterygoid,

Palatoglossal muscles, most of intrinsicmuscles of tongue.

Hypoglossal , lingual and inferior alveolarnerves.

Sublingual & Submaxillary salivary glands.

Mucoperiosteum & adjacent buccal &lingual sulcus mucosa

FEATURES:-

1. Speech, swallowing, saliva control, manipulation of food impaired.

2. Facial disfigurement apparent.

3. Disarticulation and loss of muscles of mastication will hampermandibular movements.

4. Taste, sensory and motor losses are more extensive as compared to class 1.

Class 3 - Lateral resection of the mandible to the midline

Tissues resected : All those described in class 2 in addition to the anterior portion of the

mandible, geniohyoid, genioglossus, remaining portion of mylohyoidmuscle with lingual and buccal mucosa.

FEATURES:-

1. Restricted tongue mobility due to loss of tip of tongue andgenioglossus muscle.

2. Speech, swallowing, saliva control and manipulation of food is severelyrestricted.

3. Facial disfigurement is worse due to loss of anterior part of mandible.

4. Disarticulation and reduction in amount of basal bone reduce prosthodonticprognosis.

5. Scarring of orbicularis oris can interfere with expression of emotion

Class 4: Lateral bone graft surgical reconstruction

Lateral bone and splitthickness skin or pedicle graftcan be performed on patientswho have had:

- radical alveolectomies

- resection of mandible

distal to cuspid with or

without disarticulation.

-midline resections with or

without disarticulation.

3 Types of bone grafts are possible:-

1. Mandibular augmentation procedures.

2. Bone graft that connect a residual condyle with the largemandibular fragment.

3. Lateral bone grafts that extend from the mandibularfragment into the defect area to establish a pseudo TMJ.

Class 5 :Anterior bone graft surgical reconstruction

Tissues resected : anterior portion of the mandible

large bilateral portions of mylohyoid,geniohyoid

genioglossus and anterior digastric muscles

bilateral lingual and inferior alveolar nerves

bilateral submaxillary and submandibularsalivary glands

mucosa of lower lip

anterior floor of the mouth

ventral surface of the tongue

The mucosa retained in the labial and buccal regions is sutured to theresidual stump of the tongue and a Kirschner wire is often positioned tomaintain the mandibular fragments .

Bone graft and split thickness skin graft or pedicle graft procedures canbe used to restore anterior facial contour and bilateral mandibularfunction.

Predisposing factors

Dentures – Chronic irritation – epidermoid carcinoma– squamous cell carcinoma

Alcohol – squamous cell carcinoma in the floor of themouth – related to direct tissue contact or indirectlywith live cirrhosis and altered nutritional status

Tobacco - cigarette , cigar, pipe , chewing tobacco

Leukoplakia – white patch - can not be scraped off –reversed by removing local irritants

Oral lichen planus – recticular, plaque, and erosiveforms

Factors affecting treatment of

mandibulectomy patients

1. Location and extent of mandibular defects

Radical alveolectomy- Least debilitating.

- Main problems – loss of vertical ridge height and vestibular depth –decreased stability for soft tissue-supported prosthesis as well as the lossof load bearing tissues available for support.

- Vertical discrepancy most important when prosthesis supported by dentalimplants are considered.

Discontinuity defects

RULE OF THUMB:-The further anterior the defect, the more

disfiguring and functionally debilitating

it is likely to be.

Osbon DB. Early treatment of soft tissue injuries of the face. J Oral Surg 1969;27:480–7.

- Most debilitating and difficult to treat.

- Greatest facial disfigurement.

- Surgical reconstruction necessary or at least segmental stabilizationbefore prosthodontic treatment can be initiated.

- Mandibulectomy defects of the molar region of the mandibular body aremore well suited for surgical reconstruction compared to anterior defects.

- If muscle attachments are intact – Good prognosis

Near normal appearance and function is achievable.

Defects of the symphyseal region

2. Presence of remaining natural teeth/pre-existing implants

Patients after mandibulectomy present with few or noremaining natural teeth.

2 reasons:

1. Patients at greatest risk for squamous cell carcinoma - heavyusers of tobacco products and alcohol.

2. Teeth are usually extracted prior to radiotherapy to preventcomplications such as osteoradionecrosis.

Greater the number of teeth, better the prognosis

- Teeth present on both sides of the midline permit greaterprosthesis support since the problem of straight line designcan be avoided.

- Maximum number of abutment teeth should beincorporated in the design of the prosthesis to maximizestability and dissipate functional forces.

Ideal for rehabilitation

A maxillary complete denture will function well for

mandibulectomy patient against a reconstructed mandibular

dentition

Exceptions:

Collapse of residual proximal mandibular stump; coronoid

process against the posterior maxillary alveolus - prohibiting

adequate denture flange extension.

When a guide flange prosthesis is planned to correct mandibular

deviation - pressure from the guide flange will tend to dislodge

the maxillary denture.

3. Degree of post mandibulectomy rotation and deviation

- Loss of mandibular continuity causes deviation of theremaining mandibular segment towards the defect androtation of mandibular occlusal plane inferiorly.

Deviation: Primarily due to loss of tissue involved in surgical

resection.

Rotation:- Due to

- Pull of the suprahyoid muscles on the residual mandibular fragment causing inferior displacement and rotation around the fulcrum of the remaining condyle.

- Gravity – Loss of anchorage of elevator muscles.

Sequelae:-

Facial disfigurement

Loss of occlusal contact

Loss of ability to bring lips together for saliva control

& to initiate swallowing process

Prosthodontic prognosis in such patients can be improved byearly post resection physical therapy to reposition themandibular fragment to a more normal position and tominimize scar formation that will make deviation moresevere.

Should be carried out as early as possible. After 6-8 weekspost operatively it will not be as beneficial.

Can be in the form of

1.Physical therapy carried out by the patient himself.

2.Mandibular resection guidance prosthesis

4. Available mouth opening

- Trismus –due to surgical trauma

- Scar tissue formation will further reduce mouth opening.

- Physical therapy (Stretching exercise) should be started immediately.

- Simple test to check mouth opening:

Insert a stock mandibular impression tray in the mouth. If this cannot be accomplished, rehabilitation is unlikely to occur.

- Surgery can be done to release scar tissue. However, not very beneficial as it returns to the same in a short period of time.

5. Functional limitation of the tongue

- Frequently the surgical wound is closed by suturing theremaining tissues of the floor of the mouth or tongue to theremaining buccal tissues.

This compromises: - Speech

- Swallowing

- Mastication

- Control of food bolus

- Ability to control removable prosthesis

- Lingual vestibuloplasty and skin or mucosal grafting can beused to improve tongue mobility

- Evaluation of tongue mobility

- Patients in whom anterior resection has been done, ability tolick the lips when the artificial prosthesis is placed in themouth may be difficult or impossible.

- In such cases consideration is given to lowering the anteriorocclusal plane or arranging the teeth slightly lingually.

Loss of sensory innervation will compromise tongue functionand prognosis of prosthodontic rehabilitation.

If lingual nerve is sacrificed - tongue on the defect side willpermanently remain without any feeling.

Loss of sensory capability:- Affects speech

Mastication

Prosthesis control on defect side

Loss of sensory innervation of the buccal mucosa(long buccalnerve) and lower lip(mental nerve) will reduce patient’sability to control food and saliva.

6. Compromise of vestibular extensions

Vestibular depth is critical for stability and peripheral seal.

It is also critical when mandibular continuity is restoredwith bone grafting and implants are considered.

7. Skin grafting

Skin grafts are used for surgical reconstruction either as lining forthe surface of resected soft tissue or as part of skin and connectivetissue grafts such as pedicle flaps, free flaps etc.

Advantages

1. Effective load bearing tissue.

2. Can withstand pressure from prosthesis.

3. Protects underlying bone and connective tissue well due to

rapid turnover of keratin producing cells.

Disadvantages

1. No sensory innervation.

2. Full thickness grafts may incorporate hair follicles.

3. Skin is not very compatible with titanium surface of implants.

8. Radiation therapy

Careful treatment planning is required for patients withradiation therapy.

Irradiated tissue is fragile, sensitive to manipulation,dessicated, slow to heal, prone to infection and at risk ofosteoradionecrosis.

9. Altered anatomic relationships following restoration of mandibular continuity

Reconstruction of anterior defects

- Most difficult situation for grafting

- Frequently results in a graft that is deficient anteriorly.

- Results in a severe Class II like situation.

The prosthodontic difficulties seen in rehabilitating such a patient are:-

- Inability to provide proper lower lip support for esthetics.

- Speech problems associated with mandibular dentition placed too

far lingually to allow normal articulation.

- Inability to control food bolus due to lack of motor function oflips and muscles of the lower face.

- Excessive display of mandibular teeth due to patient’s inabilityto maintain normal lower lip posture.

- Difficulty gaining adequate space for prosthesis placementwithout encroaching on function of tongue.

- Misalignment of remaining unresected mandibular fragmentsand resultant relationship between maxillary and mandibularteeth.

Reconstruction of posterior defects

- More predictable from prosthodontic point of view as comparedto anterior defects.

- The mediolateral position of the graft is frequently seen lateral tothe original position of the mandibular body.

- Thus the prosthesis must be built in cross bite to maintain thedenture teeth over the supporting base of the bone graft.

Angled dental implants- the prosthesis they support must be

cantilevered lingually to permit tooth contact.

Inadequate space after surgical

reconstruction- limits prosthesis

or implant placement.

Excessive space after surgical

reconstruction- problem to control

forces on remaining teeth or implants

Immediate vs delayed reconstruction Factors determining whether to reconstruct at the

time of tumor resection (immediate) or as a secondaryprocedure (delayed).

Amount and character of remaining soft tissue

Anatomic location of the defect

Size of bone defect

General health of patient

Prognosis for tumor control

Experience of the surgeon

Extensive soft tissue loss – require additional procedurefor soft tissue augmentation, thus precludingimmediate graft.

If immediate reconstruction is desired but soft tissueappear inadequate for proper watertight oral closure – aforehead flap may be useful

Flaps should be – broadly based, as thick as possible.

The size, extent and prognosis of tumors requiringresection are important factors.

Relatively small defect – immediate reconsturction

Spectrum malignant tumors requiring extensive hardand soft tissue resection with a radical neck dissection –immediate implant followed by delayed graft.

Since tumor recurrences occur frequently within 1st year

Medically compromised patients – observe the responseto primary surgery before subjecting to secondprocedure

Location of resection is another important factor

Defects at symphysis require immediate stabilization,or remaining mandibular fragments will colapsemedially and superiorly because of muscle pull and scarcontracture

Immediate stabilization is less important in lateralmandibular defects.

Relating surgical considerations to

prosthodontic treatment

Marginal mandibulectomy:-

Soft tissues are mainly used to reconstruct marginal

mandibulectomies.

They may be: - Skin graft

- Local flap

- Pedicle flap

- Microvascular free flaps

(MVFF)

Skin grafts serve as excellent prosthesis-bearing surfaces.

However when soft tissue bulk is required or recipient bed ispreviously irradiated - Microvascular free flaps are thetreatment of choice.

Discontinuity mandibulectomy:-

- Previously soft tissue local flaps (mainly the residual tonguesutured to the border of the defect) and pedicle flaps(pectoralis muscle) were used.

- MVFF have revolutionized the treatment of discontinuitydefects.

- Microvascularized bone is mainly obtained from:

1.Fibula- most common

2.Iliac crest

- Soft tissue MVFF are obtained from:

1.Forearm

2.Rectus muscle

Mandibular malposition after bony reconstruction

May be due to:

1. Minimal proximal mandible on the surgicalside to attach the bone graft.

2. Mandibular segments are not stabilized andmaintained in their pre-operative relation toeach other during grafting procedures.

3. Delayed reconstruction may not be able toovercome scar tissue formation completely.

4. The bone grafts used i.e the fibula and the iliac crest grafthave some inherent problems:

- Lacks height compared to the residual mandible

-Pyramidal in shape being narrower at the occlusal surface

-Fibula is grafted to restore inferior border of the mandible,which is necessary to restore facial form. This tends to placefibula buccally in the plane of the cheek.

-Since bone is placed buccally in the cheek, implants distal tothe premolar area cause constant soft tissue and infectionproblems.

Prosthetic Rehabilitation of

mandibulectomy patients

Mandibular Guidance

Loss of continuity of the mandible destroys the balance andsymmetry of mandibular function

Leading to altered mandibular movements and deviation ofthe residual fragment towards the surgical side.

Methods to reduce mandibular deviation

Intermaxillary fixation

Use of mandibular based guidance restorations

Use of palatally based guidance restorations

Intermaxillary Fixation One approach to reducing the deviation associated with

resection of the mandible

- use arch bars and elastics or wire in dentulous patients.

- “gunning splint” in edentulous patients.

Resection guidance restorations If intermaxillary fixation is not employed –

2weeks postsurgically, the patient should be placed on anexercise program.

Following maximum opening, grasping the chin andmoving the mandible away from the surgical side.

These movements tend to loosen scar contracturereduce trismus, and improve maxillomandibularrelationships.

If extensive resection and a considerable period oftime has elapsed, guidance procedures are much moredifficult and a compromised occlusal relationship mayresult.

For guidance prosthesis mandibular teeth must bepresent.

Once an acceptable occlusal relationship isestablished, the guidance prosthesis may be discardedor used occasionally to reinforce proprioceptivemechanism.

Guidance prosthesis Robinson and Rubright described Mandibular

guidance prosthesis

It consists of a RPD framework with a metal flangeextending 7 to 10 mm laterally and superiorly on thebuccal aspect of the bicuspids and molars on thenondefect side.

This flange engages the maxillary teeth duringmandibular closure.

If the completed guidance ramp is to be formulated in acrylic resin, autopolymerizing material is added to the prosthesis which is seated in the mouth.

As the resin reaches dough stage, themandible is manipulated into the desiredinterocclusal relationship.

The resin should be manipulated toextend 7 to 10 mm superiorly. Theprosthesis is removed from the mouth andthe resin is allowed to polymerize.

Palatally based guidance restoration

This is a guidance ramp and an index to a maxillaryprosthesis.

Indicated for patients who has severe deviationwhich prevents manipulation of mandible into anyform of acceptable contact.

These maxillary prosthesis are usually constructed ofacrylic resin with either cast or wrought wireretainers.

The full palatal coverage prosthesis is constructedfollowing conventional prosthodontic guidelines.

A mix of autopolymerizing acrylic resin is prepared andadded to the palatal prosthesis along the lateral andanterior borders on the nondefect side.

The prosthesis is replaced in the mouth and themandible is manipulated to the desired position, thusestablishing an index in the palate.

The patient should be able to close into the index withappropriate manual manipulation of the mandible.

When the patient returns, the mandible will usuallyexhibit more movement laterally toward the nonsurgical side, requiring adjustment of the palatal ramp.

• If and when an acceptable intercuspalposition is achieved, a cast mandibularguidance prosthesis may be necessary tomaintain mandibular position.

Speech aids and speech therapy

Cantor et al 1969, noted speech improvement by loweringpalatal vault prosthetically into the space of Donders toaccommodate for restricted tongue movements.

The palate was lowered by means of a retainer for thedentulous patients and by a palatal acrylic resin extensiononto the upper denture for edentulous patients.

• Misarticulation of speech sounds by mandibular resections.

Scott 1970, investigated the potential benefit of intensivespeech therapy for mandibulectomy patients andconcluded that:

Placement of a prosthesis, although improves the quality ofspecific sounds, does not improve discourse and

Intensive speech therapy improved speech significantly forpatients both with and without prosthesis.

• Speech therapy is most effectivemeans of improving articulation inmandibulectomy.

Tongue prosthesis

The loss of tongue impairs functions of stomatognathicsystem.

Moore 1972, suggested that tongue prosthesis providesarticulation along with movements of the mandible andcheeks.

Loss of tongue leads to difficulty in controlling saliva andliquids.

Pooling of the fluids in the altered floor of the mouthstimulates cough reflex and/or leading to aspiration.

Prosthetic Rehabilitation of

Dentulous Patients

Lateral Discontinuity Defects (Class 2 And 3)

Often resected in the region of 2nd premolar and 1st

molar. If there are no other missing teeth in the arch, aprosthesis is usually not indicated.

Framework design should be similar to a Kennedy class2 design, with extension into the vestibular areas of theresection.

The forces of occlusion are unilateral and consequentlythe axis of rotation (fulcrum line) of the partialdenture deviates from the norm.

Major connector – depends on theheight of floor of the mouth.

Minor connector – minimize thestress on abutment teeth.

Occlusal rests – near the defect

Retention – use of various types ofclasp assemblies on distalabutments.

If anterior and posterior teeth from resected sidemissing and posterior teeth on unresected side aremissing, prosthesis have 3 denture base regions.

Rests – on as many teeth as possible

Minor connectors – enhance stability and wroght wireretainers are acceptable alternative to bar clasps.

Altered cast impression – used to get max. soft tissuecoverage.

Maxillomandibular records – made with soft wax andminimum occlusal pressure applied.

Acrylic resin teeth

When less than ideal occlusal relationships must beaccepted, it may be necessary to establish an occlusalramp lingual to maxillay teeth on the unresected site.

Class 3 resection – defect to the midline orfarther toward the intact side, leaving halfor less of the mandible remaining.

Design of framework – similar to type 2resection

In this resection – greater chance ofprosthesis dislodgement caused by lack ofsupport under anterior extension.

Defects With Mandibular Continuity Anterior Defects (Class 5)

Patients with anterior inner table resections andpatients with anterior composite resections in whommandibular continuity has been reestablished byreconstructive surgery.

These patients display unusual soft tissueconfigurations and compromised bony support.

Prosthesis for these patients enhance esthetics, speechand control of saliva.

Indirect retention – longmesial rests on the 2nd Molars

Minor connector – relievedistal aspect and proximalplates

Edentulous areas are recordedwith an altered cast impression

Thermoplastic waxes are usedto record movable tissue beds.

Esthetics, occlusion and speech – verify at try-in stage

Prosthesis is delivered with periodic monitoring.

Defects with Mandibular Continuity Lateral Defects (Class 1, 4)

Inferior border of the mandible is intact, and normalmovements can be expected.

Compromised denture bearing area – because of closureof the defect using adjacent lining mucosa or presenceof split thickness skin graft.

If defect is unilateral and posterior – kennedy class 2framework design

If marginal resection in anterior area – kennedy class 4framework design

Anterior marginal resections some times include partof the anterior tongue and floor of the mouth.

The remaining teeth often collapse lingually andnecessitate labial bar as major connector.

Buccal, lingual and labial functional contours – helpsin stabilization of the prosthesis.

Extremely long lever arms & compromised edentulousbearing surfaces contribute to excessive movement ofprosthesis during function.

The ‘ribbon rest’ closely parallels the axis of rotation.The anterior and posterior proximal plates move freelyduring function.

The buccal retainer on the molar and the labialretainer on the cuspid are placed at the height ofcontour.

The occlusion should be refined to achieve contact incentric occlusion only and patient should beinstructed to masticate on the side of the residualmandibular dentition.

Prosthetic Rehabilitation of

Edentulous Patients

Management Of Discontinuity Defects

Complete dentures in these patients are primarily foresthetics.

They improve lip and cheek contour and replace missingteeth.

Factors Determining The Prosthetic Prognosis For Complete Dentures

The prognosis is more favourable if the resection islimited to the cuspid region anteriorly.

If the motor and/or sensory control of the tongue hasbeen significantly compromised by the resection, theprosthetic prognosis becomes extremely guarded.

Severe deviation of the mandible causes instability ofthe dentures.

Post surgical lip posture and control, does haveimportant prosthodontics implications.

Due to radiation therapy, there will be reduction insalivary flow which leads to increased risk of mucosalirritation and compromised peripheral seal.

Impression

Primary impression – irreversible hydrocolloidimpression material

Final impression – border moulding with modelingplastic and an elastic impression material

Some clinicians advocate making a functionalimpression of the polished surfaces of mandibularprosthesis

Centric Registration

In maxilla, wax rim used – widened on unresected sidein order to account for deviation of the mandible

Determine VDO and VDR

Centric occlusion registration – obtained with wax orplaster

The clinician should manipulate the mandible andplace it in the most advantageous position within thereach of the patient.

Occlusal schemes and Lateral registrations

Swoop 1969, suggested “non anatomic teeth” forpatients with abnormal jaw relationships and angularpath of closure.

“Neutral Zone” identification facilitates positioning ofthe mandibular teeth.

The wax rim is fabricated according to the neutralzone.

Special attention should be paid of developingappropriate contours of the rim in contact with theinside of the upper and lower lip.

After the wax rims have been altered and registationsobtained, the maxillary and mandibular casts aremounted on a suitable articulator.

It is advisable to place the maxillary anterior teethlingual to, and mandibular anterior teeth labial to,their accustomed position.

Lip tooth relationship can be improved if the verticaloverlap is increased so that the amount of toothdisplayed and the smile line are consistent with a morelabial or normal position of the maxillary teeth.

Generally, in mandible the posterior teeth on theunresected side will be buccal to the crest ofedentulous alveolus, especially in the bicuspid region.

The posterior mandibular teeth on the surgical sideusually are placed lingual to the crest of theedentulous ridge.

Contour and support for the corner of the mouth andthe lop on the resected side are best accomplished bythickening the denture flange below the crest of theridge.

After arranging all teeth in the maxillary prosthesis,ramps of 10mm wide and 3-4mm horizontal overlapwith the lower teeth should be provided.

After tooth arrangements have been finalized, the occlusalcontact of the mandibular teeth is checked with themaxillary ramp.

The patient should be able to establish contact with rampswithout guidance.

After trial prosthesis have been perfected, they areprocessed following customary procedures.

The use of prosthesis for mastication should be deferredfor at least a week. As the patient uses the prosthesis, someadjustment of the ramps usually necessary.

Anterior Border Defects

The prognosis is usually favorable especially if avestibuloplasty has been completed.

The mandibular movements and maxillomandibularrelationships are usually within the normal limits forthese patients.

Careful placement of the mandibular anterior teethand flange contour in this area is suggested.

Review of literature

They supported this concept by quoting Fish (1933) who gavethis concept, and stressed on the importance of polishedsurface for the retention and stability of the denture.

Shifman and Lepley(1982): Neutral zone or ‘denturespace’ concept for marginal mandibulectomy patients.

In this method short and narrow artificial teeth which willnot interfere with the denture space were selected.

They were arranged on the diagnostic cast; occlusion andesthetics were verified clinically. This was done in self-cureacrylic resin and space was present underneath theocclusion for impression material. This prosthesis wasretained by simple Adams or embrasure claps.

A functional impression of the defect side is made usingmodelling compound for muscle trimming and iscompleted with an impression wax.

The released prosthesis is than cured and finished in theusual manner.

Cantor and Curtis(1971): Swallowing technique in edentulous patient

A preliminary alginate impression of the mandibularfragment is made in a modified stock tray.

A narrow area, supported by bone and free of any muscularactivity, is drawn on the diagnostic cast and a perforatedacrylic resin custom tray is constructed that conforms tothis area.

Two lateral columns that extend toward the maxillary ridgeare formed on the tray.

Modeling compound “stops” are placed under the columntray for stability and to provide space for the impressionmaterial.

Modeling compound is then added to the lateral columnsextending them superiorly until firm bilateral contact ismade with the maxilllary residual alveolar ridge.

The vertical height of the columns should exceed thepostsurgical physiologic rest position by at least 2 to 3 mm.

The lower part of the oral cavity is filled with an alginateimpression material that has been mixed with approximatelyone third more water than is recommended by themanufacture.

The column tray is placed through the hydrocollooid materialuntil it is seated firmly on the alveolar mucosa.

The mandible is then closed until the maxillary ridge restsare properly seated, and the custom tray is securely in placewith the tongue resting between the columns on the tray.

At this point, the patient begins to swallow, and betweeneach swallowing cycle, he puckers his lips.

The patient continues these two motions until the alginatematerial has set.

Swatantra agarwal, Praveen G, Samarth Kumaragarwal and Sankalp sharma (2011), suggested TwinOcclusion in which they did functional rehabilitation ofhemimandibulectomy patient, who had undergoneresection without reconstruction.

Maxillary arch representing

kennedy’s class IBite record

OPG reveals resection of mandible of left side

Intercuspation obtained by twin

occlusion on nonresected side

Mounted cast on articulator with

arrangement of teeth

Occlusal view of definitive prosthesis

placed in maxilla

Summary & Conclusion

Management of mandibular defects is one of the mostchallenging aspects of maxillo-facial prosthetics. Thesedefects affect not only function but also appearance andthus the prosthodontists has to fulfill the dualresponsibility of restoring function and appearance.

With the advent of advanced surgical and bone graftingtechniques, satisfactory prosthodontic prognosis can beachieved for such patients. However there are still someinherent problems in these procedures which have notbeen completely overcome.

On his part the prosthodontists should be able toefficiently plane and execute treatment because the scopeof patients with mandibular defects may vary form thecompletely edentulous patient to the patient with few teethremaining or patients requiring implant supportedprosthesis.

References

John Beumer, Maxillofacial rehabilitation prosthodontic and surgicalreconstruction, 1st edition 1979

Taylor TD, Clinical maxillofacial prosthetics, 1st edition 2000.

William R Laney, Maxillofacial prosthetics, postgraduate dental handbook series, Vol 4.

Kenneth L Stewart, Clinical removable partial prosthodontics, 2nd

edition.

Osbon DB. Early treatment of soft tissue injuries of the face. J OralSurg 1969;27:480–7.

Cantor R and Curtis TA Prosthetic management of edentulousmandibulectomy patients - Part 1. J Prosthet Dent, 1971; 25:447-455.

Cantor R and Curtis TA Prosthetic management of edentulousmandibulectomy patients - Part 2- J Prosthet Dent, 1971;25:547-555.

Cantor R and Curtis TA Prosthetic management of edentulousmandibulectomy patients - Part 3- J Prosthet Dent, 1971;25:671-678.

Shifman A and Lepley JB Prosthodontic management of postsurgicalsoft tissue deformities associated with marginal mandibulectomies. JProsthet Dent, 1982; 48:178-183.

Swoope CC Prosthetic management of resected edentulous mandibles.J Prosthet Dent, 1969; 21:197-201.

Desjardins RP Occlusal considerations in partial mandibulectomypatients . J Prosthet Dent, 1979; 41:308-311.

Kelly EK Partial denture design applicable to the maxillofacial patient. JProsthet Dent, 1965; 15:168-173.

Ackerman AJ The prosthodontic management of oral and facial defectsJ Prosthet Dent, 1955; 5:413-432.

Aramany MA and Myers EN Intermaxillary fixation followingmandibular resection. J Prosthet Dent, 1977; 37:437-443.

Maxillofacial rehabilitation prosthodontic and surgical considerations,John Beumer, Thomas A. Curtis & David N. Firtell; 1st edition 1979

Scannell JB Practical considerations in dental treatment of patientswith head and neck cancer. J Prosthet Dent, 1965; 15:764-778.

Schaff NG Oral reconstruction for edentulous patients after partialmandibulectomies. J Prosthet Dent, 1976; 36:292-297.