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Different types of definitive obturator are:

(i) Closed hollow bulb design

(ii) Open obturator design

Hollow bulb obturator

• Hollow bulb obturator is a type of a definitive obturator which is

given approximately 6 months postsurgery.

General considerations

• Bulb fabrication is not necessary in cases where the central palate

defect is small.

• It should not cause movement of the eye during mastication.

• It should be a single piece rather two piece to aid in colour matching

and better patient acceptance.

• It should not be too large because insertion of the prosthesis will be

tedious to the patient, especially in cases where there is restricted

mouth opening.

Advantages

• As it is hollow, the weight is considerably reduced on the

unsupported side.

• It results in better acceptance by the patient.

• As the prosthesis is light, it is better retained and improves the

physiological function.

• Lightness of obturator does not cause excessive atrophy and

physiological changes in the muscle balance.

• It aids in speech resonance.

• It aids in deglutition, as it decreases pressure on the surrounding

tissues.

Types of hollow bulb obturator

(i) Closed hollow bulb obturator – single/two piece type

(ii) Open hollow bulb obturator

Methods of fabrication

• Acrylic resin obturator

• Silicone bulb obturator

• Balloon obturators

• Light-cured hollow obturators

Technique for fabrication for edentulous patients (V.A. Chalian)

• After final impression, cast is poured and the undesirable undercuts

are blocked.

• Stabilized baseplate is flowed in the defect area.

• Wax lid is placed over the defect area to leave it hollow and to

provide the effect of complete palate.

• Occlusal rims are fabricated and the jaw relations are recorded.

• Teeth are arranged and wax try-in is done in conventional manner.

• During the laboratory procedure, the palatal defect is filled with

modelling clay and is given a palatal shape.

• A false lid is fabricated with autopolymerizing acrylic resin.

• The remaining temporary waxed denture is flasked and processed

conventionally.

• The lid is then added to the master base to close the palatal portion

of the hollow bulb and is sealed with self-curing acrylic resin.

• The denture is later finished and polished as routine procedure (Fig.

32-5).

FIGURE 32-5 Definitive closed hollow bulb obturator.

Aramany’s classification of maxillary defects

M. Aramany (1978) classified postsurgical maxillary defects on the

basis of the relationship of the defect to the remaining abutment teeth.

Rationale for classification

• Increase in number of patients undergoing resection of the maxilla

• Need for definitive prosthesis after resection

• Increase in percentage of younger patients

Classification

Class I: The resection is done along the midline of the maxilla and the

teeth are maintained on one side of the arch; this is the most

common maxillary defect (Fig. 32-6).

Class II: The defect is unilateral, retaining the anterior teeth on the

contralateral side. The central incisor and sometimes all the anterior

teeth to the canine or premolars are preserved (Fig. 32-7).

Class III: The defect occurs in the central portion of the hard palate

and may involve part of the soft palate (Fig. 32-8).

Class IV: The defect crosses the midline and involves both sides of the

maxilla (Fig. 32-9).

Class V: Surgical defect is bilateral and lies posterior to the remaining

anterior teeth (Fig. 32-10).

Class VI: Surgical defect which is anterior to the remaining abutment

teeth; this is the least frequently occurring class, occurs mostly in

trauma or congenital defects rather than in planned surgical

intervention (Fig. 32-11).

FIGURE 32-6 Aramany class I – midline resection of maxilla.

FIGURE 32-7 Aramany class II – unilateral defect with

retained anterior teeth on contralateral side.

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FIGURE 32-10 Aramany class V – bilateral defect posterior

to remaining anterior teeth.

FIGURE 32-11 Aramany class VI – bilateral defect anterior to

remaining teeth.

Soft palate obturators

Classification of the soft palate defects on the basis of location and

nature of the defect was given by J. Beumer and T.A. Curtis.

The classification is as follows:

(i) Total soft palate defects: This involves the entire soft palate.

(ii) Posterior border defects:

• Median posterior border defects: This involves the

posterior half of the soft palate.

• Lateral posterior border defects: This involves the

lateral half of the soft palate and often the lateral

pharyngeal wall.

Types of the soft palate obturator

Palatal lift prosthesis: Given when all the structures are intact except

the posterior border of the soft palate.

Meatus obturator: Given when defect involves the hard and soft

palates.

Objectives of soft palate obturators

• To control nasal emission during speech

• To prevent leakage of foreign material into the nasal passage during

deglutition

Palatal lift prosthesis

• This was first described by P. Gibbons and H. Bloomer (1958).

• It is indicated in patients with palatopharyngeal incompetence

exhibiting compromised motor control of the soft palate and related

musculature.

Objective

To displace the soft palate to the level of the normal palatal elevation

enabling closure by pharyngeal wall action (Fig. 32-12)

FIGURE 32-12 Palatal lift prosthesis.

Indications

• Myasthenia gravis

• Cerebrovascular accidents

• Traumatic brain injuries

• Cerebral palsy

• Injuries of the soft palate

Contraindications

• In case of inadequate retention of the prosthesis

• If the patient is not cooperative.

• If palate cannot be displaced.

Advantages

• Gagging is minimized.

• Access to the nasopharynx for the obturator is facilitated.

• Function of the tongue is not compromised.

• Lift portion of the prosthesis can be developed sequentially to aid in

patient’s adaptation of the prosthesis.

Meatal obturator

• It is first described by A. Schalit (1946) and J. Sharry (1950).

• It is indicated in patients with extensive defect of the soft palate

and/or patient having very active gag reflex.

• It is the obturator of choice when retention of the prosthesis is an

issue in edentulous patients.

• It extends superiorly and slightly posteriorly from the hard palate

border and separates the oral and nasal cavities at this level (Fig. 32-

13).

FIGURE 32-13 Meatal obturator.

Advantages

• It has less weight than a conventional obturator.

• Downward displacement force from the obturator extension is

closer to the supporting tissues of the parent prosthesis.

• It provides improved retention and stability of the prosthesis.

• It provides more physiological separation between oral and nasal

structures.

Disadvantages

• It does not provide valving mechanism for speech.

• It provides static obturation.

Mandibular defects

Classification of mandibular defects

R. Cantor and T. Curtis (1971) devised a prosthetic classification of

the mandibular defects on the basis of amount of resection of the

mandible and was limited to edentulous patients.

Class I: Radical alveolectomy with preservation of mandibular

continuity. A portion of the alveolar process and body of the

mandible along with the mucoperiosteum was resected. Prognosis

of the treatment was good.

Class II: Lateral resection of the mandible distal to the cuspid. The

condyle, ramus and body of the mandible distal to the cuspid were

resected. Prognosis for this class is fair.

Class III: Lateral resection of mandible to the midline. Tissues

resected in class II and the anterior portion of the mandible.

Prognosis for this class is poor (Fig. 32-14).

Class IV: Lateral bone graft surgical reconstruction. This can be

performed in the patients of any of above three classes.

Reconstruction is done by augmentation procedures, bone graft

connecting a residual condyle with large mandibular segment or

lateral bone grafts. Prognosis varies with the type of reconstructive

surgery (Fig. 32-15).

Class V: Anterior bone graft surgical reconstruction. Anterior portion

of the mandible is resected along with the adjacent structures.

Prognosis depends on how well the graft takes up.

Class VI: Resection of the anterior portion of the mandible without

reconstructive surgery to unite the lateral fragments. Prognosis is

very poor for this type of defect.

FIGURE 32-14 Class III – resection.

FIGURE 32-15 Class IV – Lateral bone graft surgical

reconstruction.

I.K. Adisman (1962) classified mandibular resection as follows:

Partial resection: In this type, part of mandible is resected in definite

sections (e.g. ramus, hemimandibulectomy, between the mental

foramen).

Partial and step resection: In this type, part of the mandible is

resected but steps are made surgically in the residual mandible to

preserve the anterior mandibular arch by retaining as much of the

lower border of the mandible as possible.

Total or subtotal resections: In this type, entire mandible is resected

or mandible is resected up to the coronoid process and the condyle

is left intact.

Marginal resection: In this type, only marginal sections of the

mandible are resected and the continuity of the bone is intact.

Segmental resection: In this type, segments of the body of the

mandible are removed involving the condylar process. These are

repaired by splint or bone grafts at the time of the surgical resection.

Prosthetic management of the mandibular defects

For dentulous patients

(i) Guide plane prosthesis

• Mandibular guidance appliance

• Palatal-based guidance

(ii) Snap-on prosthesis for segmental resection of partially dentulous

mandible

(iii) Prosthesis for segmental resection of fully dentulous mandible

(iv) Overlay or superimposed prosthesis for marginal excision of

dentulous mandible

(v) Superimposed prosthesis

For edentulous patients

(i) Complete dentures with double row of teeth in the upper denture

on the nonresected side (Fig. 32-16).

(ii) Complete denture with palatal ramp on the nonresected side.

FIGURE 32-16 Complete denture with double row of teeth on

unresected side.

The treatment of the maxillofacial patients should include a careful

preoperative evaluation consisting of the following:

• Careful clinical and radiographic evaluation

• Diagnostic models

• Jaw relation records

• Facial photographs

• Interaction of prosthodontist with other surgeon

The rehabilitation of the maxillofacial patient depends on the extent

and location of the defect:

• Amount of residual mandible

• Amount of deviation

• Remaining kinaesthetic sense and control

• Nature of denture-bearing area

Extraoral prosthesis

Ocular or eye prosthesis

It is defined as ‘a maxillofacial prosthesis that artificially replaces an eye

missing as a result of trauma, surgery, or congenital absence. The prosthesis

does not replace missing eyelids or adjacent skin, mucosa or muscle’. (GPT

8th Ed)

• Ocular prosthesis is an artificial replacement for the bulb of the eye.

• Causes of ocular defects are trauma, neoplasm or congenital

conditions such as cryptophthalmos and microphthalmos.

• Ocular prosthesis is made 10–14 days postsurgery.

• At the time of surgery, a conformer is usually placed into the socket

to maintain the fornices.

• Conformer is made of clear acrylic and should be large enough to

support the lids and keep them from collapsing until the artificial

eye is fabricated.

• The eye socket is carefully examined to analyse the amount of

orbital adipose tissue and the extent of atrophy of muscle and other

related tissues.