Procedures and fabrication of obturators

INTRODUCTIONThe most common of intra oral defects are in the form of cleft or opening in the palate. These defects may be acquired or congenital defect. Acquired defect is due to injuries or surgical excision of tumor. Congenital defect is due to malformation.

Terminologies• Maxillofacial prosthetics :

The branch of prosthodontics concerned with the restoration and/or replacement of the stomatognathic and craniofacial structures with prosthesis that may/may not be removed on a regular or elective basis.

• Maxillofacial prosthesis :

Any prosthesis used to replace part / all of any stomatognathic and / or craniofacial structure.

(Glossary of Prosthodontic Terms- ed 8, J Prosthet dent 2005;94;18)

OBTURATOR :

“Obturare – to stop up”

A maxillofacial prosthesis used to close a congenital /

acquired tissue opening, primarily of the hard palate

and / or contiguous alveolar / soft tissue structures.

(Glossary of Prosthodontic Terms- ed 8, J Prosthet dent 2005;94;18)

HISTORY Ambroise Pare : the first person to close a defect.

one variation of this device a dry sponge was attached to the upper surface of the disc. When the sponge becomes moist by the secretion and it expands and hold the prosthesis in place.

another variation -turn buckle type of mechanism to hold the prosthesis in place.

Pierre Fuchard : Father of scientific dentistry contributed significantly to maxillofacial prosthetics.

described two types of palatal obturators.

wings in the shape of propellers which can be folded together while being inserted and spread out after insertion with a special key.

butterfly wings are made to open by a key after the closed wings have been inserted through the palatal perforation.

William Morton : has been known to treat palatal defect patients with a gold plate to which the patients missing teeth are soldered.

Kingsley described artificial appliances for the restoration of conginital and acquired defects of the palate, nose or orbits.

Functions of an obturator• keep the wound or defective area clean, ,enhance

the healing of traumatic or post surgical defects.

• reshape or reconstruct the defect.

• It also improves or makes speech possible.

• In important area of esthetics -can be used to correct lip an cheek position.

• benefit the morale of patients with maxillary defects.

Functions of an obturator

• When deglutition and mastication are impaired, it can be used to improve functions.

• It reduces the flow of exudates into the mouth.

• The obturator can be used as a stent to hold dressing or packs post surgically.

Fabrication procedures of obturators

Defect consideration:

Congenital Acquired Developmental

Cleft palate Accidents Prognathism

Cleft lip Surgery Retrognathism

Facial cleft Pathology

Radiation burns

Obturators for Congenital Defects of Palate:

A simple base plate type to correct the swallowing feeding and speech.

Obturators with a tail, consisting of a speech

appliance or a speech aid prosthesis.

The third type is an overlay or superimposed denture.

Obturators for Acquired Palatal defects:

Immediate temporary/surgical obturator.

Treatment/Transitional/Interim obturator.

Definitive or permanent obturator.

1978 Dr. Mohammed Aramany presented a system of classification of postsurgical maxillary defects.

He divided the defects into six categories based on the relationship of the defect to the remaining teeth and the frequency of occurrence.

Class I : most frequent defect.

The resection is performed along the midline of maxilla, the teeth are maintained on one side of the arch.

•Mohamed A. Aramany – Basic principles of obtuarator design for partially edentulous patients. Part I : Design principles. JPD 40:554, 1978.

Mohamed A. Aramany – Basic principles of obtuarator design for partially edentulous patients. Part I : Design principles. J.Prosth,Dent. 40:554, 1978.

Class II : similar to kennedy’s RPD class II

The defect is unilateral, retaining the anterior teeth on the contralateral side.

Presurgical consultation with the surgeons can modify a class I to class II.

Class III :

The defect occurs in the central portion of the hard palate and may involve part of soft palate.

Class IV :

The defect crosses the midline and involves both sides of the maxillae.

Class V :

The defect is bilateral and lies posterior to the remaining abutment teeth.

Class VI : rare defect

The defect is lies anterior to the remaining abutment teeth.

due to trauma / may be a congenital defect.

Design consideration

optimum obturator design enhances

communication among prosthodontists The general principles of RPD design : Rigid major connector

Guide planes

Design that maximizes support

Rests

Direct retainers

Control of occlusal plane

Forces

Developing optimum obturator design enhances communication among prosthodontists .

The prognosis of obturator will improve with

Size and curvature of the arch

Quality of the tissue covering the ridge and lining the defect.

Abutment alignment

Availability of teeth on the defect side

• Class I– Linear design

Support- located in a linear fashion.Stability –palatal surface of premolars and buccal surface of molars. Retention –buccal surface of the premolar and

palatal surface of molars

Mohamed A. Aramany – Basic principles of obtuarator design for partially edentulous patients. Part II: Design principles. J.Prosthet.Dent; 40:656, 1978.

• Class I– tripodal design

2 or 3 anterior teeth are splinted.

Retention –from labial surface of anterior teeth with gate design or an I bar on the central incisor;

-Buccal surface of the molars

Stability –from molars palatally Support – rest on the distal surface of the first premolar

Class II – tripodal design

Support- perpendicular to the fulcrum line rest is placed Stability –from palatal surfaces of abutments Retention – from buccal surfaces of the abutment teeth

Class III- quadrilateral configuration

•The design is based on quadrilateral configurations.

•Support is widely distributed on both premolars and molars.

•Retention is derived from the buccal surfaces and stabilization from the palatal surfaces.

Class IV: linear design

The design is linearSupport –on the center of all remaining teeth.Stability-palatal on the premolars; buccal on the molars. Retention- mesially on the premolars. palatally on the molars.

Class V: Tripodal configuration

•Splinting of at least two terminal abutment teeth on each side is suggested.

•I –bar clasps are placed bilaterally on the buccal surface of the most distal teeth.

• Stabilization and support are located on the palatal surfaces.

Class VI- quadrilateral configuration

•2 anterior teeth are splinted bilaterally and connected by a transverse splint bar.•A clip attachment may be used without an elaborate partial framework. •If the defect is large,or the remaining teeth are in less than optimal condition,a quadrilateral configuration design is followed.

BIOMECHANICS

The obturator may be displaced superiorly with the stress of mastication and will tend to drop without occlusal contact.

The degree of movement will vary • with the number and position of teeth that are available

for retention,• the size and configuration of the defect, • the amount and contour of the remaining palatal shelf, • height of the residual alveolar ridge,• the size, contour, and lining mucosa of the defect and

the availability of undercuts

Forces on Obturators

These forces can be • Vertical dislodging force• Occlusal vertical force• Torque or rotational force• Lateral force• Anterior posterior force.

Mohamed A. Aramany – Basic principles of obtuarator design for partially edentulous patients. Part II: Design principles. J.Prosthet.Dent; 40:656, 1978.

Dislodging and rotational forces

The weight of the nasal extension of the obturator exerts dislodging and rotational forces on abutment teeth.

To resist these forces -weight of the obturator be minimal -direct retention and extending the

buccal wall of the nasal extension superiorly.

Occlusal vertical forces

• Activated during mastication and swallowing.• Wide distribution of occlusal rests will help

counteract such force

Lateral forces

It can be minimized by• Covering the medial wall of the defect by a

palatal flap.• Proper selection of the occlusal scheme• Elimination of premature occlusal contacts• Wide distribution of the stabilizing

components.

• Lack of retention, stability and support are common prosthodontic treatment problems for patients who have had a maxillectomy.

Desjardins R.P. : Obturator prosthesis design for acquired maxillary defects. J. Prosthet. Dent, 1978, 39; 424.

•Desjardins R.P. : Obturator prosthesis design for acquired maxillary defects. J. Prosthet. Dent, 1978, 39; 424. •Desjardins R.P. : Obturator prosthesis design for acquired maxillary defects. J. Prosthet. Dent, 1978, 39; 424.

Retention support stability Within the residual maxilla

Teeth

Alveolar ridge

Within the defect

Residual soft palate

Residual hard palate

Lateral scar band

Height of lateral wall

Anterior nasal aperature

Within the residual maxilla

Residual teeth

Alveolar ridge

Residual hard palate Within the defect

floor of the orbit,

the bony structures of the pterygoid plate

the anterior surface of the temporal bone near the infratemporal fossa

The nasal septum may be used if the defect extends beyond the midline.

Within the residual maxilla

bracing components of the prosthesis frame work.

Within the defect

Maximal extension of the prosthesis in all lateral directions must be provided.

Occlusion

Obturator size and extension

Prosthodontic Management:-

• If the defect is to be restored prosthetically, prior to surgery, the prosthodontist should examine the patient thoroughly,

• make impressions for diagnostic casts, • mount these casts on suitable articulators with

jaw relation record and obtain appropriate dental radiographs.

Types of obturators

Surgical obturator: 

It is defined as a temporary prosthesis used to restore the

continuity of the hard palate immediately after surgery or

traumatic loss of a portion or all of the hard palate. The obturator

may be placed immediately after surgery or seven to ten days

post surgically.

Inter rim obturator: 

It was made following completion of initial healing

following surgical resection of a portion or all of one or

both maxillae; frequently many or all teeth in the defect

area are replaced by this prosthesis. This prosthesis

replaces the surgical obturator which is usually inserted at

or immediately following the resection.

Definitive obturator :

• A definitive obturator is made when it is

deemed that further tissue changes or recurrence

of tumor are unlikely and a more permanent

prosthetic rehabilitation can be achieved; it is

intended for long- term use.

OBTURATOR FOR

EDENTULOUS PATIENTS WITH MAXILLECTOMY DEFECTS

• Primary surgical enhancements that can improve prosthesis outcome are:

• Maintain as much hard palate as possible

• Remove the inferior turbinate(to have space with in the surgical defect for height of the medial wall of obturator bulb)

• Skin graft the maxillary sinus walls

Phases of prosthetic restoration

Surgical obturator prosthesis:

Use of immediate surgical obturator is less

common for the edentulous patient than the

dentulous patient because of seemingly invasive

method of securing the prosthesis.

Securing the prosthesis requires use of

palatal bone screw,

sutures in to the surrounding mucosa,

or circumzygomatic wires.

Interim obturator prosthesis :

Impression : 5-10 days after

surgery.

The base plate used for the surgical

obturator can be relined and

modified to serve as the interim

prosthesis.

Patient movements, speech and swallowing evaluation during border molding :

Perform exaggerated head movements

Turning right - left with head level

Flex – extend - neck

The mandible moved laterally

The peripheries of the bulb portion will likely be 2-3 cm in height and there is no need to fill entire sinus space.

If the prosthesis is extended below the palatal plane , problems occur :

Space required for tongue function is violated.

Injured soft palate junction will contract – causing irritation to the patient.

The posterior border will be extended over the cut edge of the soft palate

Insertion of interim prosthesis : After the tissue conditioner impression – it can be used as a wax

pattern - flasked -packed in self cure / heat cure resin.

The patient should be instructed not to leave the prosthesis out for more time than is needed to clean the surgical site.

Revisions: every 10-14 days over the next 2 months due to tissue changes in the surgical site.

Definitive obturator prosthesis :

4-6 months after surgery ;

Timing will vary depending on ;

Size of the defect

Progress of healing

Prognosis for tumor control

Effectiveness of present obturator

Is not indicated until –

surgical site is healed and dimensionally stable

Patient is prepared physically and emotionally for the restorative care.

Preliminary impression :

Should offer maximum extension within the surgical site.

Cavity is large - regardless of the tissue / bony undercuts – not

necessary to block the cavity which creates under extended

impression.

Stock edentulous tray - necessary to support the surgical side of

the material with compound / wax. necessary to inject the

material into surgical cavity.

Final impression :

Custom acrylic resin tray should extend 2-3mm into the cavity,

border molded and then impressed with a definitive impression

material

Compound should be added incrementally and the tray should

be supported diagonally against the residual palate / alveolus ;

With each increment the swallowing and head movements should be made

The cavity is convex from inferior-superior and at the height of the convexity the cavity walls begin to turn toward the center of the cavity, at this point the superior aspect of the prosthesis bulb should terminate ;

Jaw relationship records :

If it is an intra oral maxillectomy the lip and cheek can be easily supported by dentition of the Obturator.

If more of the maxillary bones are resected tooth position and the flange of the prosthesis must be placed palatally

Processed record bases are ideal for jaw relation records.

Maxillary anterior rim – wet-dry line of lower lip –there should be attempt to displace the contracted lip – however if the prosthesis begins to loose retention the wax rim will require reduction of facial aspect.

When making the centric relation record – manually stabilize the maxillary prosthesis,

Try-in appointment -all records verified

The final palatal contours should be evaluated

Place wax / reduce resin until the palate is symmetric.

Pressure indicating paste – ask the patient to swallow and count, and the heavy areas should be reduced.

TROUBLE SHOOTING THE OBTURATOR PROSTHESIS

• Leakage into the nose :

continued fibrosis in the tissues

Prosthesis is disclosed with a tissue conditioning material –

swallowing and speech improve the disclosing material

should be evaluated where the tissue conditioner is thickest.

• Hypernasal speech :

Disclosure of the bulb often reveals that the surface contact is

adequate and the prosthesis is adequately closed at the

periphery.

Relining of the prosthesis periphery will not alter the

hypernasal speech.

If there is adequate space to add a pharyngeal bulb to the

posterior medial aspect of the prosthesis, this bulb can pass

superiorly to the cut edge of soft palate and extend into the

pharynx.

So the conventional obturation prosthesis will obturate the hard

palate defect and the extension will obturate the nasopharynx.

• OBTURATOR FOR DENTULOUS PATIENTS WITH MAXILLECTOMY DEFECTS

A foam impression technique for maxillary defects

Schmaman, Mdent, Carr. A foam impression technique for maxillary defects. J Prosthet Dent 1992;68:324-4.

• Surgical obturator prosthesis :

• Design : It should be designed and fabricated

with the understanding that it can’t be tried in

and adjusted preoperatively but must fit and

function as intended without adjustment.

May be fabricated with holes placed at periphery

to permit suturing / wiring.

• Fabrication and use :The teeth in the area of resection are removed

surrounding alveolar process in the planned defect area is reduced by approximately 2mm.

Substantial interdental and soft tissue undercuts are blocked out and the cast is duplicated.

If clasps are added, it is important to place them in areas that will not interfere with seating of obturator nor interfere with occlusion of opposing teeth.

2 thickness of baseplate wax is adapted to the duplicate cast as outlined,.

• Post surgical obturator :

Design : original cast is evaluated for suitability as a master cast.

If the cast surgery was more conservative than the actual procedure, the cast should suffice for creation of the base portion of the obturation.

If the surgery was less aggressive. It will be necessary to use the unaltered cast made from preoperative impression.

Fabrication and use :

Fabricated of resin with wire retentive clasps in strategic locations.

Substantial retentive undercuts and multiple clasps may be required to retain the post surgical obturator.

The resin base portion of the prosthesis should contact the axial surface of all remaining teeth whenever possible.

HOLLOW BULB OBTURATOR Advantages : The wt of the prosthesis reduced – comfortable and efficient. The lightness of prosthesis

• Improves problems of retention • Increases physiologic function • Decreases the consciousness of wearing a denture.

• Doesn’t cause excessive atrophy and physiologic changes in muscle balance.

Decrease in pressure to the surrounding tissues aids in deglutition and encourages regeneration of tissue.

OPEN / CLOSE OBTURATOR

Open: Patient complains of food, fluid and mucous accumulations

Bad odor and altered taste sensation

Benefit to patient

Reduced wt ; ease of fabrication; increased speech intelligibility.

Closed : Prevent food and fluid collection Reduce air space Allows maximum extension

But

Fluid can be absorbed through porosity in the resin seal and it can’t be cleaned (closed)

This creates a medium for growth of microorganisms.

Techniques:

Several techniques are used for the fabrication of hollow bulb obturator .

The commonly used ones are:

1.Two piece hollow obturator

2.One piece hollow obturator

FABRICATION OF ONE PIECE HOLLOW BULB OBTURATOR

Procedure

- Try the trial denture in the mouth and make necessary modifications.

- Waxup the denture after the try in.

- Invest the denture in the flask in the usual manner.

Construction of autopolymerizing acrylic resin shim

- Relieve the entire defect area with one thickness of base plate wax.

- Place three stops in the wax which will be deep enough to reach the underlying stone of the master cast.

- Contour a layer of dough consistency acrylic resin over the wax relief

-

Close the flask, Allow the resin to cure for 15 min.

Trim all the excess of acrylic resin from the shim.

Replace the heat cure acrylic resin shim using 3 stops for correct positioning.

Placement of acrylic resin shim and denture processing Reinsert the processed acrylic resin shim over the still soft acrylic

resin mix in the defect.

Add more acrylic resin to the top half of the flask and packing is done.

Cure the resin in the usual manner.

Deflask it and trim and polish in usual manner

V

FABRICATION OF TWO PIECE HOLLOW BULB OBTURATOR Most frequently used technique

More hygenic & more esthetic.

Method:

1. The master cast with the clasps in place is then waxed over with base plate wax approximately 2mm thick. This includes the defect area, the base,the medial,and the posterior & the labial walls, keeping open the palatal ridge side.

Modelling Clay is sculpted to the palatal defect and missing alveolus.

Modelling clay covered with tinfoil as a separating medium,& next the lid, false palate,& ridge are waxed.

After wax lid is separated, the tinfoil & modelling clay from the master pattern are discarded,& the wax lid & master cast with the clasps & wax pattern are flasked separately.

The 2 portions of the prosthesis are boiled out & processed with heat cure resin.after processing, the 2 parts are deflasked.

the margin of the lid portion is perforated for retention & then sealed over the main base in its proper position.this is accomplished by applying monomer to the adjoining periphery &then luting 2 parts with self curing resin.

Alternative method for fabrication of a closed hollow obturator

Glen, Donald,Santra. Alternative method for fabrication of a closed hollow obturator. J Prosthet Dent 1986;55:485.

Hollow obturator with removable lid

Phankosol P, Martin JW. Hollow obturator with removable lid. J Prosthet Dent 1985;54:98-100.

Mouth guard material- lid

Simplified method of making hollow obturator

Matalon V, La Fuente H. A simplified method for making a hollow obturator. J Prosthet Dent 1976;36:580-2.

A simplified technique for fabricating a lightweightobturator

• simple procedure that utilizes polyurethane foam for the core.

• efficient and economical

Tanaka Y, Gold HO, Pruzansky S. A simplified technique for fabricating alightweight obturator. J Prosthet Dent 1977;38:638-42.

Hollow obturator with resilient denture liner

Kamadjaja: Manufacturing hollow obturator with resilient denture liner. Dent. J., Vol. 39. 2006: 16–18

Light cured hollow obturators

Benington IC. Light-cured hollow obturators. J Prosthet Dent 1989;62:322-5.

Light-cured combination obturator prosthesis.

Uses the combination of VLC denture base and indirect resilient relining materials

Polyzois GL. Light-cured combination obturator prosthesis. J Prosthet Dent1992;68:345-7.

Buccal flange obturator

Koray oral. Construction of buccal flange obturator prosthesis. J Prosthet Dent1979;41:193

Combination obturator

Geogary Parr. A combination obturator prosthesis. J Prosthet Dent 1979;41:329

An innovative investment method -of a closed hollowobturator prosthesis

Karen S. McAndrew,Sandra Rothenberger, Glenn E. An innovative investment method -of a closed hollow obturator prosthesis.J.Pros dent, 1998;80:129-32.

Technique for quick conversion of an obturator into a hollow bulb

Asher, Jackson, Robert:Technique for quick conversion of an obturator into a hollow bulbJ.Pros dent, 2001;85:129-32.

INFLATABLE OBTURATOR

Payne, Welton. An inflatable obturator for use following maxillectomy. J.Pros Dent, 1965;15:175.

Magnets retaining maxillaryobturator prostheses

Boucher, Edwin: Prosthetic restoration of a maxilla And associated structures.J Prosthet Dent 1966;16:154-60.

Implants retaining edentulous maxillaryobturator prostheses

Roumanas, Nishimura, Davi. Clinical evaluation of implants retaining edentulous maxillary obturator prosthesess.J Prosthet Dent 1997;77:184-90.

MANAGEMENT OF THE SOFT PALATE DEFECT

Defects of soft palate frequently present as perflexing

problems to the clinician. One among is lack of universal terminology.

Abnormalities of soft palate can occur in different ways. defects grouped in to congenital, acquired or developmental.

Beyond etiology defects are also classified based on anatomy and physiology of involved structures.

Palatopharyngeal insufficiency : when some / all of the anatomic structure of the soft palate is absent.

Palatopharyngeal incompetence : soft palate is of normal dimension but lacks movement because of disease / trauma affecting muscular and / or neurologic capacity.

Palatopharyngeal inadequacy : includes incompetence and / or insufficiency but may also suggest a reduction or absence of pharyngeal wall function.

A pharyngeal obturator prosthesis / speech aid / speech bulb prosthesis, extends beyond the residual soft palate to create separation between the oropharynx and nasopharynx.

The pharyngeal obturator prosthesis does not displace the soft palate but replaces missing portions of the soft palate.

TECHNICAL CONSIDERATIONS OF PHARYNGEAL OBTURATOR PROSTHESIS

Obturator section of the prosthesis is formed after oral portion of the prosthesis is completed.

A retentive loop is extended posteriorly: – This extension should be parallel and as close to the palatal plane as possible.

High fusing modeling compound : added to retentive loop

After the warmed modeling compound addition is inserted, the patient is instructed

To flex the neck fully to achieve contact of the chin to the chest: this movement will establish contact of the posterior aspect of the obturator with the soft tissue covering the anterior tubercle of the atlas.

Lateral aspects of the obturator are formed by rotation and flexion of the neck to achieve chin contact with right and left shoulder.

Compound is re warmed and inserted and the patient is asked to swallow warm water to elicit pharyngeal muscle activity

When the border molding is completed there should be :

No escape of liquid from the oral-nasal cavities.

Speech should sound normal, with the patient able to articulate plosive sounds such as p and b yet still be able to form the nasal consonants m, n and ng.

If either set of sounds is less than satisfactory the borders should be checked for over / under extension.

A coating of mouth temperature wax is adapted – for 8-10 mins during which the neck movements, swallowing and speech tests are performed.

If the patient is unable to breathe comfortably – a compromise will be necessary between completely sealing the port and reducing the lateral aspects of the obturator – such a reduction may result in return of hyper nasality.

Inferior portion of the obturator is maintained parallel to the horizontal hard palate:

This design is indicated when the entire soft palate has been lost in an edentulous patient. (Taylor &Desjardins)

The meatus obturator projects vertically – this vertical portion of the prosthesis is made in modeling compound supported by wire loop extending vertically into the area of the posterior nares

A meatus obturator is designed to close the posterior nasal choanae through a vertical extension from the distal aspect of the maxillary prosthesis.

Technical considerations with meatus obturator :

Prosthesis is inserted with a rotational path

Incremental additions are made to register the

anatomy of the posterior nasal openings in low fusing

Compound.

When the anatomy of both the posterior nasal openings are

registered the patient should not be able to breathe through

the nose with the obturator in place.

After the meatus extension has been processed onto the

denture, it is necessary to determine whether the patient is

satisfied with the extension or it would be preferable to

provide for nasal breathing.

A small hole should be placed through each side of the

prosthesis so that breathing is possible through both nostrils.

Evaluation of effectiveness of treatment

• Following treatment pt will experience hypernasal speech if the palatopharyngeal contact is ineffective.if contact is excess the pt will experience hyponasal speech.(Millard&Marshall)

• pt reports of food or fluid regurgitation may indicate inadequate palatopharyngeal closure.

JPD1970;24:304

CONCLUSION A majority of Patients with congenital and acquired defects of the maxilla can be rehabilitated with a fair amount of clinical success if the prosthodontist has a sound knowledge and skill of diagnosis, the principles and techniques involved in the fabrication of the obturator prosthesis.

A properly fabricated obturator can help restore the anatomy and function of the lost tissues and goes a long way in rehabilitation and improving the quality of life of such patients.

Thank You