Radiation displacement prostheses for dentulous patients

Radiation dentulous

displacement patients

prostbs

for

Mohamed A. Aramany, B.D.S., M.Sc.,* and Joe 8. Drane, D.D.S.** School of Dental Medicine, University of Pittsburgh, and M. D. Anderson Hospital and Tumor Institute, Houston, Texas

D 1 rost h eses used

in the various modalities of radiotherapy in the oral and paraoral regions have been classified by Drane and Rahnl as locators, carriers, and stents. Stems are the most common prostheses constructed for radiotherapists by dentists. The technique described for the construction of the stents frequently demands lengthy clinical and laboratory procedures. 2* 3 Patients with intraoral lesions suffer from the inconvenience of lengthy dental manipulations. Also, dentists involved in hospital work are often pressed for time. Thus, the development of a simplified technique for the construction of radiation stents is essential. OBJECTIVES Intraoral stents for radiotherapy serve placing the tongue, lips, or cheeks away stances, the lesion is displaced and held placed in the oral cavity to facilitate the during every treatment period. In addition, the stent serves to protect contiguous normal

several functions. The stents help in disfrom the path of radiation. In other inin the same place whenever the stent is application of the beam on the same site inserting lead (or lead alloy) shields in tissues.

PROCEDURE Patients who are to receive radiotherapy to the head and neck must be given a thorough oral examination before the beginning of the treatment. If the teeth are to be retained, the patient receives prophylactic treatment to improve oral hygiene and is provided with a fluoride carrier to be used during and after the radiotherapy. Frequently, patients who require radiation for lesions in the floor of the mouth, tongue, or palate need a radiation stent. A simple direct wax-pattern technique was developed for the construction of radiation stents in dentulous patients. *Associate Professor University of Pittsburgh.

and

Director,

Maxillofacial

**Professor, Maxillofacial Prosthetics, and Center, The University of Texas Dental Branch.

Prosthetics, Director,

Regional

School

of Dental

Maxillofacial

Medicine, Restorative

ifl%:r‘2’

Radiation

Fig. 1. A recurrent floor

Fig.

squamous cell carcinoma of the mouth, and gingivae. 2. A double thickness of baseplate wax

is located is pressed

displacement

in the anterior on the occlusal

two surface

prosthesis

thirds

213

of the tongue,

of the mandibular

teeth.

Fig. 3. The wax pattern registers the imprints Fig. 4. The imprints of the maxillary teeth the softened

wax

made

by the cusps.

are obtained

by

allowing

the patient

to close

on

rims.

Before the construction of the stent, the radiotherapist marks the tentative field of radiation with the dentist present. The objectives to be achieved by the stent are also discussed at this time. The procedure requires one short clinical appointment during which the wax pattern is formed. The pattern is processed either in cold-curing or heat-curing acrylic resin.

FORMING THE WAX PATTERN The patient is asked to open his mouth, and the lesion is examined (pig. 1). The required interocclusal separation is measured with a Boley gauge. A double thickness of hard-setting baseplate wax is softened and cut with a pair of scissors to the general shape of the mandibular arch. The wax is lightly pressed on the occlusal surface of the teeth and shaped to cover the tongue while it is in the required position (Fig. 2). This tongue depressor pattern is cooled and removed from the patient’s mouth (Fig. 3). Wax rims are built on the superior surface of the pattern on either side. The occluding surfaces of the rims are softened, and the pattern is placed in the mouth. The

214

Aramany

Fig. 5. The waxed stent is checked in relation to the tentative radiation Fig. 6. The tongue depressor part of the stent extends posteriorly the

J. Prosthet. February.

and Drane

Deny. 1972

field. to control

the position

of

tongue.

patient is instructed to open his mouth as wide as he can. The pattern is inserted in its previous place on the mandibular teeth. The patient is instructed to close lightly until the previously determined jaw separation is attained (Fig. 4). The pattern is cooled with air and removed from the mouth. The indentations of the maxillary teeth are reduced with a sharp knife to the level that includes only the occlusal surfaces. The wax pattern may be checked in relation to the tentatively marked radiation treatment field before dismissing the patient (Fig. 5). Radiographs are made on the simulator to assure the effectiveness of the stent. Usually, this step is made later, after the stent has been finished. Certain modifications of the wax pattern may be necessary to achieve additional requirements. The tongue depressor may be extended further posteriorly for patients receiving radiation to the soft palate (Fig. 6). I n other patients, a flange may be built to displace the tongue or the cheeks. All modifications are made before flasking the stent. PROCESSING Although clear heat-cured resin gives the best looking stent, the use of coldcuring resin reduces the laboratory time with less chance of increasing the vertical jaw separation. The wax pattern is half-flasked with the tongue depressor facing upward. The flasking is completed, and the wax is eliminated. The opened flask is painted with a tinfoil substitute. The bottom part of the flask is packed with cold-curing acrylic resin dough. One trial closure of the flask is usually sufficient. The flask is kept under pressure for 30 to 45 minutes after which time the stent is deflasked, finished, and polished. PLACEMENT

OF THE STENT

The radiation stent is tested in the mouth by personnel in the radiotherapy department. One or more radium seeds are implanted in the region of the lesion for localization, and the stent is inserted. The patient is placed on the simulator, and

Volume Number

27 2

Radi.ation

Fig. 7. A radiograph clusion of the maxillary

displacement

prosthesis

made on the simulator shows the tentative radiation arch. The seed indicates the site of the tumor.

Fig. 8. A radiograph made excluded from the field.

after

the

insertion

of the

stent.

Note

that

field. the

Note

maxillary

215

the inarch

is

Fig. 9. A recurrent squamous cell carcinoma is located at the margins of the surgical site on the soft palate with the stent in place. The lesion and the position of the tongue can be easily seen. The stent enables the tongue and mandible to be displaced from the field of radiation.

the field is adjusted on the monitor screen. Lateral radiographs are made the field (Figs. 7 and 8). The stent is kept in a sterilizing solution in the radiotherapy department placed in the mouth during the treatment period, and then it is removed, and kept in the cold sterilizer until the following day. The treatment period about six weeks. The stents are kept in the maxillofacial department after ment is completed for educational purposes.

to verify and is cleaned, averages the treat-

ADJUSTMENTS The stent may be adjusted by grinding interfering sites. Additional vertical separation of the jaws may be achieved by adding cold-curing occlusal surface of the stent in the oral cavity.

increase in resin to the

DISCUSSION Radiation ation therapy.

stents are short-term

prostheses

used only for the duration

of the radi-

216

Aramany

J. Pro&et. Dent. Februsry, 1972

and Drane

The oral lesions are usually painful. Lengthy intraoral manipulations for making the impressions and jaw relation records cause great discomfort to the patient” The simplified technique shortens the chair-side time to less than 30 minutes. The laboratory steps including pouring the casts and mounting them on the articulator are eliminated. The design of the stent allows the dentist to view the lesion and the position of the tongue (Fig. 9). In addition, the stent effectively controls the tongue position and permits the reproduction of the same degree of jaw separation for every treatment period. The use of cold-curing resin reduces the curing time of the stent. SUMMARY A simplified technique for the construction of radiation stents for dentulous patients was discussed. The technique involves the use of a direct wax pattern from which a stent is made of cold-curing resin. References 1.

2. 3. 4.

Drane, J. B., and Rahn, A. 0.: Maxillofacial Prosthetics, in MacComb, W. S., and Fletcher, G. H.: Cancer of the Head and Neck, Baltimore, 1967, The Williams and Wilkins Company, p. 517-537. Santiago, A.: Use of Intra-oral Prosthesis in Radiotherapy, Med. Rec. & Ann. 58: 3-11, 1965. Santiago, A.: An Intra-oral Stent for the Direction Beam Therapy, J. PROSTHET. DENT. 15: 938, 1965. Jerbi, F. C., Ramsey, 0. W., and Drane, J. B.: Prostheses, Stents and Splints for the Oral Cancer Patient, CA 18: 341-352, 1968. DR. ARAMANY: CLEFT PALATE CENTER UNIVERSITY OF PITTSBURGH PITTSBURGH, PA. 15213 DR. DRANE: THE UNIVERSITY OF TEXAS M. D. ANDERSON HOSPITAL HOUSTON, TEXAS 77025

DENTAL BRANCH AND TUMOR INSTITUTE