BLACK
SUMMARY A technique for fabrication of a gated surgical prosthesis to allow for immediate obturation of the dentate patient is described. This proskhesis offers a wide range of stabilizing options and provides a simpler, smoother transition between wire-stabilized and removable obturation.
3. Academy of Denture Prosthetics. Principles, concepts, and practices in prosthodontics-1989. J PROSTHETDENT 1989;61:88-109. 4. Frame RT, King GE. A surgical interim prosthesis. J PROSTHETDENT
1981;45:108-10. 5. Desjardins R. Early rehabilitative management of the maxillectomy patient.J PROSTHETDENT1989;61:344-5. 6. Huryn JM, Pire JD. The maxillary immediate surgical obturator prosthesis.J PROSTHETDENT1989;61:344-5. Rep&t requests to: DR. WILLIAM&BLACK
REFERENCES 1. Cancer facts and figures, 1988. The American Cancer Society, New York, 1988. 2. Gainsford JC, ed. Symposium on cancer of the head and neck, ~012. St Louis: CV Mosby, 1969:101-3.
A foam impression
technique
SCOTT&WHITE CLINIC Z~OISOUTH~UTSTREET TEMPLE,TX 76508
for maxillary
defects
J. Schmaman, BDS, MDent,a and L. Carr, BDS, MDentb University
of ‘Witwatersrand,
Johannesburg,
South
Africa
This article presents a technique used to overcome the problems of withdrawal of maxillectomy defect impressions with or without limited space as the result of trismus.(J PROSTHET DENT 1992;68:342-4.)
aSpecialist/Lecturer, Department of Prosthetic bSenior Specialist/Senior Lecturer, Department Dentistry.
B&W37619
Dentistry. of Prosthetic
U
se of the established impression techniques of recording maxillary defects can result in various problems for the clinician. Many maxillary defects are characterized by a cleft or opening that is smaller than the width of the nasal cavity (Fig. 1). A common problem in recording maxillectomy defects is the presence of large undercuts, which create difficulty in withdrawing the impression. Impression material that is too rigid can traumatize the tissue on removal, but more elastic materials, such as irreversible hydrocolloids, often tear. This is particularly true when a composite prosthesis requires a section that projects into the nasal cavity. An additional problem in certain patients is trismus, which limits access to the defect. A few impression techniques are mentioned in the literature. Luebkel describes a sectiona tray for use in patients with trismus. Beumer et aL2 advocate a method in which the impression is refined with modeling plastic, a soft flowing wax, and an elastic impression material to record the defect. Carl3 indicates the need for adhesives and undercuts that add additional alginate to a set impression when necessary.
TECHNIQUE An intraoral primary impression of the maxilla and the entry to the defect is taken in the conventional manner with irreversible hydrocolloid. 2. A special tray is fabricated on the cast of the residual maxillary structures. A mushroom-shaped acrylic resin retention-relocating button is added to the special tray (Fig. 2 [blue]). 1.
Fig. 342
1. The defect.
AUGUST
1992
VOLUME
68
NUMBER
2
FOAM
Fig.
IMPRESSIONS
FOR
MAXILLARY
DEFECTS
Fig.
4. Withdrawing the impression.
Fig.
5. Impression ready for casting.
2. Special tray and siliconerubber impressionin po-
sition.
Fig.
3. Injecting foam with modified syringe and nipple.
3. A 20ml disposableplastic syringe ismodified to received a latex feeding nipple (Fig. 3). The tip of the nipple is cut to widen the aperture to approximately 5 mm. 4. The nasopharynx and orifices within the defect are blocked with petrolatum gauze. 5. Pressurepoints and extensionsof the custom tray are adjusted with a pressure-indicatingmaterial. 6. After adhesiveis applied to the tray, siliconerubber impressionmaterial is loaded onto the tray; the retentionrelocating button is excluded. An impressionof the reTHE
JOURNAL
OF PROSTHETIC
DENTISTRY
sidual structures, including the perimeter of the defect, is taken in the normal manner (Fig. 2 [black]). 7. The impressionis withdrawn and is checked for detail and extension. Any material that hascrept onto the retention-relocating button is removed with a scalpel blade. The tray with the rubber impressionis replaced in the mouth and is held securely in position. The patient is instructed to breathe through the mouth during the next procedure. 8. The plunger is removed from the syringe and the nipple is folded to prevent leakagewhile the syringe is being loaded. The desiredvolume (3 ml) of Silastic Foam liquid (Silastic Foam Dressing,Dow-Corning Medical S.A., Valbonne, France) is poured into the syringe. Catalyst is added according to the manufacturer’s instructions, and the material is rapidly and thoroughly mixed with a thin spatula. 9. The plunger is replaced and the nipple is inserted into the nostril that is continuous with the defect. The foam 343
SCHMAMAN
is rapidly injected through the nostril into the nasal cavity, and the syringe is removed (Fig. 3). 10. The defect and nasal cavity are filled when the foam, which expandsto four times its original volume, exudes from the nostril. After setting is complete, this excess foam is removed with scissors. 11. The tray with the rubber impressionis removed from the mouth, and the retention-relocating button is withdrawn from the extremely elastic foam. 12. The foam impressionis removed by inserting a finger into the nostril and pushing the foam downward into the oral cavity and by simultaneously,pulling the foam from inside the oral cavity out through the mouth. The foam disengagesfrom the undercuts (Fig. 4). 13. The foam impressionof the defect is relocated onto the acrylic resin button and is luted with sticky wax (Fig. 5). 14. To fabricate a cast, the foam is initially painted with a thin coat of stone to give it rigid support. When this stone layer has set, the cast is poured in the conventional manner. Although the foam doesnot yield the sameaccuracy as
344
AND
CARR
conventional impressionmaterials do, it can be usedwith success.The advantagesof this technique are that the impressioncan be easily removed from severeundercuts and that it is easierto remove when trismus is present. A disadvantage of this technique is that the rapid reaction of the foam liquid to the catalyst limits the time in which the operator can perform the procedure. This technique can be modified and used in other situations. REFERENCES 1. Luebke RJ. Sectional impression tray for patients with constricted oral opening. J PROSTHET DENT 1984;52(1):135-7. 2. Beumer III J, Curtis TA, Firtell DN. Maxillofacial rehabilitation. St. Louis: The C.V. Mosby Company, 1979:221-6. 3. Carl W. Preoperative and immediate postoperative obturators. J PROSTHET DENT 1976;36(3):298-305. Reprint
requests
to:
DR. J. SCHMAMAN DEPARTMENT OF PROSTHETIC DENTISTRY UNIVERSITY OF WITSWATERSRAND, JOHANNESBURG PO WITS 2050 SOUTH AFRICA
AUGUST
1992
VOLUME
68
NUMBER
2
SUMMARY A technique for fabrication of a gated surgical prosthesis to allow for immediate obturation of the dentate patient is described. This proskhesis offers a wide range of stabilizing options and provides a simpler, smoother transition between wire-stabilized and removable obturation.
3. Academy of Denture Prosthetics. Principles, concepts, and practices in prosthodontics-1989. J PROSTHETDENT 1989;61:88-109. 4. Frame RT, King GE. A surgical interim prosthesis. J PROSTHETDENT
1981;45:108-10. 5. Desjardins R. Early rehabilitative management of the maxillectomy patient.J PROSTHETDENT1989;61:344-5. 6. Huryn JM, Pire JD. The maxillary immediate surgical obturator prosthesis.J PROSTHETDENT1989;61:344-5. Rep&t requests to: DR. WILLIAM&BLACK
REFERENCES 1. Cancer facts and figures, 1988. The American Cancer Society, New York, 1988. 2. Gainsford JC, ed. Symposium on cancer of the head and neck, ~012. St Louis: CV Mosby, 1969:101-3.
A foam impression
technique
SCOTT&WHITE CLINIC Z~OISOUTH~UTSTREET TEMPLE,TX 76508
for maxillary
defects
J. Schmaman, BDS, MDent,a and L. Carr, BDS, MDentb University
of ‘Witwatersrand,
Johannesburg,
South
Africa
This article presents a technique used to overcome the problems of withdrawal of maxillectomy defect impressions with or without limited space as the result of trismus.(J PROSTHET DENT 1992;68:342-4.)
aSpecialist/Lecturer, Department of Prosthetic bSenior Specialist/Senior Lecturer, Department Dentistry.
B&W37619
Dentistry. of Prosthetic
U
se of the established impression techniques of recording maxillary defects can result in various problems for the clinician. Many maxillary defects are characterized by a cleft or opening that is smaller than the width of the nasal cavity (Fig. 1). A common problem in recording maxillectomy defects is the presence of large undercuts, which create difficulty in withdrawing the impression. Impression material that is too rigid can traumatize the tissue on removal, but more elastic materials, such as irreversible hydrocolloids, often tear. This is particularly true when a composite prosthesis requires a section that projects into the nasal cavity. An additional problem in certain patients is trismus, which limits access to the defect. A few impression techniques are mentioned in the literature. Luebkel describes a sectiona tray for use in patients with trismus. Beumer et aL2 advocate a method in which the impression is refined with modeling plastic, a soft flowing wax, and an elastic impression material to record the defect. Carl3 indicates the need for adhesives and undercuts that add additional alginate to a set impression when necessary.
TECHNIQUE An intraoral primary impression of the maxilla and the entry to the defect is taken in the conventional manner with irreversible hydrocolloid. 2. A special tray is fabricated on the cast of the residual maxillary structures. A mushroom-shaped acrylic resin retention-relocating button is added to the special tray (Fig. 2 [blue]). 1.
Fig. 342
1. The defect.
AUGUST
1992
VOLUME
68
NUMBER
2
FOAM
Fig.
IMPRESSIONS
FOR
MAXILLARY
DEFECTS
Fig.
4. Withdrawing the impression.
Fig.
5. Impression ready for casting.
2. Special tray and siliconerubber impressionin po-
sition.
Fig.
3. Injecting foam with modified syringe and nipple.
3. A 20ml disposableplastic syringe ismodified to received a latex feeding nipple (Fig. 3). The tip of the nipple is cut to widen the aperture to approximately 5 mm. 4. The nasopharynx and orifices within the defect are blocked with petrolatum gauze. 5. Pressurepoints and extensionsof the custom tray are adjusted with a pressure-indicatingmaterial. 6. After adhesiveis applied to the tray, siliconerubber impressionmaterial is loaded onto the tray; the retentionrelocating button is excluded. An impressionof the reTHE
JOURNAL
OF PROSTHETIC
DENTISTRY
sidual structures, including the perimeter of the defect, is taken in the normal manner (Fig. 2 [black]). 7. The impressionis withdrawn and is checked for detail and extension. Any material that hascrept onto the retention-relocating button is removed with a scalpel blade. The tray with the rubber impressionis replaced in the mouth and is held securely in position. The patient is instructed to breathe through the mouth during the next procedure. 8. The plunger is removed from the syringe and the nipple is folded to prevent leakagewhile the syringe is being loaded. The desiredvolume (3 ml) of Silastic Foam liquid (Silastic Foam Dressing,Dow-Corning Medical S.A., Valbonne, France) is poured into the syringe. Catalyst is added according to the manufacturer’s instructions, and the material is rapidly and thoroughly mixed with a thin spatula. 9. The plunger is replaced and the nipple is inserted into the nostril that is continuous with the defect. The foam 343
SCHMAMAN
is rapidly injected through the nostril into the nasal cavity, and the syringe is removed (Fig. 3). 10. The defect and nasal cavity are filled when the foam, which expandsto four times its original volume, exudes from the nostril. After setting is complete, this excess foam is removed with scissors. 11. The tray with the rubber impressionis removed from the mouth, and the retention-relocating button is withdrawn from the extremely elastic foam. 12. The foam impressionis removed by inserting a finger into the nostril and pushing the foam downward into the oral cavity and by simultaneously,pulling the foam from inside the oral cavity out through the mouth. The foam disengagesfrom the undercuts (Fig. 4). 13. The foam impressionof the defect is relocated onto the acrylic resin button and is luted with sticky wax (Fig. 5). 14. To fabricate a cast, the foam is initially painted with a thin coat of stone to give it rigid support. When this stone layer has set, the cast is poured in the conventional manner. Although the foam doesnot yield the sameaccuracy as
344
AND
CARR
conventional impressionmaterials do, it can be usedwith success.The advantagesof this technique are that the impressioncan be easily removed from severeundercuts and that it is easierto remove when trismus is present. A disadvantage of this technique is that the rapid reaction of the foam liquid to the catalyst limits the time in which the operator can perform the procedure. This technique can be modified and used in other situations. REFERENCES 1. Luebke RJ. Sectional impression tray for patients with constricted oral opening. J PROSTHET DENT 1984;52(1):135-7. 2. Beumer III J, Curtis TA, Firtell DN. Maxillofacial rehabilitation. St. Louis: The C.V. Mosby Company, 1979:221-6. 3. Carl W. Preoperative and immediate postoperative obturators. J PROSTHET DENT 1976;36(3):298-305. Reprint
requests
to:
DR. J. SCHMAMAN DEPARTMENT OF PROSTHETIC DENTISTRY UNIVERSITY OF WITSWATERSRAND, JOHANNESBURG PO WITS 2050 SOUTH AFRICA
AUGUST
1992
VOLUME
68
NUMBER
2
