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Maxillofacial prosthodontic management of a facial defect complicatedby a necrotic frontal bone flap: A clinical report
1998 JUDSON C. HICKEY SCIENTIFIC WRITING AWARD Maxillofacial prosthodontic management of a facial defect complicated by a necrotic frontal bone flap: A clinical report Ansgar C. Cheng, BDS, MS,a David Morrison, CDT,b Alvin G. Wee, BDS, MS,c Walter G. Maxymiw, DDS,d and Daphne Archibaldb Ontario Cancer Institute, Princess Margaret Hospital, Toronto, Ontario, Canada
The rehabilitation of patients with tumor resective surgery involving the facial area creates numerous challenges for both the surgical and maxillofacial prosthetic teams.1,2 Although immediately reconstructing the tissue defect with autogenous tissues plays a major role in maxillofacial reconstruction,3 sculpting the autogenous tissue into intricate anatomy for larger nasal defects is difficult. A midfacial surgical defect may influence the patient’s self-esteem as well as his or her body image.4-9 The sooner the surgical defect is rehabilitated, the earlier the patient will be able to return to normal daily activities, with the realization that ablative surgery does not result in a permanent handicap.10,11 This clinical report describes the clinical and laboratory procedures for fabricating a facial prosthesis using a custom-made metallic substructure over a necrotic frontal bone flap.
CLINICAL REPORT A 77-year-old white man was referred to the Dental Oncology Group of the Ontario Cancer InstitutePrincess Margaret Hospital for a postsurgical maxillofacial prosthetic assessment. His medical record revealed a history of ethmoid sinus squamous cell carcinoma displacing his dura below the frontal lobe. A partial rhinectomy involving the superior two-thirds of his nose and resection of the ethmoid sinus were performed. Access to the ethmoid sinus was gained through a midsegmental frontal bone flap. Immediately after the tumor resection, the frontal bone flap was repositioned and covered with local soft tissue. Postoperatively, 6000 cGy of external beam radiation therapy was delivered to the affected area. The soft tissue overlying the midsegmental frontal bone flap became necrotic approximately 10 months after the initial tumor resection surgery. A rectus abdominal free-flap was harvested to re-cover the exposed frontal bone flap. The rectus abdominal freeflap became nonvital as a result of secondary infection aHead
of Maxillofacial Prosthetics.
bAnaplastologist. cAssistant
Professor, Section of Restorative Dentistry, Prosthodontics and Endodontics, College of Dentistry, The Ohio State University, Columbus, Ohio. dChief of Department of Dentistry. J Prosthet Dent 1999;82:3-7. JULY 1999
Fig. 1. Frontal view of patient with facial defect and exposed necrotic frontal bone flap.
and was removed. The patient was closely followed for daily local debridement with saline irrigation. Although a bone scan revealed loss of vitality in the exposed frontal bone flap, there were no symptoms (Fig. 1). Sequestration of the frontal bone flap was anticipated and surgical removal of the necrotic bone was delayed. Metallic cranial implants have been proposed for reconstructing cranial bony defects12,13 but they have not been widely accepted because of their high thermal and electrical conductivity, which may precipitate headaches and adversely affect the accuracy of electroencephalograms.14-16 The immediate maxillofacial prosthodontic treatment goal was to return the patient THE JOURNAL OF PROSTHETIC DENTISTRY 3
THE JOURNAL OF PROSTHETIC DENTISTRY
CHENG ET AL
Fig. 2. Completed facial cast.
Fig. 3. Completed wax pattern for facial prosthesis with board tissue coverage over forehead area to enhance retention, support, and stability.
to regular daily activity as soon as possible. In addition, prosthetic coverage of the forehead area was planned to improve esthetics, provide additional retention for a midfacial prosthesis, and offer mechanical protection to the exposed midsegmental frontal bone flap. The use of a thermoformed shell as a preparation template to ensure the desired relationship between the external contour of complete crown restorations and intracoronal structures (posts and cores) has been reported by various authors.17-22 A similar procedure was used to develop the definitive contour of the facial prosthesis in this case. A transitional midfacial prosthesis with a metallic substructure was planned.
for the laboratory phase of the fabrication of the prosthesis (Fig. 2). On the stone cast, the area of the exposed bone flap was blocked out by applying a layer of 32-gauge wax. An impression was made of the blocked out facial cast in polyvinyl siloxane (Reprosil, Dentsply, Milford, Del.) and poured in refractory material (Cerafina, Whip Mix Corp, Louisville, Ky.). A preliminary wax pattern of the facial prosthesis was accomplished on the master facial cast. The position of the facial wax pattern was further verified with a clinical try-in (Fig. 3). After marginal adaptation and contour were confirmed, the wax pattern for the facial prosthesis was sealed to place on the stone cast. The forehead area of the completed wax pattern and master cast was duplicated in dental stone. The forehead area of the prosthesis was vacuum-formed in 0.02-in transparent plastic shell matrix material (temporary splint material, Buffalo Dental Manufacturing Co Inc, Syosset, N.Y.) on a vacuum-forming machine (Vacuum Forming Machine, Henry Schein, Port Washington, N.Y.) (Fig. 4). This transparent matrix was carefully
PROCEDURE Tissue undercuts of the patient’s nasal and forehead defects were blocked out, and an impression of the surgical defects was made in polysulfide impression material (Permlastic, Kerr Manufacturing Co, Romulus, Mich.). The impression was poured in ADA-type V dental stone (Die Keen, Bayer Corp, South Bend, Ind.) 4
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CHENG ET AL
THE JOURNAL OF PROSTHETIC DENTISTRY
Fig. 4. Clear vacuum-formed shell over forehead area of stone duplicate of facial wax pattern.
Fig. 6. Metallic substructure for forehead area.
Fig. 5. Wax pattern for forehead metallic substructure was developed on refractory cast. Spatial relationship with contour of facial prosthesis was verified with vacuum-formed shell.
removed from the cast and examined for accuracy. The matrix was then used as a template for the development and spatial verification of the metallic substructure (Fig. 5). On the refractory cast, a wax pattern of the prosthetic framework was made in 32-gauge wax. The vacuum-formed transparent template was used to verify clearance between the wax pattern of the metal substructure and the external surface of the facial prosthesis. Retentive loops and beads were used to enhance the retention of the silicone elastomer to the bonding areas of the prosthetic framework. The wax patterns were then invested (Cerafina, Whip Mix Corp), cast in dental alloy (Olympia, J.F. Jelenko, Newark, N.J.), recovJULY 1999
ered, and the bonding areas were air-particle abraded with 100 µm aluminum oxide (Fig. 6). Silicone elastomer (2186, Factor II Inc, Lakeside, Ariz.) was mixed and intrinsic colorants were applied according to the basic skin tone of the patient. Opaque colorant (White pigment, Factor II Inc) was mixed with a small quantity of the colored silicone to establish a custom opaque agent and then applied to the metallic forehead framework in a thin layer to disguise the dark metal shade. It was polymerized according to the directions of the manufacturer. The completed wax pattern for the facial prosthesis was flasked in ADA type V dental stone (Die Keen) in the usual manner. The wax pattern was eliminated using a standard boil-out technique. The metallic framework for the forehead was positioned on the invested facial cast. A tissue-colored silicone elastomer was then bulk-filled and the material was processed according to the manufacturer’s directions. After processing, the prosthesis was removed from the mold (Fig. 7). Excess flash was removed from the prosthesis, and extrinsic color was applied to the prosthesis to blend with the patient’s skin tone (Fig. 8).
DISCUSSION A large facial defect can be a barrier for a patient to return to normal daily activities. Cranial bone defects 5
THE JOURNAL OF PROSTHETIC DENTISTRY
CHENG ET AL
Fig. 7. Tissue surface of completed facial prosthesis.
Fig. 8. Facial prosthesis inserted with tissue adhesive.
can cause cranial disfigurement and potential mechanical brain trauma. In this clinical report, the tissue defect was complicated by a necrotic frontal bone flap. Although natural sequestration was expected, this unique clinical presentation provided an atypical challenge to the maxillofacial prosthodontist. An epithesis with a metallic substructure over the cranial defect rapidly restored the defect, reduced the disfigurement, and provided mechanical protection. Regular routine debridement of the defect could then be carried out by simply removing this prosthesis. The effects of direct contact between a necrotic bone flap and maxillofacial prosthetic material has not been well documented and the implication of further trauma to the defect should not be overlooked. Direct contact between the prosthesis and the bone flap should be avoided. Application of a vacuum-formed matrix to assist the fabrication of a facial prosthesis with a metallic substructure enables the prosthodontist and anaplastologist to more easily control the finished contour of the metallic substructure and the external contour of facial prosthe-
ses. The 3-dimensional extension of the metallic substructure in relation to the contour of the prosthesis is directly visualized before the completion of the prosthesis. Thus, the use of available space within the bulk of the prosthetic material can be optimized without fear of exposing the metallic substructure or the retentive elements. The spatial relationship between various retentive elements can be evaluated directly during the laboratory phase and this approach is recommended when the available space or bulk of the prosthesis is limited. Similar procedures can be used for other maxillofacial defects when space becomes a concern. Although the laboratory cost for this procedure is higher than for facial prosthesis entirely made of silicone, this method does not require any change in clinical techniques and provides the prosthodontist with a practical option.
6
SUMMARY Partial resection of the facial area with an exposed necrotic bone flap is a relatively uncommon clinical presentation and it presents a unique surgical and prosVOLUME 82 NUMBER 1
CHENG ET AL
thetic rehabilitation. The immediate goals of prosthetic management include restoration of esthetics and protection of the necrotic bone flap. Clinical and laboratory procedures for fabricating a facial prosthesis by using a custom-made metallic substructure over a necrotic frontal bone flap has been described and the advantages and disadvantages of this procedure were reviewed. REFERENCES 1. Laney WR. Restoration of acquired oral and perioral defects. In: Laney WR, Gibiliso JA, editors. Diagnosis and treatment in prosthodontics (chapter 15). Philadelphia: Lea & Febiger; 1983. p. 377-446. 2. Johns ME. Complications in otolaryngology—head and neck surgery (vol 2). Oral and dental rehabilitation. Philadelphia: Decker, Inc; 1986. p. 131-3. 3. Gullane PJ. Nasal reconstruction. J Otolaryngol 1980;9:6, 455-61. 4. Reisberg DJ, Habakuk SW. Nasal conformer to restore facial contour. J Prosthet Dent 1990;64:699-701. 5. Zarb GA, Bergman B, Clayton JA, MacKay HF, editors. Prosthodontic treatment for partially edentulous patients. St Louis: CV Mosby; 1978. p. 201-22. 6. Breitbart W, Holland J. Psychosocial aspects of head and neck cancer. Semin Oncol 1988;15:61-9. 7. Bronheim H, Strain JJ, Biller HF. Psychiatric aspects of head and neck surgery. Part II: body image and psychiatric intervention. Gen Hosp Psychiatry 1991;13:225-32. 8. Gamba A, Romano M, Grosso IM, Tamburini M, Cantu G, Molinari R, et al. Psychosocial adjustment of patients surgically treated for head and neck cancer. Head Neck. 1992;14:218-23. 9. Rappaport Y, Kreitler S, Chaitchik S, Algor R, Weissler K. Psychosocial problems in head-and-neck cancer patients and their change with time since diagnosis. Ann Oncol 1993;4:69-73. 10. Beumer J, Curtis T, Marunick M. Maxillofacial rehabilitation: prosthodontic and surgical considerations. Tokyo: Ishiyaku EuroAmerica, Inc; 1996. p. 377-453. 11. Argerakis GP. Psychosocial considerations of the post-treatment of head and neck cancer patients. Dent Clin North Am 1990;34:285-305.
JULY 1999
THE JOURNAL OF PROSTHETIC DENTISTRY
12. Simske SJ, Sachdeva R. Cranial bone apposition and ingrowth in a porous nickel-titanium implant. J Biomed Mater Res 1995;29:527-33. 13. Datti R, Cavagnaro G, Camici S. Stainless steel wire mesh cranioplasty: ten years’ experience with 183 patients (100 followed up). Acta Neurochir (Wien) 1985;78:133-5. 14. Spence WT. Form fitting cranioplasty. J Neurosurg 1954;11:219. 15. Sessions RB, Jolfe SK, Moiel RH, Cheek WR. Wire mesh foundation for methyl methacrylate cranioplasty. Laryngol 1974;84:1020-30. 16. Shaw RC, Thering HR. Reconstruction of cranial defects. Clin Plast Surg 1975;2:539-49. 17. Preston JD. A systemic approach to the control of esthetic form. J Prosthet Dent 1976;35:393-402. 18. Aquilino SA, Jordan RD, Turner KA, Leary MJ. Multiple cast post and cores for severely worn anterior teeth. J Prosthet Dent 1986;55:430-3. 19. Fehling AW, Wolfert RE. Multiple cast post and cores for anterior teeth: rationale and technique. J Prosthet Dent 1988;59:558-62. 20. Halhoul NM, El-Baghdady Y. Multiple direct pattern for cast post and core in anterior teeth. J Prosthet Dent 1984;52:36-7. 21. Netti CA, Nagy WW. A simplified matrix for making direct cores. J Prosthet Dent 1992;67:569-71. 22. Bluche LR, Bluche PF, Morgano SM. Vacuum-formed matrix as a guide for the fabrication of multiple direct patterns for cast posts and cores. J Prosthet Dent 1997;77:326-7.
Reprint requests to: DR ANSGAR C. CHENG DEPARTMENT OF DENTISTRY ONTARIO CANCER INSTITUTE—PRINCESS MARGARET HOSPITAL 610 UNIVERSITY AVE TORONTO, ONTARIO M5G 2M9 CANADA FAX: 416-292-4340 E-MAIL: [email protected] Copyright © 1999 by The Editorial Council of The Journal of Prosthetic Dentistry. 0022-3913/99/$8.00 + 0. 10/1/98828
7
The rehabilitation of patients with tumor resective surgery involving the facial area creates numerous challenges for both the surgical and maxillofacial prosthetic teams.1,2 Although immediately reconstructing the tissue defect with autogenous tissues plays a major role in maxillofacial reconstruction,3 sculpting the autogenous tissue into intricate anatomy for larger nasal defects is difficult. A midfacial surgical defect may influence the patient’s self-esteem as well as his or her body image.4-9 The sooner the surgical defect is rehabilitated, the earlier the patient will be able to return to normal daily activities, with the realization that ablative surgery does not result in a permanent handicap.10,11 This clinical report describes the clinical and laboratory procedures for fabricating a facial prosthesis using a custom-made metallic substructure over a necrotic frontal bone flap.
CLINICAL REPORT A 77-year-old white man was referred to the Dental Oncology Group of the Ontario Cancer InstitutePrincess Margaret Hospital for a postsurgical maxillofacial prosthetic assessment. His medical record revealed a history of ethmoid sinus squamous cell carcinoma displacing his dura below the frontal lobe. A partial rhinectomy involving the superior two-thirds of his nose and resection of the ethmoid sinus were performed. Access to the ethmoid sinus was gained through a midsegmental frontal bone flap. Immediately after the tumor resection, the frontal bone flap was repositioned and covered with local soft tissue. Postoperatively, 6000 cGy of external beam radiation therapy was delivered to the affected area. The soft tissue overlying the midsegmental frontal bone flap became necrotic approximately 10 months after the initial tumor resection surgery. A rectus abdominal free-flap was harvested to re-cover the exposed frontal bone flap. The rectus abdominal freeflap became nonvital as a result of secondary infection aHead
of Maxillofacial Prosthetics.
bAnaplastologist. cAssistant
Professor, Section of Restorative Dentistry, Prosthodontics and Endodontics, College of Dentistry, The Ohio State University, Columbus, Ohio. dChief of Department of Dentistry. J Prosthet Dent 1999;82:3-7. JULY 1999
Fig. 1. Frontal view of patient with facial defect and exposed necrotic frontal bone flap.
and was removed. The patient was closely followed for daily local debridement with saline irrigation. Although a bone scan revealed loss of vitality in the exposed frontal bone flap, there were no symptoms (Fig. 1). Sequestration of the frontal bone flap was anticipated and surgical removal of the necrotic bone was delayed. Metallic cranial implants have been proposed for reconstructing cranial bony defects12,13 but they have not been widely accepted because of their high thermal and electrical conductivity, which may precipitate headaches and adversely affect the accuracy of electroencephalograms.14-16 The immediate maxillofacial prosthodontic treatment goal was to return the patient THE JOURNAL OF PROSTHETIC DENTISTRY 3
THE JOURNAL OF PROSTHETIC DENTISTRY
CHENG ET AL
Fig. 2. Completed facial cast.
Fig. 3. Completed wax pattern for facial prosthesis with board tissue coverage over forehead area to enhance retention, support, and stability.
to regular daily activity as soon as possible. In addition, prosthetic coverage of the forehead area was planned to improve esthetics, provide additional retention for a midfacial prosthesis, and offer mechanical protection to the exposed midsegmental frontal bone flap. The use of a thermoformed shell as a preparation template to ensure the desired relationship between the external contour of complete crown restorations and intracoronal structures (posts and cores) has been reported by various authors.17-22 A similar procedure was used to develop the definitive contour of the facial prosthesis in this case. A transitional midfacial prosthesis with a metallic substructure was planned.
for the laboratory phase of the fabrication of the prosthesis (Fig. 2). On the stone cast, the area of the exposed bone flap was blocked out by applying a layer of 32-gauge wax. An impression was made of the blocked out facial cast in polyvinyl siloxane (Reprosil, Dentsply, Milford, Del.) and poured in refractory material (Cerafina, Whip Mix Corp, Louisville, Ky.). A preliminary wax pattern of the facial prosthesis was accomplished on the master facial cast. The position of the facial wax pattern was further verified with a clinical try-in (Fig. 3). After marginal adaptation and contour were confirmed, the wax pattern for the facial prosthesis was sealed to place on the stone cast. The forehead area of the completed wax pattern and master cast was duplicated in dental stone. The forehead area of the prosthesis was vacuum-formed in 0.02-in transparent plastic shell matrix material (temporary splint material, Buffalo Dental Manufacturing Co Inc, Syosset, N.Y.) on a vacuum-forming machine (Vacuum Forming Machine, Henry Schein, Port Washington, N.Y.) (Fig. 4). This transparent matrix was carefully
PROCEDURE Tissue undercuts of the patient’s nasal and forehead defects were blocked out, and an impression of the surgical defects was made in polysulfide impression material (Permlastic, Kerr Manufacturing Co, Romulus, Mich.). The impression was poured in ADA-type V dental stone (Die Keen, Bayer Corp, South Bend, Ind.) 4
VOLUME 82 NUMBER 1
CHENG ET AL
THE JOURNAL OF PROSTHETIC DENTISTRY
Fig. 4. Clear vacuum-formed shell over forehead area of stone duplicate of facial wax pattern.
Fig. 6. Metallic substructure for forehead area.
Fig. 5. Wax pattern for forehead metallic substructure was developed on refractory cast. Spatial relationship with contour of facial prosthesis was verified with vacuum-formed shell.
removed from the cast and examined for accuracy. The matrix was then used as a template for the development and spatial verification of the metallic substructure (Fig. 5). On the refractory cast, a wax pattern of the prosthetic framework was made in 32-gauge wax. The vacuum-formed transparent template was used to verify clearance between the wax pattern of the metal substructure and the external surface of the facial prosthesis. Retentive loops and beads were used to enhance the retention of the silicone elastomer to the bonding areas of the prosthetic framework. The wax patterns were then invested (Cerafina, Whip Mix Corp), cast in dental alloy (Olympia, J.F. Jelenko, Newark, N.J.), recovJULY 1999
ered, and the bonding areas were air-particle abraded with 100 µm aluminum oxide (Fig. 6). Silicone elastomer (2186, Factor II Inc, Lakeside, Ariz.) was mixed and intrinsic colorants were applied according to the basic skin tone of the patient. Opaque colorant (White pigment, Factor II Inc) was mixed with a small quantity of the colored silicone to establish a custom opaque agent and then applied to the metallic forehead framework in a thin layer to disguise the dark metal shade. It was polymerized according to the directions of the manufacturer. The completed wax pattern for the facial prosthesis was flasked in ADA type V dental stone (Die Keen) in the usual manner. The wax pattern was eliminated using a standard boil-out technique. The metallic framework for the forehead was positioned on the invested facial cast. A tissue-colored silicone elastomer was then bulk-filled and the material was processed according to the manufacturer’s directions. After processing, the prosthesis was removed from the mold (Fig. 7). Excess flash was removed from the prosthesis, and extrinsic color was applied to the prosthesis to blend with the patient’s skin tone (Fig. 8).
DISCUSSION A large facial defect can be a barrier for a patient to return to normal daily activities. Cranial bone defects 5
THE JOURNAL OF PROSTHETIC DENTISTRY
CHENG ET AL
Fig. 7. Tissue surface of completed facial prosthesis.
Fig. 8. Facial prosthesis inserted with tissue adhesive.
can cause cranial disfigurement and potential mechanical brain trauma. In this clinical report, the tissue defect was complicated by a necrotic frontal bone flap. Although natural sequestration was expected, this unique clinical presentation provided an atypical challenge to the maxillofacial prosthodontist. An epithesis with a metallic substructure over the cranial defect rapidly restored the defect, reduced the disfigurement, and provided mechanical protection. Regular routine debridement of the defect could then be carried out by simply removing this prosthesis. The effects of direct contact between a necrotic bone flap and maxillofacial prosthetic material has not been well documented and the implication of further trauma to the defect should not be overlooked. Direct contact between the prosthesis and the bone flap should be avoided. Application of a vacuum-formed matrix to assist the fabrication of a facial prosthesis with a metallic substructure enables the prosthodontist and anaplastologist to more easily control the finished contour of the metallic substructure and the external contour of facial prosthe-
ses. The 3-dimensional extension of the metallic substructure in relation to the contour of the prosthesis is directly visualized before the completion of the prosthesis. Thus, the use of available space within the bulk of the prosthetic material can be optimized without fear of exposing the metallic substructure or the retentive elements. The spatial relationship between various retentive elements can be evaluated directly during the laboratory phase and this approach is recommended when the available space or bulk of the prosthesis is limited. Similar procedures can be used for other maxillofacial defects when space becomes a concern. Although the laboratory cost for this procedure is higher than for facial prosthesis entirely made of silicone, this method does not require any change in clinical techniques and provides the prosthodontist with a practical option.
6
SUMMARY Partial resection of the facial area with an exposed necrotic bone flap is a relatively uncommon clinical presentation and it presents a unique surgical and prosVOLUME 82 NUMBER 1
CHENG ET AL
thetic rehabilitation. The immediate goals of prosthetic management include restoration of esthetics and protection of the necrotic bone flap. Clinical and laboratory procedures for fabricating a facial prosthesis by using a custom-made metallic substructure over a necrotic frontal bone flap has been described and the advantages and disadvantages of this procedure were reviewed. REFERENCES 1. Laney WR. Restoration of acquired oral and perioral defects. In: Laney WR, Gibiliso JA, editors. Diagnosis and treatment in prosthodontics (chapter 15). Philadelphia: Lea & Febiger; 1983. p. 377-446. 2. Johns ME. Complications in otolaryngology—head and neck surgery (vol 2). Oral and dental rehabilitation. Philadelphia: Decker, Inc; 1986. p. 131-3. 3. Gullane PJ. Nasal reconstruction. J Otolaryngol 1980;9:6, 455-61. 4. Reisberg DJ, Habakuk SW. Nasal conformer to restore facial contour. J Prosthet Dent 1990;64:699-701. 5. Zarb GA, Bergman B, Clayton JA, MacKay HF, editors. Prosthodontic treatment for partially edentulous patients. St Louis: CV Mosby; 1978. p. 201-22. 6. Breitbart W, Holland J. Psychosocial aspects of head and neck cancer. Semin Oncol 1988;15:61-9. 7. Bronheim H, Strain JJ, Biller HF. Psychiatric aspects of head and neck surgery. Part II: body image and psychiatric intervention. Gen Hosp Psychiatry 1991;13:225-32. 8. Gamba A, Romano M, Grosso IM, Tamburini M, Cantu G, Molinari R, et al. Psychosocial adjustment of patients surgically treated for head and neck cancer. Head Neck. 1992;14:218-23. 9. Rappaport Y, Kreitler S, Chaitchik S, Algor R, Weissler K. Psychosocial problems in head-and-neck cancer patients and their change with time since diagnosis. Ann Oncol 1993;4:69-73. 10. Beumer J, Curtis T, Marunick M. Maxillofacial rehabilitation: prosthodontic and surgical considerations. Tokyo: Ishiyaku EuroAmerica, Inc; 1996. p. 377-453. 11. Argerakis GP. Psychosocial considerations of the post-treatment of head and neck cancer patients. Dent Clin North Am 1990;34:285-305.
JULY 1999
THE JOURNAL OF PROSTHETIC DENTISTRY
12. Simske SJ, Sachdeva R. Cranial bone apposition and ingrowth in a porous nickel-titanium implant. J Biomed Mater Res 1995;29:527-33. 13. Datti R, Cavagnaro G, Camici S. Stainless steel wire mesh cranioplasty: ten years’ experience with 183 patients (100 followed up). Acta Neurochir (Wien) 1985;78:133-5. 14. Spence WT. Form fitting cranioplasty. J Neurosurg 1954;11:219. 15. Sessions RB, Jolfe SK, Moiel RH, Cheek WR. Wire mesh foundation for methyl methacrylate cranioplasty. Laryngol 1974;84:1020-30. 16. Shaw RC, Thering HR. Reconstruction of cranial defects. Clin Plast Surg 1975;2:539-49. 17. Preston JD. A systemic approach to the control of esthetic form. J Prosthet Dent 1976;35:393-402. 18. Aquilino SA, Jordan RD, Turner KA, Leary MJ. Multiple cast post and cores for severely worn anterior teeth. J Prosthet Dent 1986;55:430-3. 19. Fehling AW, Wolfert RE. Multiple cast post and cores for anterior teeth: rationale and technique. J Prosthet Dent 1988;59:558-62. 20. Halhoul NM, El-Baghdady Y. Multiple direct pattern for cast post and core in anterior teeth. J Prosthet Dent 1984;52:36-7. 21. Netti CA, Nagy WW. A simplified matrix for making direct cores. J Prosthet Dent 1992;67:569-71. 22. Bluche LR, Bluche PF, Morgano SM. Vacuum-formed matrix as a guide for the fabrication of multiple direct patterns for cast posts and cores. J Prosthet Dent 1997;77:326-7.
Reprint requests to: DR ANSGAR C. CHENG DEPARTMENT OF DENTISTRY ONTARIO CANCER INSTITUTE—PRINCESS MARGARET HOSPITAL 610 UNIVERSITY AVE TORONTO, ONTARIO M5G 2M9 CANADA FAX: 416-292-4340 E-MAIL: [email protected] Copyright © 1999 by The Editorial Council of The Journal of Prosthetic Dentistry. 0022-3913/99/$8.00 + 0. 10/1/98828
7