- Email: [email protected]
Late effects of orbital enucleation and radiation on maxillofacial prosthetic rehabilitation: A clinical report
Late effects of orbital enucleation and radiation on maxillofacial prosthetic rehabilitation: A clinical report Supanut Tummawanit, DDS,a Binit Shrestha, BDS, MSc,b Sita Thaworanunta, DDS, MS, MSc,c and Theerathavaj Srithavaj, BS, MS, DDSc Faculty of Dentistry, Mahidol University, Bangkok, Thailand The retinoblastoma is one of the most common tumors of the eye diagnosed in childhood. The treatment for patients with retinoblastoma includes surgical removal of the lesion along with adjunctive chemotherapy and radiotherapy. If the tumor is controlled, these treatments can have secondary adverse effects pertaining to the growth and development of orofacial structures in young patients. This clinical report describes the prosthetic rehabilitation of a patient who underwent enucleation followed by radiation therapy and adjunctive chemotherapy to treat the primary diagnosis of retinoblastoma. This therapy resulted in a combination of dental and facial growth and developmental abnormalities. (J Prosthet Dent 2013;109:291-295) Retinoblastoma is the most common malignant tumor involving the eye that is diagnosed in childhood. The tumor originates in the retinal bed and is usually observed by the third year of life.1 Treatment modalities have been evolving and have resulted in the improved survival rate of children diagnosed with retinoblastoma. Chemotherapeutic drugs are now incorporated into the management of the tumor to reduce its size and to allow local ophthalmologic surgery to remove residual disease.2 Surgical enucleation and external beam radiation therapy (EBRT) are indicated in advanced intraocular disease with diffuse vitreous or subretinal seeding, although EBRT does have adverse effects on the growth and development of orofacial structures.3,4 Abnormalities in the crown and root formation of deciduous and permanent teeth have been reported.5 Facial deformities may include atrophic soft tissues and hypoplastic facial bones, leading to cosmetic deformity and psychosocial stress for the patient.6 To treat these developmental abnormalities, a
multidisciplinary treatment approach is indicated to achieve the most ideal functional, physical, and psychological outcomes. The purpose of this clinical report was to describe the prosthodontic rehabilitation of a patient who underwent enucleation to treat the primary diagnosis of retinoblastoma, followed by radiation therapy and adjunctive chemotherapy, which secondarily resulted in a combination of dental and facial developmental abnormalities.
CLINICAL REPORT A 16-year-old Thai female with an acquired right orbital defect was referred for the fabrication of an orbital prosthesis. The history revealed that she had been diagnosed with retinoblastoma of the right eye in 1989 when she was 1-year old. Enucleation of the right eye was performed in the same year, followed by postenucleation adjunctive chemotherapy and radiotherapy. Thirty-three fractionated dosages of EBRT for a total of 60 Gy were delivered to the right or-
bital and maxillary region. Initially, prosthetic rehabilitation for the ocular defect was performed by fabricating an ocular prosthesis, but because of the continual radiation fibrosis of the eyelids and surrounding soft tissues, the ocular prosthesis dislodged frequently until she could no longer wear it. In 2003, the inferiolateral orbital wall was reconstructed with synthetic bone graft (Medpor; Porex Surgical Inc, Newnan, Ga) to improve the compromised contour of the orbital bones and a split-thickness skin graft harvested from the thigh region was used to cover the synthetic bone graft (Medpor; Porex Surgical Inc). The eyelids were also removed in the hope of making the tissue bed more able to bear an orbital prosthesis. No complications in the healing of the grafted area were reported, even though adjunctive hyperbaric oxygen (HBO) therapy was not employed. In 2004, the initial visit showed that the patient had undergone a right ocular enucleation along with removal of the eyelids. Although orbital reconstruction had been performed,
Presented at the 7th Biennial Congress of the Asian Academy of Prosthodontics, Shanghai China, October 2011.
Resident, Maxillofacial Prosthetics Service. Instructor, Maxillofacial Prosthetics Service. c Assistant Professor, Maxillofacial Prosthetics Service. a
b
Tummawanit et al
292
Volume 109 Issue 5
1 Frontal view of patient before prosthetic rehabilitation. the patient still exhibited hypoplastic orbital bones and a midfacial depression; in addition, the lower half of the face had deviated to the right, resulting in facial asymmetry (Fig. 1). The patient also had a concave facial profile with a flattened nose. Intraoral findings exhibited a hypoplastic maxillary arch and normal mandibular arch resulting in severe skeletal Class III malocclusion (Fig. 2A). In the maxillary arch, the central incisors exhibited normal development of their clinical crowns and roots, the lateral incisors were noted to be microdontic, and the left canine was malpositioned in the premolar region (Fig. 2B). Radiographic examination showed the residual roots of the maxillary right first molar with shortening of the roots of the maxillary left first molar. The rest of the maxillary dentition was not present. The mandibular arch exhibited the absence of right and left third molars and right first and second premolars (Fig. 2C). A treatment plan, which included the fabrication of an adhesive-retained silicone orbital prosthesis, was developed in an attempt to rehabilitate the orbit and the maxillary and mandibular arches. The rehabilitation
of the arches included orthodontic alignment of the remaining mandibular dentition with fixed appliances and increased occlusal vertical dimension to establish a more appropriate arch form and occlusal plane. The margins of the orbital prosthesis was unaffected by the lip and cheek contours, so it was decided to fabricate a silicone orbital prosthesis to address the esthetic needs of the patient. Irreversible hydrocolloid impression material (Jeltrate Fast Set; Dentsply Intl, York, Pa) was used to record a moulage impression of the acquired defect. A customized ocular prosthesis was fabricated and a waxing of the orbital prosthesis was made from baseplate wax (Cavex 100; Cavex, Haarlem, Netherlands), which was clinically assessed at the evaluation appointment to determine the proper facial contours and dimensions. The final waxing was completed and invested with a Type IV dental stone (Nok Stone; Lafarge Prestia, Cholburi, Thailand). Room temperature vulcanizing silicone (MDX 4-4210; Factor II Inc, Lakeside, Ariz) was mixed with intrinsic stains (KT699 Functional intrinsic staining kit; Factor II Inc) according to the manu-
The Journal of Prosthetic Dentistry
facturer’s recommendation and was packed into the mold. After vulcanization, the orbital prosthesis was extrinsically stained (Dry Earth Pigments; Factor II Inc), fixed with silicone adhesive (Silastic Medical Adhesive Type-A; Dow Corning Corp, Midland, Mich), and inserted in 2005. The residual roots of the maxillary right first molar were extracted. A maxillary interim overdenture with an increased occlusal vertical dimension of 5 mm was fabricated according to conventional denture techniques and was provided to the patient.7 The patient reported that her masticatory ability was adequate with the new interim maxillary prosthesis (Fig. 3), and she continued to wear it without any complaints for the duration of the mandibular orthodontic therapy. The patient was seen every 8 to 10 weeks. The maxillary left and right lateral incisors were considered to have a poor prognosis because of short roots and Class 1 mobility and were eventually extracted. In 2008, after completion of the orthodontic alignment of the mandibular teeth (Fig. 4A), definitive prosthetic rehabilitation was performed. Complete-coverage metal telescopic crowns (PC Dental Laboratory, Bangkok, Thailand) were fabricated on the remaining maxillary dentition (Fig. 4B), which would be used for the support and retention of the overdenture. The telescopic crowns were designed with a parallel path of insertion. Border molding was performed with a customized photopolymerized polymethyl methacrylate resin (Lightplast Base Plates; Dreve Dentamid GmbH, Unna, Germany) tray and a low-fusing modeling plastic impression compound (Kerr Green Stick; Kerr Corp, Romulus, Mich). The definitive impression was made with a polysulfide impression material (Light bodied Permlastic; Kerr Corp). The impression was poured with a Type IV dental stone (Nok Stone; Lafarge) to fabricate the definitive cast. A cobalt-chromium (Vitallium; Dentsply Intl) framework was designed for the maxillary overdenture, with
Tummawanit et al
293
May 2013
A
B
C 2 A, Interarch relationship with severe radiation-induced skeletal Class III malocclusion before treatment. B, Maxillary occlusal view before treatment. C, Mandibular occlusal view before treatment.
3 Interim overdenture prosthesis during orthodontic treatment.
indentations on the tissue surface of the framework to improve frictional retention between the framework and the telescopic crowns. A wax occlusion rim was prepared and the maxillomandibular jaw relationships were recorded in centric relation and then articulated in a semi-adjustable articulator (Hanau Wide-Vue II; Whip Mix Corp,
Tummawanit et al
Louisville, Ky). After a clinical assessment of the anatomic contour trial tooth arrangement, the definitive maxillary overdenture was processed in the laboratory and then inserted (Fig. 4C). Instructions were given for proper hygiene along with a prescription for fluoride paste (GC Tooth Mousse; GC Dental Products Corp, Alchi, Japan),
and maintenance and regular followup were scheduled every 6 months. In 2009, it was decided to fabricate another orbital prosthesis because the initial prosthesis had discolored and its margin degraded (Fig. 5).
294
Volume 109 Issue 5
A
B
C 4 A, Maxillary occlusal view after insertion of telescopic crowns. B, Mandibular occlusal view after completion of orthodontic treatment. C, Interarch relationship after insertion of overdenture.
5 Adhesive-retained orbital prosthesis.
The Journal of Prosthetic Dentistry
Tummawanit et al
295
May 2013 DISCUSSION Despite tumor control, the standard adjunctive treatment of retinoblastoma for young children can have long-term adverse effects pertaining to the growth and development of orofacial and dental structures. The severity of facial and dental abnormalities depends on the child’s age and the intensity, dose, and frequency of the treatment type. Enucleation is indicated for advanced invasive retinoblasomas where the tumor may spread into the optic nerve, choroid, or directly into the orbit.2 Radiation doses between 60 and 65 Gy will most likely alter the growth and development of children and can increase the risk of complications.8 Orbital bone grows rapidly during the first year of life, with significant growth of the medial and the lateral walls. Remodeling of the orbital bone continues to the age of 5 to 7 years, when 94% of the adult orbital size is attained.9 The combination of high radiation dosage along with involvement of the maxillary and orbital regions in the radiation field at a young age had cumulative adverse effects on the patient’s growth. The side effects evidently resulted in the formation of soft tissue radiation fibrosis, severe maxillary and orbital hypoplasia, and multiple dental abnormalities such as missing and malformed teeth. One of the most significant complications after EBRT is osteoradionecrosis (ORN), which is the exposure of irradiated bone tissue that fails to heal over a period of 3 months without a residual or recurrent tumor.10 A radiation dosage greater than 60 Gy, a large volume of involved bone in the primary radiation field, the time after radiation, concurrent or adjuvant chemotherapy, and acute trauma from surgical procedures can increase the risk of ORN. When surgical procedures are indicated, preoperative and postoperative adjunctive HBO therapy has been used to reduce the incidence of ORN, but HBO therapy has also been reported either to fail or
Tummawanit et al
to have any beneficial or curative effects on ORN.11 Moreover, the effects of HBO therapy on tumor recurrence remain widely debated.12 Orthognathic surgery followed by distraction osteogenesis with HBO therapy has been used to correct maxillary hypoplasia.13 This type of intervention was avoided in this patient because of the lack of antral space and the potential for questionable healing potential after radiation. The use of craniofacial implants can provide a higher degree of retention for the orbital prosthesis and can free the patient from dependency on skin adhesives. Because of the need for further bone augmentation and the risk of radiation-related complications, the placement of intraoral and extraoral implants was not considered. Therefore, a conservative treatment protocol with an adhesive-retained facial prosthesis and a maxillary overdenture retained by telescopic crowns was followed in lieu of other more high risk options. This approach fulfilled the patient’s esthetic and functional needs.
SUMMARY The age-related adverse effects of treatment for retinoblastoma pose a great challenge for the rehabilitation team. Surgical removal of the eye and EBRT at an early age can negatively influence midfacial and dental development. Although the restoration of the resulting acquired defects was time consuming, the conservative treatment was rendered to minimize the risk of complications and adequately restore patient function. High precision radiation therapy techniques such as IMRT and 3D-IMRT could have confined the radiation field and significantly minimized radiation-related side effects to the growth and development of orofacial structures. However, these treatment options were not available at the time of the patient’s diagnosis.
REFERENCES 1. Hurwitz RL, Shields CL, Shields JA, et al. Retinoblastoma. In: Pizzo PA, Poplack DG, editors. Principles and Practice of Pediatric Oncology. 6th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2011. p. 809-37. 2. Shields CL, Shields JA. Diagnosis and management of retinoblastoma. Cancer Control 2004;11:317-27. 3. Kaste SC, Hopkins KP, Jenkins JJ 3rd. Abnormal odontogenesis in children treated with radiation and chemotherapy: imaging findings. Am J Roentgenol 1994;162:1407-11. 4. Lin P, O’Brien JM. Frontiers in the management of retinoblastoma. Am J Ophthalmol 2009;148:192-8. 5. Doline S, Needleman HL, Petersen RA, Cassady JR. The effect of radiotherapy in the treatment of retinoblastoma upon the developing dentition. J Pediatr Ophthalmol Strabismus 1980;17:109-13. 6. Chintagumpala M, Cheves-Barrios P, Paysse EA, Plon SE, Hurwitz R. Retinoblastoma: review of current management. Oncologist 2007;12:1237-46. 7. Smith DE. Interim dentures and treatment dentures. Dent Clin North Am 1984;28:253-71. 8. Goldwein JW. Effects of radiation therapy on skeletal growth in childhood. Clin Orthop Relat Res 1991;262:101-7. 9. Waitzman AA, Posnick JC, Armstrong DC, Pron GE. Craniofacial skeletal measurements based on computed tomography: part II. Normal values and growth trends. Cleft Palate Craniofac J 1992;29:118-28. 10.Marx RE. Osteoradionecrosis: a new concept of its pathophysiology. J Oral Maxillofac Surg 1983;41:283-8. 11.Annane D, Depondt J, Aubert P, Villart M, Gehanno P, Gajdos P, et al. Hyperbaric oxygen therapy for radionecrosis of the jaw: a randomized, placebo-controlled, doubleblind trial from the ORN96 study group. J Clin Oncol 2004;22:4893-900. 12.Feldmeier JJ, Carl U, Hartmann K. Hyperbaric oxygen: does it promote growth or recurrence of malignancy? Undersea Hyperbar M 2003;30:1-18. 13.Nolte JW, Jansma J, Becking AG. Distraction osteogenesis of maxilla and midface in postradiotherapy patients. J Oral Maxillofac Surg 2012;70:1145-51. Corresponding author: Dr M.L. Theerathavaj Srithavaj Maxillofacial Prosthetic Service Mahidol University 6th Yothi Street Rajathevee Pharayathai Bangkok 10400 THAILAND Fax: +6623548491 E-mail: [email protected] Acknowledgments The authors thank P’Anun, for meticulous technical skills during the fabrication of the intra- and extra-oral prostheses. Copyright © 2013 by the Editorial Council for The Journal of Prosthetic Dentistry.
multidisciplinary treatment approach is indicated to achieve the most ideal functional, physical, and psychological outcomes. The purpose of this clinical report was to describe the prosthodontic rehabilitation of a patient who underwent enucleation to treat the primary diagnosis of retinoblastoma, followed by radiation therapy and adjunctive chemotherapy, which secondarily resulted in a combination of dental and facial developmental abnormalities.
CLINICAL REPORT A 16-year-old Thai female with an acquired right orbital defect was referred for the fabrication of an orbital prosthesis. The history revealed that she had been diagnosed with retinoblastoma of the right eye in 1989 when she was 1-year old. Enucleation of the right eye was performed in the same year, followed by postenucleation adjunctive chemotherapy and radiotherapy. Thirty-three fractionated dosages of EBRT for a total of 60 Gy were delivered to the right or-
bital and maxillary region. Initially, prosthetic rehabilitation for the ocular defect was performed by fabricating an ocular prosthesis, but because of the continual radiation fibrosis of the eyelids and surrounding soft tissues, the ocular prosthesis dislodged frequently until she could no longer wear it. In 2003, the inferiolateral orbital wall was reconstructed with synthetic bone graft (Medpor; Porex Surgical Inc, Newnan, Ga) to improve the compromised contour of the orbital bones and a split-thickness skin graft harvested from the thigh region was used to cover the synthetic bone graft (Medpor; Porex Surgical Inc). The eyelids were also removed in the hope of making the tissue bed more able to bear an orbital prosthesis. No complications in the healing of the grafted area were reported, even though adjunctive hyperbaric oxygen (HBO) therapy was not employed. In 2004, the initial visit showed that the patient had undergone a right ocular enucleation along with removal of the eyelids. Although orbital reconstruction had been performed,
Presented at the 7th Biennial Congress of the Asian Academy of Prosthodontics, Shanghai China, October 2011.
Resident, Maxillofacial Prosthetics Service. Instructor, Maxillofacial Prosthetics Service. c Assistant Professor, Maxillofacial Prosthetics Service. a
b
Tummawanit et al
292
Volume 109 Issue 5
1 Frontal view of patient before prosthetic rehabilitation. the patient still exhibited hypoplastic orbital bones and a midfacial depression; in addition, the lower half of the face had deviated to the right, resulting in facial asymmetry (Fig. 1). The patient also had a concave facial profile with a flattened nose. Intraoral findings exhibited a hypoplastic maxillary arch and normal mandibular arch resulting in severe skeletal Class III malocclusion (Fig. 2A). In the maxillary arch, the central incisors exhibited normal development of their clinical crowns and roots, the lateral incisors were noted to be microdontic, and the left canine was malpositioned in the premolar region (Fig. 2B). Radiographic examination showed the residual roots of the maxillary right first molar with shortening of the roots of the maxillary left first molar. The rest of the maxillary dentition was not present. The mandibular arch exhibited the absence of right and left third molars and right first and second premolars (Fig. 2C). A treatment plan, which included the fabrication of an adhesive-retained silicone orbital prosthesis, was developed in an attempt to rehabilitate the orbit and the maxillary and mandibular arches. The rehabilitation
of the arches included orthodontic alignment of the remaining mandibular dentition with fixed appliances and increased occlusal vertical dimension to establish a more appropriate arch form and occlusal plane. The margins of the orbital prosthesis was unaffected by the lip and cheek contours, so it was decided to fabricate a silicone orbital prosthesis to address the esthetic needs of the patient. Irreversible hydrocolloid impression material (Jeltrate Fast Set; Dentsply Intl, York, Pa) was used to record a moulage impression of the acquired defect. A customized ocular prosthesis was fabricated and a waxing of the orbital prosthesis was made from baseplate wax (Cavex 100; Cavex, Haarlem, Netherlands), which was clinically assessed at the evaluation appointment to determine the proper facial contours and dimensions. The final waxing was completed and invested with a Type IV dental stone (Nok Stone; Lafarge Prestia, Cholburi, Thailand). Room temperature vulcanizing silicone (MDX 4-4210; Factor II Inc, Lakeside, Ariz) was mixed with intrinsic stains (KT699 Functional intrinsic staining kit; Factor II Inc) according to the manu-
The Journal of Prosthetic Dentistry
facturer’s recommendation and was packed into the mold. After vulcanization, the orbital prosthesis was extrinsically stained (Dry Earth Pigments; Factor II Inc), fixed with silicone adhesive (Silastic Medical Adhesive Type-A; Dow Corning Corp, Midland, Mich), and inserted in 2005. The residual roots of the maxillary right first molar were extracted. A maxillary interim overdenture with an increased occlusal vertical dimension of 5 mm was fabricated according to conventional denture techniques and was provided to the patient.7 The patient reported that her masticatory ability was adequate with the new interim maxillary prosthesis (Fig. 3), and she continued to wear it without any complaints for the duration of the mandibular orthodontic therapy. The patient was seen every 8 to 10 weeks. The maxillary left and right lateral incisors were considered to have a poor prognosis because of short roots and Class 1 mobility and were eventually extracted. In 2008, after completion of the orthodontic alignment of the mandibular teeth (Fig. 4A), definitive prosthetic rehabilitation was performed. Complete-coverage metal telescopic crowns (PC Dental Laboratory, Bangkok, Thailand) were fabricated on the remaining maxillary dentition (Fig. 4B), which would be used for the support and retention of the overdenture. The telescopic crowns were designed with a parallel path of insertion. Border molding was performed with a customized photopolymerized polymethyl methacrylate resin (Lightplast Base Plates; Dreve Dentamid GmbH, Unna, Germany) tray and a low-fusing modeling plastic impression compound (Kerr Green Stick; Kerr Corp, Romulus, Mich). The definitive impression was made with a polysulfide impression material (Light bodied Permlastic; Kerr Corp). The impression was poured with a Type IV dental stone (Nok Stone; Lafarge) to fabricate the definitive cast. A cobalt-chromium (Vitallium; Dentsply Intl) framework was designed for the maxillary overdenture, with
Tummawanit et al
293
May 2013
A
B
C 2 A, Interarch relationship with severe radiation-induced skeletal Class III malocclusion before treatment. B, Maxillary occlusal view before treatment. C, Mandibular occlusal view before treatment.
3 Interim overdenture prosthesis during orthodontic treatment.
indentations on the tissue surface of the framework to improve frictional retention between the framework and the telescopic crowns. A wax occlusion rim was prepared and the maxillomandibular jaw relationships were recorded in centric relation and then articulated in a semi-adjustable articulator (Hanau Wide-Vue II; Whip Mix Corp,
Tummawanit et al
Louisville, Ky). After a clinical assessment of the anatomic contour trial tooth arrangement, the definitive maxillary overdenture was processed in the laboratory and then inserted (Fig. 4C). Instructions were given for proper hygiene along with a prescription for fluoride paste (GC Tooth Mousse; GC Dental Products Corp, Alchi, Japan),
and maintenance and regular followup were scheduled every 6 months. In 2009, it was decided to fabricate another orbital prosthesis because the initial prosthesis had discolored and its margin degraded (Fig. 5).
294
Volume 109 Issue 5
A
B
C 4 A, Maxillary occlusal view after insertion of telescopic crowns. B, Mandibular occlusal view after completion of orthodontic treatment. C, Interarch relationship after insertion of overdenture.
5 Adhesive-retained orbital prosthesis.
The Journal of Prosthetic Dentistry
Tummawanit et al
295
May 2013 DISCUSSION Despite tumor control, the standard adjunctive treatment of retinoblastoma for young children can have long-term adverse effects pertaining to the growth and development of orofacial and dental structures. The severity of facial and dental abnormalities depends on the child’s age and the intensity, dose, and frequency of the treatment type. Enucleation is indicated for advanced invasive retinoblasomas where the tumor may spread into the optic nerve, choroid, or directly into the orbit.2 Radiation doses between 60 and 65 Gy will most likely alter the growth and development of children and can increase the risk of complications.8 Orbital bone grows rapidly during the first year of life, with significant growth of the medial and the lateral walls. Remodeling of the orbital bone continues to the age of 5 to 7 years, when 94% of the adult orbital size is attained.9 The combination of high radiation dosage along with involvement of the maxillary and orbital regions in the radiation field at a young age had cumulative adverse effects on the patient’s growth. The side effects evidently resulted in the formation of soft tissue radiation fibrosis, severe maxillary and orbital hypoplasia, and multiple dental abnormalities such as missing and malformed teeth. One of the most significant complications after EBRT is osteoradionecrosis (ORN), which is the exposure of irradiated bone tissue that fails to heal over a period of 3 months without a residual or recurrent tumor.10 A radiation dosage greater than 60 Gy, a large volume of involved bone in the primary radiation field, the time after radiation, concurrent or adjuvant chemotherapy, and acute trauma from surgical procedures can increase the risk of ORN. When surgical procedures are indicated, preoperative and postoperative adjunctive HBO therapy has been used to reduce the incidence of ORN, but HBO therapy has also been reported either to fail or
Tummawanit et al
to have any beneficial or curative effects on ORN.11 Moreover, the effects of HBO therapy on tumor recurrence remain widely debated.12 Orthognathic surgery followed by distraction osteogenesis with HBO therapy has been used to correct maxillary hypoplasia.13 This type of intervention was avoided in this patient because of the lack of antral space and the potential for questionable healing potential after radiation. The use of craniofacial implants can provide a higher degree of retention for the orbital prosthesis and can free the patient from dependency on skin adhesives. Because of the need for further bone augmentation and the risk of radiation-related complications, the placement of intraoral and extraoral implants was not considered. Therefore, a conservative treatment protocol with an adhesive-retained facial prosthesis and a maxillary overdenture retained by telescopic crowns was followed in lieu of other more high risk options. This approach fulfilled the patient’s esthetic and functional needs.
SUMMARY The age-related adverse effects of treatment for retinoblastoma pose a great challenge for the rehabilitation team. Surgical removal of the eye and EBRT at an early age can negatively influence midfacial and dental development. Although the restoration of the resulting acquired defects was time consuming, the conservative treatment was rendered to minimize the risk of complications and adequately restore patient function. High precision radiation therapy techniques such as IMRT and 3D-IMRT could have confined the radiation field and significantly minimized radiation-related side effects to the growth and development of orofacial structures. However, these treatment options were not available at the time of the patient’s diagnosis.
REFERENCES 1. Hurwitz RL, Shields CL, Shields JA, et al. Retinoblastoma. In: Pizzo PA, Poplack DG, editors. Principles and Practice of Pediatric Oncology. 6th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2011. p. 809-37. 2. Shields CL, Shields JA. Diagnosis and management of retinoblastoma. Cancer Control 2004;11:317-27. 3. Kaste SC, Hopkins KP, Jenkins JJ 3rd. Abnormal odontogenesis in children treated with radiation and chemotherapy: imaging findings. Am J Roentgenol 1994;162:1407-11. 4. Lin P, O’Brien JM. Frontiers in the management of retinoblastoma. Am J Ophthalmol 2009;148:192-8. 5. Doline S, Needleman HL, Petersen RA, Cassady JR. The effect of radiotherapy in the treatment of retinoblastoma upon the developing dentition. J Pediatr Ophthalmol Strabismus 1980;17:109-13. 6. Chintagumpala M, Cheves-Barrios P, Paysse EA, Plon SE, Hurwitz R. Retinoblastoma: review of current management. Oncologist 2007;12:1237-46. 7. Smith DE. Interim dentures and treatment dentures. Dent Clin North Am 1984;28:253-71. 8. Goldwein JW. Effects of radiation therapy on skeletal growth in childhood. Clin Orthop Relat Res 1991;262:101-7. 9. Waitzman AA, Posnick JC, Armstrong DC, Pron GE. Craniofacial skeletal measurements based on computed tomography: part II. Normal values and growth trends. Cleft Palate Craniofac J 1992;29:118-28. 10.Marx RE. Osteoradionecrosis: a new concept of its pathophysiology. J Oral Maxillofac Surg 1983;41:283-8. 11.Annane D, Depondt J, Aubert P, Villart M, Gehanno P, Gajdos P, et al. Hyperbaric oxygen therapy for radionecrosis of the jaw: a randomized, placebo-controlled, doubleblind trial from the ORN96 study group. J Clin Oncol 2004;22:4893-900. 12.Feldmeier JJ, Carl U, Hartmann K. Hyperbaric oxygen: does it promote growth or recurrence of malignancy? Undersea Hyperbar M 2003;30:1-18. 13.Nolte JW, Jansma J, Becking AG. Distraction osteogenesis of maxilla and midface in postradiotherapy patients. J Oral Maxillofac Surg 2012;70:1145-51. Corresponding author: Dr M.L. Theerathavaj Srithavaj Maxillofacial Prosthetic Service Mahidol University 6th Yothi Street Rajathevee Pharayathai Bangkok 10400 THAILAND Fax: +6623548491 E-mail: [email protected] Acknowledgments The authors thank P’Anun, for meticulous technical skills during the fabrication of the intra- and extra-oral prostheses. Copyright © 2013 by the Editorial Council for The Journal of Prosthetic Dentistry.