- Email: [email protected]
Orbital floor reconstruction with autogenous mandibular symphyseal bone grafts
J Oral Maxillofac Surg 55:327-330, 1997
Orbital Floor Reconstruction With Autogenous Mandibular Symphyseal Bone Grafts VEJAYAN
KRISHNAN,
BDS, MS,* AND JAMES
V. JOHNSON,
DDS, MS-f
Purpose: This article shows the usefulness of the mandibular symphysis as a source of bone graft for the reconstruction of the orbital floor. Patients and Methods: A retrospective study was conducted on 16 patients who had isolated blowout fractures (n = 10) or orbital floor defects (n = 6) reconstructed with mandibular symphyseal bone grafts. Symphyseal bone grafts were used when the defects were less than 2 cm in diameter. Patients were examined at recall visits for any evidence of unsuccessful reconstruction by checking extraocular movements, and evidence of diplopia or enophthalmous. Results: During a mean follow-up of 12 months (range, 9 to 36 months), patients had no postoperative complaints. There were no instances of infection at the surgical sites, and none of the grafts were extruded or lost. There was good restoration of the orbital floor, with no clinical evidence of enophthalmous or diplopia. Extraocular movements were intact in all patients. Conclusion: The mandibular symphysis is a readily available source of autogenous bone that can be harvested with minimal morbidity. Its contour is suitable for use in orbital floor reconstruction. It merits consideration when autogenous bone grafts are considered for orbital floor defects less than 2 cm in diameter.
Orbital floor defects have been repaired with several types of alloplastic,1X2 allogeneic,3,4 and autogenous5-9 materials. Autogenous grafts are best tolerated by the surrounding tissues. “,I ’ However, they require a second surgical procedure to harvest, which may increase the morbidity. This report describes the use of mandibular symphyseal bone grafts for reconstruction of the orbital floor.4 This provides a satisfactory source with minimum morbidity. Patients
service at the University of Texas-Houston. During a 3-year period from June 1990 to June 1993, 16 patients who presented with isolated blowout fractures (n = 10) or orbital floor defects associated with other facial fractures (n = 6) were reconstructed with mandibular symphyseal bone grafts. These patients were selected for this treatment based on the size of the bony defect and the patients’ acceptance of the donor site. Data were obtained by clinical examinations by either one of the two authors at recall visits. Patients were examined for any limitation of extraocular movements, diplopia, or enophthalmous. The surgical sites were examined for evidence of infection, extrusion of the bone graft at the infraorbital rim, and loss of contour at the symphysis. Patients were questioned about the sensation in the infraorbital and mental regions. Indications to operate on these patients were diplopia, infraorbital nerve parasthesia, enophthalmous by clinical examination, and radiographic evidence of an orbital floor defect. The surgical approach to the orbital floor involved a transconjunctival incision in 14 patients and a subciliary incision in two patients. After the orbital floor exploration, the bone graft
and Methods
This retrospective study was conducted at the teaching hospitals of the Oral and Maxillofacial Surgery * Clinical Instructor, Oral and Maxillofacial Surgery, University of Detroit Mercy; and Staff Surgeon, Detroit Receiving Hospital, Detroit, MI. t Professor, Oral and Maxillofacial Surgery, University of Texas-Houston, Houston, TX. Address correspondence and reprint requests to Dr Krishnan: 25916 Dequindre, Warren, MI 48091. 0 1997 American Association 0278-2391/97/5504-0003$3,00/O
of Oral and Maxillofacial
Surgeons
327
328
FIGURE 1. graft harvest.
ALTERNATE
Mandibular
symphysis
with osteotomies
performed
BONE
GRAFT
FOR
ORBITAL
FLOOR
RECONSTRUCTION
for
FIGURE
d
was harvested. Local anesthesia was infiltrated in the mandibular labial vestibule, and a vestibular incision was made from the first premolar on one side to the opposite first premolar. The mandible was then exposed anterior to the mental foramina and from the roots of the anterior teeth to the inferior border. A no. 702 fissure bur was used to outline the bone graft. Depending on the size needed, the bone graft was obtained from either side of the symphysis or it crossed the midline. The superior bur cut was beveled at 45” to avoid damage to the roots of the anterior teeth. The distal osteotomy was also bevelled at 45” to facilitate placement of the osteotome for removal of the graft. The osteotomies are performed only through the outer cortical plate of the mandible (Fig 1). A small curved osteotome was placed in the beveled distal osteotomy and used to remove the bone graft. Small portions of cancellous bone attached to the cortical plate were removed with rongeurs or a bone reduction bur. The bone graft was reduced in thickness or contoured as desired with the use of a reduction bur. The bone graft
2.
Bone plate fixated
to the bone graft on the side table.
was then placed in the orbital, floor with the concave, outer surface against the periorbita and fixed to the orbital floor or the infraorbital rim with a microplate or screws. When screws are used, the bone graft was held in place while the screw-hole was drilled through it and into stable bone of the orbital floor. When bone plate fixation was used, it was first attached to the graft on the side table (Fig 2). The graft and attached bone plate are then placed in the orbital floor and the bone plate was adapted to the infraorbital rim or floor and fixed (Fig 3). The surgical, site was then closed in the standard fashion. Hemostasis in the graft donor site was achieved using bone wax. The mentalis muscle was reattached, and the incision was closed.
Table 1. Summary of Data on Patients With Orbital Floor Defects Repaired With Mandibular Symphyseal Bone Grafts Number of patients M:F ratio Mean age (yr) Blowout fractures Orbital floor defects associated with midface fractures Mean follow-up (mo) Limited extraocular movements Enophthalmous Neurosensory deficits: Infraorbital Mental
16 7:l 28 (range, 10 6 12 (range, None None None None
22 to 50)
9 to 36)
FIGURE 3. Intraoperative photograph the orbital floor fixed to the infraorbital
showing the bone graft rim with a bone plate.
in
KRISHNAN
AND
JOHNSON
FIGURE 4. A, Coronal CT scan showing a right orbital floor defect associated with a zygomatico-maxillary complex fracture. B, Coronal CT scan showing repaired orbital floor. The contour of the orbital floor has been restored by the bone graft. C, 20.month follow-up Water view radiograph showing good restoration of the orbital floor by the bone graft (arrows). The bone graft has maintained its form even after this time.
Results The follow-up ranged from 9 to 36 months, with a mean of 12 months. None of the patients reported any postoperative complaints. There was no clinical evidence of enophthalmous or diplopia, and the extraocular movements were intact. There were no instances of infection either at the grafted or the donor sites. None of the grafts were lost or extruded. Normal chin contour was maintained, without any evidence of step deformities or chin ptosis. No sensory deficits of the
infrorbital nerve or the mental nerve were noted. A summary of the data is shown in Table 1. Postoperative radiographs revealed restoration of the contour of the orbital floor (Figs 4B, C). Discussion Orbital floor defects have been reconstructed with autogenous bone grafts from the calvarium,” antral wa11,9 ilium,7,13 rib,7S13and mandible.5.6S8 The choice of a particular source is dependent on several factors.
330
DISCUSSION
These include surgical access, the size of the defect to be repaired, donor site morbidity, and the quality and quantity of available bone. Bone grafts from the antrum and the mandible have low postoperative morbidity and can be obtained with relative ease. The quality of the bone grafts from the antrum is variable because of the different thickness of the antral wall in various sites.14 The buccal and lingual cortical plates of the mandible have consistent thickness and quality.14 Therefore, the mandible is a more desirable donor site. Grafts from the lingual plate of the mandible5 and the lateral aspect of the mandibular ramus have been used for orbital floor reconstruction. The mandibular symphysis, however, is more accessible in comparison with the lingual plate and the lateral ramus. Additionally, the contour of the bone graft conforms to the orbital floor quite readily. This has been previously shown by Bagatin4 who reconstructed six orbital floor defects with mandibular symphyseal bone grafts. Grafts measuring 2 by 4 cm can be harvested from the symphysis. Grafts of this dimension would find application in the repair of the majority of orbital floor defects. When bone grafts from the mandible5,6’s and the maxillary antrum’ have been used for the repair of orbital floor defects, there have been no instances of their loss attributable to infection. This has also been our experience. This may be a result of the use of pre and perioperative antibiotics as well as the vascularity in the maxillofacial region.15 There should be no objection, therefore, to harvesting a bone graft from the contaminated oral cavity and placing it in the orbital floor. The mandibular symphysis has been used as a source of bone grafts for alveolar cleft repair,7 alveolar ridge augmentation,16 and orbital floor reconstruction.8 This source is, however, often overlooked when an autogenous bone graft is needed for orbital floor reconstruction. Our experience has shown that the mandibular symphysis is an excellent source of bone for reconstruction of the orbital floor. It can be harvested with relative ease and low morbidity, and the quality and
contour of the bone graft is very adaptable for the reconstruction of the orbital floor. Such bone grafts can be used to repair defects measuring up to 2 cm in diameter. The maxillofacial surgeon should, therefore, consider using this readily available source of bone when reconstructing the orbital floor. References 1. Girdler NM, Hosseini M: Orbital floor reconstruction with autogenous bone harvested from the mandibular lingual cortex. Br J Oral Maxillofac Surg 30:36, 1992 2. Laskin JL, Edwards DM: Immediate reconstruction of an orbital complex fracture with autogenous mandibular bone. J Oral Surg 35:149, 1977 3. Converse JM, Smith B: Reconstruction of floor of orbit by bone grafts. Arch Ophthalmol 44:749, 1950 4. Bagatin M: Reconstruction of orbital defects with autogenous bone from mandibular symphysis. J Craniomaxillofac Surg 15:103, 1987 5. Roncevic R, Malinger B: Experience with various procedures in the treatment of orbital floor fractures. J Maxillofac Surg 9:81, 1981 6. Kaye BL: Orbital floor repair with antral wall bone grafts. Plast keconstr Surg 37162, 1966 7. Sindet-Pedersen S. Enemark H: Mandibular bone grafts for reconstruction of alveolar clefts. J Oral MaxillofacSurg 46:533, 1988 8. Iannetti G, D’ Arco F: The use of lyophilized dura in reconstruction of the orbital floor. J Maxillofac Surg 5:58, 1977 9. Waite PD, Clanton JT: Orbital floor reconstruction with lyophilized dura. J Oral Maxillofac Surg 46:727, 1988 10. Antonyshyn 0, Gruss JS, Galbraith DJ, et al: Complex orbital fractures: A critical analysis of immediate bone graft reconstruction. Ann Plast Surg 22:220, 1989 11. Polley JW, Ringler SL: The use of teflon in orbital floor reconstruction following blunt facial trauma: A 20-year experience. Plast Reconstr Surg 79139, 1987 12. Prowler JR: Immediate reconstruction of the orbital rim and floor. J Oral Surg 23:5, 1965 13. Enneking WF: Histological investigation of bone transplants in immunologically prepared animals. J Bone Joint Surg Am 39:597, 1957 14. DuBrul EL: Sicher’s Oral Anatomy. St. Louis, MO, CV Mosby, 1980, p 90 15. Hammack BL, Enneking WF: Comparative vascularization of autogenous and homogenous bone transplants. J Bone Joint Surg Am 42:811, 1960 16. Misch CM, Misch CE, Resnik RR, et al: Reconstruction of maxillary alveolar defects with mandibular symphysis grafts for dental implants. Int J Oral Maxillofac Implants 7:360, 1992
J Oral Maxillofac Surg 55:330-332, 1997
Discuss/on Orbital Floor Reconstruction With Autogenous Mandibular Symphyseal Bone Grafts Daniel Lew, DDS University
of Iowa
Isolated orbital
Hospital
and Clinic,
Iowa
City, Iowa
floor fractures represent up to 21.4% of
all fractures of the midface.’ The issues regarding these fractures can be divided into a series of questions. The first is whether there is need for a graft in all such cases. Second, if there is, what material should be used, taking into account the efficacy of the treatment, the morbidity, and the longterm results of the procedure undertaken? In determining the need to construct an orbital floor, the first consideration is whether Lockwood’s suspension liga-
Orbital Floor Reconstruction With Autogenous Mandibular Symphyseal Bone Grafts VEJAYAN
KRISHNAN,
BDS, MS,* AND JAMES
V. JOHNSON,
DDS, MS-f
Purpose: This article shows the usefulness of the mandibular symphysis as a source of bone graft for the reconstruction of the orbital floor. Patients and Methods: A retrospective study was conducted on 16 patients who had isolated blowout fractures (n = 10) or orbital floor defects (n = 6) reconstructed with mandibular symphyseal bone grafts. Symphyseal bone grafts were used when the defects were less than 2 cm in diameter. Patients were examined at recall visits for any evidence of unsuccessful reconstruction by checking extraocular movements, and evidence of diplopia or enophthalmous. Results: During a mean follow-up of 12 months (range, 9 to 36 months), patients had no postoperative complaints. There were no instances of infection at the surgical sites, and none of the grafts were extruded or lost. There was good restoration of the orbital floor, with no clinical evidence of enophthalmous or diplopia. Extraocular movements were intact in all patients. Conclusion: The mandibular symphysis is a readily available source of autogenous bone that can be harvested with minimal morbidity. Its contour is suitable for use in orbital floor reconstruction. It merits consideration when autogenous bone grafts are considered for orbital floor defects less than 2 cm in diameter.
Orbital floor defects have been repaired with several types of alloplastic,1X2 allogeneic,3,4 and autogenous5-9 materials. Autogenous grafts are best tolerated by the surrounding tissues. “,I ’ However, they require a second surgical procedure to harvest, which may increase the morbidity. This report describes the use of mandibular symphyseal bone grafts for reconstruction of the orbital floor.4 This provides a satisfactory source with minimum morbidity. Patients
service at the University of Texas-Houston. During a 3-year period from June 1990 to June 1993, 16 patients who presented with isolated blowout fractures (n = 10) or orbital floor defects associated with other facial fractures (n = 6) were reconstructed with mandibular symphyseal bone grafts. These patients were selected for this treatment based on the size of the bony defect and the patients’ acceptance of the donor site. Data were obtained by clinical examinations by either one of the two authors at recall visits. Patients were examined for any limitation of extraocular movements, diplopia, or enophthalmous. The surgical sites were examined for evidence of infection, extrusion of the bone graft at the infraorbital rim, and loss of contour at the symphysis. Patients were questioned about the sensation in the infraorbital and mental regions. Indications to operate on these patients were diplopia, infraorbital nerve parasthesia, enophthalmous by clinical examination, and radiographic evidence of an orbital floor defect. The surgical approach to the orbital floor involved a transconjunctival incision in 14 patients and a subciliary incision in two patients. After the orbital floor exploration, the bone graft
and Methods
This retrospective study was conducted at the teaching hospitals of the Oral and Maxillofacial Surgery * Clinical Instructor, Oral and Maxillofacial Surgery, University of Detroit Mercy; and Staff Surgeon, Detroit Receiving Hospital, Detroit, MI. t Professor, Oral and Maxillofacial Surgery, University of Texas-Houston, Houston, TX. Address correspondence and reprint requests to Dr Krishnan: 25916 Dequindre, Warren, MI 48091. 0 1997 American Association 0278-2391/97/5504-0003$3,00/O
of Oral and Maxillofacial
Surgeons
327
328
FIGURE 1. graft harvest.
ALTERNATE
Mandibular
symphysis
with osteotomies
performed
BONE
GRAFT
FOR
ORBITAL
FLOOR
RECONSTRUCTION
for
FIGURE
d
was harvested. Local anesthesia was infiltrated in the mandibular labial vestibule, and a vestibular incision was made from the first premolar on one side to the opposite first premolar. The mandible was then exposed anterior to the mental foramina and from the roots of the anterior teeth to the inferior border. A no. 702 fissure bur was used to outline the bone graft. Depending on the size needed, the bone graft was obtained from either side of the symphysis or it crossed the midline. The superior bur cut was beveled at 45” to avoid damage to the roots of the anterior teeth. The distal osteotomy was also bevelled at 45” to facilitate placement of the osteotome for removal of the graft. The osteotomies are performed only through the outer cortical plate of the mandible (Fig 1). A small curved osteotome was placed in the beveled distal osteotomy and used to remove the bone graft. Small portions of cancellous bone attached to the cortical plate were removed with rongeurs or a bone reduction bur. The bone graft was reduced in thickness or contoured as desired with the use of a reduction bur. The bone graft
2.
Bone plate fixated
to the bone graft on the side table.
was then placed in the orbital, floor with the concave, outer surface against the periorbita and fixed to the orbital floor or the infraorbital rim with a microplate or screws. When screws are used, the bone graft was held in place while the screw-hole was drilled through it and into stable bone of the orbital floor. When bone plate fixation was used, it was first attached to the graft on the side table (Fig 2). The graft and attached bone plate are then placed in the orbital floor and the bone plate was adapted to the infraorbital rim or floor and fixed (Fig 3). The surgical, site was then closed in the standard fashion. Hemostasis in the graft donor site was achieved using bone wax. The mentalis muscle was reattached, and the incision was closed.
Table 1. Summary of Data on Patients With Orbital Floor Defects Repaired With Mandibular Symphyseal Bone Grafts Number of patients M:F ratio Mean age (yr) Blowout fractures Orbital floor defects associated with midface fractures Mean follow-up (mo) Limited extraocular movements Enophthalmous Neurosensory deficits: Infraorbital Mental
16 7:l 28 (range, 10 6 12 (range, None None None None
22 to 50)
9 to 36)
FIGURE 3. Intraoperative photograph the orbital floor fixed to the infraorbital
showing the bone graft rim with a bone plate.
in
KRISHNAN
AND
JOHNSON
FIGURE 4. A, Coronal CT scan showing a right orbital floor defect associated with a zygomatico-maxillary complex fracture. B, Coronal CT scan showing repaired orbital floor. The contour of the orbital floor has been restored by the bone graft. C, 20.month follow-up Water view radiograph showing good restoration of the orbital floor by the bone graft (arrows). The bone graft has maintained its form even after this time.
Results The follow-up ranged from 9 to 36 months, with a mean of 12 months. None of the patients reported any postoperative complaints. There was no clinical evidence of enophthalmous or diplopia, and the extraocular movements were intact. There were no instances of infection either at the grafted or the donor sites. None of the grafts were lost or extruded. Normal chin contour was maintained, without any evidence of step deformities or chin ptosis. No sensory deficits of the
infrorbital nerve or the mental nerve were noted. A summary of the data is shown in Table 1. Postoperative radiographs revealed restoration of the contour of the orbital floor (Figs 4B, C). Discussion Orbital floor defects have been reconstructed with autogenous bone grafts from the calvarium,” antral wa11,9 ilium,7,13 rib,7S13and mandible.5.6S8 The choice of a particular source is dependent on several factors.
330
DISCUSSION
These include surgical access, the size of the defect to be repaired, donor site morbidity, and the quality and quantity of available bone. Bone grafts from the antrum and the mandible have low postoperative morbidity and can be obtained with relative ease. The quality of the bone grafts from the antrum is variable because of the different thickness of the antral wall in various sites.14 The buccal and lingual cortical plates of the mandible have consistent thickness and quality.14 Therefore, the mandible is a more desirable donor site. Grafts from the lingual plate of the mandible5 and the lateral aspect of the mandibular ramus have been used for orbital floor reconstruction. The mandibular symphysis, however, is more accessible in comparison with the lingual plate and the lateral ramus. Additionally, the contour of the bone graft conforms to the orbital floor quite readily. This has been previously shown by Bagatin4 who reconstructed six orbital floor defects with mandibular symphyseal bone grafts. Grafts measuring 2 by 4 cm can be harvested from the symphysis. Grafts of this dimension would find application in the repair of the majority of orbital floor defects. When bone grafts from the mandible5,6’s and the maxillary antrum’ have been used for the repair of orbital floor defects, there have been no instances of their loss attributable to infection. This has also been our experience. This may be a result of the use of pre and perioperative antibiotics as well as the vascularity in the maxillofacial region.15 There should be no objection, therefore, to harvesting a bone graft from the contaminated oral cavity and placing it in the orbital floor. The mandibular symphysis has been used as a source of bone grafts for alveolar cleft repair,7 alveolar ridge augmentation,16 and orbital floor reconstruction.8 This source is, however, often overlooked when an autogenous bone graft is needed for orbital floor reconstruction. Our experience has shown that the mandibular symphysis is an excellent source of bone for reconstruction of the orbital floor. It can be harvested with relative ease and low morbidity, and the quality and
contour of the bone graft is very adaptable for the reconstruction of the orbital floor. Such bone grafts can be used to repair defects measuring up to 2 cm in diameter. The maxillofacial surgeon should, therefore, consider using this readily available source of bone when reconstructing the orbital floor. References 1. Girdler NM, Hosseini M: Orbital floor reconstruction with autogenous bone harvested from the mandibular lingual cortex. Br J Oral Maxillofac Surg 30:36, 1992 2. Laskin JL, Edwards DM: Immediate reconstruction of an orbital complex fracture with autogenous mandibular bone. J Oral Surg 35:149, 1977 3. Converse JM, Smith B: Reconstruction of floor of orbit by bone grafts. Arch Ophthalmol 44:749, 1950 4. Bagatin M: Reconstruction of orbital defects with autogenous bone from mandibular symphysis. J Craniomaxillofac Surg 15:103, 1987 5. Roncevic R, Malinger B: Experience with various procedures in the treatment of orbital floor fractures. J Maxillofac Surg 9:81, 1981 6. Kaye BL: Orbital floor repair with antral wall bone grafts. Plast keconstr Surg 37162, 1966 7. Sindet-Pedersen S. Enemark H: Mandibular bone grafts for reconstruction of alveolar clefts. J Oral MaxillofacSurg 46:533, 1988 8. Iannetti G, D’ Arco F: The use of lyophilized dura in reconstruction of the orbital floor. J Maxillofac Surg 5:58, 1977 9. Waite PD, Clanton JT: Orbital floor reconstruction with lyophilized dura. J Oral Maxillofac Surg 46:727, 1988 10. Antonyshyn 0, Gruss JS, Galbraith DJ, et al: Complex orbital fractures: A critical analysis of immediate bone graft reconstruction. Ann Plast Surg 22:220, 1989 11. Polley JW, Ringler SL: The use of teflon in orbital floor reconstruction following blunt facial trauma: A 20-year experience. Plast Reconstr Surg 79139, 1987 12. Prowler JR: Immediate reconstruction of the orbital rim and floor. J Oral Surg 23:5, 1965 13. Enneking WF: Histological investigation of bone transplants in immunologically prepared animals. J Bone Joint Surg Am 39:597, 1957 14. DuBrul EL: Sicher’s Oral Anatomy. St. Louis, MO, CV Mosby, 1980, p 90 15. Hammack BL, Enneking WF: Comparative vascularization of autogenous and homogenous bone transplants. J Bone Joint Surg Am 42:811, 1960 16. Misch CM, Misch CE, Resnik RR, et al: Reconstruction of maxillary alveolar defects with mandibular symphysis grafts for dental implants. Int J Oral Maxillofac Implants 7:360, 1992
J Oral Maxillofac Surg 55:330-332, 1997
Discuss/on Orbital Floor Reconstruction With Autogenous Mandibular Symphyseal Bone Grafts Daniel Lew, DDS University
of Iowa
Isolated orbital
Hospital
and Clinic,
Iowa
City, Iowa
floor fractures represent up to 21.4% of
all fractures of the midface.’ The issues regarding these fractures can be divided into a series of questions. The first is whether there is need for a graft in all such cases. Second, if there is, what material should be used, taking into account the efficacy of the treatment, the morbidity, and the longterm results of the procedure undertaken? In determining the need to construct an orbital floor, the first consideration is whether Lockwood’s suspension liga-