J Oral Maxillofac Surg
62:82-89, 2004, Suppl 2
Reconstruction of Extensive Maxillary
Defects Using Zygomaticus Implants
Brian L. Schmidt, DDS, MD, PhD,* M.A. Pogrel, DDS, MD, FRCS,† Carl W. Young, DDS, MD,‡
and Arun Sharma, DDS, MS§
Purpose: Maxillary reconstruction after maxillectomy remains a great challenge for the reconstructive
oral and maxillofacial surgeon. This article is a clinical retrospective analysis of patients reconstructed
with zygomaticus implants after maxillary ablation.
Patients and Methods: The design of the study was a retrospective review of 9 patients requiring
near-total or total maxillectomy for pathologic reasons. Clinical records, photographs, and radiographs
were studied. Financial billing statements were reviewed to determine charges for implant reconstruction and method of payment.
Results: Maxillary reconstruction using zygomaticus and standard endosseous implants was performed
in 9 patients. Maxillary resection was performed for the following reasons: salivary gland malignancy (n
⫽ 2), squamous cell carcinoma (n ⫽ 5), maxillary mucormycosis (n ⫽ 1), and extensive maxillary atrophy
and infection secondary to subperiosteal maxillary implant placement (n ⫽ 1). A total of 28 zygomaticus
implants and 10 standard endosseous implants were used to reconstruct the 9 patients. Six zygomaticus
implants and 3 standard endosseous implants failed. The time of zygomaticus implant placement ranged
from placement at the time of resection to 3.2 years after the resection. Five patients received radiation
therapy. Five patients have been reconstructed with a maxillary obturator and have been functioning
with the prosthesis for a minimum of 2 years.
Conclusion: The combination of zygomaticus and standard endosseous implants can be used to reliably
reconstruct patients after extensive resection of the maxilla.
© 2004 American Association of Oral and Maxillofacial Surgeons
J Oral Maxillofac Surg 62:82-89, 2004, Suppl 2
The reconstruction of a maxillary defect after tumor
resection continues to pose a challenge for the reconstructive oral and maxillofacial surgeon. The currently
available maxillary reconstructive techniques include
placement of a prosthetic obturator, local and regional
flaps, and microvascular free flaps.1-5 The different reconstructive techniques have specific indications and
advantages depending on the ablative defect, the medical status of the patient, and the patient’s prognosis. The
maxillary obturator has a long history of effectively managing the functional, cosmetic, and psychological problems associated with a maxillectomy defect. However,
when extensive resections are required, significant
problems with obturator retention, support, and stability can be encountered after the ablation of retentive
maxillary anatomy. Zygomaticus implants were originally designed for reconstruction of the atrophic, edentulous maxilla.6 Zygomaticus implants have also been
used to establish retention and support for a maxillary
prosthesis after maxillectomy. However, to date there
has not been a review of patients reconstructed with
zygomaticus implants after maxillectomy. The purpose
of this study was to review the clinical outcome of
patients who have had maxillectomy for pathologic reasons and have been reconstructed with zygomaticus
implants.
Received from the University of California, San Francisco, San
Francisco, CA.
*Assistant Professor, Department of Oral and Maxillofacial Surgery.
†Professor and Chair, Department of Oral and Maxillofacial Surgery.
‡Resident, Department of Oral and Maxillofacial Surgery.
§Associate Clinical Professor, Department of Preventive and Restorative Dental Sciences.
This paper was presented at the American Association of Oral
and Maxillofacial Surgeons, 85th Annual Meeting, Orlando, FL,
September 2003.
Address correspondence and reprint requests to Dr Schmidt:
Department of Oral and Maxillofacial Surgery, C-522, University of
California, San Francisco, San Francisco, CA 94143-0440; e-mail:
[email protected]
© 2004 American Association of Oral and Maxillofacial Surgeons
0278-2391/04/6209-0209$30.00/0
doi:10.1016/j.joms.2004.06.027
82
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SCHMIDT ET AL
Table 1. PATIENTS RECONSTRUCTED WITH ZYGOMATICUS AND STANDARD ENDOSSEOUS IMPLANTS
FOLLOWING MAXILLECTOMY
Patient
Age
Diagnosis
Maxillary
Defect
Zygomaticus
Implants
Standard
Implants
1
2
3
4
5
6
7
8
9
Total
69
76
46
85
72
79
69
47
75
ACC
PLGA
SCC
SCC
SCC
SCC
SCC
Mucormycosis
Atrophy/infection
Near total
Near total
Total
Near total
Anterior
Total
Total
Near total
Near total
2
2
4
2
4
4
4
4
2
28
1
1
2
2
Zygomaticus
Failures
Standard
Failures
2
1
3
2
2
10
1
6
2
3
NOTE. The total number of implants that were placed and failed is listed for each patient. The diagnosis and reason for maxillectomy are
listed. The maxillary defect refers to the maxilla in a transverse dimension.
Abbreviations: ACC, adenoid cystic carcinoma; PLGA, polymorphous low-grade adenocarcinoma; SCC, squamous cell carcinoma.
Schmidt et al. Zygomaticus Implant Reconstruction of Maxilla. J Oral Maxillofac Surg 2004.
Patients and Methods
The design of this study was a retrospective review. Nine patients treated with zygomaticus implants and standard endosseous implants after maxillary resection were evaluated. The surgical and
prosthodontic records, radiographs, and clinical
photos were reviewed to obtain the following information: patient demographics, pathologic reason for maxillary resection, extent of maxillary resection, number of zygomaticus and standard
endosseous implants placed, number of implants
that failed, time from resection to implant placement, requirement for radiation therapy, and prosthetic outcome. Financial billing statements were
reviewed to determine the charges and source of
payment for implant placement.
Results
A total of 9 patients with extensive maxillary
resections were reconstructed with a combination
of 28 zygomaticus and 10 standard endosseous implants (Table 1). The indications for extensive maxillectomy included mucormycosis (Fig 1), salivary
gland malignancy (Fig 2), squamous cell carcinoma,
and extensive maxillary atrophy and infection after
placement of a subperiosteal implant (Table 1).
Patients were either reconstructed with a combination of zygomaticus and standard endosseous implants (Figs 1, 2) or double bilateral zygomaticus
implants (Fig 3) alone if no maxillary bone was
available for placement of standard endosseous implants. Six of the 28 zygomaticus and 3 of the 10
standard endosseous implants have failed (Table 1).
All failures occurred at stage II implant surgery. The
time of implant placement, history of radiation ther-
apy, and prosthetic outcome are listed in Table 2.
One patient had 60 Gy of radiation to the anterior
maxilla 23 years before implant placement. Four
patients had radiation therapy approximately 2
weeks after placement of the implants. Five of the
9 patients have been fully reconstructed with a
maxillary obturator with excellent speech, swallowing, and aesthetics. These 5 patients have been
functioning with the prosthesis for 2 to 3 years with
no loss of implants. Two remaining patients are in
the process of osseointegration of the implants before construction of the maxillary obturator. Two
patients have died from malignancy. Table 3 lists
the charges and source of payment for all implants.
The total professional fee for placement of 28 zygomaticus and 10 standard endosseous implants
was $56,905 minus the surgery center or operating
room charge. Eight of 9 patients were required to
pay for the implants out-of-pocket. Medical insurance payment for the implants, hospital charges,
and prosthodontic charges was received for 1 patient. All cases were performed with general anesthesia in the surgery center or operating room.
Discussion
To the best of our knowledge this study is the first
to evaluate clinical outcome after maxillary reconstruction with zygomaticus implants after extensive
maxillectomy. We found that the combination of zygomaticus and standard endosseous implants can be
used to retain and support a maxillary obturator after
extensive resection of the maxilla. Twenty-one percent of zygomaticus and 30% of standard endosseous
implants failed. This failure rate is higher than tradi-
84
ZYGOMATICUS IMPLANT RECONSTRUCTION OF MAXILLA
FIGURE 1. Reconstruction of an extensive maxillary defect with zygomaticus and standard endosseous implants after resection for maxillary
mucormycosis. A, The patient initially presented with a small draining fistula involving the left maxilla. B, The patient was taken to the operating room
for biopsy. The entire maxilla was noted to be necrotic. The microbiologic diagnosis demonstrated mucormycosis. C, Extensive resection of the
maxilla, including the piriform rims and buttress regions, was required. After resection there was little remaining maxilla and a denture could not be
supported. D, The patient was reconstructed with 4 zygomaticus implants. One standard endosseous implant was placed in the left piriform rim
region.
Schmidt et al. Zygomaticus Implant Reconstruction of Maxilla. J Oral Maxillofac Surg 2004.
tionally encountered,7 and there are a number of
possible explanations for implant failure in patients
after extensive maxillectomy.
One likely explanation for zygomaticus implant
failure after extensive maxillectomy is radiation
therapy. Two of the 3 patients who experienced
zygomaticus implant failure had received radiation
therapy. One patient received radiation over 3
years before implant placement and 2 patients had
implants placed at the time of resection and radiation therapy was started 2 weeks later. Radiation
has a clear impact on the reparative capacity of
bone.8 It has been previously shown that the success rate for standard endosseous implants is lower
in the irradiated oral and maxillofacial region.9
Parel and Tjellstrom10 reported a success rate of
only 61.1% for craniofacial implants placed in irradiated bone. There has not been a study published
that answers the question of whether implants
should be placed before or after radiation therapy.
The issue of hyperbaric oxygen therapy in patients
having implant reconstruction after radiation therapy is also controversial.11 Our current protocol is
to place the zygomaticus implants at the time of
resection given that most patients will require radiation therapy within 2 to 3 weeks of maxillary
resection. In the single patient that we placed zygomaticus implants after radiation therapy, the time
of implant placement was over 3 years after radiation therapy and hyperbaric oxygen therapy was
not given. Two of 4 zygomaticus implants and 1 of
2 standard endosseous implants failed in this patient. Despite these implant failures the patient
could be reconstructed with the remaining 2 zygomaticus and 1 standard endosseous implants. The
patient has been functioning with the obturator for
3 years. Given the possibility of implant failure in
these patients, we place as many standard and/or
zygomaticus implants as dictated by the available
bone.
85
SCHMIDT ET AL
FIGURE 1 (cont’d). E, The implants were supported with cross arch stabilization. F, Intraoral view with the obturator in place. G, Posterior-anterior
view without obturator demonstrating lack of upper lip support. H, With the denture in place the patient has adequate upper lip support with normal
speech and swallowing.
Schmidt et al. Zygomaticus Implant Reconstruction of Maxilla. J Oral Maxillofac Surg 2004.
Another possible explanation for implant failure is
that the biomechanical forces placed on zygomaticus
and standard implants after an extensive maxillectomy are significantly greater than the forces observed in a conventional implant reconstructive case.
The quality and quantity of remaining bone available
for osseointegration after an extensive maxillectomy
are compromised. The lever arm placed on zygomaticus implants is significantly greater than the lever
arm placed on standard endosseous implants. In most
of the cases in this study, resection of the palatal bone
was required. Therefore, the only bone available for
integration of the zygomaticus implant is the zygomatic bone at the junction of the temporal and frontal
process. Additionally, with standard endosseous implants the occlusal force is generally parallel to the
long axis of the implant. In the case of zygomaticus
implants the implant is at a 30° to 60° angle relative to
the occlusal force. These biomechanical requirements
possibly contribute to zygomaticus implant failures in
patients after extensive maxillectomy. One finding
from this study that argues against biomechanical
factors as the etiology of failure is that all implant
failures occurred at stage II surgery, before loading.
86
ZYGOMATICUS IMPLANT RECONSTRUCTION OF MAXILLA
FIGURE 2. Reconstruction of near-total maxillectomy defect after resection for adenoid cystic carcinoma. A, Biopsy-proven adenoid cystic
carcinoma involving almost the entire maxilla. B, The panoramic radiograph shows evidence of maxillary osteolysis. C, A near-total
maxillectomy was performed. D, Intraoperative view. The maxillary alveolus and buttresses and a portion of the nasal septum were resected.
E, A postoperative axial computed tomography shows the extent of maxillary resection required. The pterygoid plates were retained.
Postoperatively, a denture could not be retained given the loss of retentive maxillary anatomy. The patient had significant problems with nasal
regurgitation. F, Postreconstruction panoramic radiograph. Bilateral zygomaticus implants were placed, and a standard endosseous implant
was placed into the left pterygoid plate.
Schmidt et al. Zygomaticus Implant Reconstruction of Maxilla. J Oral Maxillofac Surg 2004.
87
SCHMIDT ET AL
FIGURE 2 (cont’d). G, All 3 implants were rigidly fixed to provide cross-arch stabilization. H, The intaglio surface of the denture. A bulk of acrylic
was placed anteriorly to provide a mucosal seal to prevent nasal regurgitation. I and J, Anteroposterior and lateral view with obturator in place. The
patient had normal speech with no nasal leakage.
Schmidt et al. Zygomaticus Implant Reconstruction of Maxilla. J Oral Maxillofac Surg 2004.
This finding further points to radiation therapy as a
contributing factor to implant failures in these cases.
In this study we did not evaluate quality of life after
maxillary reconstruction with zygomaticus and standard implants. Few studies have evaluated quality of
life after maxillary reconstruction. A single quality-of-
life study has been performed to evaluate the outcome of maxillary reconstruction with a maxillary
prosthetic obturator.3 More recently, Rogers et al
evaluated quality of life in patients requiring maxillectomy for oncologic reasons.12 These authors compared maxillary reconstruction with a microvascular
88
ZYGOMATICUS IMPLANT RECONSTRUCTION OF MAXILLA
FIGURE 3. Radiographs of patient reconstructed with bilateral double zygomaticus implants. The patient required total maxillectomy for maxillary
squamous cell carcinoma. There was not adequate bone for standard endosseous implants. A, Postoperative lateral cephalogram. An attempt was
made to separate the 4 zygomaticus implants as much as possible in 3 planes of space. B, Postoperative posteroanterior cephalogram. Zygomaticus
implants were placed to capture the maximum amount of bone at the junction of the temporal and frontal processes of the zygoma. The patient has
completed radiation therapy and is awaiting stage II implant surgery.
Schmidt et al. Zygomaticus Implant Reconstruction of Maxilla. J Oral Maxillofac Surg 2004.
free flap to reconstruction with a maxillary obturator
without implants. To explore the broad concepts of
health-related quality of life and subjective outcome,
the authors used 8 quality-of-life questionnaires, including the Denture Satisfaction13 and Obturator
Functioning Scale.3 The authors found that there was
no difference in quality of life between the patients
reconstructed with a microvascular free flap to those
reconstructed with a prosthetic obturator. It is important to note that within this quality-of-life study 10 of
18 patients who were reconstructed with a free flap
were unable to wear a denture.12 We have shown that
zygomaticus and standard endosseous implants offer a
reliable method to retain, support, and stabilize a
maxillary obturator after maxillary resection. We have
found that patients reconstructed with this method
Table 2. TIME OF IMPLANT PLACEMENT, RADIATION THERAPY, AND PROSTHETIC OUTCOME
Patient
Age
1
2
3
4
5
6
7
8
9
69
76
46
85
72
79
69
47
75
Diagnosis
ACC
PLGA
SCC
SCC
SCC
SCC
SCC
Mucormycosis
Atrophy/infection
Time From
Resection to
Reconstruction
8.4 mo
0
10 d
9.6 mo
3.2 yr
7d
0
9.6 mo
10.8 mo
Radiation
Therapy
Prosthestic
Reconstruction
Years
Functioning
With Prosthesis
Postimplant
Postimplant
Postimplant
Yes
3
Yes
Yes
2
3
Yes
Yes
2
3
Preimplant
Postimplant
Schmidt et al. Zygomaticus Implant Reconstruction of Maxilla. J Oral Maxillofac Surg 2004.
89
SCHMIDT ET AL
Table 3. PATIENT CHARGE AND METHOD OF PAYMENT FOR IMPLANT RECONSTRUCTION
Patient
Age
Diagnosis
1
2
3
4
5
6
7
8
9
Total
69
76
46
85
72
79
69
47
75
ACC
PLGA
SCC
SCC
SCC
SCC
SCC
Mucormycosis
Atrophy/infection
Zygomaticus
Implants
Standard
Implants
2
2
4
2
4
4
4
4
2
28
1
1
2
2
2
2
10
Charge
$5,600
$5,770
$5,100
$6,720
$6,720
$5,100
$8,800
$6,375
$6,720
$56,905
Patient
Payment
Insurance
Payment
$5,600
$5,770
$5,100
$6,720
$6,720
$5,100
$8,800
$5,717
$6,720
$45,430
$5,717
NOTE. The fee listed is exclusive of the facility, anesthesia, and prosthodontic costs.
Schmidt et al. Zygomaticus Implant Reconstruction of Maxilla. J Oral Maxillofac Surg 2004.
are able to wear a maxillary obturator, have highly
favorable speech and aesthetics, and are able to drink
and eat without nasal leakage. However, patients will
most likely have to bear the financial burden associated with this method of implant reconstruction.
Given the complex nature of the ablative maxillary
defect after extensive maxillary resection, this
method of maxillary reconstruction is acceptable for
this challenging patient population.
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