Myxofibroma of the maxilla. Reconstruction with iliac crest graft and dental implants after tumor resection.

Abstract

Odontogenic fibromyxomas are benign odontogenic tumors of mesenchymal origin of rare presentation in the oral cavity, which exhibit locally aggressive behavior and are prone to local recurrence. The controversy has mainly been on therapeutic management with recommendations varying, depending on the clinical cases, from simple curettage of lesion to segmental bone resection. We present a case report describing the reconstruction of an osseous defect in the maxilla and the restoration with dental implants in a 32 year old female patient after radical surgical excision due to an odontogenic fibromyxoma with locally aggressive behavior. The primary reconstruction of maxillary discontinuity defect was carried out by an immediate non-vascularized cortico-cancellous iliac crest graft. Using a computer-guided system for the implant treatment-planning, three dental implants were secondary placed in the bone graft by means of flapless implant surgery. The patient was subsequently restored with an implant-supported fixed prosthesis that has remained in continuous function for a period of three years. The surgical, reconstructive and restorative treatment sequence and techniques are discussed.

Full text

Page 1

Med Oral Patol Oral Cir Bucal-AHEAD OF PRINT Myxofibroma of the maxilla. Reconstruction with graft and implants
Journal section: Oral Surgery
Publication Types: Case Report
Myxofibroma of the maxilla. Reconstruction with iliac crest graft
and dental implants after tumor resection
Pedro Infante-Cossío 1, Rafael Martínez-de-Fuentes 2, Alberto García-Perla-García 3, Emilio Jiménez-Caste-
llanos 4, Lourdes Gómez-Izquierdo 5
1 Profesor Titular Vinculado, Servicio de Cirugía Oral y Maxilofacial, Hospital Universitario Virgen del Rocío, Universidad de
Sevilla
2 Profesor Asociado de Prótesis Estomatológica, Facultad de Odontología, Universidad de Sevilla
3 Profesor Asociado, Servicio de Cirugía Oral y Maxilofacial, Hospital Universitario Virgen del Rocío, Sevilla
4 Catedrático de Prótesis Estomatológica, Facultad de Odontología, Universidad de Sevilla
5 Facultativo Especialista del Servicio de Anatomía Patológica, Hospital Universitario Virgen del Rocío, Sevilla
Correspondence:
Servicio de Cirugía Oral y Maxilofacial
Hospital Universitario Virgen del Rocío
Av. Manuel Siurot. 41013-Sevilla, Spain
pinfante@us.es
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Abstract
Odontogenic fibromyxomas are benign odontogenic tumors of mesenchymal origin of rare presentation in the oral
cavity, which exhibit locally aggressive behavior and are prone to local recurrence. The controversy has mainly
been on therapeutic management with recommendations varying, depending on the clinical cases, from simple
curettage of lesion to segmental bone resection. We present a case report describing the reconstruction of an os-
seous defect in the maxilla and the restoration with dental implants in a 32 year old female patient after radical
surgical excision due to an odontogenic fibromyxoma with locally aggressive behavior. The primary reconstruc-
tion of maxillary discontinuity defect was carried out by an immediate non-vascularized cortico-cancellous iliac
crest graft. Using a computer-guided system for the implant treatment-planning, three dental implants were sec-
ondary placed in the bone graft by means of flapless implant surgery. The patient was subsequently restored with
an implant-supported fixed prosthesis that has remained in continuous function for a period of three years. The
surgical, reconstructive and restorative treatment sequence and techniques are discussed.
Key words: Odontogenic fibromyxoma, maxilla, reconstruction, dental implants, computer-assisted surgery.
Introduction
Odontogenic fibromyxomas are rare benign odontogen-
ic tumors of mesenchymal origin. They occur more
frequently between 10 and 40 years of age with an inci-
dence of approximately 0.07 new cases per million peo-
ple per year (1). They are more common in females and
located mainly in the mandible. Histologically they are
composed of large amounts of intercellular substance
rich in acid mucopolysaccharides and made up of loose
myxomatous connective tissue, fibroblasts and myofi-

Page 2

Med Oral Patol Oral Cir Bucal-AHEAD OF PRINT Myxofibroma of the maxilla. Reconstruction with graft and implants
broblasts. Patches of trabeculae of woven bone and cap-
illaries are dispersed by the lesion (2).
There is a wide variety in clinical and radiologic ap-
pearance of odontogenic fibromyxomas, being the most
common form of presentation as an asymptomatic ex-
pansion in the jaw and a multilocular radiolucent image.
Although they are a slow-growing lesion, they show a
persistent and destructive pattern. As they grow they
usually displace and resorb teeth causing pain and fa-
cial deformity. In the maxilla, they have the potential of
destroying bone extensively and invading the maxillary
sinuses. Its histological and radiological features make
it difficult to differentiate from other odontogenic tu-
mors and occasionally may be misinterpreted as a ma-
lignant lesion.
Odontogenic fibromyxomas exhibit locally aggressive
behavior and are prone to local recurrence. The con-
troversy has mainly been on therapy with recommen-
dations varying from simple curettage of the lesion to
radical surgery. Although curettage of the lesion is used
for treatment, it is associated with a high recurrence rate
up to 25% (3). It typically occurs during the first 2 years
after removal (4). The treatment of choice in large, de-
structive and expansile lesions is surgical removal with
safety margins of at least 1.5 cm to prevent recurrence
of the neoplasm. In most cases, tumor ablation usually
involves the sacrifice of adjacent teeth.
The reconstruction of patients with continuity defects
of the maxilla after tumor resection including the loss of
several teeth is very challenging. The basic method for
providing bone with osteogenic capacity in the maxil-
lary area is carried out by non-vascularized bone grafts.
Autogenous bone grafts taken from the iliac crest have
demonstrated to be a very reliable means for the re-
construction of maxillofacial defects after ablation of
tumors (5). Subsequent to the osseous anatomic recon-
struction, masticatory function of missing teeth can be
achieved by placing dental implants and using implant-
supported prosthesis. When raising a flap during the
implant surgery in patients who have previously under-
gone a bone reconstruction with iliac crest graft, one of
the main risks is often damage to the graft vasculariza-
tion from periostium, thus producing an unpredictable
bone resorption.
The purpose of the present article is to report an unusual
case of an aggressive fibromyxoma in the maxilla, with
emphasis on the surgical treatment, reconstruction of
maxillary discontinuity defect with an iliac crest graft,
and restoration with an implant-supported prosthesis
using a computer-guided system for the treatment-plan-
ning and precise placement of dental implants by means
of flapless surgery.
Case Report
A 32-year-old woman presented to consultation in Feb-
ruary 2006 with a history of swelling in the anterior
maxillary region. Three months before the patient had
felt mobility in the maxillary right canine and first
premolar. From then on, a swelling invol ving the buccal
vestibule in the anterior maxilla and palate was grow-
ing gradually, although it caused her no pain. Intraoral
examination revealed an ex pansive bony mass involv-
ing the buccal maxillary right canine region, extend-
ing to the area of the maxillary right lateral incisive and
first premolar, also affecting palate but less evident. On
palpation the swelling had hard consistency, and buccal
and palatal cortices were expanded. Panoramic radio-
graph showed a 2x1 cm well-demarcated radiolucent le-
sion of multiloculated appearance involving the anterior
right maxilla, and root resorption in the right maxillary
canine, first premolar and lateral incisive (Fig. 1a). In
computed tomography (CT), an expansible 2x1x1 cm le-
sion was visualized perforating and destroying the buc-
cal and palatal cortical bone, homogeneous hypoden-
sity with peripheral septi and an aggressive radiological
pattern (Fig. 1b). The lesion was in close relation with
the maxillary sinus and nasal cavity (Fig. 1c). Intraoral
incisional biopsy was performed under local anesthe-
sia, which revealed a collection of fibroblastic tissue
and islands of odontogenic epithelium with calcium.
The diagnosis was compatible with odontogenic fibro-
myxoma.
Fig. 1. 1a. Panoramic radiograph showing a radiolucent image of
multiloculated appearance involving the maxilla, and root resorp-
tion in the right maxillary canine, first premolar and lateral in-
cisive. 1b. Axial CT showing an expansive and osteolytic lesion
destroying the buccal and palatal cortical bone. 1c. Coronal CT
demonstrating an aggressive radiological pattern in close relation
with the maxillary sinus and nasal cavity.

Page 3

Med Oral Patol Oral Cir Bucal-AHEAD OF PRINT Myxofibroma of the maxilla. Reconstruction with graft and implants
Under general anesthesia the lesion was removed en
bloc via an intraoral approach with bone security mar-
gins, along with the involved teeth from maxillary right
central incisive through first premolar. The surgical
specimen consisted of a partial segmental maxillecto-
my just above the floor of the nasal cavity and maxillary
sinus (Fig. 2a). After removal of the lesion, the surgi-
cal defect received an immediate reconstruction using
a cortico-cancellous anterior iliac crest graft (Fig. 2b),
and two miniplates were fixed to stabilize it. Soft tis-
sue closure was achieved by local flaps. The patient was
discharged from the hospital on the third postoperative
day. There were no postoperative complications. Histo-
logical examination of the excised lesion showed abun-
dantly myxoid connective stroma, areas of moderately
dense collagen fibers, and strands of odontogenic epi-
thelium within the connective tissue stroma. The pres-
ence of myxomatous tissue, along with areas of moder-
ately dense collagen fibers, led to the final diagnosis of
myxofibroma odontogenic (Fig. 2c).
Six months post-surgery, a panoramic radiograph and
CT was performed confir ming complete integration of
the graft, with no evidence of tumor recurrence (Fig.
3a). For miniplates re trieval, a re-entry was performed
through a minimal incision in the vestibule. Two weeks
later, an osseus-dento-suported surgery template was
planned and constructed using the NobelGuide® pro-
gramme (Nobel Biocare® AB, Gothenburg, Sweden).
One anchor pin was used to provide additional stabi-
lization of the surgical template. Via the guided surgi-
cal template, two Bränemark Systems MKIII TiUnite
implants 3.75 mm in diameter and 13 mm long and
one Nobelspeedy Groovy NP 3.3×13 mm (Nobel Bio-
care® AB) were inserted in the iliac crest graft through
a minimally invasive flapless implant surgery. After
placement of implants, the guided surgical template
was removed, and healing abutments screwed. Primary
stability of implants was achieved. Three months later,
a partial implant-suppor ted prosthesis made of metal-
resin was constructed. After 3 years, no recurrence of
the tumor has occurred. The patient is being reviewed
in periodic checks. Follow up must be performed once
a year up to 10 years. The patient has a high level of
comfort and satisfaction (Figs. 3b, c and d).
Discussion
The therapeutic approach to the fibromyxoma is still
today a controversy. The treatment of choice consists
of surgical resection. However, no unanimous consen-
sus exists concerning the extension of surgery. A more
conservative approach is normally considered for small
lesions which can be treated with curettage and simple
enucleation (6). An alternative approach may include
the addition of a peripheral ostectomy to remove a cir-
cumferential margin of bone around the tumour. Larger
tumours often require more extensive resection as re-
currence rates are as high as 25% (3). The absence of
Fig. 2. 2a. Surgical specimen of the maxilla including the involved
teeth. 2b. Maxillary defect after tumor resection and immediate re-
construction using a cortico-cancellous iliac crest graft. 2c. Abun-
dant myxoid stroma, areas of moderately dense collagen fibers, and
strands of odontogenic epithelium within a connective tissue stroma
(hematoxylin and eosin 100x).
Fig. 3. 3a. Axial CT showing a well-integration of the bone graft.
3b. Panoramic radiograph of the 3 implants placed in the graft three
years later without recurrence of lesion. 3c. Intraoral view of the re-
construction with the implants and the structure for the prosthesis.
3d. View of the partial implant-supported prosthesis.

Page 4

Med Oral Patol Oral Cir Bucal-AHEAD OF PRINT Myxofibroma of the maxilla. Reconstruction with graft and implants
capsule and infiltrative growth of the myxomatous tis-
sue to the adjacent bone determine the high rate of re-
currence when conservative enucleation and curettage
are performed (1). Recurrence is the result of local inva-
sion into cancellous bone beyond radiographically vis-
ible margins in the absence of encapsulation (4). Recur-
rence is minimized with a more aggressive treatment
by performing a partial or complete segmental bone
resection, which is particularly indicated in the max-
illa. Therefore, a radical resection including an osseous
margin of at least 1.5-2 cm seems to be the best option to
prevent recurrences of large fibromyxomas (4).
In our case, an aggressive approach was chosen due to
the fact that a local destructive behavior was encoun-
tered (perforation of cortical bone, important tumour
expansion, and infiltration in a short period of time).
We performed a partial segmental maxillectomy, which
consisted of an en bloc resection of the tumor with sur-
gical margins beyond the radiographic margins of bone,
up to the edge of the maxillary sinus and nasal cavity
that were preserved (7).The possibility of carrying out a
pri mary maxillary reconstruction with optimal results
both aesthetic and functional encouraged us to choose
this option, moreover if in a second stage we could place
dental implants and restore with an implant-supported
prosthesis. Although the tendency towards recurrence
after this radical resection is very low, postoperative
follow-up of our patient for 10 years is advisable.
Bone reconstruction can be immediate or delayed fol-
lowing the surgical procedure, and can be performed
with autogenous bone grafts from iliac crest (8) or mi-
crovascularized free flaps (9). In our experience, small
maxillary bone defects (smaller than 5 cm) can be recon-
structed using cortico-cancellous iliac crest bone graft
(7). Iliac crest can be recommended in almost all recon-
structive situations because it reinforces the resistance
of the maxilla, re-establishes its continuity improving
facial contour, and provides adequate height and width
of bone. Once the graft has consolidated, these recon-
structions have proved to be very acceptable aestheti-
cally and functionally to support dental prostheses or
for the insertion of dental implants (5,9).
However, iliac crest bone grafts present the major prob-
lem of its unpredictable resorption. The capacity for
resorption is low if the graft is covered adequately by
the periosteum of the flap, which promotes the re-vas-
cularization and incorporation of the transplanted bone
from an early stage. An additional problem occurs in the
maxilla if the graft keeps in contact and communication
with natural cavities, as the resorption of the graft may
be higher due to compromised re-vascularization and
exposition to possible infection. Many publications in
the last few years have reported very good results with
the use of implants and implant-supported prostheses in
reconstructed patients after tumor resection, and dem-
onstrated that they seem to reduce bone resorption sig-
nificantly, probably due to the fact that prosthetic load
stimulates the graft and inhibits bone resorption (5,10).
The period of time of delay between bone graft recon-
struction and implant placement can fluctuate from 4 to
6 months. This waiting time would allow us to verify
the consolidation and re-vascularization of the grafted
bone, decreasing the risk of excessive graft resorption.
When placing implants, one of the significant difficul-
ties posed is to ensure the proper positioning within the
reconstructed alveolar ridge. In our patient, it was the
authors’ opinion that a minimally invasive flapless sur-
gical technique would have several benefits compared to
the conventional surgical procedure of raising a flap be-
fore implant insertion. Flapless surgery would not only
generate less postoperative bleeding and minor swelling
(11), but also less damage to the vascularization of the
graft as the periostium would remain intact.
The importance of dental implant treatment planning
using 3-D CT-scan is increasing. Computer-guided sur-
gery allows greater accuracy in determining the number
of implants, their location and positioning, offers more
advantages to use the amount of available bone and im-
prove stability in soft bone, and also facilitates mini-
mally invasive surgery (12). It is a very suitable proce-
dure to insert implants with precision in selected loca-
tions and areas with anatomical limitations, such as the
inferior alveolar nerve, nasal cavity or maxillary sinus
(13). Its usefulness has been also demonstrated in the
treatment of atrophic maxilla. However, to the best of
our knowledge, the use of a computer-guided system for
the treatment-planning and subsequent accurate place-
ment of dental implants by means of flapless surgery
has been no reported in a patient who previously had
undergone a reconstruction of the maxilla with an iliac
crest graft.
The planning procedure through a computerized meth-
od based on 3-D CT-scan images made it possible to
preview in advance the more favorable implant location,
and the fabrication of a customized guided surgical
template (14). The combined use of a software planning
program and a customized template allowed the place-
ment of implants by means of a flapless surgery (No-
belGuide®) without raising a mucoperiostal flap (15),
which enabled a surgical procedure where only it took a
small opening of the mucosa for the optimal positioning
of implants with precision. This treatment sequence had
several advantages. It made it possible the safe insertion
of the implants according to bone volume and without
intruding any anatomical cavities; the procedure pro-
vided minimal post-operative discomfort to the patient
by reducing swelling and pain (5); and by omission of
raising the mucoperiosteal flap, the postoperative bone
resorption potentially associated with the procedures of
full-thickness mucoperiosteal flap was prevented.

Page 5

Med Oral Patol Oral Cir Bucal-AHEAD OF PRINT Myxofibroma of the maxilla. Reconstruction with graft and implants
References
1. Simon EN, Merkx MA, Vuhahula E, Ngassapa D, Stoelinga PJ.
Odontogenic myxoma: A clinicopathological study of 33 cases. Int J
Oral Maxillofac Surg. 2004;33:333-7.
2. Boleaga-Durán B, Palacios E. Odontogenic myxoma of the max-
illa. Ear Nose Throat J. 2007;86:444-6.
3. Lo Muzio L, Nocini P, Favia G, Procaccini M, Mignogna MD.
Odontogenic myxoma of the jaws: a clinical, radiologic, immuno-
histochemical, and ultrastructural study. Oral Surg Oral Med Oral
Pathol Oral Radiol Endod. 1996;82:426-33.
4. King TJ 3rd, Lewis J, Orvidas L, Kademani D. Pediatric maxillary
odontogenic myxoma: A report of 2 cases and review of manage-
ment. J Oral Maxillofac Surg. 2008;66:1057-62.
5. Chiapasco M, Colletti G, Romeo E, Zaniboni M, Brusati R. Long-
term results of mandibular reconstruction with autogenous bone
grafts and oral implants after tumor resection. Clin Oral Implants
Res. 2008;19:1074-80.
6. Hernández Vallejo G, Cohn C, García Peñín A, Martínez Lara
S, Llanes Menéndez F, Montalvo Moreno JJ. Myxoma of the jaws.
Report of three cases. Med Oral. 2001;6:106-13.
7. Leiser Y, Abu-El-Naaj I, Peled M. Odontogenic myxoma - A case
series and review of the surgical management. J Craniomaxillofac
Surg. 2009;37:206-9.
8. Schneck DL, Gross PD, Tabor MW. Odontogenic myxoma: Report
of two cases with reconstruction considerations. J Oral Maxillofac
Surg. 1993;51:935-40.
9. Chiapasco M, Abati S, Ramundo G, Rossi A, Romeo E, Vogel G.
Behaviour of implants in bone grafts or free flaps after tumor resec-
tion. Clin Oral Implants Res. 2000;11:66-75.
10. Pogrel MA, Podlesh S, Anthony JP, Alexander J. A comparison
of vascularized and nonvascularized bone grafts for reconstruc-
tion of mandibular continuity defects. J Oral Maxillofac Surg.
1997;55:1200-6.
11. Rocci A, Martignoni M, Gottlow J. Immediate loading in the
maxilla using flapless surgery, implants placed in predetermined
positions, and prefabricated provisional restorations: A retrospective
3-year clinical study. Clin Implant Dent Relat Res. 2003;5: 29-36.
12. Rubio Serrano M, Albalat Estela S, Peñarrocha Diago M, Peñar-
rocha Diago M. Software applied to oral implantology: Update. Med
Oral Patol Oral Cir Bucal. 2008;13:E661-5.
13. Engelke W, Capobianco M: Flapless sinus floor augmentation us-
ing endoscopy combined with CT scan-designed surgical templates:
Method and report of 6 consecutive cases. Int J Oral Maxillofac Im-
plants. 2005;20:891-7.
14. Casap N, Wexler A, Tarazi E. Application of a surgical navigation
system for implant surgery in a deficient alveolar ridge postexcision
of an odontogenic myxoma. J Oral Maxillofac Surg. 2005;63:982-8.
15. Parel SM, Triplett RG. Interactive imaging for implant planning,
placement, and prosthesis construction. J Oral Maxillofac Surg.
2004; 62:41-7.