Research Article

1. Surgical Management of
Ameloblastoma in Children

2. Authors
 I-Yueh Huang, DDS, MS,a Sheng-
Tsung Lai, DDS,b Chung-Ho Chen,
DDS,c
 Chun-Ming Chen, DDS, MS,d Chung-
Wei Wu, DDS, MS,e and Yee-Hsiung
Shen, DDS,f
 Kaohsiung, Taiwan
 KAOHSIUNG MEDICAL UNIVERSITY

3. Objective
The purpose of this study was to
report experience in the treatment
of ameloblastoma in Taiwanese
children and to discuss the treatment
regimen

4. Study design
Fifteen patients, all younger than 18
years of age, with a diagnosis of
ameloblastoma in our department
between January 1991 and December
2004 were selected for study. Data
included sex, age at surgery, tumor
type, size and site of lesion, primary
surgical methods, use of adjuvant
therapy, complications, recurrences,
and course of follow-up.

5. Results
 Ages ranged from 9 to 17 (average was
13.7 years). Nine were male, 6 were
female; the sex ratio was 1.5:1.
 Fourteen lesions were in the mandible (1 in
the symphysis, 13 in the mandibular posterior
area) and only 1 was in the maxilla. The size
of the lesions ranged from 4*2.5 cm to 8*8
cm. Clinical typing included 8 unicystic type,
3 multicystic type, and 4 solid types. Of the
histologic types, 5 were plexiform, 3 were
mixed type, and 3 were acanthomatous type.
Complications included numbness of the
lower lip and contour defect of the face.
Three cases (20%) were recurrent, and 1
patient had 2 recurrences.

6. Conclusions
Good results can be achieved in the
treatment of ameloblastoma in
children using conservative
surgery.
 In the event of recurrence, a second
surgery can be successful. Patient
compliance and careful follow-up are
important.
(Oral Surgery Oral Medicine Oral
Pathology Oral Radiology
Endodontology 2007;104:478-85)

7. Ameloblastoma is the most common
aggressive benign odontogenic tumor of
the jaws.
The tumor is often asymptomatic,
presenting as a slowly enlarging facial
swelling or an incidental finding on a
radiograph. The physical presence of the
tumor may cause symptoms such as
pain, malocclusion, loosening of teeth, or
ulceration. Ameloblastoma is a locally
destructive tumor with a propensity for
recurrence if not entirely excised.

8. A few cases of malignant change with
distant metastasis have been reported
in the literature.
 It occurs in all age groups but the
lesion is most commonly diagnosed in
the third and fourth decades.
 The tumor is considered a rarity in the
young, but the tumor grows slowly and
probably starts to develop in childhood

9. The treatment for ameloblastoma is still
controversial and poses some special
problems in children.
Because of growth of the jaw, the different
incidence,behavior, and prognosis of the
tumor make the surgical consideration
different from adults. Some reports have
encouraged aggressive resection for
ameloblastoma in children, and some
studies showed simple curettage had
good results.

10. The aim of this study was to review a
series of ameloblastoma in Taiwanese
children, and to present our
experience of surgical treatment in this
pediatric group. We hope this report
may contribute to further meta-
analysis and develop a more rational
surgical protocol for ameloblastoma in
children.

11. PATIENTS AND MATERIALS
Of 223 patients with ameloblastoma, 15
(6.8%) were 18 years or younger
when presenting to our department,
and surgery was performed during the
period January1991 to December
2004. We reviewed patient age and
sex, anatomical distribution and size
of the lesions, histologic types, clinical
types, surgical methods, recurrence,
complications, and outcome.

12. All patients underwent incisional biopsy
before the surgery. Three surgical
techniques were used:
(1) Enucleation with peripheral
ostectomy,
(2) Decompression before enucleation
with peripheral ostectomy, and
(3) Segmental resection with immediate
iliac bone graft.

13. Enucleation with peripheral
ostectomy
Enucleation with peripheral ostectomy was
performed from an intraoral approach; the
lesion being removed along the junction of
the lesion and bone, and then peripheral
bone was carefully trimmed off for 3 to 5 mm
with a large round bone burr, including any
septa for multicystic and solid types. The
wound was packed open for 2 weeks, then
the obturator was constructed and the patient
instructed to irrigate the cavity with boiled
water or normal saline. The wound was then
allowed to heal secondarily or the cavity was
filled with artificial bone substitutes and
primary closure.

14. Decompression before enucleation with
peripheral ostectomy
Decompression before enucleation with
peripheral ostectomy was used when the
lesion was found to be cystlike on biopsy, and
the pathology report confirmed
ameloblastoma. After 1 week, when the
patient returned for the biopsy report, the
benefits and risks of this plan would be
discussed; if the patient understood the plan
and agreed to comply, decompression would
be used as a first measure. Under local
anesthesia, a mucoperiosteal flap would be
reflected to expose the lesion, and a bony
window made of adequate size to allow
opening of every loculation.

15. A decompression plug would be inserted (Fig. 1),
and the wound closed.
 Patients were taught to irrigate the cavity through
the hole in the plug after each meal. Follow-up
was arranged monthly with radiographic follow-
up at 3 months to evaluate change and bony
regeneration.
From 6 to 12 months later, enucleation with
peripheral ostectomy would be performed under
general anesthesia.
Postoperative care was similar to that discussed in
the previous section “Enucleation with peripheral
ostectomy.”

18. Segmental resection with immediate iliac
bone graft
In segmental resection with immediate iliac
bone graft, the extraoral resection was made
through the mandible with a 1-cm margin of
healthy bone. The reconstruction plate and
iliac bone graft were placed immediately for 6
weeks of intermaxillary fixation.
This technique was used for all solid-type and
multicystic lesions with involvement of the
lower border or posterior border of the
mandible, and when patients and parents
chose radical surgery to decrease the chance
of recurrence

19. RESULTS
 Of the 15 patients, 9 were male and 6 were
female, a ratio of 1.5:1.
 The mean age was 13.7 years (range from 9 to
17 years). The angle region (body-angleramus)
was the most common site (10 of 15, or 66.6%),
followed by
 Mandibular body (3 of 15, or 20%),
 Symphysis(1 of 15, 6.7%),
 Maxilla (1 of 15, 6.7%). The clinical types were
as follows: 8 of 15 were unicystic (53.3%), 3
were multicystic (20%), and 4 were solid tumors
(26.7%). Pathologic typing showed 5 to be
plexiform, 3 mixed, and 3 were acanthomatous
type. Sizes of the lesions ranged from 4*2 cm to
8*8 cm.
 (Table I).

21. Treatments were direct enucleation and
peripheral ostectomy for 5 cases (3 unicystic,
1 multicystic, and 1 solid type);
decompression before enucleation with
peripheral ostectomy for 6 cases (5 unicystic
type and 1 multicystic type); and segmental
resection and iliac bone graft for 4 cases (3
solid and 1 multicystic type, which had
decompression surgery first, but did not
respond to the treatment in 3 months and it
was decided to initiate segmental resection
and bone graft).
No unicystic type recurred

22. Two of 3 multicystic-type cases were
recurrent. Of the 4 patients with solid
type, 1 treated with enucleation and
bone trimming was recurrent and then
had segmental resection and bone graft
6 years later (when the patient was 19
years old), and no recurrence thereafter.
Another 3 solid types with segmental
sectioning and bone grafts were not
recurrent. In total, 3 cases had 4
recurrences

23. Radiographic findings showed 10
monolocular lesions and 5 multilocular
radiolucent lesions. There were 2 solid-
type lesions presented in monolocular
and multilocular image groups. The
follow-up period was from 2 years to 17
years. Complications, including mild
facial deformity and permanent lip
numbness were noted in all patients with
segmental resection and bone grafts.
Only 2 cases had permanent lip
numbness after enucleation and
peripheral ostectomy.

24. DISCUSSION
 Ameloblastoma is uncommon in the pediatric
population,with only 8.7% to 15% of all ameloblastomas
in Western countries. The Asian and African reports
show a higher percentage, ranging from 14.6% to
25%.3,10 Because ameloblastoma is uncommon, only
a few surgeons have much experience in treating this
lesion. The extent of surgical excision of mandibular
ameloblastoma has been the subject of debate for
many years. Many recent reports have warned of high
recurrence rates (75%-90%) with conservative
treatment, compared with recurrence rates of 15% to
25% after radical surgery.
 One report shows a high success rate of tumor
resection, reconstruction, and rehabilitation for pediatric
patients, and declared that the current standard of care
is en bloc resection with wide margins to prevent
recurrence, with staged reconstruction with bone grafts
and an implant-supported prosthesis.

25. Ameloblastoma is usually classified into 3 types:
solid or multicystic, unicystic, and peripheral. The
cystic type of ameloblastoma is predominant in young
patients. The multicystic and solid lesions are sometimes
considered as one type because of similar behavior,
with a locally invasive tumor and high recurrence
rate, and are usually excised radically.
We would rather
classify ameloblastoma into 4 clinical types for pediatric
patients: solid, multicystic, unicystic, and peripheral.
We suggest the multicystic type should be treated
conservatively as different lesions, especially for children.

26. For multicystic ameloblastoma, many
reports suggest radical surgery where
the buccal and lingual bone plates are
sacrificed along with their periosteum
and any suspicious surrounding soft
tissue being removed. 3 patients with
multicystic type were treated by 3
different methods. The first patient, a 12-
year-old boy (Fig. 2), had decompression
treatment for 6 months and then
accepted enucleation and peripheral

29. The lesion recurred 3 years later (Fig.
4), and he had a secondary operation
with enucleation and bone trimming.
Four years after the second surgery
(Fig. 5),

32.  Four years after the second surgery (Fig. 5),
it recurred again and he had a third operation
(same procedures), and was monitored for
another 10 years (Fig. 6), for a total of 17
years of follow-up. No recurrence has been
noted so far. The first operation was
performed under general anesthesia; the
second and third operations were done under
local anesthesia.
 The patient and his parents were satisfied
with the treatment, and there was no lip
numbness, a limited number of teeth were
removed, and there was no functional
disturbance or esthetic problem.