2009-21-01-51-56-full - Saudi Dental Journal

ISSN (Print) 1013-9052
EISSN 1658-3558

The Saudi Dental Journal,
P.O. Box 52500,
Riyadh 11563,
Kingdom of Saudi Arabia

Tel.	966-1-467-7328
Fax.	933-1-467-7308 / 966-1-467-7534
Email	saudidj@ksu.edu.sa

2009-21-01-51-56-full

Multilocular ameloblastic fibro-odontoma. A case report in the
anterior maxilla

Randa Al-Fotawei, BDS, FDS RCS

Abstract

Ameloblastic fibro-odontoma is a benign, slow growing, expansile epithelial odontogenic tumor with odontogenic mesenchyme. Although it was reported in the earlier literature that ameloblastic fibro-odontoma and odontoameloblastoma are identical lesions in 1968, World Health Organization (WHO) defined this tumors as two distinctly separate lesions. Clinically, this lesion is an expansile lesion which exhibited little tendency to infiltrate bone. The majority of these tumors were reported in younger patients (mean age 11.5). The maxilla and mandible appear to be equally affected. Altered occlusion and delay in eruption of teeth are the common features. A 10-year-old female patient presented to the Oral and Maxillofacial Surgery Clinic of the College of Dentistry, King Saud University, Riyadh with chief complaint of huge swelling on the right maxilla, with retained deciduous tooth # 52 and delayed eruption of the tooth # 12. Radiographic interpretation showed well-circumscribed, multilocular cavity in right maxillary bone and right maxillary sinus. Within the cavity are varied amounts of radiopaque material that represented the hard dental structures, and impacted tooth # 13 and # 14. Careful surgical curettage of the entire two lesions and capsular fragment was done. Histopathology report revealed that it is ameloblastic fibro-odontoma. The interesting finding of the present case compared to previous reported cases were the presence of two similar lesions in the same site. This report described a relatively rare odontogenic tumor in a young patient and it emphasizes the importance of including the lesion in the differential diagnosis of any expensile lesion accompanied with delay of eruption of teeth of young age patient.

Introduction

Ameloblastic fibro-dontoma (AFO) is a rare odontogenic tumor.^1-17According to the WHO classification of odontogenic tumors, AFO is defined as a lesion similar to ameloblastic fibroma (AF) but which shows inductive changes that lead to the formation of dentin as well as enamel.^1-16
The mean age of occurrence is 11 years, with the highest frequency noticed in the 2^nddecade. There is almost equal distribution between the mandible and the maxilla, with higher frequency of the posterior part of the mandible.⁷

AFO is an asymptomatic, slow growing and expansile lesion.¹³ The majority of the lesion are associated with unerupted teeth. Radiographically, AFO shows a well-
circumscribed unilocular or multilocular radiolucency containing variable amounts of radiopaque material, related to an unerupted tooth at the margin of the lesion. Histopathology of the AFO consists of three components: (1) the ectodermal part as odontogenic epithelium; (2) the immature mesenchymal part resembling dental papilla, and; (3) the mineralized part which is made of irregularly shaped dental structure like enamel.

Treatment of choice for AFO is conservative surgery by enucleation along with the removal of the associated unerupted tooth.¹ The interesting finding of the case reported here compared to most of the previous reported cases was that the patient had well encapsulated multilocular lesions occupying the right maxilla both showing same histopathology.

Case Report

A 10-year-old female patient was referred to the Oral and Maxillofacial Surgery Department at the College of Dentistry of King Saud University in Riyadh with the chief complaint of swelling on the right side of the maxilla and delay in eruption of tooth # 12. The parents noticed that the swelling had started as two small swellings intraorally on the right anterior part of the maxillary bone. Then it increased in size and appeared as one huge lesion over a period of three years. The medical, social and family histories were unremarkable as were the results of a medical review of systems and physical examinations.

Intraoral examination revealed a circumscribed expansion of the buccal vestibule at the upper right side of the maxilla. The lining mucosa was intact, tooth # 52 was retained and # 12 missing. There was no mobility in tooth # 11 and it was not tender upon percussion. There were no neurological deficiencies. A panoramic radiograph showed a well circumscribed multilocular radiolucency with a centrally located radiopaque tooth¬like structure. The borders of the lesion were radiopaque, similar to cortical bone, and tooth # 23 and # 24 were in the sinus cavity (Fig. 1). Aspirations revealed clear cystic fluid.

The differential diagnosis included immature complex odontoma, adenomatoid odontogenic tumours, dentigerouscyst andcystic ameloblastoma. Under general anesthesia, the right anterior part of the maxilla was exposed by a buccal mucoperiostial flap. After removal of the thin cortical layer of the maxillary bone, the first lesion was enucleated from the anterior part of the maxilla. Then the other lesion which occupied the maxillary sinus was enucleated (Fig. 2). The two lesions appeared to be lobulated and well encapsulated lesions. The tooth bud of presumed tooth # 14 was also removed (Fig. 3). The bony defect was well irrigated and the flap was sutured using interrupted sutures. The patient tolerated the operation well.

The pathological examination showed a mixed odontogenic tumor comprising lesional odontogenic epithelium, odontogenic ectomesenchyme, dentinal tissue, enamel and enamel matrix formation, with some ameloblastomatous epithelium in some areas (Fig. 4). The cystic spaces were numerous and of various sizes (Fig. 5). The calcified eosinophilic material was dentin-like tissue while the basophilic material was enamel matrix. In other areas, there were small amorphous calcifications (Fig. 6).

At 14-month follow-up, the clinical and radiological appearance of the bone and surrounding soft tissue was normal. Tooth # 13 held its normal position and tooth # 12 was about to erupt. The patient is under orthodontic treatment (Fig. 7).

Discussion

Ameloblastic fibro-odontoma (AFO) is a rare odontogenic tumour.^1-17 It accounts for 1.7% of all odontogenic tumors and 7.9% of odontogenic tumors except odontoma. The lesion is typically found in children in their first and second decades, with a male to female ratio of approximatly 3:1.¹⁹The lesion was reported to occur with equal frequency in both jaws in one series and preponderantly in the mandible in another series.¹⁷ In most cases, it is an incidental finding on radiographs of the jaw,2 but it has been reported that AFO is an expansile lesion that exhibits little tendency to infiltrate bone.¹⁹

In this case study, the lesion grew to a huge size over a 3-year period. The finding of the present case was that multilocular lesions on the right anterior part of the maxillary bone (AFO) should be differentiated from other types of odontogenic tumours.

Confusion exists regarding the relationship between AFO, ameloblastic fibroma (AF) and odontoma. Slootweg's¹⁵ and Philipsen et al. study¹⁸ concluded that AFO was an immature complex odontoma, whereas Regezi and Sciubba¹⁰ suggested that AFO was a derivative of AF. In 1968, the WHO declared that AFO and complex odontoma are separate lesions.^3-17 Most now agree that AFO exists as a distinct entity but it can be histologically distinguishable from immature complex odontoma. The relative arrangement of the soft tissues and the stage of development of the involved tooth are useful criteria for diagnosis.³

The pathogenesis of ameloblastic fibro-odontoma appears to be from an abnormal proliferation of odontogenic epithelium from a permanent tooth germ, which exerts an organizing effect on the mesodermal element with the formation of calcified dental tissues.¹⁸Histologically, the tumour mass was surrounded by fibrous capsule and was composed predominantly of a fibroblastic connective tissue matrix containing strands of odontogenic epithelium and immature tooth structures including enamel and dentin. There was a moderately cellular stroma with spindle shaped fibroblast.³

The presence of true cystic cavity histologically was supported clinically by the aspiration of cystic fluid. Malignant changes of AFO to ameloblastic fibrosarcoma are extremely rare.^2-17 Malignant transformation with metastasis was first reported in a 12 year-old after surgery.^2-11 Howell et al.¹¹ reported a case of ameloblastic fibro-odontoma that was converted to ameloblastic sarcoma.

According to the literature, local excision is an adequate surgical therapy, usually the associated tooth is removed at the same time. Recurrences of the lesion are rare. It has been reported in the literature that a few cases did recur.^9,13,14 Tasogaris and Philipsen¹³ reported only one patient with local recurrence out of 29 and 86 cases, respectively. Herzog et al.¹² reported a case of 14 year-old girl who had radical resection of the mandible after several recurrences^.5 The first and second recurrences were found at 5¬6 years, the patient was followed for 14 years. One case of recurrence was shown in each of the four studies by Amos et al.,⁷Furst et al.,⁹Hooker ¹⁴ and Tsagaris,¹³ respectively.

In conclusion, ameloblastic fibro-odontoma is a rare benign odontogenic tumour found in a young age group. It can reach sizeable proportions, as in this case report. Therefore, careful surgical enculation, which has low potential for local recurrence, was the treatment of choice. Careful follow up is recommended.

References

Killipong DH, Kusak K. Ameloblastic fibro-odontoma. J Clin Pediatr Dent 2004; 29:75-78.
Reinbard EF, Joachim SK, Thorsten J. Recurrent ameloblastic fibro-odontoma in a 10-year-old boy. J Oral Maxillofac Surg 2001; 59:1362-1366.
Hyunho C, Michael SS, David SP. Ameloblastic fibro-odontoma: A case report. J Can Dent Assoc 2002; 68:243¬246.
William RB, James QS. Ameloblastic fibro-odontoma of the anterior maxilla. Report of a case. Oral Surg Oral Med Oral Pathol 1993; 76:294-297.
Ian F, Michael PH, John PH. Recurrence of an ameloblastic fibro-odontoma in a 9-year-old boy. J Oral Maxillofac Surg 1999; 57:620-623.
Pipette EM, Tideman H, Wu PC. Massive maxillary ameloblastic fibro-odontoma: Case report with surgical management. J Oral Maxillofac Surg 1990; 48:526-530.
Amos B, Merrell PW, Carpenter WM. Relative frequency of central odontogenic tumor: Study of 1,088 cases from Northern California and comparison to studies from other parts of the world. J Oral Maxillofac Surg 2006; 64:1343-1352.
Bernholt CH, Bang G, Gilhuus-Moe O.Ameloblastic fibro-odontoma. Int J Oral Surg 1979; 8:241.
Furst I, Pharoah M, Phillips J. Recurrence of an ameloblastic fibro-odontoma in a 9- year-old boy. J Oral Maxillofac Surg 1999; 57:620.
Regezi JA, Sciubba JJ. Oral pathology: Clinical-pathologic correlations. Philadelphia, PA: Saunders, 1989:364¬368.
Howell RM, Burkes EJ. Malignant transformation of ameloblastic fibrosarcoma. Oral Surg 1977; 43:391.
Herzog U, Putzke HP, Bienengraber V, Radke C. Des ameloblastic fibrodontom-ein odontogener Mischtumor mit ubergag in ein odontogenic sarkom. Dtsch Z Mund Kiefer Gesichts Chir 1991; 15:90.
Tsagaris GT. A review of the ameloblastic fibro-odontoma (Master's thesis). Washington, DC: George Washington University, 1972.
Hooker SP. Ameloblastic odontoma: An analysis of twenty-six cases. Oral Surg 1967; 24:375-376.
Slootweg PJ. An analysis of the interrelationship of the mixed odontogenic tumors: Ameloblastic fibroma,ameloblastic fibro odontoma, and the odontomas. Oral Surg 1981; 51:226-276.
Kramer IRH, Pindborg JJ, Shear M. Histological typing of odontogenic tumors. World Health Organization International Classification of Tumors, 2nd ed. Berlin: Spring-Vertag 1992, p. 18.
Laskin DM. Odontogenic fibrodontoma. Oral Maxillofac Surg 1995; 2:647-649.
Philipsen HP, Reichart PA, Praetorius F. Mixed odontogenic tumor and odontomas. Consideration on interrelationship, review of the literature and presentation of 134 new cases of odontomas. Oral Oncol 1997; 33:86-99.
Fonseca R. Oral and maxillofacial surgery. Surg Pathol 2000; 5:384-385.

Tables and Figures

< Prev		Next >