|Year : 2017 | Volume
| Issue : 2 | Page : 125-128
Ameloblastic fibro-odontoma of maxilla with its analysis on cone beam computed tomography
Karan R Shah1, Shital S Nikam2, Ajay R Bhoosreddy1, Rajeev M Gadgil1
1 Department of Oral Medicine and Radiology, Mahatma Gandhi Vidyamandir's Karmaveer Bhausaheb Hiray Dental College and Hospital, Nasik, Maharashtra, India
2 Department of Oral Medicine and Radiology, S.M.B.T. Dental College, Sangamner, Maharashtra, India
|Date of Submission||25-Apr-2016|
|Date of Acceptance||24-Oct-2017|
|Date of Web Publication||9-Nov-2017|
Shital S Nikam
Department of Oral Medicine and Radiology, SMBT Dental College, Ghulewadi, Sangamner - 422 608, Maharashtra
Source of Support: None, Conflict of Interest: None
| Abstract|| |
The ameloblastic fibro-odontoma (AFO) is a rare mixed odontogenic tumor which shows properties of both ameloblastic fibroma and odontoma. It commonly affects children and young adults. In most cases, it is asymptomatic but may cause painless, slow growing swelling and discomfort. Radiologically, it is a well-circumscribed, mixed radiopaque and radiolucent entity consisting of radiolucency within which radiopaque foci of various sizes and shapes are seen. Histological examination shows both hard and soft tissue. The treatment of AFO usually conservative due to their benign biological behavior and consists of enucleation or surgical curettage. The purpose of this article is to present a case of an AFO in the posterior maxilla, along with discussion on clinical, radiological (including cone beam computed tomography scan), histological findings, and treatment of this tumor.
Keywords: Ameloblastic fibro-odontoma, cone beam computed tomography (CBCT), maxilla, odontogenic tumor
|How to cite this article:|
Shah KR, Nikam SS, Bhoosreddy AR, Gadgil RM. Ameloblastic fibro-odontoma of maxilla with its analysis on cone beam computed tomography. J Indian Acad Oral Med Radiol 2017;29:125-8
|How to cite this URL:|
Shah KR, Nikam SS, Bhoosreddy AR, Gadgil RM. Ameloblastic fibro-odontoma of maxilla with its analysis on cone beam computed tomography. J Indian Acad Oral Med Radiol [serial online] 2017 [cited 2020 Nov 24];29:125-8. Available from: https://www.jiaomr.in/text.asp?2017/29/2/125/217916
| Introduction|| |
Ameloblastic fibro-odontoma (AFO) is a rare mixed odontogenic tumor composed of morphologic features characteristic of both ameloblastic fibromas and complex odontomas.,, It represents approximately 3.1% of all odontogenic tumors. It is defined by the World Health Organization (WHO) as a neoplasm composed of proliferating odontogenic epithelium embedded in a cellular ectomesenchymal tissue that resembles dental papilla, and with varying degrees of inductive change and dental hard tissue formation. We report a case of large AFO in the maxillary posterior region of a young female patient, along with review of relevant clinical, radiographic, and pathological findings.
| Case Report|| |
A 19-year-old female reported to the department for asymptomatic swelling in the left maxillary posterior region, which was present since 5–6 years, that gradually increased to the present size, without any relevant medical, dental, and family history. Extraoral examination showed facial asymmetry due to a hard swelling on the left side of the middle third of face with normal appearing overlying skin [Figure 1]a. Intraoral examination revealed [Figure 1]b a swelling in the left maxillary posterior region. Lesion was around 4 × 3 cm in size, extending from mesial of 23 to distal of 27 that resulted in the obliteration of buccal vestibule and expansion of both cortical plates with pathological migration of 24, 25, 26, and clinically missing 27. The swelling was nontender and firm on palpation without any discharge. The overlying mucosa was normal in color but with indentation from the opposing teeth. Based on the finding, a provisional diagnosis of benign odontogenic cyst or tumor was made. Differential diagnoses included were dentigerous cyst as 27 was missing, and ameloblastoma as expansion of both cortical plate was present, a feature common with tumor rather than cyst. Relevant systemic diseases such as hyperparathyroidism, fibrous dysplasia were ruled by undertaking investigation, including serum calcium, serum phosphorus, and alkaline phosphatase.
|Figure 1: (a) Extraoral swelling on the left side of middle third of face; (b) Intraoral view showing swelling with indentations of the opposing teeth|
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Panoramic radiograph [Figure 2] showed a unilocular, mixed radiopaque and radiolucent lesion with well-demarcated, partly corticated margins extending from the maxillary left first premolar to maxillary tuberosity region involving maxillary sinus. However, using panoramic radiograph, it is very difficult to evaluate the expansion of cortical plate or perforation. Cone beam computed tomography (CBCT) provides the exact extent of lesion, detailed internal structure evaluation, along with involvement of surrounding structures (maxillary sinus), and presence of any perforation on cortical plates Thus, for detailed study, CBCT scan was advised. CBCT showed 4 cm × 4.2 cm × 3 cm lesion in the left maxillary posterior region without involvement of both the pterygoid plates. Axial section [Figure 3] showed buccal and palatal cortical plate expansion, with thinning and perforation of the buccal plate. The lesion also resulted in the involvement of maxillary sinus to extend till the floor of the orbit with enlargement of ostium on the left side [Figure 4] and [Figure 5]. Internal structure showed a well-defined radiopaque foci of various irregular sizes and shapes scattered throughout radiolucency. The tooth bud for 27 was missing and 28 was found to be impacted [Figure 2] and [Figure 5]. CBCT images gave a three-dimensional overview of the lesion, thereby precise surgical planning was accomplished. Based on the clinical and radiographical findings, a radiological diagnosis of immature complex odontoma was made. The differential diagnosis included lesions with mixed radiographic patterns, such as calcifying epithelial odontogenic tumor, calcifying odontogenic cyst, and AFO and adenomatoid odontogenic tumor.
|Figure 2: Cropped panoramic image showing large mixed radiopaque and radiolucent lesion in left maxillary posterior region with missing 27 and impacted 28 within lesion|
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|Figure 3: Axial CBCT image showing expansion of cortex in the left maxillary molar region and lesion extending till tuberosity with perforations in buccal cortical plate|
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|Figure 4: Coronal CBCT image showing complete opacification of left maxillary sinus with opacities (white arrow) scattered throughout the lesion and enlargement of ostium|
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|Figure 5: Sagittal CBCT image showing involvement of maxillary sinus with irregular radioapcities and impacted 28 within lesion|
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Based on the clinical and radiological features the lesion appeared to be well-defined, circumscribed, nonaggressive, and noninvasive, and hence, it was surgically enucleated under general anesthesia, through an intraoral approach without any complications; the specimen was send for histopathology. Microscopically, examination of sections stained with hematoxylin and eosin showed characteristics of both ameloblastic fibroma and odontoma [Figure 6]. It showed odontogenic epithelial cells arranged in a form of nests, islands, and long finger-like strands. Decalcified section showed irregularly arranged dentinoid, osteodentin, and pulp-like ectomesenchymal tissues. Connective tissue resembled primitive stroma of dental papilla. The present case was histopathologically diagnosed as AFO. The patient was followed postoperatively for 2 years, with no sign of recurrence.
|Figure 6: (a) Decalcified section showing irregularly arranged dentinoid, osteodentin, and pulp like ectomesenchymal tissues. (b) Odontogenic epithelial cells arranged in a form of nests, islands, long fingers-like strands, and connective tissue resembled primitive stroma of dental papilla|
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| Discussion|| |
AFO is a rare, mixed odontogenic tumor. In the past, the entity was categorized as ameloblastic fibroma, ameloblastic odontoma, and cyst adenoma until Hooker in 1967 suggested the terminology AFO. A lot of discussion exists in literature regarding AFO being a neoplasm or hamartoma., Based on their clinical and radiological features, some of them are probably true neoplasms whereas others appear to be developing odontomas (hamartomas). Literature analysis also revealed that some lesions that exhibit aggressive growth, causing considerable facial deformity and bone destruction, probably represent true neoplasms, whereas others that are small, asymptomatic, and have no bony expansion probably represent developing odontomas (hamartomas). In 2005, in WHO classification of odontogenic tumors, AFO is described as “tumor of children with a mean age between 8 and 12 years with no gender or anatomic site predilection.” Radiologically, it exhibits a well-circumscribed, unilocular, or multilocular radiolucency with varying levels of radiopacity and is often associated with an unerupted tooth.
Tumor is more common in the first two decades of life, a feature present in our case., Regarding gender and site predilection, Reichard et al. and Philipsen et al. claimed a male predilection and that it is common in mandible, whereas in this case a female patient and maxillary lesion was noted. WHO classification  and Slootweg  stated that there is no gender and anatomical site predilection. Common clinical representation consists of a well-circumscribed, nontender, slow-growing, and expanding tumor with no propensity for bony invasion, as seen in our case.
The radiographic appearance consists of a well-defined commonly unilocular or, rarely, multilocular radiolucency with a well-defined radiopaque border and with a variable amount of radiopaque material of irregular size and form, with the radiodensity of dentin and enamel, usually located in the centre of the lesion., The lesion is usually positioned coronal to the crown of the impacted tooth. Radiopaque material ranges from small spots which may be invisible on radiograph making it difficult to differentiate from ameloblastic fibroma to large areas of compact calcified masses, which is impossible to differentiate from complex odontoma.
The differential diagnosis includes lesions with mixed radiographic patterns, such as Calcifying Epithelial Odontogenic Tumor, complex odontoma and possibly adenomatoid odontogenic tumor. Three-dimensional imaging modalities provide detailed information of the imaged area avoiding the superimposition of structures as well as accurately visualize the internal structure, borders, and expansion of tumors than plain radiographic images. Compared to CT scan, CBCT has a relatively higher spatial resolution of osseous structures at lower doses of radiation.
Histopathologically, the tumor is composed of both soft and hard tissues. The tumor mass is surrounded by a fibrous capsule and is composed predominantly of a fibroblastic connective tissue matrix containing strands of odontogenic epithelium and immature tooth-like structures, including enamel and dentin. The connective tissue is moderately cellular with spindle-shaped fibroblasts. Histopathologically, differential diagnoses include amelolastic fibromas, ameloblastic fibro-dentinomas, odontoma, and odontoameloblastomas.
AFO is generally treated by conservative enucleation and curettage. The prognosis is excellent and recurrence is rare. Despite the low potential of the tumor to locally recur, a careful follow-up is recommended. Malignant transformation of AOF is rare, Howell and Burkes reported two cases of AFO that showed malignant transformation.
| Conclusion|| |
Although rare, AFO should be considered in the differential diagnosis of intraoral radiolucency that contain radiopaque material, especially when dealing with young patients. The advancement of diagnostic aids such as CBCT leads to more efficient analysis and treatment planning for atraumatic excision of the lesion, which was not possible with previous conventional radiographic methods. Early diagnosis and proper treatment planning for such uncommon cases is necessary to avoid complications later in life.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]