NoorAhmed Khoso1 , Kashif Ali Channar2 , Abdul Qadir Dall3 , Abdul Bari Memon4
How to CITE:
Khoso N A, Chnnar KA, Dall A Q, Memon A B. Ossifying fibroma: clinical, radiologic presentation and surgical difficulties. J Pak DentAssoc. 2012: 21 (02): 90 – 93
OBJECTIVES
The objective of this study was to evaluate themost important clinical and radiological features of Ossifying Fibroma (OF)&associated surgical difficulties.
METHODOLOGY
The current study was descriptive case series conducted at the Department of Oral and Maxillofacial surgery. Institute of Dentistry, liaquat University of Medical and Health Sciences Jamshoro Hyderabad fromFebruary 2010 to September 2010.Thirteen newand two recurrent patientswith ossifying Fibroma of either genderwere selected for surgery&treated.Clinical&radiographical (OPGand CTscan) examination was performed on each patient with special emphasis on site of lesion, jaw involvement, extent of disease, facial asymmetry, pain, paresthesia, tooth displacement, root resorption, inferior alveolar nerve position, and bowing of mandible.The histopathological examinationswere performed to reach the diagnosis
RESULTS
Surgical intervention was performed on all fifteen patients. Posterior location of tumor was seen in 86.6% cases. Radiographically lesion was well demarcated and was distinguishable from normal bones. Classic picture of mixed appearance with radiolucent background with radio-opaque flaks and sclerotic margin on plain radiographs andCTscanwas documented in 10 (66.6%) cases.
CONCLUSION
This study confirms the female gender predilection & was more common in 2nd & 4th decade. Maxillawas themost frequent affected sitewith facial asymmetry.MostOFs can be treated by conservative surgical excisionwith peripheral ostectomy.
KEYWORDS
Ossifying Fibroma, Fibro-osseous lesion.
Introduction
Benign fibro-osseous lesions (BFOL) of craniofacial bones are a variant group of intraosseous disease processes that manifest identical microscopic characteristics. Most Fibro-osseous lesions requires a combined evaluation of clinical, histological or microscopic and radiographic characteristics. For these pathological processes various classifications have been proposed by number of investigators and divided BFOL intomajor groups.
I.Bone dysplasias
II.Cemento-osseous dysplasias
III. Inflammatory/reactive processes
IV.MetabolicDisease: hyperparathyroidism
V.Neoplastic lesions (Ossifying fibromas).
Ossifying fibroma (BF) can be defined as a benign, slow-growing, central bone tumor, usually of the jaws, especially the mandible, composed of fibrous connective tissue within which bone is formed. Apart from above classification system recently these lesions are classified by world health organization (WHO) into osteo-genic neoplasm & non-neoplastic bone lesions. Ossifying Fibroma belong to the osteo-genic group.
In general, ossifying fibroma is an asymptomatic lesion until growth causes swelling and moderate deformation. Displacement of the teeth can be an early clinicalmanifestation.The teeth associated with the lesion preserve their vitality and may show signs of root resorption. The lesion is relatively slow-growing, as a result of which the overlying cortical bone layer and mucosa remain intact, and thus the tumor may be present for a number of years before a diagnosis is made Well expanded lesions may be painful due to nerve compression. Radiographically, the lesions vary in size from 1 to 5 cm. Well-defined areas of osteo-lysis, with varying degrees of calcification and cortical thinning is present. Peripheral sclerotic border representing osteocytic activity may also found . OF can often be easily diagnosed at the time of surgery by noting its demarcation from surrounding bone and can easily be separated from its bony bed. It is essential to make the distinction between OF and fibrous dysplasia before embarking surgery. Ossifying Fibroma is readily enucleated from its bony bed, while fibrous dysplasia closely resemble with surrounding bone clinically, making surgical removal more complicated
A strict diagnosis is required before surgical intervention. Apart from clinical & radiological characteristics; lesion should be identified histologically. In typical histological features the predominant cell is a bland spindle cell. Mitotic figures are uncommon. Admixed in the fibrous background are irregularly shaped osseous islands. These islands are similar to those seen in fibrous dysplasia, although there is a much sharper demarcation from the surrounding spindle cells. The islands of bone are often surrounded by active osteoblasts, referred to as osteoblastic rimming; a feature indicative of the diagnosis. Malignant transformation is extremely uncommon.
As there is scarcity of literature regarding the lesion and its management, therefore, the purpose of this study was to evaluate the major clinical and radiological features of available cases of Ossifying Fibroma (OF) with its surgical difficulties.
Methodology
This case series was conducted atDepartment of Oral & Maxillofacial surgery, Institute of Dentistry Liaquat University ofMedical andHealth Science over a period of more than one year from February 2010 and September 2011. Thirteen new and two recurrent patients with ossifying Fibroma of either gender were selected for surgery & treated. Clinical radiographical (OPG and CT scan) examination was performed on each patient with special emphasis on site of lesion, jawinvolvement, extent of disease, facial asymmetry, pain, paresthesia, tooth displacement, root resorption, inferior alveolar nerve position, and bowing of mandible. The histopathological examinations were performed to reach the confirmatory iagnosis. After histopathological confirmation written informed consent was taken from patients for surgical procedure and for participation in this study.All available data was entered in proforma. Resection of tumor and reconstruction plate was applied for mandibular continuity defect and primary closure was performed / surgical obturators were designed in maxillary defects. Patients were recalled on six month follow-up visit to see any recurrence and instructed to visit yearly for 3 years.
Results
Surgical intervention was performed on all fifteen patients. Thirteen patients were between 11 to 40 years and two patients above fifty and mean age of presentation was 31years (Table no I).
Posterior site (maxilla & mandible) involvement was observed in 13 (89.6%) cases. Presenting complaints were acial asymmetry, loosening of teeth and mild pain. Patients with mild to moderate facial asymmetry were12 (80%); however maxillary asymmetry was marked as compared to the mandible. Radiographically lesion was well demarcated and were distinguishable from normal bones. Classic picture of mixed appearance with radiolucent background with radio-opaque flakes and sclerotic margin on plain radiographs and CT scan was documented in 10 (66.6%) cases. Root resorption was noticed in 3 (20%) and root displacement was detected in 4 (26.6 %) cases. Down word displacement of Inferior alveolar nerve was also observed in mandibular lesion (Table III & IV). Inferior alveolar nerve displacement at lower border is identified in three (20%) cases onOPG.
Ossifying Fibroma of the maxillofacial region is not uncommon in our country. Despite its commonality no substantial local study is available regarding its clinical manifestations and difficulties encountered during surgery or treatment outcome. Most of the international studies are based on individual case reports and only a few studies have been designed as a case series in literature.
In this case series common presenting ages were second, third and fourth decades of life with mean age was 31 years. Chang CC et al , Papadaki et al have also observed that the mean age of OF patients between the third and fourth decades. HoweverMintz S in his study reported mean patient ages older than this range. This difference in affected age group is likely because of racial difference. We identified more female predilection; female: male ratio 60%: 40%. A similar female predominance has also been reported in three previous studies. Regarding the site of occurrence, we diagnosed that 60% of cases occurred in the maxillary region in contrast with the results of chang et al and Trijolet JP et al who mentioned mandiblular predilection of the lesion. OF commonly involve molar and premolar region, we found 86.6% of cases with OF in posterior region (molar and premolar) in mandible& maxilla while only 13.4 % in anterior region. This study also have comparable results to other studies as chang et al reported the presentation of lesion in molar and premolar region in 89% of cases and 11% in anterior region and Eversole et al found 77% in posterior region ( molar region 52%, and premolar 25%), rest of OF in anterior incisor (12%) and cuspid (11%) regions . Racial difference and limited sample size are probably the answer of some differences noticed against the results mentioned in literature. Facial asymmetrywas found in 12 (80%) cases, asymmetry was related to bony expansion especially on buccal side, and thiswas also a leading cause for patient presentation in our hospital.Asimilar result has also been noted in previous studies Root displacement by the lesion was noticed in 26.6%, which is in accordancewith the results of Eversole et al,Chang Radiographically lesion has variety of manifestations from radiolucent to mix (radio lucent and opaque). Interesting findingwas observed that smaller lesion of OF was radiolucent while larger one was with mixed picture. In the present study, 5(33%) cases presented with radiolucent radiographic picture and 10(77%) cases presented with mixed appearance. Thiswide radiographic difference makes clinical diagnosis difficult on initial presentation. Similar finding were also observed by some investigators.
It is generally accepted that surgically this lesion can be separated easily from normal bone. We detected that lesion is not always homogeneous at periphery; complete enucleation of lesion is not always possible especially when lesion has irregular margins especially when it is in maxilla. This may be because of the difference in bone character between mandible and maxilla and to theavailable space for expansion in the maxillary sinus the chances of residual disease in concavities or undercut is increased. We also observed a linear extension in OF in mandibular lesion and involving buccal and lingual cortex. Perhaps this finding is not discussed in previous literature but identification of this extension is all important to minimize possible chances of recurrence. Computer tomography iswell established tool to see exact extension of lesion and abutting of lesion on cortexes.
As with other studies, this study also lacks power in sample size. However, this study provides some valuable information regarding clinical, radiographic features and surgical difficulties encountered during surgery to remove lesion
Conclusion
OF is common in female patients. The most frequent affected site was in maxilla, especially the posterior region. Facial asymmetry was the most common clinical presentation .The radiographic features of OF were wellcircumscribed, mixed lesion. A significant feature which we noticed was linear extension of original jaw lesion which is abutting on buccal and lingual side on normal bone which is not mentioned in literature. Most OFs can be treated by enucleation with peripheral ostectomy without subsequent recurrence.
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