Indian Journal of Dental Research

: 2011  |  Volume : 22  |  Issue : 2  |  Page : 352--355

Cemento-ossifying fibroma

Chandramani More, Krushna Thakkar, Mukesh Asrani 
 Department of Oral Medicine, Diagnosis and Radiology, K. M. Shah Dental College and Hospital, Sumandeep Vidyapeeth University, Piparia, Vadodara, Gujarat, India

Correspondence Address:
Chandramani More
Department of Oral Medicine, Diagnosis and Radiology, K. M. Shah Dental College and Hospital, Sumandeep Vidyapeeth University, Piparia, Vadodara, Gujarat


Cemento-ossifying fibromas (COFs) are benign lesions affecting the jaws and other craniofacial bones. They commonly affect adult females between the third and fourth decade of life, predominantly occurring in the premolar/molar region of the mandible. Most of the lesions typically show slow and often expansile growth, centrally within the jaw and characteristically behave in a benign form, but occasionally they may present as an aggressive gigantiform lesion. Radiographically, they appear as well-defined unilocular or multilocular intraosseous masses. The lesion is invariably encapsulated and of mixed radiolucent densities. The tumor may grow quite extensively; thus, the term «DQ»aggressive«DQ» is sometimes applied. Surgical resection is the treatment of choice. They are insensitive to radiotherapy and recurrences are uncommon. Clinical, radiographic and histopathologic features of COF and other fibro-osseous lesions are overlapping and may cause confusion in classification, diagnosis and treatment.

How to cite this article:
More C, Thakkar K, Asrani M. Cemento-ossifying fibroma.Indian J Dent Res 2011;22:352-355

How to cite this URL:
More C, Thakkar K, Asrani M. Cemento-ossifying fibroma. Indian J Dent Res [serial online] 2011 [cited 2021 Apr 20 ];22:352-355
Available from:

Full Text

Fibro-osseous (FO) lesions are characterized by replace-ment of normal bone architecture by collagen fibers and fibroblasts that contain varying amounts of mineralized substances, which may be bony or cementum like in appearance. Many lesions contain an admixture of this calcification. FO lesions comprise fibrous dysplasia, periapical cemento-osseous dysplasia, focal cemento-osseous dysplasia, florid cemento-osseous dysplasia and cemento-ossifying fibroma (COF). FO lesions are characterized by three radiographic stages: initial or early (radiolucent), mixed (radiolucent and radiopaque) and mature (radiopaque). The radiographic pattern may vary from a diffuse, ground glass appearance to a more well-defined cyst like lesion that may appear radiolucent or contain varying amounts of radiopaque material. The COF is classified as FO lesion or non-odontogenic tumor of the jaws according to World Health Organization (WHO).

It is not always easy to diagnose and manage the FO in the mandible or maxilla because their clinical, radiographic and histological criteria often overlap causing confusion to clinicians, radiologists, pathologists and oral surgeons. This can result in difference of opinion and management of these lesions. This article reports two cases of COF involving the posterior part of mandible.

 Case Reports

Case 1

A 55-year-old woman reported to the outpatient department of Oral Medicine, Diagnosis and Radiology with a slowly progressive painless swelling over left mandibular body since 6 years. The vital signs were within normal limits. The extraoral examination [Figure 1] showed a marked ovoid swelling, approximately of 5×6 cm size, over left mandibular body which was bony hard and non-tender, with no signs of inflammation. The overlying skin was intact and no paraesthesia was noted on the surrounding structures. The regional lymph nodes were nonpalpable. Intraoral examination revealed a localized, non-tender, bony hard swelling extending from the first premolar to the third molar region with buccal cortical plate expansion obliterating the buccal vestibule [Figure 1]. The overlying mucosa appeared to be normal. Vital signs were within normal limits. Based on clinical findings, a provisional diagnosis of FO lesion of left mandible was made.{Figure 1}

Intraoral periapical radiograph of mandibular left premolar-molar region, left lateral oblique view of body-ramus region and orthopantomograph [Figure 2] revealed a single, large, well-defined mixed radiopaque-radiolucent lesion resembling cotton wool, involving the left body of mandible, extending from first premolar region postero-superiorly to involve mid-ramus and base of coronoid process, causing displacement of third molar superiorly and mandibular canal inferiorly. The lower left lateral cross-sectional occlusal radiograph showed buccal cortical plate expansion with thinning. An axial and 3D reformatted computed tomograph [Figure 3] revealed a well-defined, heterogenous, expansile, dense calcifying lesion of lower left mandibular body, extending into left ramus, and of size 73.6×44.3 mm.{Figure 2}{Figure 3}

Routine hemogram and serum chemistry (serum alkaline phosphatase and serum acid phosphatase) values were within normal range. Incisional biopsy reported a well-circumscribed and partly encapsulated lesion consisting of an abundant cellular fibrous tissue with scattered trabeculae of lamellar bone, metaplastic/woven bone and cementoid masses. The stromal cells were spindle shaped and had bland-looking nuclei [Figure 4]. These findings were consistent with COF.{Figure 4}

The lesion was surgically excised as per the traditional approach [Figure 5] and the resected segment was sent for histopathologic examination which was suggestive of COF. The resected area was surgically reconstructed and rehabilitated. The patient had an acceptable esthetic facial profile and was kept under follow-up.{Figure 5}

Case 2

A 25-year-old young woman reported with the complaint of mild continuous pain and slowly progressive swelling in the right mandibular posterior region since 5 years. Extraoral examination [Figure 3] showed non-tender, bony hard, diffuse swelling over right side of the face involving body, angle and ramus of mandible, of approximately 7×4 cm in size. Intraoral examination [Figure 3] revealed localized, non-tender, bony hard swelling extending from first premolar to third molar region, causing significant expansion of buccal and lingual cortical plates along with vestibular obliteration in the premolar and molar region. The surface texture of the overlying mucosa was intact. The vital signs were within normal limits.

Intraoral periapical radiograph of lower right first molar region and orthopantomograph [Figure 4] revealed a single, well-defined, mixed radiopaque-radiolucent lesion, mimicking cotton wool, over right body and ramus of mandible, extending antero-posteriorly from second premolar region to approximately 1 cm in front of posterior border of ramus and superiorly up to mid-ramus region and base of coronoid process with radiolucent capsule causing displacement of third molar and inferior alveolar canal inferiorly and expansion and thinning of inferior border of mandible. An axial [Figure 4] and 3D computed tomograph revealed a well-defined, expansile, dense calcifying lesion involving the right half of mandibular body extending from first premolar to right ramus. Buccal and lingual cortical plates were thinned and expanded. The third molar tooth was observed to be impacted.

Routine hemogram and serum chemistry values were within normal range. Histopathologic examination revealed the calcifications within the fibrocellular and vascular stroma to be amphiphilic to hematoxyphilic, mimicking cementoid as well as osteoid tissue. Decalcified sections revealed normal cortical plate and the underlying richly fibrocellular stroma with osteoid formation [Figure 4]. These findings were suggestive of COF.

Right hemi-mandibulectomy was performed [Figure 6] and the resected section was then surgically reconstructed which gave an acceptable esthetic facial profile to the patient and she has been kept under follow-up every 3 months.{Figure 6}


COF is an FO lesion that arises from the periodontal membrane. COF is defined by WHO [1] as a demarcated or rarely encapsulated neoplasm consisting of fibrous tissue containing varying amounts of mineralized material (bone and/or cementum). These lesions are best classified as osteogenic tumors. [2] In 1872, Menzel gave the first description of COF as a variant of ossifying fibroma. [3] A close histogenetic relationship exists between central COF and the central ossifying fibroma. In 1972, the WHO considered ossifying fibroma to be a tumor of bone origin and cementifying fibroma as a tumor of odontogenic origin. [1] However, in 1992, the WHO grouped such lesions under the common denomination of COF on the grounds that they represent histological variants of a same type of lesion. In the past, many investigators separately classified cementifying fibromas and ossifying fibromas. [2] When curvilinear trabeculae or spheroidal calcifications were encountered, the lesion was often referred to as cementifying fibroma. [2] When the bone predominated, ossifying fibroma was assigned. [2] Today, however, the term ''cemento-ossifying fibroma'' is widely used because both osseous and cemental tissues are seen commonly in a single lesion. [2] The COF is classified as fibro-osseous lesion or non-odontogenic tumor of the jaws according to WHO.

COF is a disorder of unknown etiology. Bernier hypothesized that COF in the bone might be caused by an irritant stimulus (such as tooth extraction) which may activate the production of new tissue from the remaining periodontal membranes. [4] The periodontal membrane contains multipotential cells that are capable of forming cementum, lamellar bone and fibrous tissue. [2],[5] The current theories regarding their origin include traumatic and developmental causes. [3] Cakir and Karadayi [3] reported nasopharyngeal COF originating from embryologic nests. Brademann et al. [6] explained that ectopic periodontal membrane differentiating from primitive mesenchymal cells in the petrous bone may serve as a cause of development of COF in this area, and trauma such as severe whiplash may be a factor in the induction of proliferation of COF. The ethmoidal location of COF may also be explained by incomplete migration of mesenchyme and its differentiation into periodontal membrane.

COF commonly occurs in young and middle-aged adults. There is a marked predilection for the females, with female:male ratio of 2:1. The premolar-molar region of mandible is more commonly involved than maxilla although cases have been reported in the other craniofacial bones. 70% of cases of COF involve the mandible, but a significant percentage (22%) has been found in the molar region of the maxilla, ethmoidal and orbital regions and exceptionally in petrous bone. The lesion is generally asymptomatic until the growth produces a noticeable swelling and mild deformity. Displacement of teeth may be an early clinical feature. Most of the lesions typically show slow and often expansile growth, centrally within the jaws, and characteristically behave in a benign form but occasionally they may present as an aggressive gigantiform lesion. [7]

Radiographically, it is characterized by three stages: initial or early, mixed and mature stage. In the initial/early stage, the COF appears as a well-defined radiolucent lesion with no evidence of internal radiopacities. As the tumor matures, there is evidence of calcification so that the radiolucent area becomes flecked with opacities until ultimately the lesion appears as an extremely radiopaque mass in the mature stage. An important diagnostic feature of COF is a centrifugal growth pattern rather than a linear one, and therefore, the lesions grow by expansion equally in all directions and present as a round tumor mass. [8] The borders are well defined, and a thin radiolucent line representing a fibrous capsule separates the lesion from the surrounding bone. A significant point is that the outer cortical plate, although displaced and thinned, remains intact. [8] Large mandibular lesions may cause a characteristic thinning and downward "bowing" of inferior border. [9] Teeth adjacent to or involved in the lesion may be displaced but resorption is not associated with this tumor. [9]

Microscopically, COF reveals many delicate interlacing collagen fibers, seldom arranged in discrete bundles, interspersed with large numbers of active, proliferating fibroblasts and cementoblasts. Although mitotic figures may be present in small numbers, there is seldom any remarkable cellular pleomorphism. As the lesion matures, the islands of cementum increase in number, enlarge, and ultimately coalesce. [10]

As COF is sharply circumscribed and demarcated from bone, it should be excised conservatively, but complete resection of the lesion is a must. Since COF is less vascularized and well circumscribed, it is easy to remove from the surrounding bone. Even if the tumor has reached appreciable size, the neoplasm usually is separated from the surrounding tissue. Continued growth does not necessarily follow partial removal. Sakoda et al. [5] described the procedure of a segmental resection of an extensive ossifying fibroma with the replacement of the excised segment after cryotherapy. Conservative surgery is therefore recommended even if the tumor is large with bowing and erosion of the inferior border of the mandible. Radical treatment of the tumor such as an en bloc resection should only be considered if there are recurrences due to its aggressive nature. There are several advantages of treating large COFs conservatively. For example, there is minimal morbidity after surgery, good bone formation and consolidation, no loss of sensation as well as no bone graft required from a second surgical site. In long-term follow-up cases where bowing or contours formed by these large lesions do not disappear completely with time, surgical intervention such as esthetic recontouring of the bone may be taken into consideration or recommended. The prognosis is known to be fair and recurrence after surgical removal seems to be unusual. Radiotherapy is contraindicated because of its radio-resistance and post-radiation complications.


1Kramer IR, Pindborg JJ, Shear M. The World Health Organization histological typing of odontogenic tumours: Introducing the second edition. Eur J Cancer B Oral Oncol 1993;29B:169-71.
2Neville BW, Damm DD, Allen CM, Banquet JE, editors. Oral and Maxillofacial Pathology. Philadelphia: WB Saunders; 1995. p. 468-70.
3Cakir B, Karadayi N. Ossifying fibroma in the nasopharynx: A case report. Clin Imaging 1991;15:290-2.
4Bernier J. Changes in bone and dental cementum in periodontal diseases. Med Hyg 1952;10:474.
5Sakoda S, Shiba R, Irino S. Immediate reconstruction of the mandible in a patient with ossifying fibroma by replantation of the resected segment after freezing. J Oral Maxillofac Surg 1992;50:521-4.
6Brademann G, Werner JA, Janig U, Mehdorn HM, Rudert H. Cemento-ossifying fibroma of the petromastoid region: Case report and review of the literature. J Laryngol Otol 1997;111:152-5.
7Van Heerden WF, Raubenheimer EJ, Weis RG, Kreidler J. Giant ossifying fibroma: A clinico-pathologic study of 8 tumors. J Oral Pathol Med 1989;18:506-9.
8White SC, Pharoah MJ. Oral radiology principles and interpretation. Philadelphia: Mosby; 2000. p. 444-71.
9Waldron CA. Fibro-osseous lesions of the jaws. J Oral Surg 1970;28:58-64.
10Shafer, Hine, Levy. Textbook of oral pathology. India: Elsevier; 2009. p. 126-55.