Recurrent cementoblastoma with multifocal growth and cellular atypia: a case report.

BACKGROUND: Cementoblastoma is a rare odontogenic tumor characterized by the formation of osteocementum-like tissue on a tooth root directly by neoplastic cementoblasts. Although it is categorized as benign, it has a high potential for growth with a certain degree of recurrence risk. However, there are only a few studies describing the features of recurrent cementoblastoma. The diagnosis of recurrent cementoblastoma is challenging not only due to its cytological atypia but also because of its large size and multicentric growth pattern. These characteristics suggest a potential for malignancy. CASE PRESENTATION: A 29-year-old woman was transferred to our university dental hospital complaining of swelling of the right mandible. She had a history of enucleation of cementoblastoma associated with the third molar of the right mandible. Five years after the initial treatment, imaging demonstrated well-circumscribed multicentric radiopaque lesions in the same area. Histologically, the lesion consisted of osteocementum-like tissue rimmed with polygonal or plump tumor cells. Several cells were large epithelioid cells with bizarre nucleoli, which may be reminiscent of malignant tumors. Otherwise, there were no apparent malignant findings, including proliferative activity or atypical mitotic figure. Besides, tumor cells were positive for c-FOS, a marker of osteoblastoma and cementoblastoma. Eventually, the patient was diagnosed with recurrent cementoblastoma. CONCLUSIONS: Pathological analyses of this case suggested that the recurrent event in the cementoblastoma altered its growth pattern and tumor cell shape. Moreover, in the case of enucleation surgery, long-term follow-up is important because there is some recurrent risk of cementoblastoma, although it is not high.

Histomorphometric and molecular characterization of stromal and mineralized components in fibro-osseous lesions.

BACKGROUND: Indistinct and analogous histopathological features of various fibro-osseous lesions make establishing a definitive diagnosis a challenge. There is a need for additional molecular and histochemical tools to support and differentiate these lesions in order to establish a concrete diagnosis. MATERIALS AND METHODS: A retrospective analysis of biopsied lesions in formalin-fixed paraffin-embedded sections (10 cases each of fibrous dysplasia, ossifying fibroma, and cement-osseous dysplasia) retrieved from the archives was studied for immunoexpression of osteocalcin (quantitative analysis in osteocytes), collagen characterization using Azan, Picrosirus, and Toluidine blue stain for evaluating intensity and localization of collagen fibers, and morphometric analysis of vasculature (for evaluating mean vessel density as square microns). RESULTS: Positive immunostaining of osteocalcin suggested mutations of the GNAS-1 gene found in fibrous dysplasia indirectly, as it is a negative regulator of bone formation. Osteocalcin immunopositivity was quantitatively measured in the fibro-osseous lesions, with fibrous dysplasia measuring 14.47 ± 3.628 as compared to ossifying fibroma measuring 5.23 ± 1.33, followed by cemento-osseous dysplasia measuring 2.30 ± 1.409. Toluidine blue suggests the presence of oxytalan fibers (resistant to acid hydrolysis) in ossifying fibroma and cemento-osseous dysplasia, pointing toward the pathogenesis of the lesion. Azan stain and Picrosirus (under a polarizing microscope) helped in distinguishing hard tissue characteristics (70% of cases of fibrous dysplasia showed only a magenta component followed by intermixed magenta with a blue component in 20% of cases and only 10% of cases showed magenta with blue borders whereas for ossifying fibroma, 40% of cases depicted magenta with blue borders along with the other 40% with intermixed magenta with blue component). The mean vessel density was also highest in fibrous dysplasia measuring 7.90 ± 1.079 (in Sq. micron area), followed by ossifying fibroma and cemento-osseous dysplasia. CONCLUSION: The diagnosis of fibro-osseous lesions by hematoxylin and eosin alone is confusing and thus should be supported by relatively simple histomorphometric analysis for better treatment outcomes. At the diagnostic stage of fibro-osseous lesions, evaluation of intralesional vessel size, reliable molecular marker, and histochemical nature can aid in differentiating fibrous dysplasia from central ossifying fibroma and cemento-osseous dysplasia alongside, other clinical, radiographic and pathological criteria. These parameters help in the diagnostic decision-making of fibro-osseous lesions.

[Clinical and pathological features and differential diagnosis of fibro-osseous tumors and dysplasias].

Fibro-osseous lesions is a class of diseases with obvious similarities in clinical manifestations and pathological features, which has been attracting the attention of clinicians and pathologists. The latest WHO 2022 Classification (5th edition) included six of these diseases (cemento-osseous dysplasia, segmental odontomaxillary dysplasia, fibrous dysplasia, juvenile trabecular ossifying fibroma, psammomatoid ossifying fibroma and familial gigantiform cementoma) in the " fibro-osseous tumours and dysplasias ", and put forward new ideas on the diagnosis and treatment of these diseases. According to the latest WHO 2022 Classification (5th edition), the clinical and pathological features, diagnosis and differential diagnosis of these six diseases were described.

Extraosseous cemento-ossifying fibroma beneath the left buccal mucosa: a case report.

Cemento-ossifying fibroma (COF) is a benign mesenchymal odontogenic tumor that commonly occurs in the tooth-bearing areas of the maxilla and mandible. This study reports a COF case located under the left buccal mucosa. The classification and differential diagnosis of this COF case were discussed based on the diagnosis and treatment of this case and previous literature.

Quantitative proteomic study reveals differential expression of matricellular proteins between fibrous dysplasia and cemento-ossifying fibroma pathogenesis.

BACKGROUND: Fibrous dysplasia (FD) and cemento-ossifying fibroma (COF) are the most common gnathic fibro-osseous lesions. These diseases exhibit remarkable overlap of several clinicopathological aspects, and differential diagnosis depends on the combination of histopathological, radiographic, and clinical aspects. Their molecular landscape remains poorly characterized, and herein, we assessed their proteomic and phosphoproteomic profiles. METHODS: The quantitative differences in protein profile of FD and COF were assessed by proteomic and phosphoproteomic analyses of formalin-fixed paraffin-embedded tissue samples. Pathway enrichment analyses with differentially regulated proteins were performed. RESULTS: FD and COF exhibited differential regulation of pathways related to extracellular matrix organization, cell adhesion, and platelet and erythrocytes activities. Additionally, these lesions demonstrated distinct abundance of proteins involved in osteoblastic differentiation and tumorigenesis and differential abundance of phosphorylation of Ser61 of Yes-associated protein 1 (YAP1). CONCLUSIONS: In summary, despite the morphological similarity between these diseases, our results demonstrated that COF and DF present numerous quantitative differences in their proteomic profiles. These findings suggest that these fibro-osseous lesions trigger distinct molecular mechanisms during their pathogenesis. Moreover, some proteins identified in our analysis could serve as potential biomarkers for differential diagnosis of these diseases after further validation.

Fibroma ossificante trabecular juvenil: um relato de caso / Juvenile ossifying fibroma: a case report

Objetivo: o fibroma ossificante trabecular juvenil (FOJT) é uma lesão fibro-óssea incomum, benigna, porém de comportamento agressivo. Ocorre, frequentemente, em crianças e adolescentes, com maior acometimento em maxila e mandíbula. O presente relato aborda os aspectos clínicos, imaginológicos, histopatológicos, imuno-histoquímicos e o tratamento de um caso de FOTJ. Além de discutir suas similaridades com o osteossarcoma de baixo grau e as alternativas para o seu diagnóstico. Relato de caso: paciente do sexo masculino, com 12 anos de idade, apresentando aumento de volume em mandíbula no lado esquerdo, perda de função mastigatória e de fala, com tempo de evolução de seis meses. Radiograficamente, a lesão apresentava aspecto unilocular, com limites definidos e de padrão misto. O tratamento consistiu em cirurgia de enucleação total da lesão, seguida de curetagem sob anestesia geral. A histopatologia e a ausência de marcação para MDM2 e CDK4 na imuno-histoquímica confirmaram o diagnóstico de FOTJ e excluíram o de osteossarcoma de baixo grau. No controle pós-operatório de 20 dias, o paciente relatou melhora da parestesia, da função mastigatória e da fala e ausência de dor. Não se observou recidiva no acompanhamento de 1 ano após a cirurgia. Considerações finais: a similaridade dos aspectos clínico, imaginológico e microscópico entre FOJT e osteossarcoma de baixo grau pressupõe o estudo imuno-histoquímico com os arcadores MDM2 e CDK4, minimizando equívocos no diagnóstico e orientando de forma mais eficiente o plano de tratamento adotado.(AU)

Objective: juvenile Trabecular Ossifying Fibromas (JTOF) are uncommon benign fibro-osseous lesions with a local aggressive behavior. They frequently occur in children and adolescents involving the jaw bones. This report addresses the clinical, imaging, histopathological, and immunohistochemical aspects and the treatment of a case of JTOF. In addition, it discusses similarities between JTOF and low-grade osteosarcomas and alternatives for their diagnosis. Case report: male patient, 12 years old, with a tumor in his left mandible, loss of masticatory function and speech, with a 6-month time course. Radiographically, the lesion had an unilocular aspect, with defined borders and a mixed image pattern. Treatment consisted surgical enucleation, followed by bone curettage, under general anesthesia. Histopathology presented fibrous stroma interspaced with bone trabeculae without signs of cellular malignancy. MDM2 and CDK4 markers in immunohistochemistry, confirmed the diagnosis of JTOF and excluded low-grade osteosarcoma. At the 20-day postoperative follow-up, the patient reported improvement in paresthesia, masticatory function and speech, and the absence of pain. Evaluation 1 year after surgery showed no signs of local recurrence. Final considerations: the similarity of clinical, imaging, and microscopic aspects between JTOF and low-grade osteosarcoma prompts an immunohistochemical study including MDM2 and CDK4 markers in order to improve final diagnosis and guide the treatment plan more efficiently.(AU)

Manejo cirúrgico de sequestro ósseo pósexodontia em paciente portador de displasia cemento-óssea florida: relato de caso / Surgical management of post-exodontia bone sequestral in patients with displasia bone cement-florida: case report

A displasia cemento-óssea florida (DCOF) é uma condição não neoplásica, esclerosante limitada aos ossos maxilares, relacionada ao osso do processo alveolar e, na maioria dos casos envolvendo bilateralmente a mandíbula. É uma condição rara que se apresenta nos maxilares, de forma autolimitante, evoluindo de um estágio osteolítico para osteoblástico, com prevalência pelo gênero feminino, de meia idade a idosas, melanoderma. Dessa forma, o objetivo do trabalho é relatar o caso clínico de uma paciente portadora de displasia cemento-óssea florida apresentando osteomielite local após exodontia.Paciente de 57 anos de idade, melanoderma, compareceu ao ambulatório do Hospital Manoel Victorino (Salvador, BA) do serviço de Cirurgia e Traumatologia Bucomaxilofacial, referindo histórico de exodontia do dente 47 há aproximadamente 02 anos, sem cicatrização local e presença de supuração e odor fétido. Ao exame intrabucal notou- se a presença fístula na região do dente 47 com secreção purulenta espontânea e presença de tecido necrótico. Ao exame de imagem (radiografia panorâmica), foi observado presença de lesões radiopacas multifocais das áreas posteriores mandibulares. Foi submetida a cirurgia, sob anestesia geral, para curetagem de sequestro ósseo e fechamento primário do defeito por primeira intenção e acompanhamento. O objetivo do trabalho foi relatar um caso clínico de um sequestro ósseo mandibular em uma paciente com displasia cemento- óssea florida(AU)

Flowery cementum-bone dysplasia (DCOF) is a non-neoplastic, sclerosing condition limited to maxillary bones, related to the alveolar process bone and, in most cases, bilaterally involving the mandible. When infected can lead to suppuration and kidnapping, resulting in a picture of osteomyelitis. It is a rare condition that occurs in the jaws, in a selflimiting way, evolving from an osteolytic stage to osteoblastic, with prevalence by the female gender, from middle age to the elderly, melanoderma. Therefore, the aim of this paper is to report a diagnosed case of florid cemento-ousseous dysplasia, presenting local osteomyelitis after a extraction. Patient 57 years old, melanoderma, attended the outpatient clinic of the Hospital Manoel Victorino (Salvador, BA) of the Bucomaxillofacial surgery and traumatology department, referring to a history of the right mandible exodontia for approximately 2 years, without local scarring and presence of odor and suppuration fetid The intraoral examination revealed the presence of a fistula in the region distal to the tooth 47 with spontaneous purulent secretion and necrotic tissue. At the imaging examination (panoramic radiography), the presence of multifocal radiopaque lesions of the mandibular posterior areas was observed. She underwent surgery under general anesthesia for curettage of bone sequestration and primary closure of the defect by first intention and follow-up. The objective of this study was to report a clinical case of a mandibular bone sequestration in a patient with florid cementoosseous dysplasia(AU)

A contraindication to orthodontic and endodontic treatment: periapical cemento-osseous dysplasia.

INTRODUCTION: The dental pulp is completely normal in teeth with periapical cemento-osseous dysplasia. However, orthodontic and endodontic treatments are contraindicated in cases with this injury. OBJECTIVE: Present some biological, clinical and imaging reasons opposing these contraindications and questioning which are the real ones impediments and the reasons for the lack of research on the disease, analyzing cases submitted to orthopedic treatment under controlled and ethically approved conditions. CONCLUSION: The clinician can act safely based in available knowledge and aware of the possible consequences of orthodontic movement in teeth with periapical cemento-osseous dysplasia, as well as in the proper way of making a safe and definitive diagnosis.

A contraindication to orthodontic and endodontic treatment: periapical cemento-osseous dysplasia

ABSTRACT Introduction: The dental pulp is completely normal in teeth with periapical cemento-osseous dysplasia. However, orthodontic and endodontic treatments are contraindicated in cases with this injury. Objective: Present some biological, clinical and imaging reasons opposing these contraindications and questioning which are the real ones impediments and the reasons for the lack of research on the disease, analyzing cases submitted to orthopedic treatment under controlled and ethically approved conditions. Conclusion: The clinician can act safely based in available knowledge and aware of the possible consequences of orthodontic movement in teeth with periapical cemento-osseous dysplasia, as well as in the proper way of making a safe and definitive diagnosis.

RESUMO Introdução: A polpa dentária é completamente normal nos dentes com displasia cemento-óssea periapical. Porém, os tratamentos ortodônticos e endodônticos estão contraindicados nos casos com essa lesão. Objetivo: Apresentar algumas razões biológicas, clínicas e imagiológicas, contrapondo-se essas contraindicações e questionando quais seriam os reais impedimentos e os motivos da falta de pesquisa sobre a doença, analisando casuísticas submetidas ao tratamento ortodôntico sob condições controladas e eticamente aprovadas. Conclusão: O clínico pode agir de forma segura embasado no conhecimento disponível e consciente das possíveis consequências da movimentação ortodôntica nos dentes com displasia cemento-óssea periapical, bem como na forma adequada de se fazer o diagnóstico seguro e definitivo da doença.

Odontogenic Carcinoma With Dentinoid in Long-Term Follow-up With 2 Recurrences.

Dentinoid has been mentioned as a frequent component in several types of benign odontogenic tumors; however, there are some other very rare dentinoid-producing odontogenic tumors that have been described, which are not recognized in the current World Health Organization Histological Classification of Odontogenic Tumours. In this context, we report an unusual malignant odontogenic tumor containing dentinoid located in the left maxilla of a 41-year-old man. The lesion was initially diagnosed and treated as a cemento-ossifying fibroma. After 7 years, a tumor was noted at the same location and was diagnosed as pleomorphic adenoma. The patient developed a new lesion 2 years later. Histological features included an epithelial proliferation of basaloid and clear cells, some with peripheral palisading, which were scattered both in a fibrous stroma and within an amorphous eosinophilic dentinoid product. Because of doubts about the first 2 diagnoses and the current situation, all histopathological slides were reviewed in our service as a consultation case, and the findings were consistent with the diagnosis of an odontogenic carcinoma with dentinoid. Immunohistochemical analysis was performed and an ultrastructural study by scanning electronic microscopy and energy-dispersive X-ray microanalysis was made to characterize dentinoid material. After 1 year of follow-up, the patient is alive and free of the disease. This case highlights the wide variability regarding cytological evidence of malignancy, and adds a new case of odontogenic carcinoma with dentinoid, which represents a distinct entity with locally aggressive behavior and should be considered be included in a future World Health Organization Histological Classification of Tumours.

Ossifying fibroma in the mandibular angle mimicking metastatic clear cell renal cell carcinoma: A case report.

RATIONALE: Ossifying fibroma is benign fibro-osseous neoplasm. The authors report a case of ossifying fibroma in the mandibular angle suspected as metastasis of clear cell renal cell carcinoma. PATIENT CONCERNS: A 74-year-old man presented to the primary hospital complaining of frequent urination. A tumor in the left kidney was detected via an abdominal computed tomography scan. The patient then visited the Department of Urology at our hospital. DIAGNOSES: According to whole-body imaging examinations, the patient was suspected of having renal cancer with mandibular metastasis. Also, a cystic lesion of the maxilla was revealed. INTERVENTIONS: Left nephrectomy was performed by urologists, and the patient was diagnosed with clear cell renal cell carcinoma of the left kidney. Approximately 1 month later, resection with a safety margin of the mandibular lesion and removal of the maxillary lesion were performed by oral and maxillofacial surgeons. OUTCOMES: The patient was diagnosed with ossifying fibroma of the mandible and an odontogenic keratocyst of the maxilla via a histopathological examination. Eighteen months have passed since the operation without clinical and imaging findings associated with recurrence. LESSONS: Ossifying fibroma in the mandibular angle of elderly patients is extremely rare. Surgeons should consider the possibility of metastasis when osteolytic lesions of the jaw are found in patients with cancer.

Can non-collagenous proteins be employed for the differential diagnosis among fibrous dysplasia, cemento-osseous dysplasia and cemento-ossifying fibroma?

Differential diagnosis among fibrous dysplasias, cemento-ossifying fibromas and cemento-osseous dysplasias is difficult, since there is considerable overlap of histologic features, but also extremely important, since they differ greatly in etiology, clinical behaviour, prognosis and terapeuthic approach. There is no data about the use of immunohistochemistry, a viable and accessible technique, for this purpose. The objective of this study was to investigate, comparatively, the immunohistochemical expression of major non-collagenous proteins (osteonectin [ON], osteopontin [OP], bone sialoprotein [BSP] and osteocalcin [OC]) of mineralized tissue extracellular matrix in 22 cases of fibrous dysplasias, 16 of cemento-ossifying fibromas and 16 of cemento-osseous dysplasias. ON maintained the same expression profile in all cases; the staining for OP was negative in fusiform cells producing cementoid globules and weak, as well as heterogeneous, in high mineralized matrixes; there was negativity for BSP in cementoid globules and in the fusiform cells that produce them, differently from the strong positive expression found in the majority of bone trabeculae and their peripheral cuboidal osteoblasts; and finally, the immuno-reactivity for OC was weak, except in cuboidal osteoblasts and osteocytes. We can conclude that the nature of mineralized structure and the cellular phenotype are much more responsible for variability in immunohistochemical profile than the type of lesion (fibrous dysplasias, cemento-ossifying fibromas and cemento-osseous dysplasias) which makes difficult, at least for a while, the use of these proteins with diagnosis purpose.

Benign Fibro-Osseous Lesions of the Head and Neck.

Benign fibro-osseous lesions (BFOLs) are a particularly challenging set of diagnoses for the pathologist. This diverse collection of diseases includes fibrous dysplasia, ossifying fibroma and cemento-osseous dysplasia. While all three conditions have similar microscopic presentations, their treatment and prognosis differ, demanding an accurate and definitive diagnosis. A practical and systematic approach considering the patient's history, demographics, intraoperative presentation, and gross appearance with an emphasis on radiology and histology will be discussed.

Periapical Cemento-osseous Dysplasia Is Rarely Diagnosed on Orthopantomograms of Patients with Neurofibromatosis Type 1 and Is Not a Gender-specific Feature of the Disease.

Several skeletal aberrations of the skull have been described for the tumor predisposition syndrome neurofibromatosis type 1 (NF1). Recently, periapical cemental/cemento-osseous dysplasia (COD) has been described in females affected with NF1. This reactive lesion of the hard tissues in tooth-bearing areas of the jaw has been proposed to represent a gender-specific radiological feature of NF1. The aim of this study was to investigate the prevalence of COD in patients with NF1. PATIENTS AND METHODS: The orthopantomograms (OPGs) of 179 patients with a confirmed diagnosis of NF1 were analyzed for COD. The results were compared to radiographic findings obtained in OPGs of age- and sex-matched controls. The NF1 patient group was further differentiated according to the evidence of facial plexiform neurofibroma. RESULTS: COD was a very rare finding in both groups. The extension of the diagnostic criteria including radiologically-healthy teeth and a widened periodontal gap in the periapical area only marginally increased the number of considered cases. Although there was a somewhat more common occurrence of such changes in the patient group compared to the control group and the number of affected women was greater than the number of men, none of these differences reached statistical significance. Furthermore, COD or widening of the periradicular periodontal space was not found to be associated with facial tumor type in NF1. CONCLUSION: The investigation revealed that COD is not a diagnostic feature of NF1. There is no clear association of the rare finding of COD with gender. These studies should be compared with patient groups of other ethnic backgrounds.

Cementoblastoma: An updated analysis of 258 cases reported in the literature.

PURPOSE: To investigate the recurrence rate of cementoblastomas for different variables aside from the clinical/radiologic features. METHODS: An electronic search was undertaken in November/2016. Eligibility criteria included publications having enough clinical/radiological/histological information to confirm the diagnosis. RESULTS: 141 publications (258 cementoblastomas) were included. There was an equal sex distribution. There was a high prevalence in the second/third decades of life, in the posterior regions, and in mandibular first molars. Lesions were commonly associated with bone expansion (74.9%), presence of clinical symptoms (70.2%), vital teeth (78%), root resorption (59.8%). Observations not as frequent: cortical bone perforation (16.3%), inferior displacement of the mandibular canal (23.6%). Treatment was reported for 229 cases. Twenty (11.8%) out of 170 recurred. Preservation of the involved teeth and location seem to not influence the recurrence rate, but there was a 687% higher probability (odds ratio 7.875; p = 0.048) of recurrence for lesions associated with bone expansion, and a 217% higher probability (odds ratio 3.173; p = 0.023) of recurrence for lesions presenting cortical bone perforation. CONCLUSIONS: Although the recurrence rate of cementoblastomas is not as high as previously believed, it is a relevant phenomenon (11.8%). The presence of bone expansion and cortical bone perforation seem to influence the recurrence rate.

Can Differences in Vascularity Serve as a Diagnostic Aid in Fibro-Osseous Lesions of the Jaws?

PURPOSE: Different lesions in the fibro-osseous group share microscopic features; thus, establishing a definitive diagnosis based on microscopic features alone can be a challenge. There is a need for additional microscopic tools to aid in differentiating these lesions. This study compared parameters related to vascularity among 3 lesions in the fibro-osseous group: fibrous dysplasia (FD), central ossifying fibroma (COF), and cemento-osseous dysplasia (COD). MATERIALS AND METHODS: This study was a cross-sectional analysis of biopsied lesions retrieved from 3 medical centers over a 14-year period. The primary predictor variables were the vascularity parameters (number, perimeter, and area). The outcome variables were diagnoses of FD, COF, and COD. Diagnosis was based on clinical, microscopic, and radiologic correlations. From each histopathologic slide, 5 representative fields were captured with a computerized digital camera. The number of blood vessels was counted, and the surface area and vascular perimeter were measured by tracing the perimeter of each vessel. Data were statistically analyzed using analysis of variance with logarithmic transformation and a Tukey adjustment. RESULTS: Sixty-six cases were included in the study (26 in FD group, 26 in COF group, and 14 in COD group). The mean number of vessels showed only a tendency to be larger in the FD group compared with the COF and COD groups (5.4 ± 2.6, 3.7 ± 2.3, and 3.6 ± 1.7, respectively), but the results did not reach the threshold for significance. The mean vascular perimeter was 1,385.8 ± 859.2 pixels in the FD group and 742.6 ± 661.8 in COF group after logarithmic transformation (P = .012). The perimeter in the COD group was smaller (941.1 ± 502) compared with that in the FD group, but the difference did not reach the threshold for significance. The mean area was 25,061 ± 24,875.6 in the FD group and 11,773.8 ± 21,734.4 in the COF group after logarithmic transformation (P = .004). The perimeter in the COD group was smaller (13,011.1 ± 8,338.3) compared with the FD group, but the difference did not reach the threshold for significance. CONCLUSION: The vascular content of the FD group was markedly higher than of the COF group. These vascular changes can aid in differentiating these lesions microscopically.

Diagnosis and management of benign fibro-osseous lesions of the jaws: a current review for the dental clinician.

Benign fibro-osseous lesions of the maxillofacial skeleton constitute a heterogeneous group of disorders that includes developmental, reactive (dysplastic) and neoplastic lesions. Although their classification has been reviewed multiple times in the past, the most common benign fibro-osseous lesions are fibrous dysplasia, osseous dysplasia and ossifying fibroma. For the dental clinician, the challenges involve diagnosis and treatment (or lack thereof). A careful correlation of all clinical, radiologic and microscopic features is essential to establish a proper diagnosis and a clear treatment plan. This article aimed to review the clinical, radiologic and histopathologic characteristics of benign fibro-osseous lesions of the jaws, with emphasis on their differential diagnoses. With a deeper understanding of benign fibro-osseous lesions, clinicians will be better prepared to manage these lesions in their practice.

Peripheral Cemento-Ossifying Fibroma.

Peripheral cemento-ossifying fibroma (PCOF), a relatively uncommon lesion, reactive in nature is seen as an overgrowth of the gingival tissues often leading to periodontal problems. It is a benign tumor with slow-growing potential commonly affecting the anterior maxilla whose pathogenesis till date is uncertain. It is usually challenging to diagnose peripheral cemento-ossifying fibroma based on clinical observation and examination, hence histopathological examination is mandatory to arrive at an accurate diagnosis. Recurrence of the lesion is common unless and until it is completely excised. We present the report of two cases of peripheral cemento-ossifying fibroma of our department, complaining of a mass in the gingiva of posterior maxilla and mandible.