Cemento-ossifying fibroma (COF) is a mesenchymal benign odontogenic tumor, which may lead to impacted or ectopic permanent teeth. Autotransplantation of teeth is a surgical process, in which a tooth is transplanted from one position to another in the same individual. This method can effectively restore the patient\'s mastication and aesthetics and is feasible in replacing missing teeth. This study reports a case of simultaneous COF resection combined with heterotopic canine autotransplantation to repair dentition defect, which effectively promotes the restoration of bone continuity and stability and achieves immediate and long-term aesthetic function requirements.

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.
牙骨质-骨化纤维瘤作为间充质来源的良性牙源性肿瘤，主要发生于颌骨的牙承载区。本文报道1例位于左侧颊黏膜下的牙骨质-骨化纤维瘤病变，结合该病例的诊治情况及既往相关文献，对其分类以及鉴别诊断进行讨论。.

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.
METHODS: 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.

BACKGROUND: Since there are many differential diagnoses for cemento-osseous dysplasia (COD), it is very difficult for dentists to avoid misdiagnosis. In particular, if COD is related to an embedded tooth, differential diagnosis is difficult. However, there have been no reports on the characteristics of the imaging findings of COD associated with embedded teeth. The aim of the present study was to investigate the occurrence and imaging characteristics of cemento-osseous dysplasia (COD) associated with embedded teeth, in order to appropriately diagnose COD with embedded teeth.
METHODS: The radiographs with or without histological findings of 225 patients with COD were retrospectively analyzed. A retrospective search through the picture archiving and communication system (PACS) of the Division of Oral and Maxillofacial Radiology of Kyushu Dental University Hospital was performed to identify patients with COD between 2011 and 2022.
RESULTS: Fifteen COD-associated embedded mandibular third molars were identified in 13 patients. All 13 patients were asymptomatic. On imaging, COD associated with embedded mandibular third molars appeared as masses that included calcifications around the apex of the tooth. On panoramic tomography, COD showed inconspicuous internal calcification similar to that of odontogenic cysts or simple bone cysts, especially in patients with COD only around the mandibular third molar region. Those with prominent calcification resembled cemento-ossifying fibroma, calcifying epithelial odontogenic tumor, calcifying odontogenic cyst, adenomatoid odontogenic tumor, and so on, as categories of masses that include calcifications on panoramic tomography and computed tomography.
CONCLUSIONS: The current investigation is the first to report and analyze the imaging characteristics of COD associated with embedded teeth. It is important to consider the differences between COD and other cystic lesions on panoramic tomography, and the differences between COD and masses that include calcifications on CT.

Ossifying fibroma is a type of fibro-osseous lesion categorised into cemento-ossifying fibroma and juvenile ossifying fibroma. Malignant transformation of fibro-osseous lesions is documented especially for fibrous dysplasia, but scarcity is seen when we search for malignant transformation of ossifying fibroma. Thus, we are presenting an extremely rare case of cemento-ossifying fibroma transforming into osteosarcoma with long sequential radiographic details.

A man in his 20s presented with complaints of unilateral nasal obstruction for the past 6 years that progressively worsened leading to irrational use of over-the-counter nasal decongestants. With the worsening of symptoms, a non-contrast CT was done. It showed a dense expansile sclerotic lesion of the right inferior turbinate, which was excised endoscopically. Cemento-ossifying fibromas of the inferior turbinate are rare and require assessment and surgical excision to relieve the symptom of nasal obstruction. It derives its name from the variable proportions of fibrous and mineralised tissue present in it and exclusively develops in the craniofacial region. It can be surgically managed by an endoscopic, an endonasal non-endoscopic (with a speculum) or an open approach (lateral rhinotomy, sublabial approach or mid-facial degloving). Here, we present how such a case was detected and managed surgically by the endoscopic approach, which is a minimally invasive option with shorter hospital stay and early recovery.

Cemento-ossifying fibroma (COF) and juvenile ossifying fibroma (JOF) have been considered distinct entities within the category of fibro-osseous lesions. This study aimed to assess osteoblast and osteoclast activity in COF and JOF by investigating bone resorption markers, specifically receptor activator of nuclear factor-kB (RANK), RANK ligand (RANKL), and its inhibitor osteoprotegerin (OPG). A comparative analysis of these markers was performed on all lesions. Immunohistochemistry was employed to evaluate and quantify the expression of these biomarkers in a sample of 20 cases of cemento-ossifying fibroma (COF), 15 cases of psammomatoid juvenile ossifying fibroma (PsJOF), and 10 cases of trabecular juvenile ossifying fibroma (TrJOF). The expression of osteoprotegerin was significantly higher in cemento-ossifying fibroma (33.9±13.0) compared to trabecular juvenile ossifying fibroma (27.3±9.2) and psammatoid ossifying fibroma (25.2±14.9), with the COF showing the highest expression followed by the latter two (p=0.037). There was a higher percentage (80%) of stromal fibroblast cells that showed positive expression of RANKL in cemento-ossifying fibroma (COF) compared to psammomatoid juvenile ossifying fibroma (PsJOF) (33.3%) and trabecular juvenile ossifying fibroma (TrJOF) (30.0%) when considering a positive expression score of 3 (p=0.024). Cemento-ossifying fibroma demonstrated the highest expression of osteoprotegerin and RANKL-positive stromal fibroblast cells, followed by psammomatoid juvenile ossifying fibroma and trabecular juvenile ossifying fibroma. These findings provide valuable insights into the pathogenesis of these lesions.

BACKGROUND: Odontogenic tumours are infrequent lesions. Studies on the frequency of odontogenic tumours from Latin America are scarce. This work aimed to determine the relative frequency of odontogenic tumours in a Chilean population using the 2022 World Health Organization classification.
METHODS: This is a case series retrospective study. We reviewed 35,530 samples from 1975 to 2022 from the Oral Pathology Referral Institute and the Pathological Anatomy Service, Faculty of Dentistry, University of Chile. We utilized the 2022 World Health Organization classification for histological typification.
RESULTS: According to 2022 World Health Organization classification, 544 odontogenic tumours were confirmed. The most frequent odontogenic tumours were: odontoma (n=241; 44.3%), ameloblastoma (n=109; 20.0%) and cemento-ossifying fibroma (n=71; 13.1%). Benign odontogenic tumours corresponded to 538 cases (98.9%) and malignant tumours were only six cases (1.1%).
CONCLUSIONS: In our population, odontoma was the most frequent odontogenic tumour followed by ameloblastoma and cemento-ossifying fibroma. Malignant odontogenic tumours were very rare. The results of this study are similar to reports from America, but there are some differences concerning the data from Africa and Asia.

BACKGROUND: Familial gigantiform cementoma (FGC) is a rare tumor characterized by the early onset of multi-quadrant fibro-osseous lesions in the jaws, causing severe maxillofacial deformities. Its clinicopathological features overlap with those of other benign fibro-osseous lesions. FGC eventually exhibits progressively rapid growth, but no suspected causative gene has been identified.
METHODS: In this study, three patients with FGC were recruited, and genomic DNA from the tumor tissue and peripheral blood was extracted for whole-exome sequencing.
RESULTS: Results showed that all three patients harbored the heterozygous mutation c.1067G > A (p.Cys356Tyr) in the ANO5 gene. Furthermore, autosomal dominant mutations in ANO5 at this locus have been identified in patients with gnathodiaphyseal dysplasia (GDD) and are considered a potential causative agent, suggesting a genetic association between FGC and GDD. In addition, multifocal fibrous bone lesions with similar clinical presentations were detected, including five cases of florid cemento-osseous dysplasia, five cases of polyostotic fibrous dysplasia, and eight cases of juvenile ossifying fibromas; however, none of them harbored mutations in the ANO5 gene.
CONCLUSIONS: Our findings indicate that FGC may be an atypical variant of GDD, providing evidence for the feasibility of ANO5 gene testing as an auxiliary diagnostic method for complex cases with multiple quadrants.

METHODS: Cementoblastoma (CB) is unique among odontogenic tumors because its gross pathological anatomy is pathognomonic in most cases, i.e., a rounded calcified growth that is fused to the root of a tooth and completely encapsulated by fibrous tissue. The resulting radiographic appearance is a well-defined, globular mixed radiopaque/lucent or completely radiopaque mass obliterating some details of the root, with a thin radiolucent zone surrounding the central opacity. Although hundreds of publications have covered the clinicopathologic features of CB, almost nothing is known about its true history. Also it seems there is little understanding about how the term \"CB\" was originally introduced as a pathologic entity. This report covers some overlooked papers on CB dating back to the 19th century, including the first complete description in 1888 and the first radiographic presentation in 1906.