Expressions of bax, bcl-2 and Ki-67 in Odontogenic Keratocysts (Keratocystic Odontogenic Tumor) in Comparison with Ameloblastomas and Radicular Cysts

Objective: The aim of the study was to determine the apoptotic features and proliferation potential of odontogenic keratocysts compared with ameloblastomas and radicular cysts by analysing the role of bax, bcl-2, and Ki-67

Oral Focal Mucinosis: A Case Report and Review of the Literature

Oral focal mucinosis is a rare clinicopathological entity that represents the mucosal counterpart of cutaneous focal mucinosis or cutaneous myxoid cyst. The aetiology is unknown. Oral focal mucinosis is most common in young adults. The gingiva is the most common site and the hard palate is the second most common location. A 19-year-old male patient presented with a 2 cm painless mass localized to the palatal side. An excisional biopsy was taken and sent for histopathologic evaluation to our department. Histopathologic findings were a well-circumscribed lesion composed of myxomatous connective tissue that contained bipolar, fusiform or stellate shaped fibroblasts. The aim of this study was to bring oral focal musinosis diagnosis to the attention of clinicians and pathologists when considering the differential diagnosis of gingival and palatal nodules

The Role of RANK/RANKL/OPG Signalling Pathways in Osteoclastogenesis in Odontogenic Keratocysts, Radicular Cysts, and Ameloblastomas

The aim of this study was to evaluate the immunohistochemical expression of molecules involved in osteoclastogenesis, including the receptor activator of nuclear factor kappa B (RANK), RANK ligand (RANKL) and osteoprotegerin (OPG) in odontogenic keratocysts (OKCs), which has been named as a keratocystic odontogenic tumour by the WHO, and compare their expression with radicular cysts and ameloblastomas. RANK is a member of tumour necrosis factor receptor family and it is activated by RANK ligand. OPG binds to RANKL and inactivates it. The imbalance of these factors could cause the differential bone resorption activity in some diseases and tumours. The expression of these molecules was evaluated in ameloblastomas (n = 20), OKCs (n = 20), and radicular cysts (n = 20) by immunohistochemistry. Immunohistochemical reactivity for RANK, RANKL, and OPG was detected in neoplastic and nonneoplastic epithelium and connective tissue cells. RANK showed the greatest expression in OKCs followed by ameloblastomas, with the lowest expression seen in radicular cysts. Expression of RANKL was detected in all lesions and no significant differences were observed between groups. OPG was expressed very low in all groups. In the stroma, the number of RANK positive cells was higher in OKCs when compared with ameloblastomas and radicular cysts but radicular cyst had higher numbers of RANKL positive cells in the stroma than ameloblastomas. The molecular system of RANK/RANKL/OPG is variably expressed in OKCs, radicular cysts, and ameloblastomas and this system may be involved in the osteoclastogenic mechanisms in OKCs and ameloblastomas. Advanced studies could further clarify the role of RANK, RANKL, and OPG in mediating tumour associated bone osteolysis

Teriparatide and the treatment of bisphosphonate-related osteonecrosis of the jaw: a rat model

Objectives: The objectives of this study were to establish a bisphosphonate-related osteonecrosis of the jaw (BRONJ) rat model and to analyse the effects of teriparatide (TP) on this model. Methods: Sprague-Dawley rats were divided into three groups: I—zoledronic acid (ZA, n = 10); II—ZA and teriparatide (ZA + TP, n = 10); III—control (n = 10). Osteonecrosis was induced by administering zoledronic acid to groups ZA and ZA + TP. A week after the injections, rats underwent extraction of the first left mandibular molar. Following a four week period, TP was administered to the ZA + TP group for 28 days. Upon killing, extraction sockets were examined clinically, radiologically and histopathologically. Results: Clinical examination revealed necrotic bone exposure in none of the animals. MicroCT (µCT) examination showed that bone mineral density of the newly formed bone in the extraction socket was lower in the ZA group than in the ZA + TP group (p < 0.05). Histopathological examination revealed that only the ZA and ZA + TP groups developed osteonecrosis, and the osteonecrotic bone area in the ZA group was larger than that in the ZA + TP group (p < 0.05). Tartrate-resistant acid phosphatase (TRAcP) enzyme histochemistry revealed that the number of detached and large osteoclasts were higher in the ZA group than in other groups, whereas the number of apoptotic osteoclasts in both ZA and ZA + TP groups were higher than in the control group (p < 0.05). Conclusions: Our data indicate that bisphosphonate-related osteonecrosis of the jaw model used in the present study is an attractive model to investigate treatment modalities and that TP might be an effective treatment in BRONJ