ODONTOGENIC TUMORS: WHERE ARE WE IN 2017?

Odontogenic tumors are a heterogeneous group of lesions of diverse clinical behavior and histopathologic types, ranging from hamartomatous lesions to malignancy. Because odontogenic tumors arise from the tissues which make our teeth, they are unique to the jaws, and by extension almost unique to dentistry. Odontogenic tumors, as in normal odontogenesis, are capable of inductive interactions between odontogenic ectomesenchyme and epithelium, and the classification of odontogenic tumors is essentially based on this interaction. The last update of these tumors was published in early 2017. According to this classification, benign odontogenic tumors are classified as follows: Epithelial, mesenchymal (ectomesenchymal), or mixed depending on which component of the tooth germ gives rise to the neoplasm. Malignant odontogenic tumors are quite rare and named similarly according to whether the epithelial or mesenchymal or both components is malignant. The goal of this review is to discuss the updated changes to odontogenic tumors and to review the more common types with clinical and radiological illustrations

Evaluation of the effectiveness of esterified hyaluronic acid fibers on bone regeneration in rat calvarial defects

Hyaluronic acid (HA) constitutes one of the major components of the extracellular matrix domain in almost all mammals. The aim of this study was to evaluate the regenerative capacity of HA matrix in rat calvarial bone defects and compare with those of different combinations of resorbable collagen membrane (M) and bovine-derived xenograft (G). Twenty-four 3-month-old male Sprague-Dawley rats weighing 200-250 g were included. Control group was created by leaving one defect empty from 2 critical size defects with 5 mm diameter formed in the calvarial bones of 8 rats. In the same rats, the other defect was treated with HA matrix alone. One of the 2 defects formed in other 8 rats was treated with HA+G and the other with HA+M. One of the 2 defects formed in the remaining 8 rats was treated with G+M and the other with HA+G+M. The animals were sacrificed at 4 weeks. Histologic, histomorphometric, and immunohistochemical analyses were performed. Both HA matrix alone and its combinations with G and M supported new bone formation (NBF). However, NBF was significantly greater in G+M and HA+G+M groups compared to control and HA alone (P<0.001). Bone morphogenetic protein-2 was expressed with varying degrees in all groups, without any difference among them. Within the limitations of the present study, HA matrix, used alone or in combination with G and M, did not contribute significantly to bone regeneration in rat calvarial bone defects