Notch 1 Receptor, Delta 1 Ligand and HES 1 Transcription Factor are Expressed in the Lining Epithelium of Periapical Cysts (Preliminary Study)

Periapical cyst is a chronic inflammatory disorder of periradicular tissues. The precise pathological mechanisms involved in periapical cyst enlargement remain unclear. Notch signaling is an evolutionarily conserved pathway with a regulatory role in cell fate decisions during development and in carcinogenesis. To date, there are no published data available on the expression of Notch signaling components in periapical cysts or any other jaw cyst. In this immunohistochemical study we have examined the expression of the receptor Notch 1, the ligand Delta 1 and the transcription factor HES 1 in the epithelium of well defined periapical cysts. Immunostaining reaction of Notch 1, Delta 1 and HES 1 was observed in the cytoplasm and/or the cytoplasmic membrane and occasionally in the nucleus in the majority of epithelial cells of all periapical cysts. The present observations indicate that Notch pathway is active in the epithelium of periapical cysts. It can be speculated that activation of epithelial cells of periapical cysts is associated with activation of Notch pathway and imply involvement of this pathway in periapical cyst growth and expansion

Effect of autologous platelet-rich plasma in combination with a biphasic synthetic graft material on bone healing in critical-size cranial defects

Purpose: The aim of the study was to investigate the effect of autologous platelet-rich plasma (PRP) on the osteogenic potential of a biphasic synthetic graft material composed of hydroxyapatite and beta-tricalcium phosphate (HAβA-TCP) in critical-size cranial defects in rabbits. Materials and Methods: Three circular bicortical critical-size cranial defects were created in each of 18 rabbits. The first of the defects was grafted with autologous PRP and HAβA-TCP, the second was grafted with HAβA-TCP without PRP, and the third was left unfilled as a negative control. Animals were euthanized at 2, 4, and 6 weeks after surgery. Harvested tissue specimens were evaluated histologically and histomorphometrically. Several parameters associated with osteoclastic and osteoblastic activitieswere measured and calculated. The results were statistically analyzed using the 1-way analysis of variance statistical method. Results: Histologic analysis of the samples showed bone tissue formation at all experimental sites including untreated control defects. A statistically significant difference in new bone formation between the defects treated with HAβA-TCP + PRP and defects treated with HAβA-TCP alone was not observed. Control untreated defects showed the greatest bone regeneration. Conclusions: In this animal model, autologous PRP had no effect on bone healing in addition to a biphasic HAβA-TCP synthetic graft material after 2, 4, and 6 weeks of implantation. Copyright © 2012 by Mutaz B. Habal, MD

Osteogenic activity of β-tricalcium phosphate in a hydroxyl sulphate matrix and demineralized bone matrix: a histological study in rabbit mandible.

Currently, in oral and maxillofacial surgery, there is a clinical need for efficient bone grafting materials, and various efforts are being made to improve materials used as bone substitutes to facilitate faster and denser bone regeneration. The purpose of this study was to evaluate in vivo the osteogenic potential of synthetic β-tricalcium phosphate in a hydroxyl sulphate matrix (β-TCP/HS) and human demineralized bone matrix (DBM) putty. Sixteen New Zealand White rabbits were used. In each animal, two bone defects (8 mm length × 3 mm width × 3 mm depth) were created in the left and right regions of the mandible, respectively. The defect on one side, chosen randomly, was filled with β-TCP/HS (group A) or DBM putty (group B), while the defect on the opposite side was left unfilled in order to serve as a control site. Two animals in each group were sacrificed at the end of the 1st, 3rd, 5th and 6th week after surgery, respectively, and the osteotomy sites were processed for histological evaluation. Our findings confirmed that β-TCP/HS and human DBM putty possess osteogenic activity and can support new bone formation, although at a slower rate than the spontaneous healing response, in rabbit mandibular osseous defects

Biological response to β-tricalcium phosphate/calcium sulfate synthetic graft material: An experimental study

PURPOSE: The aim of this study was to evaluate the effect of a biphasic synthetic bone graft material composed of β-tricalcium phosphate (β-TCP) and calcium sulfate (CS) in 12 New Zealand rabbits. MATERIALS AND METHODS: A circular bicortical critical-size cranial defect was created in each of 12 rabbits. The defects were grafted with β-TCP/CS. Animals were euthanized at 3 and 6 weeks. Harvested tissue specimens were evaluated histologically and histomorphometrically. Parameters associated with new bone formation and graft resorption were measured and calculated. The results were statistically analyzed using the Mann-Whitney test. RESULTS: Our data demonstrated the biocompatibility of synthetic β-TCP/CS, as no inflammatory response was observed, and no fibrosis was developed between the graft particles and the newly formed bone. Moreover, β-TCP/CS acted as an osteoconductive scaffold that allowed a significant bone regeneration and graft biodegradation with time. CONCLUSION: In this animal model, synthetic β-TCP/CS proved to be a biocompatible, osteoconductive, and bioresorbable bone graft substitute. Copyright © 2013 by Lippincott Williams & Wilkins

Adenoid cystic carcinoma of the head and neck. Clinicopathological analysis of 23 patients and review of the literature

Adenoid cystic carcinoma (ACC) is a rare epithelial tumor with a distinct natural history characterized by an indolent but persistent growth, late onset of distant metastases and eventual death of patients. Between 1991 and 2003, 23 patients with ACC were treated in our Department. Surgery with a curative intent followed by radiotherapy (RT) was applied in 22 patients. Complete resection was achieved in 72.73% of patients. Local recurrence occurred in 26% of patients. Positive margins emerged as the only statistically significant parameter (p < 0.0001) influencing the development of local recurrence. Distant metastasis (DM) occurred in 47.8% of patients. In 54.5% of the patients developing DM, this occurred between 5 and 10 years after the initial treatment. DM was influenced by perineural invasion (p = 0.04) and was disassociated from local control of the tumor. The mean overall survival of our patients was 70.58 months and the mean disease free survival 61.85 months. Perineural invasion (p = 0.048) and DM (p = 0.001) had a statistically significant impact on final patients’ outcome. The most important factor influencing survival was DM. Its late onset, irrespectively of local control, supports the hypothesis that ACC has a potential to develop DM in the very early phases of tumor growth. (c) 2005 Elsevier Ltd. All rights reserved

Sarcomas of the head and neck. Results from the treatment of 25 patients

Aims. Head and neck sarcomas comprise a heterogenous and biologically diverse group of rare neoplasms. In an effort to clarify some of the obscure clinical. behavior of head and neck sarcomas, we present our experience and review the relevant Literature. Methods. Retrospective analysis of patients with histologically proven head and neck sarcomas treated in a tertiary Hospital, Department between 1992 and 2002. Results. During this period, 25 patients with head and neck sarcomas were registered. Follow-up ranged from 8 to 144 months. Twenty-three. patients were treated with surgery as the primary modality; 14 were treated by surgery alone. Clear margins were obtained in all. of them and local control was achieved in 12/13. The 2-and 5-year survival rates for the entire group were 80 and 40%, respectively. Mean overall survival time of our patients was 62 months (median 52 months). Conclusions. Surgical, treatment remains the cornerstone of therapeutic management of head and neck sarcomas. (C) 2004 Elsevier Ltd. ALL rights reserved