Biological response to ß-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 ß-tricalcium phosphate (ß-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 ß-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 ß-TCP/CS, as no inflammatory response was observed, and no fibrosis was developed between the graft particles and the newly formed bone. Moreover, ß-TCP/CS acted as an osteoconductive scaffold that allowed a significant bone regeneration and graft biodegradation with time. CONCLUSION: In this animal model, synthetic ß-TCP/CS proved to be a biocompatible, osteoconductive, and bioresorbable bone graft substitute.

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 (HA/ß-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 HA/ß-TCP, the second was grafted with HA/ß-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 activities were 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 HA/ß-TCP + PRP and defects treated with HA/ß-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 HA/ß-TCP synthetic graft material after 2, 4, and 6 weeks of implantation.

Functional results of speech and swallowing after oral microvascular free flap reconstruction.

PURPOSE: To study speech and swallowing in patients who underwent microvascular free flap reconstruction after major surgery of the oral cavity. PATIENTS AND METHODS: Twenty patients, 17 men and 3 women, with a mean age of 58.5 years (range 27-79 years) were included in the study. Squamous cell carcinoma was the most common malignancy. Swallowing assessment was performed through videofluoroscopy, using three consistencies of barium meal. The recorded swallows were assessed for the ability to hold the bolus during the oral phase, lip seal, tongue movement, residue in the floor of the mouth, laryngeal penetration and aspiration. Speech function regarding intelligibility and articulation was objectively assessed. RESULTS: Fifteen out of 20 patients (75%) had a good lip seal. Fourteen patients (73.6%) had adequate control of bolus, while in 89.4% the neotongue motility was satisfactory. Vallecular residue was noted in 25% of patients, laryngeal penetration in two (10%), while three patients (15%) continued to have significant aspiration, which necessitated continuous feeding through a gastrostomy. Postoperative speech intelligibility and articulation was satisfactory in 75 and 62.5% of the patients, respectively. CONCLUSIONS: Microvascular free flap reconstruction of major defects after oral resections rehabilitates the functions of swallowing and speech in acceptable levels, improving quality of life in these patients.

Mucoepidermoid carcinoma of the salivary glands. Review of the literature and clinicopathological analysis of 18 patients.

Salivary gland carcinomas are a rare and clinically diverse group of neoplasms among which mucoepidermoid carcinomas (MEC) are reported to be the most frequently encountered. During the years 1994-2004 18 patients with MEC were treated in our Department. All patients underwent surgery with a curative intent, and in 11 of them treatment was supplemented by radiotherapy. Follow up ranged from 6 to 120 months. Twelve (66.6%) MECs originated from the major salivary glands with the majority located in the parotid. Histologically, 50% of tumors were classified as low grade, 28% as intermediate and 22% as high-grade MECs. Positive surgical margins were documented in six cases (33%) and all in tumors of high or intermediate histological grade. All these patients received adjuvant radiotherapy and one developed local recurrence. Local recurrence occurred in two more patients with histologically free margins. Both received postoperative radiotherapy. Distant metastases were documented in four patients all between 14 and 24 months after surgical treatment. An association between local recurrence and distant metastasis might be suggested since all patients with local recurrences subsequently developed distant metastases. The 5-year overall disease specific survival rate was 85%. Statistical multivariate analysis demonstrated that the factor that significantly correlated with overall survival was the histological grade of tumors (Log Rank test: p=0.013). A trend towards poorer survival was observed in patients aged over 50 years. Our results also suggested a potential benefit of postoperative radiotherapy for patients with positive margins.

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.

Osteogenic activity of ß-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 ß-tricalcium phosphate in a hydroxyl sulphate matrix (ß-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 ß-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 ß-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.

VEGF and ki 67 expression in squamous cell carcinoma of the tongue: An immunohistochemical and computerized image analysis study.

Over-expression of ki 67 and vascular endothelial growth factor (VEGF) is a frequent finding in squamous cell carcinoma (SCC) of the oral mucosa. The expression of VEGF and ki 67 proteins was studied in a cohort of 87 patients with primary, previously untreated SCC of the tongue, using computerized image analysis (CIA) in order to determine the potential prognostic significance of these factors. Immunohistochemical analysis was performed with monoclonal anti-ki 67 (MIB 1) and anti-VEGF antibodies. A digital image analysis assay was applied for the evaluation of the results. Using CIA, VEGF over-expression was observed in 24/87 (27.5%) of the examined cases and this finding correlated to the stage of the disease (p=0.05). ki 67 was over-expressed in 49/87 (56.3%) of the cases and correlated to the size of the tumors (p=0.05). Cox regression analysis showed that there was no prognostic significance associating VEGF protein expression to survival status of the examined patients (p=0.77), whereas ki 67 over-expression was strongly correlated to poor prognosis (p=0.017). The size of the primary tumors was also strongly correlated to survival status of the patients (p=0.024), whereas stage of disease showed a borderline statistical significance (p=0.091).

Tumors of the submandibular gland: clinicopathologic analysis of 23 patients.

PURPOSE: Tumors of the submandibular gland are rare, comprising less than 2% of head and neck neoplasia. Both benign and malignant lesions show a mild symptomatology, resulting in late presentation and in advanced stage of disease. The purpose of this article was to report our experience in treating submandibular gland neoplasia during the last 10 years. PATIENTS AND METHODS: The medical records of all patients with histologically confirmed epithelial tumors of the submandibular gland were retrospectively reviewed. This review found 23 patients with 9 benign and 14 malignant tumors. The collection of data included demographic data, diagnostic procedures, operative and pathology reports, complications, additional treatment, and follow-up. RESULTS: There were 10 men and 13 women with a mean age of 60 years. Pleomorphic adenoma was the most frequently encountered benign tumor; adenocarcinoma and adenoid cystic carcinoma had an equal presentation in the malignant group of patients. Eleven of the 14 patients with malignant tumors presented in advanced stages of disease (stage III and IV). Surgery was the sole treatment for the benign tumors. There were no recurrences. In the majority of cases, patients with malignant tumors were treated with surgery and postoperative radiotherapy. Eight patients died during the follow-up period, giving a mortality rate of 61.5%. CONCLUSION: Benign submandibular gland tumors manifest a mild course of disease, and local excision along with the gland is a safe and effective method of treatment. Malignant tumors have a poor symptomatology that results in late diagnosis. Radical surgery and postoperative radiotherapy is the treatment of choice. Prognosis depends on the histopathology and biologic behavior of the specific type of malignant tumor.