The Use of Collagen-Based Materials in Bone Tissue Engineering.

Synthetic bone substitute materials (BSMs) are becoming the general trend, replacing autologous grafting for bone tissue engineering (BTE) in orthopedic research and clinical practice. As the main component of bone matrix, collagen type I has played a critical role in the construction of ideal synthetic BSMs for decades. Significant strides have been made in the field of collagen research, including the exploration of various collagen types, structures, and sources, the optimization of preparation techniques, modification technologies, and the manufacture of various collagen-based materials. However, the poor mechanical properties, fast degradation, and lack of osteoconductive activity of collagen-based materials caused inefficient bone replacement and limited their translation into clinical reality. In the area of BTE, so far, attempts have focused on the preparation of collagen-based biomimetic BSMs, along with other inorganic materials and bioactive substances. By reviewing the approved products on the market, this manuscript updates the latest applications of collagen-based materials in bone regeneration and highlights the potential for further development in the field of BTE over the next ten years.

Morphometric analysis of the stylohyoid complex.

PURPOSE: Stylohyoid complex is anatomical structure predisposed to numerous individual variations. These may result in its extreme elongation, medial deviation and finally Eagle's syndrome occurrence. The aim of this study was to measure the length, angulation, evaluate morphological variations of stylohyoid complex by computed tomography and, subsequently, relate obtained data to the gender and the age of the evaluated cases. MATERIALS AND METHODS: The material included CT scans of stylohyoid complexes of 282 individuals. The entire length, maximal thickness, and angulation of the stylohyoid complexes in the coronal, transverse, and sagittal planes were measured. RESULTS: According to their morphology, orientation and length, stylohyoid complexes were classified into six morphological types. Elongated, bent, segmented, and segmented with attached stylohyoid ligament for the lesser horns of the hyoid bone stylohyoid complex types were characterized by significantly greater length, while pseudoarticulated type was characterized by significantly lower length in relation to normal stylohyoid complex type. The elongated type was additionally significantly thicker and with significantly lower value of medial angle in transverse plain than the normal stylohyoid complex type. Elongated, bent, and segmented types were significantly more frequent in males than in females. Furthermore, the frequency of the elongated stylohyoid complex type increased, whereas normal and pseudoarticulated types decreased with age. CONCLUSIONS: In conclusion, elongated and more medially deviated stylohyoid complexes are more frequent in males than in females. Their more frequent presence in the older age groups indirectly connects this phenomenon with the aging process.

Ectopic osteogenic capacity of freshly isolated adipose-derived stromal vascular fraction cells supported with platelet-rich plasma: A simulation of intraoperative procedure.

Bone defects represent a serious problem in cranio-maxillofacial surgery. Autologous adipose-derived stromal vascular fraction (SVF) cells in combination with biological factors and bone substitutes were previously proposed as alternative to bone grafting. By simulating an intraoperative procedure we examined osteogenic capacity of the combination of two autologous components, freshly isolated adipose-derived SVF cells, and platelet-rich plasma (PRP), delivered on bone mineral matrix (BMM) carrier (SPB group) in mice ectopic bone forming model. Implantation of BMM only (B group) was a control. The presence of adipose-derived stem cells (ADSCs) in SVF was detected by immunocytochemical analysis. Expression of bone- and endothelial-related genes was compared between freshly isolated SVF and ADSCs obtained from SVF after in vitro cultivation. The implants were analyzed using expression analysis of bone-related genes at one, two, four and eight weeks and histochemical, immunohistochemical and histomorphometrical analyses at two and eight weeks after implantation. Freshly isolated adipose-derived SVF contained ADSCs and exhibited promising osteogenic and vasculogenic capacity. At two and four weeks, significantly higher expression of bone-related genes was detected in SPB group compared to B group. The signs of osteogenic process were more pronounced in SPB than in B implants. By the end of experiment, percentage of infiltrated tissue and vascularization was significantly higher in SPB than in B implants. Adipose-derived SVF cells, PRP and BMM rapidly initiated osteogenesis what makes this combination promising candidate for treatment of bone defects.

Asymptomatic flow of Rosai-Dorfman disease.

INTRODUCTION: Sinus histiocytosis with massive lymphadenopathy is a rare benign self-limiting disease of unknown etiology. The salivary gland involvement, indicating the extranodal character of the disease, often presents a diagnostic dilemma requiring immunohistochemical staining of surgically removed tumor to confirm the diagnosis. CASE REPORT: We report a 43-year-old man presented with an asymptomatic mass in the left mandibular angle. On physical examination, the lesion was described as a painless, mobile, firm-elastic consistency nodule, which measured 4 x 3 cm in diameter, with normal overlying skin. A mass with the same characteristics, dimensions 2 x 2 cm, was also noted in the right parotid region. No other changes in regional lymph nodes were detected. On macroscopic examination the lesion was firm, multilobulated, yellowish and rounded, while on microscopic examination the lesion was composed almost entirely of polygonal histiocytes with abundant cytoplasm, emperipolesis, plasma cells arranged in sheets, and lymphocytes scattered or within clusters. The observed histiocytes were found to be CD68 and S100 protein positive. CONCLUSION: Rosai-Dorfman disease is a beningn and frequently overlooked clinical and pathological entity that may be misinterpreted as a neoplastic disease.

Use of 2-Octyl-Cyanoacrylate in surgical closing of Postparotidectomy salivary fistulas.

A salivary fistula is one of possible postoperative complications in the surgery of parotid gland tumors. We present three cases of postparotidectomy salivary fistulas, successfully treated by surgical access using 2-octyl-cyanoacrylate while closing the skin layer. The previous treatment of these cases by other therapeutic options did not give satisfactory results. In a 5-year follow-up period there were no signs of fistulas relapses. The surgical access with use of 2-octyl cyanoacrylate can be one of therapeutic options for the closing of postparotidectomy salivary fistulas, especially in cases where other therapeutic accesses are not successful.

[Malignant tumors of auricula and periauricular area].

BACKGROUND/AIM: Malignant tumors of auricula and periauricular area represent seven percent of all cutaneous tumors. They appear mostly in the sixth and seventh decade. According to histological type they are basocellular and planocellular carcinomas. The most frequent etiology is the sun exposition. The aim of this study was to analyze clinical and histological characteristics and therapy of malignant tumors of auricular and periauricular area. METHODS: Totally 155 patients were treated in ORL Clinic, Clinical Center Nis during the period 1990-2006. The patients were treated surgically (59.35%), by radiotherapy (1.94%) and by combination of the two methods (38.71%). RESULTS: Since the majority of tumors were small and presented on the helix, wedge excision and primary reconstruction were performed (136), while total (9) or partial (10) auriculectomy were done in a small number of the patients. For larger lesions (T4--when lesion is greater than 4.0 cm) and neck metastasis invading cartilage or bone, parotidectomy (15), radical neck dissection (25) and temporal bone resection (9) were performed. CONCLUSION: Carcinoma of auricular and periauricular area should be confirmed by biopsy and histopathologic evaluation. In all cases an adequate excision, margin examination and observation of appropriate lymph node draining regions should be provided.