Comparative analysis of the in vivo kinetic properties of various bone substitutes filled into a peri-implant canine defect model.

PURPOSE: Deproteinized bovine bone or synthetic hydroxyapatite are 2 prevalent bone grafting materials used in the clinical treatment of peri-implant bone defects. However, the differences in bone formation among these materials remain unclear. This study evaluated osteogenesis kinetics in peri-implant defects using 2 types of deproteinized bovine bone (Bio-Oss® and Bio-Oss/Collagen®) and 2 types of synthetic hydroxyapatite (Apaceram-AX® and Refit®). We considered factors including newly generated bone volume; bone, osteoid, and material occupancy; and bone-to-implant contact. METHODS: A beagle model with a mandibular defect was created by extracting the bilateral mandibular third and fourth premolars. Simultaneously, an implant was inserted into the defect, and the space between the implant and the surrounding bone walls was filled with Bio-Oss, Bio-Oss/Collagen, Apaceram-AX, Refit, or autologous bone. Micro-computed tomography and histological analyses were conducted at 3 and 6 months postoperatively (Refit and autologous bone were not included at the 6-month time point due to their rapid absorption). RESULTS: All materials demonstrated excellent biocompatibility and osteoconductivity. At 3 months, Bio-Oss and Apaceram-AX exhibited significantly greater volumes of formation than the other materials, with Bio-Oss having a marginally higher amount. However, this outcome was reversed at 6 months, with no significant difference between the 2 materials at either time point. Apaceram-AX displayed notably slower bioresorption and the largest quantity of residual material at both time points. In contrast, Refit had significantly greater bioresorption, with complete resorption and rapid maturation involving cortical bone formation at the crest at 3 months, Refit demonstrated the highest mineralized tissue and osteoid occupancy after 3 months, albeit without statistical significance. CONCLUSIONS: Overall, the materials demonstrated varying post-implantation behaviors in vivo. Thus, in a clinical setting, both the properties of these materials and the specific conditions of the defects needing reinforcement should be considered to identify the most suitable material.

Multifocal intraoral ductal ectasia with metaplasia and focal epithelial proliferation: A case report.

Ductal ectasia with metaplasia and focal epithelial proliferation in the oral cavity does not correspond to any existing salivary gland lesion. A 72-year-old man presented with a mass in the buccal mucosa, which was excised and initially diagnosed as a cystadenoma. An upper lip mass on the right side, which developed later, was also excised. The lesions were histologically similar, and since they were multifocal and in non-contiguous and independent sites with multiple dilated cystic structures that did not destroy the lobar architecture, the final diagnosis was confirmed as ductal ectasia with metaplasia and focal epithelial proliferation. This condition may mimic various neoplastic lesions.

Evaluation and Prediction of Healing Morphology After Closed Reduction for Unilateral Mandibular Condyle Fractures.

Although closed reduction is common for condylar fractures, bone fragments may heal improperly. This study aimed to investigate the healing morphology of unilateral condylar fractures. We retrospectively investigated 70 patients with unilateral condylar fractures. Clinico-statistical analyses were performed on the whole-condylar fracture, closed reduction, and observation/functional therapy groups. Among these patients, 52 patients aged older than 16 years underwent closed reduction. The extent of maximum mouth opening, the incidence of malocclusion, and the relationship between healing morphology and Arbeitsgemeinschaft für Osteosynthesefragen classification or trismus were analyzed in the closed reduction group. There were significant differences in age ( P= 0.008) and sex ( P =0.025) between the closed reduction and observation/functional therapy groups. However, there were no significant differences in trauma etiologies and concomitant fractures between the 2 groups. The average maximum mouth opening extent for unilateral fractures after closed reduction was 42.6±6.1 mm. Only 1 case (2.1%) of post-treatment malocclusion was observed. In all the MacLennan classification of deviation or more, regardless of the classification, upper fractures (head and upper neck) tended to heal through a spherical ( P <0.001) morphology, whereas lower fractures (lower neck and subcondylar) tended to heal through an L-shaped and lateral fusion ( P <0.001). There was no significant difference in the incidence of trismus between the healing morphology of unchanged type and others ( P =0.690). Our results elucidated the etiology, dysfunction, and healing morphology classification of unilateral mandibular condyle fractures treated with closed reduction.

Stimulation of Microvascular Networks on Sulfonated Polyrotaxane Surfaces with Immobilized Vascular Endothelial Growth Factor.

Modulation of material properties and growth factor application are critical in constructing suitable cell culture environments to induce desired cellular functions. Sulfonated polyrotaxane (PRX) surfaces with immobilized vascular endothelial growth factors (VEGFs) are prepared to improve network formation in vascular endothelial cells. Sulfonated PRXs, whereby sulfonated α-cyclodextrins (α-CDs) are threaded onto a linear poly(ethylene glycol) chain capped with bulky groups at both terminals, are coated onto surfaces. The molecular mobility of sulfonated PRX surfaces is modulated by tuning the number of threading α-CDs. VEGF is immobilized onto surfaces with varying mobility. Low mobility and VEGF-immobilization reinforce cell proliferation, yes-associated protein activity, and rhoA, pdgf, ang-1, and pecam-1 gene expression. Highly mobile surfaces and soluble VEGF weakly affect these cell responses. Network formation is strongly stimulated in vascular endothelial cells only on low-mobility VEGF-immobilized surfaces, suggesting that molecular mobility and VEGF immobilization synergistically control cell function.

A reaction-diffusion-based coding rate control mechanism for camera sensor networks.

A wireless camera sensor network is useful for surveillance and monitoring for its visibility and easy deployment. However, it suffers from the limited capacity of wireless communication and a network is easily overflown with a considerable amount of video traffic. In this paper, we propose an autonomous video coding rate control mechanism where each camera sensor node can autonomously determine its coding rate in accordance with the location and velocity of target objects. For this purpose, we adopted a biological model, i.e., reaction-diffusion model, inspired by the similarity of biological spatial patterns and the spatial distribution of video coding rate. Through simulation and practical experiments, we verify the effectiveness of our proposal.