Evaluating Disease Patterns of Military Working Dogs in the Republic of Korea: A Retrospective Study.

The purpose of this study was to evaluate disease patterns among military working dogs (MWDs) at the Armed Forces Medical Research Institute (AFMRI) to provide basic medical data on Korean MWDs. The medical records of procedures performed at AFMRI between November 2017 and March 2021 were reviewed. Physical examination, diagnostic imaging, and laboratory tests were performed according to the status of each dog. A total of 353 MWDs (215 males and 138 females; mean age, 6 ± 3 years) were analyzed in this study. Among Korean MWDs, gastrointestinal (GI) disorders are the most frequently diagnosed, followed by dental and musculoskeletal disorders. Foreign body (FB) ingestion had the highest prevalence of GI disorders, with the most common FB being a leather collar or leash. General and dental surgeries, including removal of gastric FB and tooth extraction, were routinely performed at the AFMRI. Preventative care focusing on dental disease and FB ingestion may be helpful for effective performance and good quality of life in MWDs, with the regular assessment and prevention of environmental factors that may contribute to behavioral problems such as FB ingestion, coprophagy, and anorexia.

Effect of bone mineral with or without collagen membrane in ridge dehiscence defects following premolar extraction.

BACKGROUND: The purpose of this investigation was to evaluate the regenerative response to deproteinized porous bovine bone mineral (BM) when used alone or in combination with a bioresorbable porcine-derived bilayer collagen membrane (CM) for alveolar ridge augmentation in dogs. MATERIALS AND METHODS: The mandibular premolars were extracted unilaterally and three ridge defects were induced in six mongrel dogs. Each defect site was randomly assigned to one of the following treatment groups: BM alone (group A), BM in combination with CM (group B), or neither membrane nor bone graft, which served as a control (group C). No adverse events occurred during the experimental period. Dental computed tomography (CT) scans were taken after postoperative periods of 8 and 16 weeks. RESULTS: The percentage of CT-derived bone density in groups A and B was significantly different from that of group C (p < 0.01) at 8 and 16 weeks. The percentage of CT-derived bone density of the dogs in Group B was significantly higher than that of those in group A at 8 and 16 weeks (p < 0.01). Gross evaluation of the 3-dimensional CT reconstruction image of the canine mandibles after 16 weeks of implantation showed that group B had the greatest amount of bone augmentation and excellent thickness of the buccal aspect of the alveolar ridge. CONCLUSION: These results suggest that BM leads to more successful bone regeneration for guided bone regeneration procedures, especially in conjunction with the use of a CM as a barrier in order to promote the regeneration of canine alveolar ridge defects.

Comparison of immediate and delayed implantation using the square-threaded and resorbable-blasted-media-treated surface implant system.

A variety of dental implant systems are now available that optimize bone-to-implant contact. The present study was performed to compare the outcomes, by measuring peri-implant osseointegration, following immediate and delayed insertion of square-threaded and resorbable-blasted-media (RBM)-treated surface implants in the dog's mandible. Three dogs were used and four implants were inserted in each dog. All implants were used for histological and histomorphometrical evaluations. The contact lengths and osseointegrated areas following immediate implantation were 74.99% and 56.08%, and those following delayed implantation were 78.22% and 66.08%, respectively. The implantation method in dogs using the square-threaded and RBM treated surface implant system achieved higher percentages of osseointegration than previously reported and the two implantation techniques did not differentially influence osseointegration. Thus, immediate implantation of this implant system, which minimizes the number of surgical procedures, is an optimal clinical method to replace extracted teeth in dogs.

Evaluation of Bone Regeneration on Polyhydroxyethyl-polymethyl Methacrylate Membrane in a Rabbit Calvarial Defect Model.

This study was conducted to evaluate the capacity of guiding bone regeneration of polyhydroxyethyl-polymethyl methacrylate (PHEMA-PMMA) membrane as a guided tissue regeneration membrane for bone defects. Two 8-mm diameter transosseous round defects were made at the parietal bone of 18 New Zealand White rabbits. Defects were covered with or without PHEMA-PMMA membrane. Radiological and histological evaluation revealed that the bone tissue over the defect was more regenerated with time in both groups. However, there was significantly more bone regeneration at 8 weeks in the experimental group than the control group (p<0.05). There was no sign of membrane degradation or tissue inflammation and no invasion of muscle and fibrous tissue into defects. PHEMA-PMMA is a potential material for guided tissue regeneration membrane as it induces no adverse tissue reaction and effectively supports selective bone regeneration.

A viscoelastic chitosan-modified three-dimensional porous poly(L-lactide-co-ε-caprolactone) scaffold for cartilage tissue engineering.

Biomaterials have been playing important roles in cartilage regeneration. Although many scaffolds have been reported to enhance cartilage regeneration, none of the scaffolds available are optimal regarding mechanical properties, integration with host cartilage and providing proper micro-environment for chondrocyte attachment, proliferation and differentiation. In the current study, chitosan-modified poly(L-lactide-co-ε-caprolactone) (PLCL) scaffolds were fabricated to simulate the main biochemical components of cartilage, as well as their interaction with the aim to endow them with viscoelasticity similar to native cartilage. Porous PLCL scaffolds were fabricated with porogen-leaching, freeze-extraction and freeze-gelation before chitosan was cross-linked. The acquired porous scaffolds had pore sizes ranging from 200 to 500 µm and about 85% porosity with good interconnection between individual pores. Chitosan was successfully cross-linked to PLCL scaffolds, as validated by ninhydrin staining and X-ray photoelectron spectroscopy (XPS). The viscoelasticity of the scaffolds was similar to that of bovine cartilage and they had a relatively good recovery ratio from compression deformation, while the Young's modulus was one order of magnitude less than cartilage. Not only could the chitosan-modified PLCL scaffolds promote cell adhesion and proliferation, but also they could significantly enhance excretion of aggrecan and type-II collagen, as testified by both histology and quantitative PCR, compared with PLCL scaffolds. With the fabrication of biomimetic scaffolds, it is possible to make scaffolds for cartilage tissue engineering, which are not only biocompatible, but also have mechanical properties similar to native cartilage.