Guided bone regeneration is a well-established technique used for augmentation of deficient alveolar ridges. Predictable regeneration requires both a high level of technical skill and a thorough understanding of underlying principles of wound healing. This article describes the 4 major biologic principles (i.e., PASS) necessary for predictable bone regeneration: primary wound closure to ensure undisturbed and uninterrupted wound healing, angiogenesis to provide necessary blood supply and undifferentiated mesenchymal cells, space maintenance/creation to facilitate adequate space for bone ingrowth, and stability of wound and implant to induce blood clot formation and uneventful healing events. In addition, a novel flap design and clinical cases using this principle are presented.

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Although the lateral wall sinus lift is a predictable clinical procedure to increase vertical bone height resulting in implant success rates comparable to that of native bone, the issue of extended healing periods remains troublesome. Clinicians and researchers have investigated several methods, including addition of growth factors and peptides, to reduce this healing time and enhance bone formation within the subantral environment. Platelet-rich plasma (PRP) is an autologous blood product containing high concentrations of several growth factors and adhesive glycoproteins. The incorporation of PRP into the sinus graft has been proposed as a method to shorten healing time, enhance wound healing, and improve bone quality. This article reviewed pertinent literature assessing the effect of PRP on sinus augmentation. Currently, the literature is conflicting with respect to the adjunctive use of PRP in sinus augmentation. Factors that may contribute to this variability include variable/inappropriate study design, underpowered studies, differing platelet yields, and differing graft materials used. In addition, methods of quantifying bone regeneration and wound healing differ between studies. At present, because of limited scientific evidence, the adjunctive use of PRP in sinus augmentation cannot be recommended. Further prospective clinical trials are urgently needed.

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Pancreatic ductal adenocarcinoma, an extremely aggressive cancer, has high metastatic potential. Cutaneous metastasis is very uncommon, representing only <10% of all cases, presenting mostly around the umbilical region. Non-umbilical metastasis is even rarer, and the significance remains unknown. In this article, we describe a case of a 76-year-old gentleman who initially presented with an asymptomatic scalp lesion, which on biopsy revealed metastatic adenocarcinoma of pancreatic origin. Detailed workup revealed extremely high tumor burden with metastases involving muscles, subcutaneous tissues, bone, lung, spleen, liver, and colon. Cutaneous involvement in pancreatic cancer represents poor survival with widespread dissemination of the disease. The involvement of some sites and not others and the extreme degree of aggressiveness might reflect subgroups of this cancer with different molecular biology. Identifying these groups may have utility in determining prognosis and stratifying treatment for patients. This will hopefully translate into better diagnostic tests and therapies in the near future.