Patients seeking implantation often have several systemic diseases, which will introduce complications to treatment. This paper reviews the risk assessments and prevention of systemic diseases in patients with oral implant therapy with the relevant literature. The patients with cardiovascular diseases are prone to stroke and cardiac arrest, and anticoagulants and antihypertensive drugs will complicate cases. The potential risks of endocrine system diseases are infections and crises caused by unstable hormone levels. The risks of respiratory diseases are dyspnea and swallowing devices. The difficulty of treating patients with neuropsychiatric diseases is attributable to poor cooperation and adverse effects of the drugs. Bone and joint system diseases may decrease the success of implantation. Hematological system, digestive system and kidney diseases may lead to hemorrhage. By inquiring about detailed medical and medication history, evaluating vital signs and detecting important objective indicators, performing targeted measures, discussing with specialists, and observing patients closely, clinicians can avoid the abovementioned risks.

The jaw and femur are commonly used sites in basic research for modeling bone defects or inserting implants. An increasing number of studies have identified that the jaw and femur indeed show great differences in embryonic development and growth, histomorphology and bone metabolism. A literature review showed that, compared with the femur, the main osteogenic pathway of the jaw may have better osteogenic ability, and its stem cells have better proliferation and osteogenic differentiation ability. However, the jaw structure is less regular, the osteogenic differentiation ability of its osteoblasts is mineralization slightly weak, and the immune cells of the jaw are more sensitive to cytokines. These may be the reasons why the osseointegration of the jaw implant is different from that of the femur in animal experiments, but its specific mechanism has not been clarified.

Ideal osseointegration is intimately related to favorable osteoimmune properties around dental implants. An increasing number of in vitro and in vivo studies have indicated that the Hippo-YAP signaling pathway is involved in this biological process. In this article, the implicated roles of Hippo-YAP the signaling axis in peri-implant osteoimmunology were summarized by reviewing relevant evolving literature. The discrepancy concerning the Hippo-YAP signaling regulatory effect on osteogenesis and polarization direction were analyzed as well as propose the potential mechanism, which may be caused by the maturation of osteogenesis-related cells and heterogeneity of macrophages. More attention should be given to the requirements of promoting osteogenesis and patterns of regulating the immune microenvironment by Hippo-YAP in future studies.

Bone defects caused by diseases or surgery are a common clinical problem. Researchers are devoted to finding biological mechanisms that accelerate bone defect repair, which is a complex and continuous process controlled by many factors. As members of transcriptional costimulatory molecules, Yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif (TAZ) play an important regulatory role in osteogenesis, and they affect cell function by regulating the expression of osteogenic genes in osteogenesis-related cells. Macrophages are an important group of cells whose function is regulated by YAP/TAZ. Currently, the relationship between YAP/TAZ and macrophage polarization has attracted increasing attention. In bone tissue, YAP/TAZ can realize diverse osteogenic regulation by mediating macrophage polarization. Macrophages polarize into M1 and M2 phenotypes under different stimuli. M1 macrophages dominate the inflammatory response by releasing a number of inflammatory mediators in the early phase of bone defect repair, while massive aggregation of M2 macrophages is beneficial for inflammation resolution and tissue repair, as they secrete many anti-inflammatory and osteogenesis-related cytokines. The mechanism of YAP/TAZ-mediated macrophage polarization during osteogenesis warrants further study and it is likely to be a promising strategy for bone defect repair. In this article, we review the effect of Hippo-YAP/TAZ signaling and macrophage polarization on bone defect repair, and highlight the regulation of macrophage polarization by YAP/TAZ.