Dll4 Inhibition Promotes Graft Retention in Fat Grafting Enriched with Adipose-Derived Stem Cells.

Autologous fat grafting is among the safest and most effective treatments for soft-tissue restoration and augmentation, and many efforts have been made to improve its efficiency, including adipose-derived stem cell (ASC) supplementation. Here, we investigated the role of Notch ligand Delta-like ligand 4 (Dll4) in angiogenesis within grafted fat and its effect on graft retention, as well as the effect of Dll4 inhibition on ASC supplementation. Using a murine fat graft model, we investigated the expression of Dll4 in fat grafts and assessed the graft volume, vascularity, and perfusion within the graft, and ASC differentiation patterns depending on the blockade of Dll4. The underlying mechanism of Dll4 inhibition on ASC supplemented fat grafts was investigated using transcriptome analysis. Dll4 was highly expressed in vascular endothelial cells (ECs) within grafted fat, where Dll4-blocking antibody treatment-induced angiogenesis, promoting fat graft retention. In addition, its effect on fat graft retention was synergistically improved when ASCs were concomitantly supplemented. The expression of junctional proteins was increased in ECs, and inflammatory processes were downregulated in grafted fat upon ASC supplementation and Dll4 inhibition. Dll4 inhibition induced vascularization within the grafted fat, thereby promoting graft retention and exhibiting synergistic effects with concomitant ASC supplementation. This study serves as a basis for developing new potential therapeutic approaches targeting Dll4 to improve graft retention after cell-assisted transfer.

Big Data Statistical Analysis of Facial Fractures in Korea.

BACKGROUND: The big data provided by Health Insurance Review and Assessment (HIRA) contains data from nearly all Korean populations enrolled in the National Health Insurance Service. We aimed to identify the incidence of facial fractures and its trends in Korea using this big data from HIRA. METHODS: We used the Korean Standard Classification of Disease and Cause of Death 6, 7 for diagnosis codes. A total of 582,318 patients were included in the final analysis. All statistical analyses were performed using SAS software and SPSS software. RESULTS: The incidence of facial fractures consistently declined, from 107,695 cases in 2011 to 87,306 cases in 2016. The incidence of facial fractures was the highest in June 2011 (n = 26,423) and lowest in January 2014 (n = 10,282). Nasal bone fractures were the most common, followed by orbit and frontal sinus fractures. The percentage of nasal bone fractures declined, whereas those of orbital fractures increased from 2011 to 2016 (P < 0.001). Among orbital fractures, inferior wall fractures were the most common, followed by medial wall fractures. Among mandibular fractures, angle fractures were the most common, followed by condylar process and symphysis fractures. Although it was difficult to predict the most common type of zygomatic and maxilla fractures, their incidence consistently declined since 2011. CONCLUSION: We observed trends in facial fractures in Korea using big data including information for nearly all nations in Korea. Therefore, it is possible to predict the incidence of facial fractures. This study is meaningful in that it is the first study that investigated the incidence of facial fractures by specific type.