A Comparative Study of the Effects of Platelet-Rich Fibrin, Concentrated Growth Factor and Platelet-Poor Plasma on the Healing of Tooth Extraction Sockets in Rabbits

Background：Autologous platelet concentrate has been widely used to encourage the regeneration of hard and soft tissues. Up to now, there are three generations of autologous platelet concentrates. Many studies have shown that different autologous platelet concentrates have different healing effects. However, these differences still need to be further verified and discussed. The purpose of this study was to explore and compare the effects of platelet-rich fibrin, concentrated growth factor and platelet-poor plasma on the healing of tooth extraction sockets in New Zealand rabbits. Methods：A total of 24 healthy male New Zealand white rabbits aged 8-12 weeks were selected. The experimental animals were randomly divided into four groups: three experimental groups were respectively implanted with PPP, CGF and PRF gel after bilateral mandibular anterior teeth were extracted, and the control group did not implant any material. The alveolar bone of the mandibular anterior region was taken at 2, 4 and 8 weeks after operation. The height and width of the extraction wound were detected by CBCT, the growth of the new bone was observed by HE and Masson staining, and the expression of osteogenic genes was detected by real-time PCR. Data were analyzed using IBM SPSS statistical package 22.0.Results: The radiological results showed that alveolar bone absorption in all groups gradually increased over time. However, the experimental groups showed lower amounts of bone absorption. The histological results showed that new bone formation was observed in all groups. Over time, the new bone trabeculae of the CGF group became closely aligned while those in the PPP and PRF groups remained scattered. PCR results showed that the expression of BMP-2 and ALP was higher in the experimental groups than the control group.Conclusion: In conclusion, the application of PRF, CGF and PPP in tooth extraction sockets effectively promoted bone regeneration. CGF showed more effective bone induction and tissue regeneration ability in the long term.

The Role of GPR56 in Neurofibromatosis type 1 Secondary to Scoliosis

Background: Scoliosis is a common manifestation of neurofibromatosis type 1, causing significant morbidity. The etiology of dystrophic scoliosis in neurofibromatosis type 1(NF1) is not fully understood and its therapies are lacking. This article focused on how GPR56 affected the development of NF1 cells and the related factors of osteoblast and osteoclast. Methods: Through RNA-sequencing, G-protein-coupled receptor (GPR56) was found highly differential expressed in the NF1 with scoliosis samples. We measured the GPR56 how affected the NF1 cells in vitro. Then we tested the influence of GPR56 in osteoclasts and osteoblasts. Results: We reported that knockdown GPR56 promoted the proliferation and cell cycle progression of NF1 cell. Furthermore, knockdown GPR56 can inhibited the osteoblastic differentiation and osteoclast formation, but had greater influence on osteoblastic differentiation, which indicated that knockdown GPR56 can promote the deterioration of NF1 tumors, meanwhile break the dynamic balance of bone formation and bone absorption, leading to increased bone resorption and eventually scoliosis. Conclusions: In conclusion, we found that GPR56 may inhibit the proliferation and cell cycle progression of NF1. Furthermore, GPR56 can promote osteoblastic differentiation and osteoclast formation, but had greater influence on osteoblastic differentiation, which indicated that knockdown GPR56 can promote the deterioration of NF1 tumors, meanwhile break the dynamic balance of bone formation and bone absorption, leading to increased bone resorption.

Relationship of T2 Value of High-signal Line on MRI to the Fragment in Osteochondral Lesion of the Talus

Background: Magnetic resonance imaging (MRI) is useful for evaluating the stability of an osteochondral lesion of the talus (OLT). A T2 high-signal line between the fragment and its bed on MRI is known as a reliable indicator of an unstable lesion. However, the lesion exhibits various conditions even if a T2 high-signal line is observed. The purpose of this study was to evaluate the relationship between the T2 value of a high-signal line and the condition of the area between the fragment and its bed in OLT. Methods: T2 values of the T2 high-signal line and those of joint fluid were measured from preoperative MRI images in 46 ankles with OLT and the T2 ratio (high-signal line / joint fluid) was calculated. The relationship between the T2 ratio and CT, arthroscopic, and histologic findings was examined. Results: The mean T2 ratio was 0.48. T2 ratios of cystic lesions (0.62) or bone absorption (0.67) in the bed were significantly higher than those without a cyst (0.40) or no absorption (0.40). The T2 ratio of an unstable lesion (0.51) was significantly lower than that of a stable lesion (0.29). In histologic findings, there were 2 separate patterns: chondral and subchondral bone separations. The T2 ratio of the chondral separation (0.60) was significantly higher than that of bone separation (0.48). Conclusion: This study showed that the T2 ratio on a high-signal line was a predictor of stability, cyst, and bone absorption in OLT. Level of evidence: Level III, comparative series.

CpG oligodeoxynucleotides inhibit the proliferation and osteoclastic differentiation of RAW264.7 cells

Clinical prevention and treatment of periodontitis-induced bone absorption remains a challenge.

Role of the Btk-PLCγ2 Signaling Pathway in the Bone Destruction of Apical Periodontitis

Chronic apical periodontitis is characterized by alveolar bone absorption in the apical region and is the result of the participation of various inflammatory mediators. Studies have shown that the Bruton tyrosine kinase- (Btk-) phospholipase Cγ2 (PLCγ2) signaling pathway plays an important role in bone absorption, but it is unknown whether it plays a role in apical periodontitis bone destruction. Therefore, this study verified the role of Btk and PLCγ2 in bone resorption of apical periodontitis by in vivo and in vitro experiments. In the in vivo experiment, a mice model of apical periodontitis was established; apical bone resorption was confirmed by the numbers of osteoclasts and HE staining. Btk, PLCγ2, and nuclear factor of activated T-cells 1 (NFATc-1) were detected by immunohistochemical staining. In the in vitro experiment, lipopolysaccharides (LPS) were used to stimulate osteoclast precursor cell RAW264.7 to establish an inflammatory microenvironment and detect osteoclast differentiation. By silencing Btk, the expression of Btk, PLCγ2, and NFATc-1 was detected by real-time qPCR and Western blot, and osteoclastogenesis was detected by enzyme histochemical staining to further confirm the role of Btk in bone resorption. It was found that the expression of Btk, PLCγ2, and NFATc-1 changed significantly with the progression of inflammation and bone destruction, indicating that Btk and PLCγ2 may be involved in the progression of inflammation in apical periodontitis and bone absorption. In vitro experiments confirmed that the differentiation of osteoclasts and the expression of PLCγ2 and NFATc-1 were significantly inhibited after silencing Btk expression, but osteoclast precursor cells could be differentiated due to the proinflammatory factor lipopolysaccharide. This study demonstrates that Btk and PLCγ2 are key factors involved in the apical inflammatory response and bone destruction.

Paranasal Augmentation Using Multi-Folded Expanded Polytetrafluorethylene (ePTFE) in the East Asian Nose

Background Paranasal augmentation has commonly been performed utilizing alloplastic materials such as silicone or porous polyethylene. However, there are problems such as bone absorption, implant migration, and infection risk attributable to intraoral approaches. Objectives The authors attempted anterior positioning of the alar crease junction as an adjunct method of rhinoplasty. The authors aimed to determine the long-term results of the intranasal approach for placement of multi-folded expanded polytetrafluorethylene (ePTFE). Methods A retrospective review was conducted of patients who underwent intranasal surgical approach for paranasal augmentation employing multi-folded ePTFE implants in 19 septorhinoplasties who were followed-up for 3 to 10 years. Patient charts were reviewed for demographic information, concomitant operations, and complications. Preoperative and postoperative photographs were utilized to evaluate operative outcomes. The photographs were reformatted to 2-dimensional images employing standard photographic methods. Results Of the 19 patients treated, 17 were female and 2 were male; ages ranged from 18 to 58 years. All patients reported improvement in their lateral profiles and were pleased at follow-up. There were no major complications, no nerve or vascular supply compromise, and no cases of implant malposition. The average increase in soft tissue outline near the alar crease junction was more than 3.2 mm (P < 0.001), but the alar base did not became wider. Conclusions Paranasal augmentation with multi-folded ePTFE is a simple, safe, and effective method that can readily improve the lateral profile. In particular, the intranasal approach combined with rhinoplasty can synergistically improve outcomes and lead to greater patient satisfaction. Level of Evidence: 4