[Assessing the influence of chin prominence on perceived facial aesthetics among three groups of observers].

PURPOSE: To assess the influence of chin prominence on facial aesthetics with 3D images, to investigate the cognitive boundaries of chin prominence among orthodontists, general dentists and laypeople and compare the variance of their cognitive data, in order to provide quantitative reference for selection of clinical treatment. METHODS: A 3D facial image was obtained by 3dMD. The soft tissue pogonion point was altered in 2 mm increments from -10 to 10 mm with Geomagic Wrap 2015, in order to represent retrusion and protrusion of the chin. These images were rated by orthodontists, general dentists and laypeople with VAS scores. Multivariate mixed linear regression was used to analyze the influence of gender, age and chin prominence on VAS scores, and whether there were differences among different groups with SAS 9.4 software package. ANOVA was also applied for comparison of each prominence. RESULTS: This study was composed of 243 subjects, including 90 orthodontists, 101 general dentists and 52 laypeople. Chin prominence had significant effect on VAS scores. VAS scores decreased by 0.8910 for each unit increase in chin retrusion and decreased by 1.0958 for each unit increase in chin protrusion（P<0.01）. Desire for treatment started when chin retrusion exceeded 6 mm in orthodontist group and layperson group, 4 mm in general dentist group, and chin protrusion reached 6 mm in all groups（VAS scores <5）. There was no significant difference in the scores among orthodontists, general dentists and laypeople with the variance of chin prominence, and there was no significant difference in gender and age. CONCLUSIONS: Chin prominence had significant effect on facial aesthetics. Soft tissue pogonion point located on the zero meridian was considered as the most attractive. Treatment needs increased significantly when chin protrusion reached 6 mm or chin retrusion exceeded 6 mm. There was no significant difference in the assessment among orthodontists, general dentists and laypeople.

[Research progress of nano-hydroxyapatite complexes in bone tissue regeneration].

As the nano-hydroxyapatite is the main inorganic component of bone tissue of the human body, artificial synthesis of nano-hydroxyapatite has attracted the most attention in the field of hard tissue repair. To make up multiple aspects of limitations for nano-hydroxyapatite material itself, nano-hydroxyapatite complexes have been widely evaluated and applied in bone repair. This paper reviewed the common nano-hydroxyapatite complexes and their research progress in bone regeneration. Supported by Research Fund of Science and Technology Committee of Shanghai Municipality (12NM0501600, 13NM1402102) and Medicine and Engineering Cross Project of Shanghai Jiao Tong University (YG2012MS29).

Osteogenic potential of bone marrow stromal cells derived from streptozotocin-induced diabetic rats.

Type 1 diabetes mellitus (T1DM) is associated with a series of bone complications, which are still a great challenge in the clinic. Bone marrow stromal cells (BMSCs) are crucial to bone remodeling and are attractive candidates for tissue engineering. Hence, we aimed to investigate whether impaired functions of BMSCs play a role in the pathogenesis of bone complications associated with T1DM. BMSCs were isolated from normal and streptozotocin-induced diabetic rats, and their proliferation and osteogenic differentiation ability were analyzed. Diabetic BMSCs demonstrated reduced proliferation ability, osteoblast gene expression, alkaline phosphatase activity and mineralization. Nude mice transplanted with diabetic BMSCs in a calcium phosphate cement scaffold exhibited reduced new bone formation, as detected by hematoxylin and eosin staining and immunohistochemistry. These changes may be partially related to impaired insulin and insulin-like growth factor 1 (IGF-1) signaling. Weak gene expression of insulin receptor (IR), IGF-1, insulin-like growth factor 1 receptor (IGF-1R), and insulin receptor substrate-1 (IRS-1) was observed in the diabetic BMSCs compared with normal BMSCs, together with decreased protein level of IGF-1, IGF-1R, IRS-1 and phosphorylated extracellular signal-regulated kinase. Therefore, impaired proliferation and osteogenic potential of BMSCs may be responsible for bone complications related to T1DM, mediated partially by impaired insulin and IGF-1 signaling. These findings may provide a new target with which to devise strategies for therapy.

[Construction and detection of gene expression vector of the Von Hippel-Lindau in bone marrow stromal cells].

PURPOSE: To construct siRNA-VHL expression vector and detect the effect of VHL gene interference on BMSCs. METHODS: According to the dog's VHL gene sequences, four pairs of siRNA oligo were designed and synthesized. Using vector cloning kit reorganization, four pairs of double-stranded siRNA were inserted into the expression vector (pcDNA™ 6.2-GW/EmGFPmiR) and 4 siRNA expression plasmids (SR144-1,SR144-2,SR144-3,SR144-4) were constructed. With the vector universal primers, colony PCR was screened. The positive clones were sequenced to verify whether the sequence of insert fragments in recombinant clones was consistent with oligo sequences designed or not. Interference vector transiently transfected the BMSCs. qPCR and Western blot were used to detect the gene silencing effect. In order to improve transfection efficiency of siRNA-VHL as well as the effect of the VHL gene silencing, pLenti-mi-VHL was constructed. RESULTS: Through sequencing the plasmids cloned, the fragment sequences inserted in recombinant clones were consistent with the designed oligo sequences. After 24 h and 48 h transfection of BMSCs cells by plasmids, SR144-4 showed the best effect of interference by qPCR and Western blot. Through comparing the sequencing results, the inserted fragment sequences were completely correct and the pLenti-mi-VHL was successfully constructed. CONCLUSION: The siRNA-VHL expression vector for BMSCs is successfully constructed and applicable for further experiments. Supported by Research Fund of Science and Technology Commission of Shanghai Municipality (Grant No.9411954800) and Foundation for Open Project from Shanghai Key Laboratory of Stomatology (Grant No.S30206).