This paper introduces what signals are actually transmitted in every procedure of the start-up process of Mx8000 Exp double-slice spiral CT and what relevant parts are acted.Some troubles related to start-up process is briefly presented.

Objective: To investigate the bone healing of rigid internal fixatio n(RIF) during Le Fort I Osteotomy.Methods: We regarded rabbits as study objects and evaluated the form of bone healing by bone histomorphometry.Results:There was significant difference in the degree of the new bone formation between groups,and the degrees in group A were much higher than that in group B at any stages .Conclusion:The use of RIF in orthognathic surgery can speed the bone healing.`

BACKGROUND:Studies have found that combination of two of chitosan (CS), nano-hydroxyapatite (nHA) and poly(lactide-co-glycolide) (PLGA) can improve the mechanical properties and biocompatibility of the composite stent in certain extent as wel as improve osteogenic differentiation of the cels, but there is a certain distance from the ideal bone tissue engineering scaffolds.
OBJECTIVE:To study biocompatibility and osteoinductive activity of nHA/CS/PLGA scaffolds with different proportions in vitro.
METHODS: nHA/CS/PLGA scaffolds were prepared at mass ratio of 10:10:80, 10:20:70, 20:10:70 respectively by particle leaching method. And human bone marrow stem cels (hBMSCs) were co-cultured with these scaffolds in vitro. Adhesion, proliferation, and osteoinductive activity of these scaffolds were examined qualitatively and quantitatively by growth curve of hBMSCs on scaffolds. Gene expression of alkaline phosphatase activity and osteocalcin was detected by RT-PCR.
RESULTS AND CONCLUSION: hBMSCs could be attached, proliferated, and osteoinduced better on the nHA/CS/PLGA scaffold with the mass ratio of 20:10:70, compared to the other two groups of scaffolds. The differences were significant statisticaly (P< 0.05). Alkaline phosphatase and osteocalcin expressions were respectively higher in the scaffold with the mass ratio of 20:10:70 after 9-27 days of co-culture and 15-27 days of co-culture, in comparison with the other two groups of scaffolds. These findings indicate that the nHA/CS/PLGA scaffolds with the mass ratio of 20:10:70 demonstrated preferable biocompatibility and osteogenic inductivity, which is expected to be a promising scaffold material for bone tissue engineering.

Objective: To clone mouse rod opsin promoter (ROP) and establish transgenic mice harboring mouse rod opsin promoter and enhanced green fluorescent protein(mROP-EGFP) fusion gene. Methods: Mouse ROP was cloned from C57BL/6 mouse genomic DNA by polymerase chain reaction (PCR). Expression vector of mROP-EGFP fusion gene were constructed by recombination DNA technique. It was identified by restriction endonucleases digestion and confirmed by DNA sequencing. After Not I restriction endonuclease digestion, the coding elements were microinjected into male pronuclei of mice zygotes to generate transgenic mice. The pups were evaluated by PCR at genomic DNA level and mated with normal mouse. Expression of GFP in retina of transgenic mice was detected by fluorescent microscope. Results: 2. 1 kb mouse rod opsin promoter fragment was amplified from mice genome DNA. Expression vector pmROP-EGFP was constructed successfully. Following microinjection of coding sequence of pmROP-EGFP, 3 pups were verified to integrate the mROP-EGFP fusion gene in their genomic DNA by PCR assay, named C57-TgN (mROP-EGFP )SMMU21, C57-TgN (mROP-EGFP)SM-MU26 and C57-TgN(mROP-EGFP) SMMU27. They could express GFP in retina. Conclusion: 2. 1 kb mouse rod opsin promoter is cloned and expression vector pmROP-EGFP is constructed. mROP-EGFP fusion gene transgenic mice are established, which harboring mROP-EGFP gene and expressing GFP in their retina. This is valuable for studying the development of brain and retina, pathogenesis of retina disorder and retina transplanting.

BACKGROUND: Mis Seven implant has become more and more popular in oral implant restoration, and the clinical application in dentate-deficient patients remains to be studied. OBJECTIVE: To explore the short-term effects of the Mis Seven implant system on fixed restorations in dentition loss. METHODS: Nineteen patients undergoing fixed dental prostheses with the Mis Seven system due to dentition loss at the Department of Implants of the Stomatological Hospital of Guangzhou Medical University between April 2015 and December 2017 were included. Three patients had missing maxillary and maxillary dentition and unilateral maxillary teeth. Six patients were loss of maxillary dentition, and there were 10 cases of unilateral mandibular dentition missing. The total dental implants were 134. All cases were implanted and fixed for one stage. Clinical examination, alveolar bone and inter-implant image performance and post-load repair effect at 6, 12 and 24 months of follow-up were used as evaluation indicators. RESULTS AND CONCLUSION: (1) In 134 implants, failure was in 2 cases due to surrounding tissue infection. The success rate of before implant restoration was 98.51％, and the success rate after repair was 100％. (2) The stability of dentition of 19 patients was good, showing good occlusion. No mechanical complications or biological complications occurred. The stability of the restoration was 100％. (3) The vertical absorption of bone tissue around all implants was less than 0.2 mm at 6, 12, 24 months after repair, suggesting that the implant has no obvious edge bone resorption. The gingival tissues around all implants were healthy, and no unhealed inflammation or hyperkeratosis appeared. (4) These results imply that the Mis Seven system in the dentition defect fixation exhibits good short-term clinical results.

Sinus floor elevation was needed in 11 patients having 15 implant sites with the residual bone height (RBH) was less than 10 mm in the posterior maxillary region from Feb to May 2017. The RBH ranged from 3.10 to 8.34 mm [averaged (6.18±1.60) mm]. RBH<6 mm was observed in 40% implant sites (6 implant sites) and RBH≥6 mm was observed in 60% implant sites (9 implant sites). The thickness of the sinus floor membrane correspond to the implant site measured by cone beam CT (CBCT) ranged from 0.50 to 4.24 mm [averaged (1.21±0.92) mm]. Sequential drills with stops were used to perforate the cortical bone of the sinus floor firstly, then the transcrestal around detached sinus floor elevation technique (TADSFET) was carried with osteotomes. Anorganic bovine bone was used as the augmentation material.Fifteen implants were placed in 15 implant sites. CBCT pictures showed that there was a smooth and continuous tent-shaped apophysis on each lifted site and no air fluid level was observed in the sinus immediately after operation. The mean elevated height of the 15 implant sites was (7.83±1.57) mm (ranged from 5.94 to 11.01 mm). The mean follow-up time was 7.91 months (7-10 months). The survival rate was 100% during the follow up period.

Alveolar bone is an important anatomic basis for implant-supported denture restoration, and its different degrees of defects determine the choices of bone augmentation surgeries. Therefore, the reconstruction of alveolar bone defects is an important technology in the clinical practice of implant restoration. However, the final reconstructive effect of bone quality, bone quantity and bone morphology is affected by many factors. Clinicians need to master the standardized diagnosis and treatment principles and methods to improve the treatment effect and achieve the goal of both aesthetic and functional reconstruction of both jaws. Based on the current clinical experience of domestic experts and the relevant academic guidelines of foreign counterparts, this expert consensus systematically and comprehensively summarized the augmentation strategies of alveolar bone defects from two aspects: the classification of alveolar bone defects and the appropriate selection of bone augmentation surgeries. The following consensus are reached: alveolar bone defects can be divided into five types (Ⅰ-0, Ⅰ-Ⅰ, Ⅱ-0, Ⅱ-Ⅰ and Ⅱ-Ⅱ) according to the relationship between alveolar bone defects and the expected position of dental implants. A typeⅠ-0 bone defect is a bone defect on one side of the alveolar bone that does not exceed 50% of the expected implant length, and there is no obvious defect on the other side; guided bone regeneration with simultaneous implant implantation is preferred. Type Ⅰ-Ⅰ bone defects refer to bone defects on both sides of alveolar bone those do not exceed 50% of the expected implant length; the first choice is autologous bone block onlay grafting for bone increments with staged implant placement or transcrestal sinus floor elevation with simultaneous implant implantation. Type Ⅱ-0 bone defects show that the bone defect on one side of alveolar bone exceeds 50% of the expected implant length, and there’s no obvious defect on the other side; autologous bone block onlay grafting (thickness ≤ 4 mm) or alveolar ridge splitting (thickness > 4 mm) is preferred for bone augmentation with staged implant placement. Type Ⅱ-Ⅰ bone defects indicate that the bone plate defect on one side exceeds 50% of the expected implant length and the bone defect on the other side does not exceed 50% of the expected implant length; autologous bone block onlay grafting or tenting techniques is preferred for bone increments with staged implant implantation. Type Ⅱ-Ⅱ bone defects are bone plates on both sides of alveolar bone those exceed 50% of the expected implant length; guided bone regeneration with rigid mesh or maxillary sinus floor elevation or cortical autologous bone tenting is preferred for bone increments with staged implant implantation. This consensus will provide clinical physicians with appropriate augmentation strategies for alveolar bone defects.