Objective:To observe the effect of orbital implant shrink range on the stress distribution in bone-implant interface. Methods:The 3D finite element analysis of craniofacial and orbital implant models with the implant length of 3,4,6 and 10 mm,and with the shrink range of0.05,0.1 and 0.15 mm were established respectively.The stress in the bone-implant interface were calculat-ed and analyzed.Results:The stress increased with the increase of implant shrink range.The stress produced by the implant with 0.15 mm shrink range decreased.The stress of the implant of 10 mm was lower than that of other implants with the shrink range of 0.1 and 0.15 mm.Conclusion:The maximal implant shrink range of 0.1 mm in the model can meet the clinical requirements in orbital implant planning.

AIM: To study the effects of Yangyu Tuji (YYTJ) on delayed healing wound of diabetic rats caused by streptozotocin (STZ). METHODS: SD male rats were randomly divided into control group (control), model group (model); and 3 different dose groups of YYTJ. 55 mg/kg STZ were given by intraperitoneal injection except for control group. After 30 days, a round skin of 1.6 cm diametre was excised on all dorsal back of rats. The healing time and healing rate were observed according to re-epithelization. The content of collagenⅠ and Ⅲ was observed by Picric acid-Sirius red staining , Matrix metalloproteinase-1, 13 (MMP-1, -13), tissue inhibitor of metalloproteinases-1 (TIMP-1) by immuno-histochemistry assay. All data were analyzed by IPP software. RESULTS: The healing time in each group treated with YYTJ was shorter than that in model group (P

BACKGROUND:Alveolar distraction osteogenesis is an important method for treating alveolar bone atrophy, the osteogenesis process and biomechanics play a crucial role in the fol owing implantation and repair. At present, no related experimental studies are found.
OBJECTIVE:To analyze the biomechanical and histological characteristics of alveolar distraction osteogenesis in a canine model.
METHODS:Twelve adult mongrel canines received premolars extraction and alveoloplasty in mandible to establish an atrophy alveolar model. After 3 months, a segmental alveolar osteotomy was performed in the randomly selected unilateral atrophy alveolar and two intra-osseous distractors were placed. After a 7-days latency period, the alveolar ridge was augmented at a rate of 1.0 mm/d for 5 days. After a consolidation of 1, 2, and 3 months, the canines were sacrificed and the specimens of the distracted alveolar bone were harvested for clinical, radiographic, histological and biomechanical analysis.
RESULTS AND CONCLUSION:The alveolar distractors obtained good healing with surrounding tissue. The atrophy alveolar bones were augmented for (4.80±0.50) mm and (5.12±0.47) mm by clinical and radiographic findings immediately after distraction, respectively. The bone trabeculae in the distracted chamber matured from 1 to 3 months of consolidation by histological analysis. The shearing force of alveolar distraction chamber increased from 1 to 3 months. After 3 months’ consolidation, the shearing force of distracted chamber was comparable to host bone. The histological and biomechanical property of distracted alveolar chamber is comparable to host bone after 3 months’ consolidation.

AIM:Cinnamyl aldehyde (CA) is one alcohol ingredient derived from Cinnamomum cassia,which is widely used in treating chronic skin wound in Chinese medicine with the curative effect of ‘rescuing YANG’. The purpose of the present study was to investigate the expression of c-Fos, c-Myc proteins at different time points in NIH3T3 treated with CA and explore the possible mechanism of promoting cell proliferation by CA. METHODS: MTT assay was used for observing cell proliferation. Expression of c-Fos and c-Myc proteins in NIH3T3 cells were assessed by immunocytochemistry assay. RESULTS: The cell proliferation was promoted obviously when CA concentration was between 8.8?10-2 ?g/L and 8.8?10 ?g/L. CA at concentration of 5.5 ?g/L significantly induced expression of c-Fos, c-Myc proteins at 2-3 h after the stimulation compared with control group (P

OBJECTIVETo assess the effects of 1-step method of changing the buccal position of the transported bone after distraction on early bone formation.

METHODSThe custom-made bidirectional distraction devices were used. Total of 8 adult mongrel dogs were procured. The bilaterally mandible premolars were extracted. After 1 month, the complete osteotomy was performed and the devices were placed. The gradual distraction was started after 1 week latency at the rate of 1 mm per day, total 6 mm in height was achieved. The 1-step method of changing the buccal position of the transported bone was performed the day after the vertical distraction period in one side of the animals, and the other side as the controlled side. All animals were killed after a 7 days consolidation. The vascular system was stained post mortem carbon ink perfusion to assess possible damages. Quantitative evaluations of bone density were performed with dual-energy X-ray absorptiometry (DEXA), analysis of the ratio of vascular square was conducted in a computer.

RESULTSAll animals tolerated the procedures well. After vertical distraction, the tested side can be moved 3 mm in buccal direction. DEXA examination showed that the density of the distracted bone was no statistical difference in both the tested and the controlled side. Vascular damage was not observed, and there was no statistical difference in the ratio of vascular square by analyzing the histological section in computer.

CONCLUSIONIn some extent, 1-step method of changing the buccal position of the transported bone after distraction can mold the regenerate bone to correct the axial displacement, without endangering early callus formation and vascularization.

Animals ; Bone Density ; Bone Regeneration ; Bone and Bones ; Dogs ; Mandible ; Osteogenesis ; Osteogenesis, Distraction

Objective : To investigate the feasibility of using UV curable calcium hydroxide as temporary crown binder. Methods : 242 patients with temporary crown were selected and randomly divided into three groups according the order of registration week each month, and respectively underwent temporary crown cement with TempoCemNE (n = 78), Provicol (n = 80) and Calcimol LC (n = 84) for each tooth. The retention effect and the status of the gum and the pulp were observed at one week after operation. Results : There was no significant difference between the three groups in the retention effect and the status of the gum and the pulp (χ12 = 5.553, P1 = 0.062 > 0.05; χ22 = 4.783, P2 = 0.091 > 0.05; χ32 = 3.290, P3 = 0.193 > 0.05). There was a good effect of temporary crown cement in three groups of TempoCemNE, Provicol and Calcimol LC. Conclusion Calcimol LC can be used as a new type of temporary crown cement with good bonding performance and the protection to gums and pulp, and simple operation.

To evaluate the clinical results of reconstruction orbital defect with craniomaxillofacial implant. Three patients with orbital defect were treated with ten implants. The magnetic abutments were attached six months after one stage operation and the prostheses were fabricated. Within 11 to 47 months of follow up, all implants were stable with successful osseointegration. The prosthesis fit the orbital defects well. Reconstruction of orbital defect with craniomaxillofacial implant can be considered as a viable alternative treatment.