BACKGROUND:The functional reconstruction of large maxillary defects is a significant challenge due to the lack of bony support.In this paper.a new approach for segmental maxillary reconstruction and bony support foundation is put forward and tested by animal experiment.OBJECTIVE:To evaluate the possibility of segmental maxillary regeneration by internal curve distraction osteogenesis of zygoma with the self-developed distractor.DESIGN:Animal experiment.SETTING:Department of Stomatology.the 252 Hospital of Chinese PLA.MATERIALS: Two healthy female hybrid canines of 1-1.5 years old and 20-25 kg were selected. Internal curve distractor was composed of three parts:curve track,movable part and a flexible central thread bar fixed at the center of the curve track.The former two parts,which was made of TC4,(Ti-6AI-4V),and the flexible central thread bar was made of nickel titanium wire. A 360° of counter clockwise rotation of the distraction activator achieved an advancement of 0.35 mm for the movable part;the maximum distraction length allowed by the distractor was 25 mm.METHODS: The experiment was carried out in the animal experimental center of Fourth Military Medical University of Chinese PLA from October 2003 to February 2004. The segmental defect of 18-20 mm in width was made in maxilla and zygoma to simulate maxillary defects.Then an osteotomy distal to the defect was performed to create the variable transport disk. The distractor was fixed to the residual zygoma and zygomatic arch for internal curve distraction osteogenesis.After a latency period of 5 days,the distraction started at a ratio of 1.05 mm per day (0.35 mm once,3 times per day) for 13 consecutive days. Before and after distraction and at the second, fourth and eighth week of consolidation, the bone radiographs of residual zygoma and zygomatic arch were taken routinely.MAIN OUTCOME MEASURES: The general condition of the animals and distractor, and the quality and quantity of new formation bone in the distracted gap.RESULTS:Canines and distractor were in good condition during the experimental period.X-ray film showed that at the end of distraction, the bony transport disks were distracted about 12 mm around arc.At the 8th week of consolidation,the density of new bone was close to that of normal bone,and the curved bony regeneration was almost completed.CONCLUSION: The serf-designed curve internal distractor is fit the condition of major maxillary defects,and could be used for the internal curve distraction of zygoma.

BACKGROUND: The maxilla is the functional and aesthetic keystone of the midface. However, because of the irregularity and complexity, the functional reconstruction of large maxillary defect is a significant challenge.OBJECTIVE: To set up a new method for maxillary reconstruction by distraction osteogenesis of zygoma and free fibula composite flap.DESIGN: Case observation.SETTING: Department of Stomatology, the 252 Hospital of Chinese PLA.PARTICIPANTS: A patient who suffered from right total maxillectomy and left subtotal maxillectomy. The subject was proved by the Department of Stomatology, the 252 Hospital of Chinese PLA in November 2005. The procedure and consequences of the treatment were told to the patient and his wife before the operation. They greed and signed on the consent book.METHODS: The bilateral internal curve distraction osteogenesis of zygoma (first stage) and transfer of free fibula composite flap (second stage) were performed on the patient. First stage: Following the total maxillectomy, the distraction osteogenesis of zygoma was performed. First, the complete osteotomy was performed on the biliteral remaining zygoma with oscillating saw and osteotome. The transport disks distal to the defect about 10 mm in length were made. Then the internal curve distractors were installed with titanium screws bilaterally and the pedicled buccal fat pad was used to cover the right distractor and separate it from oral and nasal cavities. Due to the skin grafting had been undertaken in the former surgery, no special measure was needed in the left side. After irrigation with normal saline, the wounds were closed with the distraction activator exiting through the soft tissue in the temporal region. Distraction began after a week and proceeded at 0.2 mm twice per day for 21 consecutive days in the right side and 16 days in the left. Consolidation was fixed for eight months. Second stage: By the original Weber's incision, distractors were exposed and released. With new bone formed well in the distracted gap, the bony support was founded in the low position of maxilla. The free fibula composite flap was harvested and the medial-mandibular tunnel was made as described by hidalgo and Peng. After that, the flap was transferred to the recipient site with the pedicle through the tunnel into the neck, then with the help of surgical plate, the fibula bone was remodeled as maxillary arch and fixed to the "bony support" with titanium plates. Following that, the microvascular anastomoses were performed. By the measure, the maxillary cavity was filled by peroneus longus muscle and the maxillary alveolar process was rebuilt by fibula bone. During the procedure, the condition of the distractors and fibula flap, the effect of osteogenesis and the reconstruction was checked by general observation and panoramic film.MAIN OUTCOME MEASURES: The general condition of the distractors and the flap;the effect of osteogenesis and reconstruction.RESULTS: The distractors were in good condition and fibula healed well. By the distraction osteogenesis of zygoma, bony support was set up in the low position of maxilla, the midfacial appearance was restored and the defects was reduced. By the transfer of free fibula composite flap, the defect was restored, the maxillary alveolar process was rebuilt, the oronasal communication was closed, and the contour of upper lip was reestablished.CONCLUSION: The distraction osteogenesis of zygoma and free composite fibula flap can be used together for the reconstruction of large maxillary defects. A new method is set up for functional reconstruction of large maxillary defects.

Objective:To evaluate the effect of internal distraction osteogenesis in the treatment of complicated teeth-maxillofacial deformity.Methods:Clinical data of 1 0 cases with complicated teeth-maxillofacial deformity were analyzed retrospectively.In the first stage,the patients were operated by internal distraction osteogenesis.In the second stage,the distractor was removed after 3 to 6 months of consolidation period,followed by other operation for further occlusal reconstruction.Results:All the operations were per-formed as planned.The distraction distance was 7 -70 mm.The distraction process was smooth in all the cases.Occlusion was recon-structed and the deformity was corrected by following operation satisfactorily.Conclusion:Internal distraction osteogenesis is effective in the treatment of complicated teeth-maxillofacial deformity for further occlusal reconstruction and functional repair.

Objective:To analyse the causes of early implantation failure and the therapeutic measures with re-implantation after the failures.Methods:6 cases of implantation failure including early infections,loosening and non-osteointegration were reviewed and trea-ted by re-implantation therapy,and the causes of failure were discussed and the effects of re-treatment were evaluated.Results:2 cases were found to be with infection of adjacent teeth after implantation and were treated by removal of the implant,socket curettage,root ca-nal therapy(RCT)and antibiotics followed by reimplantation.Implant loosening and non-osteointegration were observed in 4 cases, which were treated by the similar methods for the implant socket.Reimplantation was successful in all 6 cases followed-up for 1 -3 years.Conclusion:Preventive measure for implantation failure should include indication selection,control of infections in adjacent teeth and periodontosis,use of GBR technic and so on.Re-implantation following proper treatment of adjacent teeth and the socket of implant is effective for the treatment of implantation failure.

Objective To evaluate the efficacy of Ganoderma lucidum preparation on the behaviors,biochemistry,and autoimmunity parameters of mouse models of APP/PS-1 double transgenic Alzheimer's disease(AD).Methods A total of 44 4-month-old APP/PS-1 double transgenic AD mice were randomly divided into AD model group,Aricept group,Ganoderma lucidum middle-dose(LZ-M)group,and Ganoderma lucidum high-dose(LZ-H)group,with 11 mice in each group.In addition,10 4-month-old C57BL/6 mice were used as the control group.Water maze test was conducted to observe the behavior changes,and the protein expressions in brain tissues were detected by Western blot analysis.The autoimmune indicators were detected by indirect immunofluorescence method.Results In the navigation experiment,the time of finding the platform was gradually shortened since the 2day in the control,LZ-H,and LZ-M groups,and the time of searching the platform in the AD model group gradually increased.On the 5day,the time of finding platform was significantly shorter in control group (t=5.607,P=0.000) and LZ-H group(t=2.750,P=0.010)than AD model group.In the space exploration experiment,the number of crossing the target platform(t=2.452,P=0.025)and the residence time in the target quadrant(t=2.530,P=0.020)in AD model group mice was significantly smaller/shorter than those in control group;in addition,the number of crossing the target platform in the AD model group was significantly smaller than that in LZ-H group(t=2.317,P=0.030)and LZ-M group(t=2.443,P=0.030),while the residence time in target quadrant decreased significantly(t=2.770,P=0.020)compared with LZ-H group;the number of crossing through the target platform quadrant(t=2.493,P=0.022)and residence time in the target quadrant(t=2.683,P=0.015)in LZ-H group were significantly higher than in Aricept group.Western blot analysis showed that the expression of ApoA1 in the brain tissues of mice in LZ-H and LZ-M groups were significantly higher than those in AD model group(P<0.01,P<0.05);Aβ-40 expression in LZ-H group was significantly lower than that in AD model group(P<0.05);the expressions of Syt1,ApoE,and ABCA1 in brain tissues of mice in LZ-H group were significantly higher than those in model group(P<0.01,P<0.05).The plasma IgG level in Aricept group(t=30.945,P=0.000),LZ-M group(t=25.639,P=0.000)and LZ-H group(t=4.689,P=0.001)were significantly higher than that in the control group.Conclusion Ganoderma lucidum preparation can improve behavior disorders of AD model mice,promote the expressions of ApoA1,ApoE and Syt1,inhibit the expression of Aβ-40 protein,and improve the autoimmune function.