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 study the feasibility of repair of partial maxillary defect by distraction osteogenesis(DO) in zygoma.Methods:Segmental maxilla- zygoma defect was made in 3 dogs. A submerged DO distractor was anchoraged on the zygoma and maxilla across the defect,the zygoma was distracted with a rate of 1.0 mm/d for ten days,the process of bone formation was examined by X-ray.Results:All dogs were in health condition within the experimental period.New bone formation was observed 2~4 weeks after operation. Complete repair of the defects was observed 8 weeks after the completion of distraction.Conclusion:The partial maxillary defect may be repaired by DO in zygoma.

Objective: To study the anatomic structure of the nasopalatine duct and the neighboring bone,provide reference for implant surgery in the incisor region. Methods: Manual quantitative measurement of the nasopalatine duct were performed in 73 maxilla specimens (38 from male and 35 from female). Results: The angle between the anterior wall of nasopalatine duct and the nasal floor was 114.80??11.00?, the angle between the cortical plate of anterior maxilla and the nasal floor 107.28??10.75?, the length of the nasopalatine duct was (15.63?2.18) mm in male, and ( 14.59 ?1.96) mm in female, the width of nasal opening of the duct was ( 4.92 ?1.46) mm in male, and (5.73?1.50) mm in female, the width of oral opening of the duct was (3.23?0.60) mm in male and (3.83?0.92) mm in female, at the level of nasal floor, the distance between the anterior wall of the duct and cortical plate of anterior maxilla was (6.15?1.90) mm. Conclusion: In front of nasopalatine duct, implants should be implanted parallel to nasopalatine duct,with an angle about 115? between the implant direction and nasal floor. The bone in front of nasopalatine duct was thin,the diameter of implants applied here should be less than 4 mm.

BACKGROUND: The rehabilitation of maxillary loss is based on maxillary prosthesis,and the most difficult problem is that retention and support of maxillary prosthesis can hardly be achieved. The employment of implants in the zygoma region provides good basis for the retention and support of maxillary prosthesis. However,during implantation in the zygoma the pe ripheral tissues may be injured, and even induce failed implantation.OBJECTIVE: To study the bone structure of the zygoma so as to provide reference for implantation in this region.DESIGN:Randomized sampling for repeated observation measurement based on maxilla specimens.SETTING: The research was completed in the prosthodontic department of stomatological college and department of human anatomy of a military medical university.PARTICIPANTS:The experiment was carried out in the Department of Human Anatomy,Fourth Military Medical University of Chinese PLA from March to May 2002. A total of 73 adult maxilla specimens(38 from males and 35 from females) were provided by the Department of Human Anatomy,Fourth Military Medical University of Chinese PLA.METHODS: Quantitative measurement of bone structure of the zygoma region was made with the cursor ruler in the 73 specimens. T-test was used to analyze the measurement data.MAIN OUTCOME MEASURES: The data of measurement: bone thickness of the zygoma, width of the lower part of the zygoma, length of the zygoma, and the distance between lower part of the zygoma and orbital floor.RESULTS: ① Bone thickness gradually decreased from the interior-inferior borderline to the exterior-superior part of the zygoma. In males, the average bone thickness 10 mm,12 mm,14 mm and 16 mm away from the interior-inferior borderline of the zygoma was 6.97 mm, 6.45 mm, 5.75 mm and 5. 01 mm, respectively, in the upper part, and 7.03 mm, 6.69 mm, 6.28 mm and 5.89 mm in the lower part. In females, the average bone thickness 4 mm,6 mm, 8 mm and 10 mm away from the interior-inferior borderline was 6.95 mm,6. 55 mm,6.28 mm and 5.31 mm in the upper part,and 6.60 mm,6. 39 mm,6.26 mm and 5.75 mm in the lower part. ② The lower part of the zygoma was 21.39 mm wide in males and 17.20 mm in females. ③ The average length of the zygoma was 21. 12 mm in males and 19.58 mm in females. ④ The average distance between lower part of the zygoma and orbital floor was 4. 17 mm in males and 3.71 mm in females.CONCLUSION:In maxillary loss,the zygoma is an optimal region for double implants at a distance of more than 15 mm. In males, the implants of 3.6 -4.0 mm in diameter and 10 - 12 mm or 14 - 16 mm in lengthcan be employed; in females, the implants of 3.4 - 3.8 mm in diameter and 4 - 6 mm or 8- 10 mm in length can be employed.The differences in bone quantity between males and females are statistically significant in the zygoma,males' better than females', so they should be treated differently during clinical practice.

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 efficacy of microvascular decompression for hemifacial spasm (HFS) caused by vertebral basilar artery compression. Methods A total of 141 patients with HFS treated by microvascular decompression in our hospital were collected in this study. The improvement of the symptoms after operation was compared between patients with HFS caused by vertebral basilar artery compression (28 cases) and patients with HFS caused by non-vertebral basilar artery compression (113 cases). Results There was no significant difference in the effective rate between the two groups of HFS (96.43%vs. 98.23%,P=0.49) with mean following-up 13.81 ± 1.57 months. And there was no significant difference in the delayed cure rate after surgery between two groups (37.04%vs. 20.72%,χ2=1.38, P>0.05). Conclusion Microvascular decompression is a safe and effective method for the treatment of HFS caused by compressed vertebral basilar artery.

Objective The incidence of traumatic brain injury (TBI) has been on the rise year by year around the globe.According to the latest Guidelines for the Management of Severe Traumatic Brain Injury (Fourth Edition) released by the Brain Trauma Foundation (BTF),there is no sufficient evidence that related medicine can promote the repairment of neural injury in the treatment of central nerve damage.The clinical treatment of TBI is facing multiple difficulties.In recent years,brain computer interface (BCI) technology has developed rapidly and shown enormous potential in TBI repairment,especially in visual and auditory restoration,neural function recovery,and cognitive restoration.BCI provides a new approach to improve the quality of life for patients.This paper reviews the application and prospect of BCI in sense,motion,and cognitive function repairment after TBI,so as to provide new insights for the treatment of TBI nerve function.