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Objective:To establish an animal model of bone distraction in the irradiated dog mandible.Methods:1 0 Chinese dogs were used.8 dogs received a unilateral irradiation of 60 Co(Group R)in the mandible with a total dose of 22.8 Gy in four 5.7 Gy frac-tions (biologically equivalent to 50 Gy/25 fractions).The other 2 dogs without irradiation served as the controls(Group C).Bilateral corticotomy was made 3 months after completion of irradiation.After a 1 -week latency period,bone distraction was activated at a rate of 0.5 mm twice daily for 1 0 days,followed by a consolidation phase of 8 weeks.New bone was evaluated by radiographic,histological and single photon emission computed tomography(SPECT)analysis.Results:One dog was excluded from the study due to anaesthetic death in group R.After 8 weeks of consolidation,no difference was found between the percent area of new bone of both groups.New bone was more mature and organized in Group C than that in Group R.SPECT analyses showed that there was active osteogenic activity in Group R.Conclusion:Distraction osteogenesis can be achieved in the irradiated dog mandible.
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<p><b>OBJECTIVE</b>To investigate the accurate and individual treatment of temporomandibular joint(TMJ) injury based on 3D digital technology.</p><p><b>METHODS</b>Maxillo-mandibular model was made using rapid prototyping technology based on the pre-operation 3D CT results. According to the 3D digital measurement results, TMJ concepts were ordered and the prosthesis was used to simulate the replacement surgery on the model. Then the joint replacement surgery was performed afterward.</p><p><b>RESULTS</b>(1)After total replacement of TMJ, no pain happened and mouth open was not limited. Three months later, the joint position was normal and stable. The month open width was 4 cm. (2)After condyle replacement, primary healing was achieved with complete survival of bone graft. No edema was seen. Symmetric facial appearance was satisfactory.</p><p><b>CONCLUSIONS</b>Bilateral individual prosthesis for total TMJ or condyle replacement is an ideal method for TMJ injury.</p>
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Humans , Arthroplasty, Replacement , Methods , Bone Transplantation , Computer-Aided Design , Imaging, Three-Dimensional , Methods , Joint Prosthesis , Mandible , Prosthesis Design , Methods , Range of Motion, Articular , Temporomandibular Joint , Wounds and InjuriesABSTRACT
BACKGROUND:Rapid prototyping technique has been recently applied in the medical reconstruction and al ows the production of individual implant for patients with tissue defects, achieving an accurate repair. OBJECTIVE:To repair discontinuous mandibular defects in dogs using rapid prototyped titanium plate in combination with autologous cancellous bone graft. METHODS:Nine hybrid canines were used, and the skul was scanned using spiral CT. Then CT data were used to construct three-dimensional digital model, in which virtual partial mandibulectomy was performed, and an individualized bone-grafting plate was designed. A titanium plate was manufactured using rapid prototyping and titanium casting. Animal experiment was then performed. A 40-mm discontinuous defect in the right mandibular body was created in the involved dogs. The defect was restored immediately using the customized plate in combination with autologous cancellous iliac blocks. Sequential radionuclide bone imaging, biomechanical testing, three-dimensional microcomputed tomographic scanning, radiology and histological examination were used to evaluate the turnover of the grafts. RESULTS AND CONCLUSION:A symmetric mandible was reconstructed using the rapid prototyped grafting plate. The grafted bone survived and got corticalized, while a fibrous intermedium was found between the bone graft and the plate. In the reconstruction of mandibular defects, optimal functional and aesthetic outcomes could be achieved using the rapid prototyped grafting plates.
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BACKGROUND: A three-dimensional spiral computer tomography can display stereoscopic pictures with multi angles on films or computer screens. However, it is hard to display complex three-dimensional anatomical morphology on two-dimensional films or computer screens. Thus, three-dimensional models are needed in craniomaxillofacial surgery simulation or conceptual design.OBJECTIVE: To establish a three-dimensional skull model using spiral computer tomography data and to explore its application in craniofacial surgery.METHODS: Skull of the patient was scanned with Picker 6000 spiral computer tomography with 2.0 slice thickness and 1.0 pitch,and the obtained data were treated in Voxel Q image workstation for three-dimensional reconstruction with volume rendering technique. After having been downloaded to personal computer at 0.1 mm interval, the transaxial two-dimensional image data were converted into two-dimensional digitized contour data by using image processing software developed by the experimental team. The wire frame and solid images of craniofacial triangular facets could be reconstructed when the digitized data were inputted into image processing software of Surfacer 9.0.RESULTS AND CONCLUSION: The three-dimensional wire frame and solid image of skull was reconstructed and computer aided design for plastic operation was accomplished on it. Then the simulacrum of underlay was obtained by rapid prototyping technology. A three-dimensional skull model could be established using spiral computer tomography data. It might play an important role in the diagnosis and treatment of tumors, injuries and abnormality in craniofacial surgery.
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BACKGROUND: There are many methods for repairing the hemifacial atrophy, the most common is preparing plaster facial mold of the patient, with wax piled on the surface to restore the patient's facial shape, and wax pattern serves as a reference of surgical pad. However, the therapeutic effect for the correction and treatment is not satisfactory due to varied abnormality and difficult plans.OBJECTIVE: To discuss the feasibility of manufacturing underlay for the treatment of hemifacial atrophy using computer-assisted design and rapid prototyping technology. METHODS: Skull of the hemifacial atrophy patient was scanned with Picker 6000 SCT, and the data obtained were processed in Voxel Q image workstation for 3-D reconstruction with volume rendering technique. After the interval lamination, the images were downloaded at 0.4-mm interval in a BMP format using CuteFTP 4.0 software. Then the transaxial 2-D image data were converted into digitized 2-D contour data by using image processing software developed by experimental team through a series of processes, including filtering, screening, noise reduction, and distortion correction. The edges and contour of the images was extracted to obtain a vector diagram of facial cranial cortical bone contour line. The digitized data were inputted into image processing software of Surfacer 9.0 for vector superposing, thus the 3-D wire frame and solid images of skull could be reconstructed. According to mirror-image symmetry relation, the point-cloud data of facial bone on the normal side was duplicated to the atrophied side. Thus a 3-D model of the underlay was produced between the atrophied bone and the mirror image of normal side. In order to compensate the atrophy of soft tissues, the model was designed 1.5 mm thicker. After the three-dimensional Surfacer data on the CAD were re-stratified, the contour editing of the underlay and the supporting set of prototype were completed in RpDataRepare, forming RP files and creating underlay template through rapidly output of the processing file for rapid prototyping required, as a reference of surgical procedures.RESULTS AND CONCLUSION: The 3-D solid model of the patient skull bone surface contour was obtained and simulacrum of the underlay was prepared with computer assistance and rapid prototyping. According to the simulacrum, the operation was carried out and got a satisfactory result. The manufacture of underlay for the treatment of hemifacial atrophy could be accomplished by computer assisted design and rapid prototyping in a highly precise and rapid manner. It is a promising technique in the field of individualized underlay making in craniofacial surgery.
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Objective To analyze the clinical characteristic and provide therapeutic techniques of maxillofacial trauma in the elderly. Methods Geriatric maxillaofacial trauma patients admitted to our hospital from January 1992 to December 2002 was retrospectively reviewed. Data were collected according to etiology, location, comorbidities, associated injuries, therapeutic methods and the outcome. The patients were compared with a control group consisting of 200 young and adult patients admitted at the same period. Results For the 126 geriatric trauma patients, the major causes were traffic accidents(61.1%) and violence assault(25.4%). A large proportion of facial injuries occurred on the lower part of the face. 69.1% of the patients presented with preexisting diseases. Most of the fractures were not treated(35.7%). The length of hospitalization and ICU stay were relatively longer when compared with the control group(P
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Objective:To establish an animal model in goats for curved mandibular regeneration by distraction osteogenesis(DO).Methods:Four goats were used.Internally installed curved mandibular distractors were activated 6 days after mandibular osteotomy on the mandibular angles or mandibular symphyses at a rate of l mm/d for 25~34 days.The mandibles were examined by roentgenography.Results:The arched defects of the mandibles in the 4 goats were reconstructed by regenerated bone by the end of DO.Conclusion:Internally installed curved distractor may be used for osteogenesis in the repaire of the arched mandibular defects.
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Objective: To study the injury characteristics of blast injury in maxillofacial region wounded by spherical explosive. Methods: Spherical explosive was used to wound maxillofacial region in rabbits , after gross observation of the trauma , bone tissue specimens were collected from 0.5 or 1.0 cm to the boundary of wound 6 hours, 3 and 7 days after wounding respectively, the samples were prepared and stained with HE and modified Mallory's trichrome staining and observed under light microscope . Microcirculation in wounded bone was studied by ink injection and observed in ground bone sections. Results: No changes were found 6 hours after injury. Inflammatory infiltration were found 3 days after injury.Osteonecrosis was observed 7 days after injury, the structure of bone beyond 0.1 cm of the wound was found to be normal and restoration of bone was observed. Conclusion : Pathological changes of mandible injured by spherical explosive are similar to those of usual fracture except that the wound of blast injury is seriously polluted.
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Objective: To develop a bio-multi-function impact device for the study of maxillofacial impact injury . Methods: This device, driven by high-pressure nitrogen air, was consisted of impact unit, laser speed-measure meter, trigger unit, operation platform and information record unit. Results: A new type of bio-multi-function impact device was manufactured with the function of the impact and project. The impact velocity is from 3 to 40 m/s and can be adjusted. The muzzle velocity of the projectile can reached from 300 to 1 500 m/s and also can be adjusted according to the demand of the experiments. It can record exactly multi-line biomechanic signals. Conclusion: The device is stable and suitable for the study of impact and projectile injury.
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Objective: To observe effects of treatment of mandibular fractures with compression or non compression internal fixation. Methods: In the in vivo study mandibular fractures were fixed by compression internal fixation on one side and non compression on other side in 15 dogs and observed radiologically and histologically. In clinical practice 42 patients with 58 mandibular fractures were treated with compression internal fixation, and 56 patients with 78 madibular fractures were treated with non compression internal fixation. Their clinical effects were evaluated by masticatory efficiency test, radiological and clinical observation after operation. Results: Primary bone healing was found histologically in group of compression fixation and bone healing through callus in group of non compression in the dogs. In the patients treated with compression internal fixation bone fracture line disappeared 1 week earlier and masticatory efficiency was heigher than in those with non comprission fixation. Conclusion: Both methods are all effective in the treatment of mandibular fractures. The miniplate is convenient in use and the indication is wide ranging. The compression plate can speed healing of mandibular fractures, but the operation is more strict technically.
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Objective: To estabish an animal model with blast injury in maxillofacial region and to study the biomechanical property of the model.Methods: Spherical explosive at different distances was used to make wound in maxillofacial region in dogs. The pressure on tissue at different level, the variation of horizontal acceleration and strain of the mandibular and temporal bone were dynamically measured.Results: About 3.5 cm?3.0 cm soft tissue defect and madibular splintered fracture occurred in maxillofacial region when the spherical explosive exploded on the surface of the dog's face and the animal survived. The pressure on mandible was respectively 3.6%?2.9% of the surface of dog's face when the spherical explosive exploded 0 and 1.00 cm away from the dog's face while the ratio of horizontal acceleration of cranium to mandibular was 1/8?1/6. Splintered fracture occurred in mandible when the mandibular strain was 11 375 ??.Conclusion: The model can be applied as an animal model with blast injuries in maxillofacial region.
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Objective To analyse the characteristics of maxillofacial injuries resulted in different causes. Methods A retrospective review was done of patients admitted to the Stomatology Hospital of Fourth Military Medical University from January, 1996 to July, 2003. Data was grouped by different causes. Results 1 188 patients were reviewed, the majority of victims caused by different causes were males, the ratio of male and female is 3.34∶1. Most industrial and sport injury occurred in men. Traffic accidents were the major cause of the midface fracture and mandibular fracture. While violence was the major cause of pure soft injure and alveolar bone fracture. Conclusions Traffic accidents and violence were the major causes of facial injury. The facial injury caused by traffic accidents, industrial accidents and fall was more serious than those caused by other causes. More emphasis should be put on the prevention and treatment of these injuries to minimize the maxillofacial malformation.
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Objective: To investigate the distraction osteogenesis technique in correction of severe retro-maxillary deformity following the repair of cleft palate. Methods:10 patients were included in the study. Orthodontic treatment was used as a regular procedure before operation. Distraction osteogenesis technique was used to correct the deformity and malocclusion. 4 of patients applied with the external distractor and others with internal distractor. Latency period was 7 days. Distraction rhythm is 0.8~1 mm/d,2~4 times/d. Consolidation period was 8~12 weeks. Orthognathic surgery was done after distraction finished when necessary. Results:The treatment process was smooth and no severe complication occurred. The maximum of distraction distance is 22 mm, and the minimum of distraction distance was 15 mm. No malunion or ununion occurred in all 10 patients. All the patients were satisfied with the results. Conclusion:Distraction osteogenesis is more suitable for correction of severe retro-maxillary deformity following the repair of cleft palate. Bone transplantation is unnecessary during the operation process with easier handling and lower risk.
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Objective:To evaluate the effect of orbital floor mesh plate in the treatment of orbital floor fracture. Methods:27 patients with orbital margin fractures were treated by surgical operation with orbital floor mesh plates or medial wall plates. All patients were observed for 3 months after operation.Results:It was observed that all patients with enophthalmos were cured and the patients with nerve injury recovered satisfactorily.Conclusion:Orbital floor mesh plate is effective in the treatment of orbital floor fracture.
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Objective: To study the treatment methodology of postoperative disostosis of maxilla in the patients with cleft palate by orthognathia. Methods: 10 cases (6 males and 4 females) of postoperative dysostois of maxilla in the patients with cleft palate were treated by orthognathia. Operation manners and orthodontic treatment were determined by orthodontists and surgeons before treatment. Orthodontic treatment included upper arch expansion, teeth alignment, leveling the Spee's curve etc. Operation on single jaw or double jaw, or extraction of one anterior tooth to decrease lower dlental arch and to coordinate with the upper jaw forward was conducted according to individual situations. Adjustment of intercuspids relation was conducted after operation. Results: In all the 10 cases discrepancy of upper and lower jaws were resolved, profiles of the faces were improved significantly, dental arch symmetry, physiological overjet and overbite were achieved. Conclusion: Orthognathia is effective in the treatment of postoperative dysostosis in the patients with cleft palate.
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砄bjective: To study the cause,clinical characteristics and treatment of zygomatic complex fractres(ZCF). Methods: Medical records of 79 cases with ZCF and followed up for 3 months to 2 years were reviwed and analysed. Reduction and cosmatic outcome were assessed by clinical evaluation and postoperative images. Results: Of the 79 patients, 87.3% were male, with the peak incidence in the age group from 20 to 40 years old(73.5%). 58.2% were due to traffic accidents, 15.2% to assalts. Incidence of malar asymmetry, enophthalmos, diplopia,limited mandiblar movement and malocclusion were 83.5%,24.1%,19.0%, 60.8% and 35.4% respectively. Of the nerve disturbances, 41.8% of the infraorbital and 13.9% of the facial nerve were involved. For the treatment the most freqently used approach was the coronal incision in combination with the maxillary vestibular incision(30.4%), followed by coronal incision alone(22.8%). 40.5% of the patients were treated by rigid internal fixation with titanium miniplates alone or combined with wire fixition(20.3%). All patients but five regained satisfactary facial appearance. Three patients still showed slightly post surgical enophthalmos and diplopia at a 6 month follow up. All of the patients with malocclusion regained their functional occlusion after treatment. Conclsions:A variety of techniques can be used in the treatment of ZCF. Among them the coronal incision in combination with other incisions or alone and rigid internal fixation can produce a satisfactary outcome.
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Objective:To observe the effects of bone marrow stromal cells(BMSCs)/coral composite strengthened by titanium mesh in the repair of mandibular defects. Methods:The rabbits' BMSCs were cultured and induced in vitro, and then were combined with coral to form the BMSCs/coral composite, which were implanted into the left mandibular defect in the size of 15 mm?8 mm in 16 rabbits. Titanium mesh was used to strengthen and fix the composites. Coral implant was used as the control in the right mandibular defect.Six and twelve weeks after operation, X-ray observation and histological examination were employed to assess the status of bone formation. Results:In the experimental group, new bone formation was found by radiography and the histological examination 6 weeks after operation. 12 weeks after operation woven bone and lamellar bone were observed in the implanted area and the bone defects were repaired, coral was disappeared, titanium was integrated with surrounding bone tissue. In the control group 12 weeks after operation the bone defects were filled by fibrous tissue, coral was disappeared. Conclusion:Titanium /BMSCs/coral composites can repair mandibular defects effectively.
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Objective: To observe collagen synthesis in the different phase of distraction osteogenesis(DO) in alveolar cleft.Methods:8 dogs were used to make experimental model of alveolar cleft and underwent the closure of the cleft by distraction osteogenesis.The animals were sacrificed on day 0, 14, 28 and 63 after completion of DO respectively. The samples were examined by histological observation and the expression of typeⅠ,Ⅱ,Ⅲ collagen was studied by immunohistochemistry staining. Results:On day 0, a lot of type Ⅲ collagen fibers were observed in the distraction area. On day 14, there was trabecula bone, collagen Ⅰexpression was stronger than collagen Ⅲ. On day 28, trabecula bone developed into network-like structure with type Ⅰ collagen expression. On day 63,lamellated bone with type Ⅰ collage expression filled the distraction area. No obvious expression of collagen Ⅱ was observed.Conclusions:The formation of new bone is mainly intramembrane osteogenesis along the distraction vector.
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This study was done based on the principle of early repair of mandible defect after firearms wound. The results showed that the delayed one stage reconstruction could be used to repair of maxillofactial defect caused by firearms wound, using vascularized graft was supperior to the free bone graft alone. The latter is not suitable for the repair of maxiUofacial firearms defects in early stage.
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Objective To design a more reasonable method by comparing three existing injury severity scores for evaluating maxillofacial injury severity according to its features by retrospective analysis. Methods Nine hundred and eighty-four cases with maxillofacial trauma (≤30 days before hospitalization) selected from 1 159 cases were stratified by the number of fractures and the sites of trauma. The injury severity was evaluated with ISS, RFISS and MISS respectively. The results of ISS/RFISS/MISS were compared and analyzed with SPSS software. Results MISS could accurately differentiate single from multiple facial injuries. It was more meaningful for evaluating different sites of facial injury compared with ISS and RFISS. Conclusion MISS can be used to evaluate maxillofacial injury objectively and accurately.