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1.
PURPOSE: The aim of this study was to evaluate the long-term outcome of resorbable poly-L-lactic/polyglycolic acid (PLLA-PGA) bone fixation devices used for fixation of maxillary and mandibular osteotomies. MATERIALS AND METHODS: Twelve patients were postoperatively evaluated. Eight patients who had undergone bilateral sagittal split mandibular osteotomies that had been fixed with PLLA-PGA screws were followed-up for up to 2 years postoperatively with radiographs. One of these patients underwent a bone biopsy for detailed histologic evaluation of the screw fixation sites. Two patients who had undergone mandibular symphyseal osteotomies were also radiographically evaluated at 18 months to 2 years postoperatively. Two patients who had Le Fort I osteotomies fixed with PLLA-PGA plates and screws underwent open exploration of the operated sites for visual examination. RESULTS: All 8 mandibular osteotomy patients showed radiographic screw hole lucency immediately after surgery that remained unchanged in the first year after surgery. By 18 months postoperatively, all 48 screw holes showed near or complete trabecular bone fill. The bone biopsy of one screw hole at 2 years postoperatively showed complete fill with normal trabecular bone. No residual polymer material or fibrous scar was seen. The mandibular symphyseal sites showed complete elimination of all screw holes by 2 years postoperatively, with only faint evidence of intraosseous tunnels. The maxillary sites showed complete bone healing along the osteotomies and no evidence of residual fixation material or bone defects in the screw holes. No communication with the maxillary sinus was seen in the fixation sites. CONCLUSION: This orthognathic patient series showed complete resorption of the PLLA-PGA fixation devices without osteolysis in maxillary and mandibular bone sites by 18 to 24 months after surgery.  相似文献   

2.
Resorbable fixation techniques for genioplasty.   总被引:3,自引:0,他引:3  
PURPOSE: This study evaluated the capability and effectiveness of resorbable bone fixation devices in genioplasty surgery. MATERIALS AND METHODS: Twenty patients underwent different genial movements that were stabilized with either 2.5-mm polylactic-polyglycolic acid lag screws or 2.0-mm polylactic-polyglycolic acid plates and screws. RESULTS: Twenty-one anterior mandibular osteotomies were performed in 20 patients. Sixteen patients had advancement (80%), 2 had horizontal setback (10%), and 2 had vertical reduction (10%). The average advancement was 7.6 mm (range, 4 to 14 mm), the average horizontal setback was 6.0 mm (range, 4 to 8 mm), and the average vertical reduction was 7.0 mm (range, 5 to 9 mm). Fixation was done using the lag screw technique in 13 patients (65%) and plate and screw fixation in 7 patients. (35%) Intraoperative stability was satisfactory in all cases. There were no postoperative infections or segmental instability up to 6 months after surgery. CONCLUSION: Resorbable polylactic-polyglycolic acid lag screw and plate and screw fixation is a viable alternative for fixation of anterior horizontal osteotomies of the mandible.  相似文献   

3.
The purpose of this study was to evaluate the intraoperative placement and clinical effectiveness of resorbable copolymeric screws for mandibular sagittal split ramus osteotomies. Thirty-seven patients who underwent bilateral sagittal split osteotomies of the mandible were fixated with three 2.5-mm copolymeric poly-L-lactic-polyglycolic (PLLA-PGA) screws on each side. No postoperative maxillomandibular fixation was applied. Twenty-five patients experienced mandibular advancement and 12 patients had setbacks. The average advancement was 6.5 mm (range, 3-17 mm) and the average set-back was 5.2 mm (range, 3-8 mm). Intraoperative placement was uncomplicated and no screws were stripped during placement. No problems in immediate postoperative stability were encountered and relapse was not evident in any patient. Follow-up ranged from 3 to 17 months. The screw holes remained evident radiographically after 1 year. Two and one-half-millimeter copolymeric PLLA-PGA resorbable screws for mandibular ramus osteotomies appear to offer clinical results comparable with metallic screw fixation.  相似文献   

4.
IntroductionResorbable screw fixation for orthognathic surgery is widely used in oral and maxillofacial surgery and has several advantages. However, surgeons are concerned about using resorbable screws in orthognathic surgery because of possible postoperative complications such as relapse, screw fracture, and infection. The purpose of this study was to evaluate the skeletal stability of bicortical resorbable screw fixation after sagittal split ramus osteotomies for mandibular prognathism.Materials and methodsThis study included 25 patients who underwent mandibular setback surgery fixed with resorbable screws after sagittal split osteotomy at the Department of Oral and Maxillofacial Surgery at Seoul National University Dental Hospital. Five resorbable screws (Inion CPS®, Inion Ltd., Finland) were applied bicortically at each osteotomy site via a transbuccal approach. No rigid intermaxillary fixation was applied on the first postoperative day. Passive mouth opening exercises were allowed, using two light, rubber elastics for guidance. The control group was 25 patients fixed with four titanium screws. The follow-up period was 12–22 months (mean 17.8 months). Postoperative skeletal changes on lateral cephalometric radiographs were analyzed and compared between the two groups preoperatively, immediately postoperatively, and 6 months postoperatively.ResultsThe average setback was 6.9 mm and no major intraoperative complications occurred. One patient experienced infection immediately after surgery that was controlled uneventfully. The data did not demonstrate any significant difference in postoperative skeletal stability between the two groups. Differences between the immediate postoperative state and 6 months after surgery were not significant. In earlier cases, especially for patients with severe mandibular prognathism, immediate postoperative elastic traction was needed for stable occlusal guidance.ConclusionsThe results of this study indicate that bicortical resorbable screws offer a clinically stable outcome for the fixation of mandibular sagittal split osteotomies in mandibular prognathism. However the resorbable screws showed less stable results vertically than the titanium screws.  相似文献   

5.
Rigid fixation is the most important issue in the bone healing process. Although internal metallic bone fixation has become increasingly popular over the past 10 years, the presence of several potential problems of metallic bone implants with the popularity of the use of biodegradable plates and screws for craniomaxillofacial fixation have increased in the last 10 years. Rigid fixation of bony fragments was achieved by bicortical applied biodegradable screws in a patient with a sagittal oblique mandibular fracture. Precise bone reduction was maintained with bicortical applied biodegradable screws in the postoperative period. The postoperative period was uneventful and the patient retained the intraoperatively achieved perfect occlusion within a 9-month follow-up period. In this particular case, the advantages of use of resorbable fixation systems are combined with the advantages of bicortical screw fixation of split osteotomy without sacrificing the stability of rigid fixation.  相似文献   

6.
PURPOSE: The object of the study was to determine the suitability of specific resorbable screws for fixation of mandibular sagittal split osteotomies by in vitro biomechanical strength testing. MATERIALS AND METHODS: Resorbable screws (2.5 mm diameter) composed of a polylactic acidpolyglycolic acid copolymer were placed in an inverted L-pattern in overlapping urethane blocks representative of sagittal split mandibular surgery. In an in vitro model at room temperature, the test specimens were statically loaded until tensile failure occurred. On a different set of test specimens, dynamic testing was done in an in vitro water bath at body temperature through cyclic loads representative of mastication until failure. RESULTS: In static testing, three 2.5-mm resorbable screws sustained an average peak load of 131 Kiloponds (Kp) (standard deviation, 5.2 Kp) with 5.5% strain at yield. In dynamic testing, the resorbable screws tolerated a 45.3-Kp load for an average of 340,675 cycles (22,783 standard deviation). Several of these test specimens did not ultimately fail and were further evaluated by static testing with an average load of 77.4 Kp until fixation failure occurred. CONCLUSIONS: These laboratory results indicate a relatively high resistance to biomechanical loads representative of mastication and suggest that 2.5-mm resorbable screws of this particular polylactic acid-polyglycolic acid copolymer may be effective in fixation of the postoperative unrestrained sagittal split mandibular osteotomy.  相似文献   

7.
OBJECTIVES: To determine any differences in the intra- and postoperative morbidities and complications between resorbable and titanium plating systems for fixation in orthognathic surgery. STUDY DESIGN: This prospective randomized clinical trial was conducted in the Oral and Maxillofacial Surgery unit of the University of Hong Kong. Patients with dentofacial deformities were randomly assigned into the titanium and resorbable fixation groups. Intraoperative data such as the surgical procedures, time for fixing each plate, and number of broken plates and screws were recorded. Subjective and objective parameters related to clinical morbidities were assessed postoperatively. RESULTS: A total of 60 patients with 177 osteotomies were included in this study. Eighty-seven osteotomies fixated with 196 titanium plates and 784 titanium screws were performed in 30 patients, whereas 90 osteotomies fixated with 165 resorbable plates and 658 resorbable screws were done in another 30. The postoperative infection rate was 1.53% (3/196) and 1.82% (3/165) in the titanium and resorbable fixation groups, respectively. These infections were mainly due to loose screws and wound dehiscence. The plate exposure rate was 1.02% (2/196) for the titanium group and 1.21% (2/165) for the resorbable group. The plate removal rate in the titanium and resorbable groups was 1.53% (3/196) and 3.63% (6/165), respectively. Statistically significant difference was shown in the plating time of step (mandibular body) and Hofer (mandibular subapical) osteotomies. There was no significant difference in the subjective clinical parameters such as wound discomfort, clinical stability of the osteotomy segments, palpability of plate, and overall satisfaction of the results between the 2 fixation groups. Similarly, objective parameters including wound dehiscence, rate of infection, plate exposure, occurrence of sinus tract, and palpability assessed by surgeons in both groups also showed no significant difference. CONCLUSION: Bioresorbable fixation devices offer similar function as titanium in fixation for orthognathic surgery and do not impose an increase in the clinical morbidities.  相似文献   

8.
This study examines the short-term stability of bimaxillary surgery following Le Fort I impaction with simultaneous bilateral sagittal split osteotomies and mandibular advancement using two standard techniques of postsurgical fixation. Fifteen adults had skeletal plus dental maxillomandibular fixation, and fifteen adults had rigid internal fixation using bone plates in the maxilla and bicortical bone screws between the proximal and distal segments in the mandible. The group with rigid internal fixation did not undergo maxillomandibular fixation. Radiographic cephalograms were analyzed during the postsurgical period to evaluate skeletal and dental stability. There was no statistical difference in postsurgical stability with rigid internal fixation or skeletal plus dental maxillomandibular fixation other than the vertical position of the maxillary molar; the skeletal plus dental maxillomandibular fixation group had a significant amount of postsurgical intrusion of the maxillary molar when compared with the rigid internal fixation group. Although the other measures showed no statistically significant difference between the experimental groups, the amount of variability in postsurgical stability in the group with skeletal plus dental maxillomandibular fixation was greater than that found in the group with rigid internal fixation.  相似文献   

9.
PURPOSE: This computer-based study used finite element analysis (FEA) to assess whether rigid fixation by resorbable polymer plates and screws can provide the required stiffness and strength for a typical mandibular angle fracture. MATERIALS AND METHODS: Two separate 3-dimensional FEA models of the mandible were generated using 8-noded hexahedral elements. The jaw segments in 1 model were fixed with titanium plates and screws as those in common use today. The jaw segments in the other model were fixed with resorbable polymer plates and screws as used in a developmental product currently in trials. A commercial finite element solver was then applied to this mesh to compute stresses and bone interfragmentary displacements for both titanium fixation and resorbable fixation. Calculated displacements were compared with each other and to established norms for healthy bone regrowth. Calculated stresses were compared with the yield strength of each material. Finally, overall stress patterns in the fractured mandibles were compared with each other. RESULTS: The study results indicate that titanium fixation more rigidly fixes the 2 bone segments in relative position. However, they also show that resorbable polymers provide sufficient stiffness to meet currently established norms for fracture immobility. Furthermore, the analyses show that resorbable polymers are capable of withstanding the stresses generated by the bite loads of postsurgical patients. The results indicate that mandibles, fixed with either titanium or resorbable materials, show nearly identical stress patterns. CONCLUSIONS: The resorbable polymer-based plates and screws tested in this investigation are of adequate strength and stiffness for their successful application to the rigid fixation of mandibular angle fractures.  相似文献   

10.
This study was designed to examine amounts of postoperative maxillary movement in patients who received Lefort I osteotomies, comparing bone plate and screw fixation with conventional transosseous wire fixation. Cephalograms of 17 patients whose maxillae were fixated with wire osseous fixation and 13 patients whose maxillae were fixed with bone plates and screws were compared at four different time periods throughout the first postoperative year. Millimeters of movement of five maxillary assessment points were assessed in the horizontal and vertical planes of space by use of a line constructed 7 degrees to sella-nasion at nasion as the horizontal reference. Results indicate that the amount of maxillary movement was similar for the two groups during the two time periods subsequent to the surgical procedure. However, it appears that the maxillae fixated with bone plates and screws were more stable than those with wire osteosynthesis during the last postoperative period (6 months to 1 year) and during the overall postoperative time interval (2 days to 1 year).  相似文献   

11.
PURPOSE: The aim of this study was to evaluate skeletal stability after double jaw surgery for correction of skeletal Class III malocclusion to assess if there were any differences between resorbable plate and screws and titanium rigid fixation of the maxilla. PATIENTS AND METHODS: Twenty-two Class III patients had bilateral sagittal split osteotomy for mandibular setback stabilized with rigid internal fixation. Low level Le Fort I osteotomy for maxillary advancement was stabilized with conventional titanium plate and screws in 12 patients (group 1) and with resorbable plate and screws in 10 patients (group 2). Lateral cephalograms were taken before surgery, immediately postoperatively, 8 weeks after surgery, and 1 year postoperatively. RESULTS: Before surgery both groups were balanced with respect to linear and angular measurements of craniofacial morphology. One year after surgery, maxillary stability was excellent in both groups. In group 1 no significant correlations were found between maxillary advancement and relapse. In group 2, significant correlations were found between maxillary advancement and relapse at A point and posterior nasal spine. No significant differences in postoperative skeletal and dental stability between groups were observed. CONCLUSION: Surgical correction of Class III malocclusion after combined maxillary and mandibular procedures appears to be a fairly stable procedure for maxillary advancements up to 5 mm independently from the type of fixation used to stabilize the maxilla. Resorbable devices should be used with caution for bony movements of greater magnitude until their usefulness is evaluated in studies with large maxillary advancements.  相似文献   

12.
Twenty patients had sagittal split osteosynthesis performed with three or four 2.5-mm resorbable screws on each side without additional fixation. The screws consisted of a poly-L-latic/polyglycolic copolymer (LactoSorb). Of the 20 patients, 17 had mandibular advancement, two had mandibular setback, and one underwent unilateral mandibular advancement after previous condylectomy. Six patients underwent simultaneous Le Fort I osteotomy and four patients had simultaneous genioplasty. Postoperative training elastics were maintained for an average of 2.5 weeks. Six of the patients have been followed for 2 years, and 14 have been followed between 1 and 2 years without observable relapse and without clinical, radiological, or histological signs of healing complications. The resorbable osteosynthesis utilized in this series of sagittal split osteotomy seems to offer reliable stability during the period of bony healing without any adverse tissue reactions.  相似文献   

13.
PURPOSE: This report describes the authors' experience with self-reinforced biodegradable bone plates and screws to stabilize maxillary and mandibular osteotomies. Patient acceptance, demographics, types of osteotomy, means of stabilization, etiology of the deformity, complications, and patient disposition are reviewed. PATIENTS AND METHODS: Seventy patients underwent 194 osteotomies of the maxilla and/or mandible. Stabilization of each osteotomy was achieved using self-reinforced polylactite bone plates and/or screws of similar size and configuration to that of titanium systems. Placement of the devices was accomplished transorally and transfacially, consistent with the osteotomy approach. Maxillomandibular elastics were used to control the position of the jaws in each patient. RESULTS: There was good patient acceptance of the material (70/74). Stabilization was accomplished as planned in all patients. Three patients experienced problems that resulted in immediate loosening of the bone screws. The remaining 67 experienced no short-term problems (6 to 24 months), and healing progressed uneventfully. In each case, acceptable occlusion and favorable aesthetic changes were noted. CONCLUSIONS: The experience with self-reinforced polylactite bone plates and screws to stabilize maxillary and mandibular osteotomies has been favorable on short-term observation.  相似文献   

14.
We present our early experience with the use of a resorbable plating system in orthognathic surgery. Thirty-one patients who have finished growing and who had dentofacial deformities that were not part of syndromes were treated by routine orthognathic repositioning procedures: maxillary (n = 8) and mandibular (n = 9) osteotomies, or bimaxillary procedures (n = 14). All skeletal fragments were fixed with resorbable plates and screws. The follow-up period ranged from 2-8 months (mean 5). All the patients recovered normally except for one who developed a localized buccal space infection. In the early postoperative period, six patients had mild mobility of the maxilla, but stability was within normal limits at six weeks postoperatively. We conclude that, though technique has an important influence on success, LactoSorb is a good fixative for maxillo-mandibular repositioning.  相似文献   

15.
The purpose of this study was to compare by qualitative histology the efficacy of rigid internal fixation with titanium system and the Lacto Sorb system in mandibular fractures in rabbits. Thirty male adult rabbits Oryctolagus cuniculus were used. Unilateral mandibular osteotomies were performed between the canine and first premolar. The animals were divided into two groups: for Group I-rigid internal fixation was performed with titanium system 1.5 mm (Synthes, Oberdorf, Switzerland), with two screws of 6 mm (bicortical) on each side of the osteotomy. For Group II-rigid internal fixation was performed with PLLA/PGA system 1.5 mm (Lacto Sorb, WLorenz, Jacksonville, FL, USA). The histological analysis evaluated the presence of inflammatory reaction, degree of bone healing and degree of resorption of the Lacto Sorb screws. The results of both fixation systems were similar, only with a small difference after 15 and 30 days. In Group I a faster bony healing was noted. But after 60 days, bony healing was similar in both groups. It is concluded that both PLLA/PGA and titanium plates and screws provide sufficient strength to permit mandibular bone healing. The resorption process of PLLA/PGA osteosynthesis material did not cause acute or chronic inflammatory reaction or foreign body reaction during the studied period.  相似文献   

16.
PURPOSE: The purpose of this study was to determine if rigid fixation with bicortical screws and/or miniplates with monocortical screws prevent mobility at the osteotomy site after bilateral mandibular sagittal split osteotomy. PATIENTS AND METHODS: Three metal bone markers were inserted in the proximal and the distal segments of the mandible during the sagittal split operation in 10 patients. These served as measurement points in postoperative follow-up by radiographic stereophotogrammetry. The patients were examined at intervals during the first postoperative year. At each examination, 2 sets of radiographic stereograms were obtained: 1 in rest position and 1 with stress applied to the osteotomy sites. The difference in the position of the proximal segment in relation to the distal segment between the 2 sets of stereograms was recorded. Findings greater than 0.4 degrees and 0.2 mm change indicated true displacement of the bone segments. RESULTS: Immediately after surgery, mobility at of the osteotomy site(s) was found in 8 of 10 patients, and after 1 year it was still present in 4 patients. CONCLUSIONS: Fixation with bicortical screws or miniplates and monocortical screws does not prevent mobility at the osteotomy site after sagittal split osteotomies. This mobility may remain as long as 1 year after surgery. The term "rigid fixation" is thus not a proper term for this kind of fixation.  相似文献   

17.
PURPOSE: This study was conducted to evaluate the postoperative stability of Le Fort I osteotomies accomplished with 2-plate versus 4-plate fixation. METHODS: This is a retrospective study involving 32 patients who underwent Le Fort I 1-piece osteotomy concurrent with orthodontic therapy. All patients were treated by 1 attending surgeon during an 18-month period. Sixteen patients were treated by plate and screw fixation consisting of 4 miniplates (group I), and an additional 16 patients were treated using 2 miniplates (group II). In group I, fixation was accomplished with 2.0-mm low-profile Lorenz (Walter Lorenz Surgical Inc, Jacksonville, FL) plates and screws placed at the piriform aperture and at the maxillary buttress. Four screws were placed in each of the plates. In group II, fixation was accomplished with 2.0-mm low-profile Lorenz plates and screws placed at the piriform aperture. Again, 4 screws were placed in each of the plates. RESULTS: Serial cephalometric evaluation at arbitrary anterior nasal spine and posterior nasal spine for both groups showed that postoperative skeletal changes in the direction of the surgical movement were seen in approximately 20% of cases; these changes averaged less than 1 mm. Postoperative skeletal changes opposite to the direction of the surgical movement were seen in approximately 30% of cases; these changes also averaged less than 1 mm. No postoperative skeletal changes were seen in approximately 50% of cases. For all measured changes about arbitrary anterior nasal spine and posterior nasal spine, there was no significant difference between groups I and II. CONCLUSION: This study suggested that postoperative skeletal changes associated with the use of 2-plate fixation do not appear to differ significantly from those seen with 4-plate fixation.  相似文献   

18.
OBJECTIVES: The aim of this study was to comparatively evaluate the resistance of 3 plating rigid internal fixation techniques for mandibular condylar process fractures. MATERIALS AND METHODS: Synthetic hemi-mandible replicas made in polyurethane were used to evaluate a control, and 3 mandibular condyle plating techniques using 2-mm system plates and screws. The plating techniques were fixation with a 4-hole plate and 4 6-mm screws, fixation with a 4-hole plate and 4 8-mm screws and fixation with 2 4-hole plates with 4 6-mm screws each. Each group was subjected to linear loading in medial to lateral and anterior to posterior directions by an Instron 4411 servohydraulic mechanical testing unit (Instron Corp, Norwood, MA). Load peak value and peak displacement were measured. Means and standard derivations were derived and compared for statistical significance using an analyses variance (P < .05) and compared by Tukey test. RESULTS: Statistically significant differences were noted between fixation groups for the different mechanical measures evaluated under the different directions of linear loading. The 2-plate fixation system presented better behavior, followed by 1 plate with 4 8-mm screws and 1 plate with 4 6-mm screws. The fixation systems used were more resistant to antero-posterior load and the use of 8-mm screws improved the resistance of the fixation when compared with 6-mm screws only in the antero-posterior test. CONCLUSION: Under the conditions tested the 2-plate fixation system provided the most favorable mechanical behavior. We can suggest that lengthy screws, with bicortical engagement, can increase the stability at fixation of mandibular condylar process fractures.  相似文献   

19.
Ten fresh mandibles from adult sheep were stripped of all soft tissues and sectioned in the midline. We did sagittal split osteotomies and 5 mm advancement on all the 20 hemimandibles. Ten hemimandibles were fixed with three 2.0 mm x 13 mm titanium bicortical screws, and the other 10 were fixed with three 2.0 mm x 13 mm poly-l-lactic acid/polyglycolic acid (PLLA/PGA) bicortical screws in an inverted L pattern. All the hemimandibles were then mounted in a servohydraulic testing unit and tested to permanent deformation. Maximum forces that the mandibles resisted before breaking, maximum displacements, and the displacement values under 20, 60, 120, and 150 N were compared using the Mann-Whitney U-test. There were no significant differences in stability between the bones fixed with titanium and those fixed with resorbable screws.  相似文献   

20.
目的 回顾性分析可吸收钉板在下颌骨髁突骨折中的应用,探讨其在髁突骨折治疗中的适应证、操作难点及注意事项。 方法 2012年7月至2018年6月,武汉大学口腔医院口腔颌面创伤与颞下颌关节外科应用可吸收钉板固定下颌骨髁突骨折患者82例(共106侧),其中髁突高位矢状骨折46侧,中位髁颈骨折26侧,低位髁颈下骨折34侧。髁头及髁颈骨折复位术均经耳屏前径路;髁颈下骨折复位术中,多数经耳屏前径路及颌下径路。髁突高位矢状骨折复位后以1~2枚可吸收长螺钉固定,髁颈及髁颈下骨折以2块可吸收板固定。术后随访6个月至3年。结果 所有患者术后未诉明显不适,面型基本对称,面部肌肉运动正常,咬合对位良好,开口度恢复,未见明显排斥反应及严重并发症。结论 可吸收钉板可应用于髁突高位矢状骨折、中位髁颈骨折、低位髁颈下骨折的开放复位内固定。应用可吸收钉板固定髁突骨较钛板钛钉复杂,需熟练掌握合适的操作技巧及注意事项。  相似文献   

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