Objective: skeletal advancement in order to improve the airway dimensions is known as one of the most effective surgical theraphy for treating obstructive sleep apnea (OSA). Distraction osteogenesis (DO) can be a bett...Objective: skeletal advancement in order to improve the airway dimensions is known as one of the most effective surgical theraphy for treating obstructive sleep apnea (OSA). Distraction osteogenesis (DO) can be a better treatment alternative in some selected cases similar to our patient. Using custom made distractors can make this technique more safe and successful. Study Design: Surgically assisted rapid palatal expansion (SARPE), bilateral intraoral mandibular distraction osteogenesis (MDO) and orthodontic treatment were tried to a 20-year-old OSA patient with orthognathic anomaly. For mandibular distraction, custom made distractors were used. Results: The initial AHI of the patient was 23.3. At the end of the treatment it decreased to 8.7. Conclusions: Distraction osteogenesis could be a better alternative than the conventional orthognathic surgery in this kind of selected patients. Customization of the distraction devices can contribute to making this procedure safer and more successful.展开更多
Objective To investigate the histological changes of rapid tooth movement in dogs treated by resistance reduction and distraction osteogenesis,aiming to establish an animal model and further to reveal the remodeling m...Objective To investigate the histological changes of rapid tooth movement in dogs treated by resistance reduction and distraction osteogenesis,aiming to establish an animal model and further to reveal the remodeling mechanism of rapid tooth movement. Methods A total of 8 local hybrid dogs were selected as subjects for this study. The second pre-molar was extracted on both sides. The experimental side underwent alvelor surgery for resistance reduction and a home-made tooth-borne intraoral distraction device was installed for rapid tooth movement,while for the other side (control side) only tooth-borne intraoral distraction device was used for rapid tooth movement. The longest active force-delivery span was 2 weeks,followed by 6-week retention. The distance between the moved tooth and anchor unit was recorded weekly,and radiography was performed for each side before and after distraction. The surrounding tissues including periodontal ligament and alveolar bone were sectioned for histological analysis. Results The average distance of tooth movement was 3.55mm on the experimental side and 1.11mm on the control side. The rate of tooth movement was notably higher (P<0.01) and no significant apical root resorption was detected by X-ray on the experimental side. The active alvelor bone remodeling was found on the tension and pressure sides. However,there was no significant difference between the experimental side and the control side after the retention period. Conclusion The rate of orthodontic tooth movement can be accelerated through resistance reduction and periodontal distraction without any unfavorable effects but at minimal anchorage loss.展开更多
BACKGROUND Bone transport and distraction osteogenesis has been widely used to treat bone defects after traumatic surgery,but,skin and soft tissue incarceration can be as high as 27.6%.AIM To investigate the efficacy ...BACKGROUND Bone transport and distraction osteogenesis has been widely used to treat bone defects after traumatic surgery,but,skin and soft tissue incarceration can be as high as 27.6%.AIM To investigate the efficacy of inserting a tissue expander to prevent soft tissue incarceration.METHODS Between January 2016 and December 2018,12 patients underwent implantation of a tissue expander in the subcutaneous layer in the vicinity of a tibial defect to maintain the soft tissue in position.A certain amount of normal saline was injected into the tissue expander during surgery and was then gradually extracted to shrink the expander during the course of transport distraction osteogenesis.The tissue expander was removed when the two ends of the tibial defect were close enough.RESULTS In all 12 patients,the expanders remained intact in the subcutaneous layer of the bone defect area during the course of transport distraction osteogenesis.When bone transport was adequate,the expander was removed and the bone transport process was completed.During the whole process,there was no incarceration of skin and soft tissue in the bone defect area.Complications occurred in one patient,who experienced poor wound healing.CONCLUSION The pre-filled expander technique can effectively avoid soft tissue incarceration.The authors’primary success with this method indicates that it may be a valuable tool in the management of incarcerated soft tissue.展开更多
Purpose: To measure the upper airway changes associated with maxillary distraction osteogenesis in cleft lip and palate patients in the immediate post operative period and 12 months later. Materials and Methods: Seven...Purpose: To measure the upper airway changes associated with maxillary distraction osteogenesis in cleft lip and palate patients in the immediate post operative period and 12 months later. Materials and Methods: Seven patients with repaired cleft lip and palate (CLP) presented with severe maxillary hypoplasia. They were examined initially at T1 predistraction phase. Records taken included radiographs (orthopantograms OPG, lateral cephalometric, posteroanterior). Cephalometric analysis was done to evaluate the upper airway. Mean age is 17 years and the reverse overjet > 6 mm. They underwent maxillary Le Fort I distraction using external rigid distracters (RED). Cephalometric analysis to evaluate the upper airway was repeated at the end of the consolidation phase T2 and twelve months after distractor removal T3. Results: The range of maxillary advancement was between 8 - 15 mm (mean 9 mm). The anteroposterior distance of the superior velopharynx (PPS) and middle velopharynx (SPPS) increased at T2. A small amount of reduction in these values was recorded at T3. The inferior velopharynx (MPS) and the oropharynx (IPS, EPS) showed minimum increase in anteroposterior distance in only two patients at T2 and no change at T3. Conclusion: All seven patients showed clinical improvement in the upper airway and an increase in the upper airway values on lateral cephalometric radiographs.展开更多
Objective: To apply trifocal distraction osteogenesis in canine model of skull segmental defects and to provide reference for clinical treatment. Methods: Six labrador dogs were selected in this study and divided into...Objective: To apply trifocal distraction osteogenesis in canine model of skull segmental defects and to provide reference for clinical treatment. Methods: Six labrador dogs were selected in this study and divided into observation group and control group randomly. Each group contained 3 dogs. Skull segmental defects models were established by surgery, and dogs in bservation group received trifocal distraction osteogenesis treatment. Bone density was observed and compared between two groups during treatment. Results: There were no significant difference in bone density between two groups on th 1st day ( P>0.05). The bone density of observation group on the 30th day, and 60th day were higher than that of control group ( P<0.01). Conclusions: Trifocal distraction osteogenesis has significant clinical effect, and it would be widely used in clinical treatment.展开更多
Aim Understanding the response of mesenchymal stem cells (MSCs) to mechanical strain and their consequent gene expression patterns will broaden our knowledge of the mechanobiology of distraction osteogenesis. Methodol...Aim Understanding the response of mesenchymal stem cells (MSCs) to mechanical strain and their consequent gene expression patterns will broaden our knowledge of the mechanobiology of distraction osteogenesis. Methodology In this study, a single period of cyclic mechanical stretch (0.5 Hz, 2,000 με) was performed on rat bone marrow MSCs. Cellular proliferation and alkaline phosphatase (ALP) activity was examined. The mRNA expression of six bone-related genes (Ets-1, bFGF, IGF-Ⅱ, TGF-β, Cbfa1 and ALP) was detected using real-time quantitative RT-PCR. Results The results showed that mechanical strain can promote MSCs proliferation, increase ALP activity, and up-regulate the expression of these genes. A significant increase in Ets-1 expression was detected immediately after mechanical stimulation, but Cbfa1 expression became elevated later. The temporal expression pattern of ALP coincided perfectly with Cbfa1. Conclusion The results of this study suggest that mechanical strain may act as a stimulator to induce differentiation of MSCs into osteoblasts, and that these bone-related genes may play different roles in the response of MSCs to mechanical stimulation.展开更多
Distraction osteogenesis(DO) is widely used for bone tissue engineering technology. Immune regulations play important roles in the process of DO like other bone regeneration mechanisms. Compared with others, the immun...Distraction osteogenesis(DO) is widely used for bone tissue engineering technology. Immune regulations play important roles in the process of DO like other bone regeneration mechanisms. Compared with others, the immune regulation processes of DO have their distinct features. In this review, we summarized the immune-related events including changes in and effects of immune cells, immune-related cytokines, and signaling pathways at different periods in the process of DO. We aim to elucidated our understanding and unknowns about the immunomodulatory role of DO. The goal of this is to use the known knowledge to further modify existing methods of DO, and to develop novel DO strategies in our unknown areas through more detailed studies of the work we have done.展开更多
Facial asymmetry can be acquired or congenital. Patients with facial asymmetry are not always functionally disturbed by the malfunction but are usually very much disturbed by their external appearance. Depending on th...Facial asymmetry can be acquired or congenital. Patients with facial asymmetry are not always functionally disturbed by the malfunction but are usually very much disturbed by their external appearance. Depending on the degree of asymmetry and deformation, the surgical procedure may vary in complexity and extent. The extent of surgery can range from a genioplasty procedure to bimaxillary osteotomy, concomitant with augmentation surgery, genioplasty and craniofacial implants along with mandibular distraction. In severe cases, the soft tissue structures on the affected side may constitute an incredible resistance to stretching and can make the surgery considerably more difficult and liable to relapse. Here we represent a case of post ankylotic facial asymmetry with occlusal cant which was treated by bimaxillary distraction osteogenesis. Simultaneous mandibular and maxillary distraction corrected the facial asymmetry without disturbing the pre-existing compensated dental occlusion, and so there was no need for prolonged and difficult orthodontic treatment.展开更多
Background: Distraction Osteogenesis is popular for long bones. And nowadays it has found its role in facial bone deficiency treatments. Purpose: We used our special designed Distractor for advancement of Maxillary de...Background: Distraction Osteogenesis is popular for long bones. And nowadays it has found its role in facial bone deficiency treatments. Purpose: We used our special designed Distractor for advancement of Maxillary deficiencies in cleft lip and palate patients. The purpose of this paper is to compare the treatment of hypoplastic, posteriorly retruded maxillary of cleft palate patients using distraction osteogenesis vs. Le fort I orthognathic surgery for length of advancement, stability and relapse, growth after distraction and soft tissue expansion and soft tissue profile changes. Meterial & Methods: In group A only Le fort I and surgical maxillary advancement sometimes with bone graft were done. In group B we used our special Distractor for Distraction Osteogenesis and advancement of the Maxillary bone. Demographic data, length of retrusion of maxilla, time length of treatment, length of advancement and relapse, SNA and SNB angles were measured and included in the study. The results were compared in each group before and after advancement and between both groups. The rate of distraction was 0.5 mm twice per day to achieve normal occlusion with 2 mm overcorrection more than calculated measures. The devices removed after 10 weeks as latency period. Results: The SNA increased at the end of distraction (p < 0.001), with no significant relapse indicating stability at 1 year after treatment. The total length of advancement in group A was 17 ± 4 mm and in group B was 20 ± 3 mm. The difference between before and after measurements in each group was significant (p = 0.002, p = 0.003 respectively). The mean length of relapse in group A was 3 ± 1 mm and in group B was 1 mm. Discussion: For the deformities and retrusions less than 7 - 8 mm, the Orthognatic surgery is the treatment of choice, however for more retrusions (>10 mm) we recommend Distraction Osteogenesis, and it preferred to start it soon in younger ages.展开更多
By using distraction osteogenesis technique, 3 cases of mandibular hypoplasia were treat ed by home made and German made jaw distractors: including one patient suffered from bilateral ankylosis of temporo mandibular j...By using distraction osteogenesis technique, 3 cases of mandibular hypoplasia were treat ed by home made and German made jaw distractors: including one patient suffered from bilateral ankylosis of temporo mandibular joint and 2 patients from deficiency of mandible. The duration of distraction osteogenesis was one month. The bone distractor was removed 3 months after operation. Satisfactory results were obtained in all 3 cases. Distraction osteogenesis can successfully be used in mandibular functional reconstruction and has much more advantages than traditional technique.展开更多
Temporomandibular joint ankylosis, a debilitating disease mainly affecting children, is characterized by progres?sive restriction of mouth opening and maxilla-mandibular developmental deformities. Craniofacial distrac...Temporomandibular joint ankylosis, a debilitating disease mainly affecting children, is characterized by progres?sive restriction of mouth opening and maxilla-mandibular developmental deformities. Craniofacial distraction osteo?genesis has been developed as a standard surgical strategy for rectification of craniofacial deformities. The purpose of this study was to assess mono-planar distraction devices for the correction of various mandibular asymmetries in patients with unilateral temporomandibular joint ankylosis who developed restricted mouth opening and mandibular retrognathia. All patients were treated using one-stage distraction osteogenesis followed by temporalis fascia interpositional arthroplasty under general anesthesia. A significant increase in mandibular ramus and base length was observed. Although an increase in anterior lower facial height was observed, it was not significant statistically.A decrease in posterior lower facial height and corpus was observed. Oblique distraction with angular osteotomy allowed lengthening of both the ramus and corpus, yielding satisfactory results and hence eliminating the need of secondary surgery. In conclusion, univector internal distractors are effective for correction of multi-planar mandib?ular deficiencies by optimizing its placement through meticulous planning.展开更多
Objective: To observe osteogenetic rate of alveolar bone on the tension side in orthodontic tooth movement through distraction osteogenesis of the periodental ligament quantificationally. Methods: The experiment was c...Objective: To observe osteogenetic rate of alveolar bone on the tension side in orthodontic tooth movement through distraction osteogenesis of the periodental ligament quantificationally. Methods: The experiment was carried in 6 dogs. The left side of jaws of each one was set as test or control side, and the other side was control or test side. On the control side, the first premorlar was moved by traditional method on the test side. A self-made distraction device was used on the test side. The newly formed alveolar bone on the tension side of moved tooth was labeled by serial tetracycline fluorochrome. Sections were observed by fluorescence microscope and pictured. Newly formed bone was measured by computer image analysis. Results: The quantity of newly formed bone was significantly different between the two methods. Newly formed bone in rapid tooth movement by distraction osteogenesis of the periodental ligament was more than that in traditional method. Conclusion: The distraction through periodental ligament could induce more rapid bone formation and excite higher osteogenetic activity than traditional method.展开更多
The purpose of this study was to compare the dentoalveolar changes produced when using two different intraoperative surgical procedures for maxillary distraction osteogenesis. Eight patients were assigned into two gro...The purpose of this study was to compare the dentoalveolar changes produced when using two different intraoperative surgical procedures for maxillary distraction osteogenesis. Eight patients were assigned into two groups according to the surgical procedure: down-fracture (DF, n = 6) vs non-down-fracture (NDF, n = 2). Lateral cephalograms and 3-D models before and after maxillary distraction were analyzed. The Mann-Whitney U test was used to compare the differences in the amounts of advancement and dento-alveolar changes between the DF and NDF groups. The significance level was established at 0.05. Although a significantly greater amount of maxillary movement was observed in the DF group (10.0 mm ± 2.2) than in the NDF group (5.9 mm ± 2.3), significantly greater arch length (8.7 mm ± 5.2) and arch width changes (6.0 mm ± 1.0) were observed in the NDF group than in the DF group, (arch lengths 3.0 mm ± 1.1 and arch width changes 3.2 mm ± 2.0). A significantly greater amount of dental anchorage loss was observed in the NDF group. The use of the NDF procedure resulted in greater amounts of dental anchorage loss than resulted from the DF procedures when tooth-borne devices were used during maxillary distraction osteogenesis. The type of surgical procedure might play an important role in the amount and direction of the dental changes.展开更多
Objective To study the ultrastructure and Ca/P clement spectrometry of distraction osteogenesis(DO) for reconstruction of cleft palate(CP),so as to explore the osteogenesis and remodeling of new bone in situ.Methods 2...Objective To study the ultrastructure and Ca/P clement spectrometry of distraction osteogenesis(DO) for reconstruction of cleft palate(CP),so as to explore the osteogenesis and remodeling of new bone in situ.Methods 23 rhesus macaques展开更多
Distraction spinal cord injury is caused by some degree of distraction or longitudinal tension on the spinal cord and commonly occurs in patients who undergo corrective operation for severe spinal deformity.With the i...Distraction spinal cord injury is caused by some degree of distraction or longitudinal tension on the spinal cord and commonly occurs in patients who undergo corrective operation for severe spinal deformity.With the increased degree and duration of distraction,spinal cord injuries become more serious in terms of their neurophysiology,histology,and behavior.Very few studies have been published on the specific characteristics of distraction spinal cord injury.In this study,we systematically review 22 related studies involving animal models of distraction spinal cord injury,focusing particularly on the neurophysiological,histological,and behavioral characteristics of this disease.In addition,we summarize the mechanisms underlying primary and secondary injuries caused by distraction spinal cord injury and clarify the effects of different degrees and durations of distraction on the primary injuries associated with spinal cord injury.We provide new concepts for the establishment of a model of distraction spinal cord injury and related basic research,and provide reference guidelines for the clinical diagnosis and treatment of this disease.展开更多
Distraction osteogenesis(DO)is a mechanobiological process of regenerating bone tissue by tension stress.DO is used clinically to lengthen bones or to treat critical size bone defects.Although DO provides satisfactory...Distraction osteogenesis(DO)is a mechanobiological process of regenerating bone tissue by tension stress.DO is used clinically to lengthen bones or to treat critical size bone defects.Although DO provides satisfactory results in many cases,the prolonged period of treatment remains a major challenge that needs to be overcome.Various attempts have been devoted to accelerating bone regeneration during DO.One common approach is manipulation of the applied mechanical loading by altering distraction strategies.In this article,we reviewed relevant in vivo animal studies exploring the effects of changing mechanical environments,by varying distraction parameters(e.g.,rate and frequency)or adding compression loading,on bone regeneration in DO.We further presented how the mechanically-regulated bone regeneration process during DO could be simulated by in silico models incorporating mechano-regulatory tissue differentiation rules.A comprehensive review of those in vivo and in silico studies may not solely provide important references for development of improved DO protocols in clinic,but also promote a deeper understanding of the mechanobiological mechanism of bone regeneration.展开更多
文摘Objective: skeletal advancement in order to improve the airway dimensions is known as one of the most effective surgical theraphy for treating obstructive sleep apnea (OSA). Distraction osteogenesis (DO) can be a better treatment alternative in some selected cases similar to our patient. Using custom made distractors can make this technique more safe and successful. Study Design: Surgically assisted rapid palatal expansion (SARPE), bilateral intraoral mandibular distraction osteogenesis (MDO) and orthodontic treatment were tried to a 20-year-old OSA patient with orthognathic anomaly. For mandibular distraction, custom made distractors were used. Results: The initial AHI of the patient was 23.3. At the end of the treatment it decreased to 8.7. Conclusions: Distraction osteogenesis could be a better alternative than the conventional orthognathic surgery in this kind of selected patients. Customization of the distraction devices can contribute to making this procedure safer and more successful.
基金supported by the Traditional Chinese Medicine Research Fund of the Administration of Traditional ChineseMedicine of Shaanxi Province (jc34)
文摘Objective To investigate the histological changes of rapid tooth movement in dogs treated by resistance reduction and distraction osteogenesis,aiming to establish an animal model and further to reveal the remodeling mechanism of rapid tooth movement. Methods A total of 8 local hybrid dogs were selected as subjects for this study. The second pre-molar was extracted on both sides. The experimental side underwent alvelor surgery for resistance reduction and a home-made tooth-borne intraoral distraction device was installed for rapid tooth movement,while for the other side (control side) only tooth-borne intraoral distraction device was used for rapid tooth movement. The longest active force-delivery span was 2 weeks,followed by 6-week retention. The distance between the moved tooth and anchor unit was recorded weekly,and radiography was performed for each side before and after distraction. The surrounding tissues including periodontal ligament and alveolar bone were sectioned for histological analysis. Results The average distance of tooth movement was 3.55mm on the experimental side and 1.11mm on the control side. The rate of tooth movement was notably higher (P<0.01) and no significant apical root resorption was detected by X-ray on the experimental side. The active alvelor bone remodeling was found on the tension and pressure sides. However,there was no significant difference between the experimental side and the control side after the retention period. Conclusion The rate of orthodontic tooth movement can be accelerated through resistance reduction and periodontal distraction without any unfavorable effects but at minimal anchorage loss.
文摘BACKGROUND Bone transport and distraction osteogenesis has been widely used to treat bone defects after traumatic surgery,but,skin and soft tissue incarceration can be as high as 27.6%.AIM To investigate the efficacy of inserting a tissue expander to prevent soft tissue incarceration.METHODS Between January 2016 and December 2018,12 patients underwent implantation of a tissue expander in the subcutaneous layer in the vicinity of a tibial defect to maintain the soft tissue in position.A certain amount of normal saline was injected into the tissue expander during surgery and was then gradually extracted to shrink the expander during the course of transport distraction osteogenesis.The tissue expander was removed when the two ends of the tibial defect were close enough.RESULTS In all 12 patients,the expanders remained intact in the subcutaneous layer of the bone defect area during the course of transport distraction osteogenesis.When bone transport was adequate,the expander was removed and the bone transport process was completed.During the whole process,there was no incarceration of skin and soft tissue in the bone defect area.Complications occurred in one patient,who experienced poor wound healing.CONCLUSION The pre-filled expander technique can effectively avoid soft tissue incarceration.The authors’primary success with this method indicates that it may be a valuable tool in the management of incarcerated soft tissue.
文摘Purpose: To measure the upper airway changes associated with maxillary distraction osteogenesis in cleft lip and palate patients in the immediate post operative period and 12 months later. Materials and Methods: Seven patients with repaired cleft lip and palate (CLP) presented with severe maxillary hypoplasia. They were examined initially at T1 predistraction phase. Records taken included radiographs (orthopantograms OPG, lateral cephalometric, posteroanterior). Cephalometric analysis was done to evaluate the upper airway. Mean age is 17 years and the reverse overjet > 6 mm. They underwent maxillary Le Fort I distraction using external rigid distracters (RED). Cephalometric analysis to evaluate the upper airway was repeated at the end of the consolidation phase T2 and twelve months after distractor removal T3. Results: The range of maxillary advancement was between 8 - 15 mm (mean 9 mm). The anteroposterior distance of the superior velopharynx (PPS) and middle velopharynx (SPPS) increased at T2. A small amount of reduction in these values was recorded at T3. The inferior velopharynx (MPS) and the oropharynx (IPS, EPS) showed minimum increase in anteroposterior distance in only two patients at T2 and no change at T3. Conclusion: All seven patients showed clinical improvement in the upper airway and an increase in the upper airway values on lateral cephalometric radiographs.
基金supported by Shanghai Municipal Science and Technology Commission, International Cooperation Projects (No. 10410702100)
文摘Objective: To apply trifocal distraction osteogenesis in canine model of skull segmental defects and to provide reference for clinical treatment. Methods: Six labrador dogs were selected in this study and divided into observation group and control group randomly. Each group contained 3 dogs. Skull segmental defects models were established by surgery, and dogs in bservation group received trifocal distraction osteogenesis treatment. Bone density was observed and compared between two groups during treatment. Results: There were no significant difference in bone density between two groups on th 1st day ( P>0.05). The bone density of observation group on the 30th day, and 60th day were higher than that of control group ( P<0.01). Conclusions: Trifocal distraction osteogenesis has significant clinical effect, and it would be widely used in clinical treatment.
基金supported by grants from the National Nature Science Foundation of China (No. 30772454)Science and Technology Bureau of Sichuan Province (No. 2006z09-013)
文摘Aim Understanding the response of mesenchymal stem cells (MSCs) to mechanical strain and their consequent gene expression patterns will broaden our knowledge of the mechanobiology of distraction osteogenesis. Methodology In this study, a single period of cyclic mechanical stretch (0.5 Hz, 2,000 με) was performed on rat bone marrow MSCs. Cellular proliferation and alkaline phosphatase (ALP) activity was examined. The mRNA expression of six bone-related genes (Ets-1, bFGF, IGF-Ⅱ, TGF-β, Cbfa1 and ALP) was detected using real-time quantitative RT-PCR. Results The results showed that mechanical strain can promote MSCs proliferation, increase ALP activity, and up-regulate the expression of these genes. A significant increase in Ets-1 expression was detected immediately after mechanical stimulation, but Cbfa1 expression became elevated later. The temporal expression pattern of ALP coincided perfectly with Cbfa1. Conclusion The results of this study suggest that mechanical strain may act as a stimulator to induce differentiation of MSCs into osteoblasts, and that these bone-related genes may play different roles in the response of MSCs to mechanical stimulation.
基金supported by grants from the National Key R&D Program of China (2016YFC1102800)National Natural Science Foundation of China (81879741, 51872332)+1 种基金Natural Science Foundation of Liaoning Province (20170541040)China Postdoctoral Science Foundation Grant (2020M681020)
文摘Distraction osteogenesis(DO) is widely used for bone tissue engineering technology. Immune regulations play important roles in the process of DO like other bone regeneration mechanisms. Compared with others, the immune regulation processes of DO have their distinct features. In this review, we summarized the immune-related events including changes in and effects of immune cells, immune-related cytokines, and signaling pathways at different periods in the process of DO. We aim to elucidated our understanding and unknowns about the immunomodulatory role of DO. The goal of this is to use the known knowledge to further modify existing methods of DO, and to develop novel DO strategies in our unknown areas through more detailed studies of the work we have done.
文摘Facial asymmetry can be acquired or congenital. Patients with facial asymmetry are not always functionally disturbed by the malfunction but are usually very much disturbed by their external appearance. Depending on the degree of asymmetry and deformation, the surgical procedure may vary in complexity and extent. The extent of surgery can range from a genioplasty procedure to bimaxillary osteotomy, concomitant with augmentation surgery, genioplasty and craniofacial implants along with mandibular distraction. In severe cases, the soft tissue structures on the affected side may constitute an incredible resistance to stretching and can make the surgery considerably more difficult and liable to relapse. Here we represent a case of post ankylotic facial asymmetry with occlusal cant which was treated by bimaxillary distraction osteogenesis. Simultaneous mandibular and maxillary distraction corrected the facial asymmetry without disturbing the pre-existing compensated dental occlusion, and so there was no need for prolonged and difficult orthodontic treatment.
文摘Background: Distraction Osteogenesis is popular for long bones. And nowadays it has found its role in facial bone deficiency treatments. Purpose: We used our special designed Distractor for advancement of Maxillary deficiencies in cleft lip and palate patients. The purpose of this paper is to compare the treatment of hypoplastic, posteriorly retruded maxillary of cleft palate patients using distraction osteogenesis vs. Le fort I orthognathic surgery for length of advancement, stability and relapse, growth after distraction and soft tissue expansion and soft tissue profile changes. Meterial & Methods: In group A only Le fort I and surgical maxillary advancement sometimes with bone graft were done. In group B we used our special Distractor for Distraction Osteogenesis and advancement of the Maxillary bone. Demographic data, length of retrusion of maxilla, time length of treatment, length of advancement and relapse, SNA and SNB angles were measured and included in the study. The results were compared in each group before and after advancement and between both groups. The rate of distraction was 0.5 mm twice per day to achieve normal occlusion with 2 mm overcorrection more than calculated measures. The devices removed after 10 weeks as latency period. Results: The SNA increased at the end of distraction (p < 0.001), with no significant relapse indicating stability at 1 year after treatment. The total length of advancement in group A was 17 ± 4 mm and in group B was 20 ± 3 mm. The difference between before and after measurements in each group was significant (p = 0.002, p = 0.003 respectively). The mean length of relapse in group A was 3 ± 1 mm and in group B was 1 mm. Discussion: For the deformities and retrusions less than 7 - 8 mm, the Orthognatic surgery is the treatment of choice, however for more retrusions (>10 mm) we recommend Distraction Osteogenesis, and it preferred to start it soon in younger ages.
文摘By using distraction osteogenesis technique, 3 cases of mandibular hypoplasia were treat ed by home made and German made jaw distractors: including one patient suffered from bilateral ankylosis of temporo mandibular joint and 2 patients from deficiency of mandible. The duration of distraction osteogenesis was one month. The bone distractor was removed 3 months after operation. Satisfactory results were obtained in all 3 cases. Distraction osteogenesis can successfully be used in mandibular functional reconstruction and has much more advantages than traditional technique.
文摘Temporomandibular joint ankylosis, a debilitating disease mainly affecting children, is characterized by progres?sive restriction of mouth opening and maxilla-mandibular developmental deformities. Craniofacial distraction osteo?genesis has been developed as a standard surgical strategy for rectification of craniofacial deformities. The purpose of this study was to assess mono-planar distraction devices for the correction of various mandibular asymmetries in patients with unilateral temporomandibular joint ankylosis who developed restricted mouth opening and mandibular retrognathia. All patients were treated using one-stage distraction osteogenesis followed by temporalis fascia interpositional arthroplasty under general anesthesia. A significant increase in mandibular ramus and base length was observed. Although an increase in anterior lower facial height was observed, it was not significant statistically.A decrease in posterior lower facial height and corpus was observed. Oblique distraction with angular osteotomy allowed lengthening of both the ramus and corpus, yielding satisfactory results and hence eliminating the need of secondary surgery. In conclusion, univector internal distractors are effective for correction of multi-planar mandib?ular deficiencies by optimizing its placement through meticulous planning.
基金Supported by the Youth Science Foundation of Stomatological Hospital, Xi'an Jiaotong University
文摘Objective: To observe osteogenetic rate of alveolar bone on the tension side in orthodontic tooth movement through distraction osteogenesis of the periodental ligament quantificationally. Methods: The experiment was carried in 6 dogs. The left side of jaws of each one was set as test or control side, and the other side was control or test side. On the control side, the first premorlar was moved by traditional method on the test side. A self-made distraction device was used on the test side. The newly formed alveolar bone on the tension side of moved tooth was labeled by serial tetracycline fluorochrome. Sections were observed by fluorescence microscope and pictured. Newly formed bone was measured by computer image analysis. Results: The quantity of newly formed bone was significantly different between the two methods. Newly formed bone in rapid tooth movement by distraction osteogenesis of the periodental ligament was more than that in traditional method. Conclusion: The distraction through periodental ligament could induce more rapid bone formation and excite higher osteogenetic activity than traditional method.
文摘The purpose of this study was to compare the dentoalveolar changes produced when using two different intraoperative surgical procedures for maxillary distraction osteogenesis. Eight patients were assigned into two groups according to the surgical procedure: down-fracture (DF, n = 6) vs non-down-fracture (NDF, n = 2). Lateral cephalograms and 3-D models before and after maxillary distraction were analyzed. The Mann-Whitney U test was used to compare the differences in the amounts of advancement and dento-alveolar changes between the DF and NDF groups. The significance level was established at 0.05. Although a significantly greater amount of maxillary movement was observed in the DF group (10.0 mm ± 2.2) than in the NDF group (5.9 mm ± 2.3), significantly greater arch length (8.7 mm ± 5.2) and arch width changes (6.0 mm ± 1.0) were observed in the NDF group than in the DF group, (arch lengths 3.0 mm ± 1.1 and arch width changes 3.2 mm ± 2.0). A significantly greater amount of dental anchorage loss was observed in the NDF group. The use of the NDF procedure resulted in greater amounts of dental anchorage loss than resulted from the DF procedures when tooth-borne devices were used during maxillary distraction osteogenesis. The type of surgical procedure might play an important role in the amount and direction of the dental changes.
文摘Objective To study the ultrastructure and Ca/P clement spectrometry of distraction osteogenesis(DO) for reconstruction of cleft palate(CP),so as to explore the osteogenesis and remodeling of new bone in situ.Methods 23 rhesus macaques
基金supported by the National Natural Science Foundation of China,No.81772421(to YH).
文摘Distraction spinal cord injury is caused by some degree of distraction or longitudinal tension on the spinal cord and commonly occurs in patients who undergo corrective operation for severe spinal deformity.With the increased degree and duration of distraction,spinal cord injuries become more serious in terms of their neurophysiology,histology,and behavior.Very few studies have been published on the specific characteristics of distraction spinal cord injury.In this study,we systematically review 22 related studies involving animal models of distraction spinal cord injury,focusing particularly on the neurophysiological,histological,and behavioral characteristics of this disease.In addition,we summarize the mechanisms underlying primary and secondary injuries caused by distraction spinal cord injury and clarify the effects of different degrees and durations of distraction on the primary injuries associated with spinal cord injury.We provide new concepts for the establishment of a model of distraction spinal cord injury and related basic research,and provide reference guidelines for the clinical diagnosis and treatment of this disease.
基金This study was supported by the National Natural Science Foundation of China[grant numbers 11702008,11832003]the Beijing Natural Science Foundation[grant numbers 7202003]the Beijing Municipal Education Commission Research Program[grant numbers KM202010005035].
文摘Distraction osteogenesis(DO)is a mechanobiological process of regenerating bone tissue by tension stress.DO is used clinically to lengthen bones or to treat critical size bone defects.Although DO provides satisfactory results in many cases,the prolonged period of treatment remains a major challenge that needs to be overcome.Various attempts have been devoted to accelerating bone regeneration during DO.One common approach is manipulation of the applied mechanical loading by altering distraction strategies.In this article,we reviewed relevant in vivo animal studies exploring the effects of changing mechanical environments,by varying distraction parameters(e.g.,rate and frequency)or adding compression loading,on bone regeneration in DO.We further presented how the mechanically-regulated bone regeneration process during DO could be simulated by in silico models incorporating mechano-regulatory tissue differentiation rules.A comprehensive review of those in vivo and in silico studies may not solely provide important references for development of improved DO protocols in clinic,but also promote a deeper understanding of the mechanobiological mechanism of bone regeneration.
