• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.6
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• pp.526-531
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• 2005

Distraction osteogenesis is a technique of bone lengthening by gradual movement and subsequent remodeling. Distraction forces applied to bone also create tension in the surrounding soft tissues, distraction histiogenesis. Distraction osteogenesis is used to correct facial asymmetry, such as patients with hemifacial microsomia, maxillary or mandibular retrusion, cleft lip & palate, alveolar defect and craniofacial deficiency. Hemifacial microsomia is characterized by unilateral facial hypoplasia, often with unilateral shortening of the mandible and subsequent malocclusion. This report describes two cases of hemifacial microsomia(type IIB). In these two cases, distraction osteogenesis was used to correct a facial asymmetry. Two patients underwent unilateral mandibular distraction osteogenesis of ascending ramus of the mandible with extraoral devices. Successful distraction osteogenesis was achieved in the patients with hemifacial microsomia.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.28 no.2
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• pp.103-113
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• 2002

Distraction osteogenesis is a biologic process of new bone formation between the surfaces of bone segments that are gradually separated by incremental traction. Distraction osteogenesis is clinically applied as a new treatment modality of mandibular hypoplasia or bony defect area in maxillofacial area by many studies of distraction devices and method. But, disadvantages of distraction osteogenesis shows unfavorably long consolidation period and relapse tendency. Therefore, this experiment was designed to investigate the effectiveness of combined application of distraction and compression force for improving of bone quality and shortening of treatment period during distraction osteogenesis. Twenty-five Sprague-Dawley rats with $300{\sim}350gm$ were used. These were divided into two group as distraction group and combination group. The distraction group was added with conventional method during distraction osteogenesis, but the combination group was applied with compression force in the consolidation period. The rats were sacrificed for gross finding, radiographic and histologic findings at 3, 6 weeks after distraction. The results were as follow: 1. On radiographic finding, all combination of distraction and compression force group appeared more radiopacity than distraction group both at 3 weeks and 6 weeks after distraction group. 2. On histologic finding, the formation of mature lamellar bone were showed increasingly in combined group at 6weeks after distraction group. From this study, we may suggest that compression force application in consolidation period during distraction osteogenesis can be useful method to improve bone quality and to shorten the treatment period. But more experimental and clinical studies is necessitated on ideal application timing and method of compression force application during distraction osteogenesis.

• The Journal of the Korean dental association
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• v.50 no.11
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• pp.670-676
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• 2012

Distraction osteogenesis and orthognathic surgery are the widely used surgical methods for treating hemifacial microsomia and cleft lip and palate, the representative forms of congenital deformity. Distraction osteogenesis is an outstanding treatment of choice when more traction is needed than what can be achieved by general orthognathic surgery. However, the stability of distraction osteogenesis has not yet been established, and in most of the cases, additional orthognathic surgery is mandatory. Moreover, the difficulty in precise control of the traction directions is another disadvantage of distraction osteogenesis. Therefore, it would be desirable not to conduct distraction osteogenesis when the patient is suitable for an orthognathic surgery. Also, distraction osteogenesis should be recognized as an accessorial method of treatment, and be used restrictively.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.3
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• pp.250-265
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• 2008

Distraction osteogenesis is a well-established clinical treatment for limb length discrepancy and skeletal deformities. Appropriate mechanical tension-stress is believed not to break the callus but rather to stimulate osteogenesis. In contrast to fracture healing, the mode of bone formation in distraction osteogenesis is primarily intramembranous ossification. Although the biomechanical, histological, and ultrastructural changes associated with distraction osteogenesis have been widely described, the basic biology of the process is still not well known. Moreover, the molecular mechanisms in distraction osteogenesis remain largely unclear. Recent studies have implicated the growth factor cascade is likely to play an important role in distraction. And current reserch suggested that mechanical tension-stress modulates cell shape and phenotype, and stimulates the expression of the mRNA for bone matrix proteins. The purpose of this study is to examine the pattern of expression of growth factors($TGF-{\beta}1$, IGF-I, bFGF) and extracellular matrix proteins(osteoclacin, osteonectin) related to osteogenesis by osteodistraction of the mandible in rabbits. 24 rabbits is used for this experiment. Experimental group are gradual distraction(0.7mm, twice/day), acute distraction(1.4mm, twice/day) and control group is only osteotomized. After 5 days latency, osteotomic site is distracted for each 7 days and 3.5 days. Consolidation period is 28 days. The animal is sacrificed at the 3th, 7th, 14th, 28th. The distracted bone is examined by immunohistochemical analysis and RT-PCR analysis. The results obtained from this study were as follow : No significant difference was found on clinical examination according to distraction rate, but gradual distraction was shown to improve regenerate bone formation on radiographic and histologic examination. Growth factors and extracelluar matrix proteins expression increased in distraction group than control group. From these results, it could be stated that graudal distraction is shown to improve and accelerate bone formation and mechanical stress like distraction has considerable effects on osteogenesis related factors. And rabbit is the most appropriate animal model for further reseach on the molecular mechanisms that mediate osteodistraction. It is believed that understanding the biomolecular mechanisms that mediate distraction osteogenesis may guide the development of targeted strategies designed to improve distraction osteogenesis and accelerate bone healing.

• Journal of Korean Neurosurgical Society
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• v.59 no.3
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• pp.233-241
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• 2016

In this review, we discuss in detail our current procedure for treating craniosynostosis using multidirectional cranial distraction osteogenesis (MCDO). The MCDO method allows all phenotypes of skull deformity to be reshaped by distraction osteogenesis, except in patients who are 5 months of age or younger and patients with posterior cranial vault problems. We report the results of clinical data of 36 children with craniosynostosis who underwent MCDO between 2005 and 2014 in our institute. This method has the following benefits, such as a high flexibility of reshaping, shorter treatment period and less invasive secondary intervention. We also discuss the other distraction osteogenesis techniques that are used to treat craniosynostosis and compare them with MCDO. The preferred procedure for correction of craniosynostosis may depend on the patient's age, the extent of deformity, and the extent of correction achievable by surgery. We can arrange the combinations of various methods according to the advantage and disadvantage of each technique.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.28 no.6
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• pp.456-463
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• 2002

Distraction osteogenesis is a well-established clinical treatment for limb length discrepancy and skeletal deformities. Appropriate mechanical tension-stress is believed not to break the callus but rather to stimulate osteogenesis. In contrast to fracture healing, the mode of bone formation in distraction osteogenesis is primarily intramembranous ossification. Although the biomechanical, histological, and ultrastructural changes associated with distraction osteogenesis have been widely described, the basic biology of the process is still not well known. Moreover, the molecular mechanisms in distraction osteogenesis remain largely unclear. Recent studies have implicated the growth factor cascade is likely to play an important role in distraction. And current reserch suggested that mechanical tension-stress modulates cell shape and phenotype, and stimulates the expression of the mRNA for bone matrix proteins. This article presents the hypotheses and current research that have furthered knowledge of the molecular biology that govern distraction osteogenesis. The gene regulation of growth factors and extracellular matrix proteins during distraction osteogenesis are discussed in this article. It is believed that understanding the biomolecular mechanisms that mediate distraction osteogenesis may guide the development of targeted strategies designed to improve distraction osteogenesis and accelerate bone healing.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.5
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• pp.368-379
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• 2004

Distraction osteogenesis is a biologic process of new bone formation between the surfaces of bone segments that are gradually separated by incremental traction. Distraction osteogenesis is clinically applied as a new treatment modality of mandibular hypoplasia or bony defect area in maxillofacial area by many studies of distraction devices and method. But disadvantage of distraction osteogenesis shows unfavorably long consolidation period and relapse tendency. Therefore. this experiment was designed to investigate the effectiveness of combined application of distraction and compression force for improving of bone quality and shortening of treatment period during distraction osteogenesis. Twenty-one Sprague-Dawley rats with $300{\sim}350gm$ were used. These were divided into two group as distraction group and combination group was applied with compression force in the consolidation period. The rat were sacrificed for gross finding, radiographic and histologic findings. at 2, 4 weeks after distraction. The result were follow : 1. On radiographic finding, all experimental groups appeared more radiopacity than control groups both at 2, 4 weeks after distraction. 2. On histologic finding, trabeculae of bone and mature lamellar bone were showed increasingly in experimental group. Ossification occured rapidly. From this study, we may suggest that compression force application in consolidation period during distraction osteogenesis can be useful method improve bone quality and to shorten the treatment period. But more experimental and clinical studis are necessitated on effects of compression force application during distraction osteogenesis.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.6
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• pp.620-627
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• 2000

The purpose of this study is to investigate the clinical and histologic changes in distraction osteogenesis according to different distraction rates in the rat's tibia. Eighteen adult rats underwent open osteotomy and attachment of an external unilateral distraction device in the middle of left tibia. Latency was allowed for 7 days before distracton began. The distraction device was activated with varying distraction rates of 0.5mm, 1mm, 2mm and same rhythm of twice a day until 5mm length gain was achieved. The animals were sacrificed at post-distraction 4, 8 weeks to observe the bony healing states. At each group, clinical, radiographic and histologic studies were done. The results obtained from this study were as follows: 1. The 0.5mm group showed excellent osteogenesis than other groups. The new bone was formed by intramembranous bone formation mostly and endochondral bone formation partly. 2. The 1mm group showed delayed osteogenesis and incomplete bony healing at 8 weeks. 3. The 2mm group showed weak osteogenesis and fibrous union or nonunion at 8 weeks. From these results, it could be stated that distraction rate of 0.5mm per day was most useful in rat's tibia. The rate of 1mm showed delayed bony healing and needed more consolidation period. Distraction osteogenesis is a excellent clinical method for regenerating local bone deficiencies in limbs and craniofacial area. The more studies needed for the higher animals and human about distraction rates and other biomechanical factors on the basis of this study.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.4
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• pp.329-338
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• 2006

Objectives: Distraction osteogenesis has recently evolved a challenging technique to overcome the limitations of conventional augmentation procedures. The aim of this report was to evaluate the clinical result of alveolar distraction osteogenesis for implant installation. Methods: Twenty five patients with alveolar ridge deficiencies were treated with vertical alveolar distraction osteogenesis by intraoral device (total 27 devices: 25 extraosseous and 2 intraosseous devices). After the latency periods of 5-7 days, activation of the device was started. The distraction rhythm and rate was 0.75-1.0 mm a day with 2 or 3 times a day. After 3-4 months, dental implants were placed with removing the distractor simultaneously. Results: On average, a vertical gain of $9.8{\pm}3.4\;mm$ was obtained by distraction osteogenesis. Total 84 implants were installed. Average follow up period was $13.5{\pm}7.5$ months. No implant was removed during the follow up period. Three patients showed infection during the distraction osteogenesis. Three devices were broken and 2 devices among them were replaced with new one. Conclusion: Relatively larger amount of alveolar bone augmentation could be obtained with distraction osteogenesis. For the ideal anatomically and functionally ideal regeneration of alveolar bone to install dental implant, the complication of distraction should be controlled.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.6
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• pp.549-558
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• 2006

During distraction osteogenesis, the angiogenic activity is crucial factor in the new bone formation. The aim of this study was to detect the autocrine growth activity in the cellular components of the distracted periosteum with observation of the expression of vascular endothelial growth factor (VEGF) and its receptors following the mandibular distraction osteogenesis. Unilateral mandibular distraction (0.5 mm twice per day for 10 days) was performed in six mongrel dogs. Two animals were sacrificed at 7, 14, and 28 days after completion of distraction, respectively. The distracted lingual periosteum was harvested and processed for immunohistochemical examinations. After then, we observed the expression of VEGF, Flt-1 (VEGFR-1), and Flk-1 (VEGFR-2) in the osteoblasts and immature mesenchymal cells of the distracted periosteum. At 7 days after distraction, the expression of VEGF and its receptors were significantly increased in the cellular components of the distracted periosteum. Up to 14 days following distraction, the increased expressions were maintained in the osteoblastic cells. At 28 days after distraction, the expression of VEGF and its receptors decreased, but VEGF was still expressed weak or moderate in the osteoblastic cells of distracted periosteum. The expression pattern of VEGF and its receptors shown here suggested that VEGF play an important role in the osteogenesis, and these osteoblastic cell-derived VEGF might act as autocrine growth factor during distraction osteogenesis. In the other word, the cellular components in the distracted periosteum, such as osteoblasts and immature mesenchymal cells, might have autocrine growth activity during distraction osteogenesis.