• Maxillofacial Plastic and Reconstructive Surgery
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• 제29권1호
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• pp.1-9
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• 2007

Purpose: To evaluate the effect of compression on the distracted area in new bone formation during mandibular distraction osteogenesis in rabbits. Materials and method: Sixteen rabbits, weighing approximately 2 Kg, and the prefabricated distraction device were used. With the rabbits under general anesthesia, we performed vertical osteotomies between the anterior and posterior mandibular teeth and then placed the distraction device. After a 5 -day latency period, the mandible was distracted to a length of 10.0 mm at a rate of 1 mm/day and then immediately compressed 4 mm in the experimental group (n=8). In the control group (n=8), the mandible was distracted to a length of 6.0 mm at a rate of 1 mm/day. Rabbits in the control group were killed at 2 and 8 weeks during the consolidation period. The specimens were evaluated with light microscope after H & E stain. Histomorphometric analysis was done at 8 week specimens. Results: All experimental animals showed mandibular elongation on the macroscopical and radiographic evaluations. At 2 week, immature bone formation was observed from the surface of the host bone margins with collagen fibers arranged parallel to the direction of distraction in the control group; in the experimental group, immature bone formation was observed adjacent to the host bone, and the collagen fibers were not arranged uniformly. At 8 week, spindle-shaped new bone formation was seen in the direction of distraction in distracted area of the control group, while in the experimental group, the newly formed bone was arranged in a multidirectional manner, like the pattern of trabeculae. In the histomorphometric analysis of 8 weeks, the area of bone deposition was $2.12{\pm}\;0.75\;inch^2$ in the experimental group and $0.87{\pm}0.51\;inch^2$ in the control group (p<0.01). The bone deposition ratio was $29.60{\pm}10.50%$ in the experimental group and $12.10{\pm}7.17%$ in the control group (p<0.01). Conclusion: These results suggest that compression after over-distraction during the mandibular distraction osteogenesis is an effective method of increasing the amount of newly formed bone in distracted area.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제30권6호
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• pp.516-525
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• 2004

Mandibular symphyseal distraction osteogenesis is an alternative approach for correcting mandibular transverse deficiencies and dental crowding. The traditional approaches for these are extraction of teeth and arch expansion with traditional orthodontic treatment. Also extractions are usually unavoidable in patients with severe crowding. The purpose of this study is to evaluate the effect of mandibular symphyseal distraction osteogenesis by use of tooth-borne expansion appliance. All of 12 patients had been performed distraction osteogenesis. The surgical procedures were accomplished under local anesthesia and intravenous sedation in an ambulatory surgical setting using a routine distraction protocol. The latency period was 5 days or 7 days after symphyseal osteotomies. The rate & rhyth is a intermittent, 0.75mm or 1.0 mm per day and stabilized for 6, 8 weeks after distraction. The time of orthodontic tooth movement after distraction was variable from 2 weeks to 8 weeks (mean 3 weeks). All patients had been evaluated with study casts, plain periapical films, panorama radiograms before & after surgery. Mandibular symphyseal distraction osteogenesis increased mandibular arch width and corrected dental crowding, with paralleling tooth-borne movement, without proclination of the mandibular incisors.

• Child Health Nursing Research
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• 제21권2호
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• pp.168-175
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• 2015

Purpose: The purpose of this study was to identify whether individualized distraction intervention using a smart phone affected pre-op anxiety of children. Methods: This was a nonequivalent control group pre-post test quasi-experimental design. The participants were 30 children in the experimental group and 30 in the control group. In experimental group, a smart phone individualized distraction intervention was given to children from the reception area to the operation room. Results: For heart rate, there were no statistically significant differences between the experimental group and control group. In the behavioral anxiety response, there were statistically significant differences between the experimental group and control group (t=-3.11, p=.003). Conclusion: The finding suggest that, for pre-op children, the individualized distraction intervention using a smart phone had some significance as a nursing intervention having a positive impact. Such interventions can help pediatric nurses to relieve pre-op anxiety and improve health of children in their care.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제28권5호
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• pp.404-416
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• 2006

Purpose : This study was to clarify the changes in mandibular condyle after unilateral mandibular distraction osteogenesis throughout histological changes and expression of matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of matrix metalloproteinase-2 (TIMP-2). Materials & Methods : Intraoral distractors were placed via submandibular incision in 8 dogs. Two unoperated animals served as controls. Distraction was performed five days after osteotomy as a rate of 0.5 mm twice per day for 10 days. Two animals were sacrificed on 7, 14, 28, and 56 days after completion of distraction, respectively. Ipsilateral condyles were harvested and processed for histological and immunohistochemical examinations. Results : The condyle cartilage is separated into four layers: fibrous layer, proliferative layer, hypertrophic layer, and calcified layer. At 7 days and 14 days after distraction, the condylar cartilage showed the decreased thickness of the articular cartilage and reduced cellularity. At 28 days after distraction, there was an increase in cellularity of fibrous, proliferative, and hypertrophic layer. However, it demonstrated reduced cellularity compared to the control. At 56 days of after distraction, the articular cartilage was an almost normal histologic structure. Positive Safranin-O staining, indicative of sulfated proteoglycans, was examined in the condylar cartilge of nonloaded control. At 7 days and 14 days after distraction, the sulfated proteoglycans is almost completely depleted from the noncalcified part of the condylar cartilage. At 28 days after distraction, there was an increase in Safranin-O staining intensity. However, the staining intensity of the experimental condyle was weaker than that of the control. At 56 days of after distraction, the condylar cartilage showed almost normal Safranin-O staining pattern. In control condyle, MMP-2 immunostaining was seen in fibrous, proliferative, and hypertrophic layer of condylar cartilage, however, it demonstrated lack of staining in fibrous and proliferative layer. At 7 days and 14 days after distraction, strong MMP-2 immunoreactivity was seen in the fibrous, proliferative and hypertrophic layer of the condylar cartilage. At 28 days after distraction, MMP-2 immunostaining was seen in the fibrous and hypertrophic layer of condylar cartilage, however, their immunoactivity was reduced. At 56 days after distraction, MMP-2 immunoreactivity showed almost normal immunostaining pattern. In control condyle, TIMP-2 immunostaining was primarily seen in fibrous and hypertrophic layer of condylar cartilage, however, it demonstrated lack of staining in proliferative layer. At 7 days after distraction, very weak TIMP-2 immunoreactivity appeared in fibrous, proliferative and hypertrophic layer of the condylar cartilage. At 14 days after distraction, weak TIMP-2 immunoreactivity was seen in the fibrous, proliferative and hypertrophic layer of the condylar cartilage. At 28 days after distraction, TIMP-2 immunoreactivity was increased in the fibrous and hypertrophic layer of condylar cartilage. At 56 days after completion of distraction, TIMP-2 immunoreactivity showed almost normal immunostaining pattern. Conclusions : The results show that short-term outcome of physiologic distraction osteogenesis may lead to degenerative changes in the condylar cartilage. These alterations in the condylar cartilage may be considered as a pressure-related degeneration of the cartilage tissue. However, the long-term results suggest that the condylar cartilage display repair activity after mandibular distraction osteogenesis.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제30권4호
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• pp.261-270
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• 2004

The purpose of this experiment was to examine the histological changes and the pattern of expression of type I, II collagen in the elongated area by distraction osteogenesis in the rabbit mandible. Sixteen rabbits weighing 2.5kg-3kg were used for this experiment. Experimental group was distracted at the rate of 0.7mm, twice/day for 7days, and control group was only osteotomized. After 5 days latency, osteotomic site is distracted for 7days. Consolidation period is 28days. The animal was sacrificed at the 3rd, 7th, 14th, 28th day after the operation. The distracted bone was examined by histological analysis and RT-PCR analysis. The results were summarized as follows: 1. Experimental group was observed that the gaps between the distracted bone edges were occupied by new bone. 2. Expression of Type I collagen were detected throughout the experiment in both groups and Expression of Type I collagen were markedly increased during distraction and consolidation period in experimental group than control group. 3. Expression of Type II collagen were detected throughout the experiment in both groups and expression of Type II collagen were maintained at high level during distraction and consolidation period in experimental group than control group. From these results, in contrast to type II collagen, type I collagen seemed to be more expressed by mechanical stimuli during distraction and consolidation period. The predominent mechanism of new bone formation in the distraction gap was intramembranous bone formation, but some of the regenerated bone was formed by endochondral ossification.

• 대한치과교정학회지
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• 제50권2호
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• pp.136-144
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• 2020

Hemifacial microsomia (HFM) patients may experience emotional withdrawal during their growth period due to their abnormal facial appearance. Distraction osteogenesis at an early age to improve their appearance can encourage these patients. Some abnormalities of the affected side can be overcome by distraction osteogenesis at an early age. However, differences in the growth rate between the affected and unaffected sides during the rest of the growth period are inevitable due to the characteristics of HFM. Therefore, re-evaluation should be performed after completion of growth in order to achieve stable occlusion through either orthognathic surgery or camouflage orthodontic treatment. An eight-year-old patient visited the clinic exhibiting features of HFM with slight mandibular involvement. He received phase I treatment with distraction osteogenesis and a functional appliance. Distraction osteogenesis was performed at the right ramus, which resulted in an open bite at the right posterior dentition. After distraction osteogenesis, a functional appliance and partial fixed appliance were used to achieve extrusion of the affected posterior dentition and settlement of the occlusion adjustment on the unaffected posterior dentition. The patient visited the clinic regularly for follow-up assessments, and at the age of 20 years, he showed facial asymmetry of the mandible, which had deviated to the right side. He received orthodontic treatment to improve the occlusion of his posterior dentition after the growth period. Without orthognathic surgery, stable occlusion and a satisfactory facial appearance were obtained through camouflage orthodontic treatment.

• 한국임상수의학회지
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• 제19권2호
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• pp.165-173
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• 2002

The purpose of this study was to evaluate the effect of chitosan-calcium sulfate mixture on early bony consolidation in osteodistracted dogs. The experimental group was divided into 3 groups: saline group(Control), chitosan group(Group CH) and chitosan-calcium sulfate mixture group(Group CH+CS). Four dogs were allocated to each group and classified into B week observation subgroups and 5 week observation subgroups, respectively. Two dogs were allocated to each subgroup. The lateral surface of the left mandibular body was exposed in the subperiosteal plane and vertical osteotomy was carried out on the mandibular body. An external distraction device was applied to the mandibular body. Mandibular distraction was started 5 days after the osteotomy at a rate of 1 m per day for a total of 10 w distraction for 10 days. After completion of distraction, chitosan, chitosan-calcium sulfate and saline were injected into the distracted zone of the group CH, group CH+CS and control. The external device was left in place for 3 or 5 weeks to allow for bony consolidation. Serial radiographs were carried out every week. Two dogs of each group, six dogs in total, were sacrificed at 3 weeks, and the other six dogs at 5 week after distraction. Bone specimens of the distracted mandibles were taken for histologic examination. New bone was not noted in the distracted zone of 3 week observation subgroups in the control and group CH. However, new bone was developed in the group CH+CS with a narrow fibrous interzone in the area of the distracted zone. While osteogenesis was mild in the margin of the distracted Bone of 5 week observation subgroup in the control, new bone was noted much in the group CH and group CH+CS. However, osteogenesis was noted more significantly in the group CH+CS than that of group CH. In conclusion, chitosan-calcium sulfate mixture was more effective on early bony consolidation in distraction osteogenesis

• Maxillofacial Plastic and Reconstructive Surgery
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• 제27권4호
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• pp.315-323
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• 2005

For reconstruction of the bony defect, distraction osteogenesis has many advantages in comparison with bone graft. However, it needs long consolidation period for sufficient bone maturity. This study is performed to evaluate the effect of PRP injection into the distracted mandible on bone formation in rabbits. Twelve house rabbits, weighing 2 kg, were used. All animals underwent bilateral mandibular osteotomy under general anesthesia. A internal distractor divice was positioned along a plane perpendicular to the line of osteotomy. After 5 days of latency period, distraction osteogenesis was started at a rate of 1 mm/day for 9 days which was distracted 9 mm totally. After completion of distraction, 0.5 ml of PRP which collected in rabbit blood was injected into the distracted mandible on experimental group, whereas no injection was done in control group. Macroscopical, radiographical, and histological, and histomorphometric examinations were performed 2, 4 and 8 weeks after distraction. All animals showed distracted mandible and severe anterior cross-bite. In radiographical findings 2 weeks after distraction, more radiopacity in the distracted gap was found in experimental group than that of control group. At 4 weeks after distraction, distracted bone was similar to normal bone in experimental group. In histological findings, 1) At 2 weeks after distraction, number of osteoblasts and angiogenesis in the distracted gap was found in experimental group than that of control group. 2) At 4 weeks after distraction, more active and distinct bone in the distracted gap was found in experimental group than that of control groups. 3) At 8 weeks after distraction, more dense and matured lamellated bone in the distracted gap was found in experimental group than that of control group. In histomorphometrical findings 8 weeks after distraction, more bone formation was observed in experimental group than control group (p<0.01). These results indicate that administration of PRP into the distracted mandible can promote bone formation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제30권3호
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• pp.193-202
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• 2004

Distraction osteogenesis(DO) is defined as a gradual mechanical process of mechanical stretching two vascularized bone surface apart with a critical rate and rhythm such that new bone forms within the expanding gap, reliably bridges the gap, and ultimately remodels to normal structure. DO has become a mainstay in bone tissue engineering and has significantly improved our armamentarium for reconstructive craniomaxillofacial procedures. But the molecular and biological mechanisms that regulate the formation of new bone during distraction osteogenesis are not completely understood. BMPs are potent osteoinductive agents. Our hypothesis was that BMPs, especially BMP-2 and BMP-4, might play an importent role in the signaling pathways that link the mechanical forces created by distraction to biological responses and in promting new bone formation. Using a rabbit's mandible, we investigated the expression of BMP-2, -4 at different time points during distraction osteogenesis. The purpose of this study is to research the pattern of expression of BMP-2, -4 in new bone formation during distraction osteogenesis of the rabbit mandible. The experimental group was applied gradual distraction (0.7mm a day by twice a day, 4.9mm in total, for 7 days) and the control group was carried out osteotomy alone. They were examined clinically, histologically, and by RT-PCR analysis. On 3 days after osteotomy, the high level of expression of BMP-2, -4 was detected. But, the expression of BMP-4 was decreased during latency period. As distraction was started, its expression was increased and maintained till postoperative 28days. In control group, the expression of BMP-4was remarkably decreased till postoperative 14 days. On the other hand, the expression of BMP-2 was no difference between experimental group and control group. The expression of BMP-4 was maintanined at high level during the entire experimental period in both group. These findings suggested that excellent bone formation during distraction osteogenesis is associated with enhanced expression of BMP-4 genes by mechanical tension stress.

• Journal of Korean Neurosurgical Society
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• 제62권4호
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• pp.450-457
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• 2019

Objective : Anterior cervical discectomy and fusion (ACDF) is commonly used surgical procedure for cervical degenerative disease. Among the various intervertebral spacers, the use of allografts is increasing due to its advantages such as no harvest site complications and low rate of subsidence. Although subsidence is a rare complication, graft collapse is often observed in the follow-up period. Graft collapse is defined as a significant graft height loss without subsidence, which can lead to clinical deterioration due to foraminal re-stenosis or segmental kyphosis. However, studies about the collapse of allografts are very limited. In this study, we evaluated risk factors associated with graft collapse. Methods : We retrospectively reviewed 33 patients who underwent two level ACDF with anterior plating using allogenous bone graft from January 2013 to June 2017. Various factors related to cervical sagittal alignment were measured preoperatively (PRE), postoperatively (POST), and last follow-up. The collapse was defined as the ratio of decrement from POST disc height to follow-up disc height. We also defined significant collapses as disc heights that were decreased by 30% or more after surgery. The intraoperative distraction was defined as the ratio of increment from PRE disc height to POST disc height. Results : The subsidence rate was 4.5% and graft collapse rate was 28.8%. The pseudarthrosis rate was 16.7% and there was no association between pseudarthrosis and graft collapse. Among the collapse-related risk factors, pre-operative segmental angle (p=0.047) and intra-operative distraction (p=0.003) were significantly related to allograft collapse. The cut-off value of intraoperative distraction ${\geq}37.3%$ was significantly associated with collapse (p=0.009; odds ratio, 4.622; 95% confidence interval, 1.470-14.531). The average time of events were as follows: collapse, $5.8{\pm}5.7months$; subsidence, $0.99{\pm}0.50months$; and instrument failure, $9.13{\pm}0.50months$. Conclusion : We experienced a higher frequency rate of collapse than subsidence in ACDF using an allograft. Of the various preoperative factors, intra-operative distraction was the most predictable factor of the allograft collapse. This was especially true when the intraoperative distraction was more than 37%, in which case the occurrence of graft collapse increased 4.6 times. We also found that instrument failure occurs only after the allograft collapse.