• Maxillofacial Plastic and Reconstructive Surgery
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• 제20권3호
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• pp.250-255
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• 1998

The purpose of this study was to evaluate the histologic change of the inferior alveolar nerve according to distraction amount following mandibular lengthening. Seven rabbits weighing about 2 kg were used. Corticotomy was performed on the mandibular body anterior to the right first premolar region and unilateral external fixation device was placed. Every effort was made to preserve the inferior alveolar nerve during the corticotomy. The rabbits were then allowed to heal for 7 days without distraction of the device. The mandible was lengthened 0.36 mm/day, 0.76 mm/day, or 1.0 mm/day. Corticotomy and lengthening of mandible were not performed in control group. After the completion of the lengthening process, a 14-day-consolidation period was allowed. After consolidation, rabbits were sacrificed, and histologic examination of the inferior alveolar nerve was performed. The results obtained were as follows : 1. In the control group, normal trifascicular pattern of inferior alveolar nerve was observed. Epineurium, perineurium, endoneurium, and axon with myelin sheath were observed in normal appearance. 2. In 0.36 mm/day distraction group, the trifascicular pattern was normally shown, and there was no destruction in epineurium, perineurium, and endoneurium. The mild changes including myelin attenuation, axoplasmic swelling and darkening were observed. 3. In 0.72 mm/day distraction group, it was possible to differentiate the epineurium from the perineurium. Two normal fascicles and one injuried fascicle were observed with a partially destructed perineurium. Most of the axons had axoplasmic swelling and darkening. 4. In 1 mm/day distraction group, it was difficult to differentiate the nerve structures such as fascicles, epineurium, perineurium, and endoneurium. The axons were severely destroyed, except few which showed decreases in size and changes in shape. Some collagen matrices were observed around the axons. These results suggest that the higher the distraction amount, the more severe the injury to the inferior alveolar nerve, fascicles, axons. Although distraction osteogenesis may be useful, the amount of distraction should be carefully selected.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제38권
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• pp.12.1-12.6
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• 2016

Background: Temporomandibular joint (TMJ) ankylosis can be accompanied by various degrees of functional and esthetic problems. Adequate mouth opening, occlusal stability, and harmonious facial form are the main goals of treatment for ankylosis. Distraction osteogenesis has proven to be an excellent treatment for lengthening the ramus-condyle unit. However, various timings for distraction have been suggested, and there is no consensus on selection criteria for performing the procedure in stages or simultaneously with other treatments. Case presentation: In this case report, concomitant intraoral distraction and gap arthroplasty was planned to treat TMJ ankylosis and associated facial asymmetry. After gap arthroplasty and 23 mm of distraction, the ramus-condyle segment was successfully lengthened and mouth opening range was significantly increased. The resultant interocclusal space was stably maintained with an occlusal splint for 4 months after distraction. Finally, good occlusion was achieved after prosthetic treatment. The remaining mandibular asymmetry was corrected with osseous contouring and augmentation surgery. The mouth-opening range was maintained at 35 mm 24 months after treatment. Conclusion: Gap arthroplasty with intraoral distraction as a one-stage treatment and subsequent contouring surgery can be applied to correct ankylosis with moderate malocclusion and facial asymmetry.

• 대한치과교정학회지
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• 제36권4호
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• pp.308-320
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• 2006

견인골 신장술의 개념을 치주인대 조직에 적용한 Liou의 급속 치아 이동 술식은 이동할 견치의 원심부 골 삭제에 의한 치조골 저항의 최소화 및 근심부의 치주조직 견인에 의한 골 형성으로 요약된다. 이는 주로 제1소구치 발치 후 견치의 견인을 요하는 환자들에 적용되어 효과적으로 치료 기간을 단축하고 양호한 결과를 얻을 수 있으나 견인 중 견치의 경사 및 정출 등 문제점이 발생하기 쉬우므로 견인이 완료될 때까지 치체이동을 유도하며 경로를 유지하는 것이 중요하다. 본 증례에서는 이러한 급속견인의 예측가능성을 높이기 위해 설측으로 연장된 견인스크류를 순측의 견고한 안내선과 병행 적용하였다. 발치 직후 미리 제작된 견치 치근 모델을 적용하여 발치와의 깊이를 형성하고 또한 교정용 미니스크류 임플란트를 이용하여 고정원을 보강하였다. 이러한 방법을 적용하여 골격성 II급 관계 및 전치 돌출을 보이는 성인 여환에서 효과적인 견치 및 전치부 견인을 통해 치료기간을 13개월로 단축할 수 있었다. 우려했던 치수의 실활 혹은 치주조직의 병소는 발견되지 않았으며 치료 후 10개월 유지 시에도 양호한 교합관계 및 치주조직의 건강상태를 보였다. 본 증례에서 소개된 방법을 통하여 급속 견인을 필요로 하는 경우에 보다 예측 가능한 방법으로 효율적인 치료를 할 수 있을 것으로 사료된다.

• 대한치과보철학회지
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• 제45권1호
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• pp.107-118
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• 2007

Statement of problem: Implant-type distractor uses a removable distraction device that has an appearance similar to that of a dental implant and utilizes many of the same techniques for placement as are used for dental implants. Material and method: In this study, 48 implant type titanium distractors were inserted into the osteotomized alveolar bone of 12 beagle dogs. After a 7-day latency period, the alveolar bone was augmented by 5mm vertically at a rate of 1.0 mm/day. The dogs were sacrificed after 4weeks, 8weeks and 12 weeks for radiographic, histologic, and histomorphometric analysis. Result: Copper equivalent value showed significant difference between 4 weeks and the other weeks(8, 12 weeks)(p<0.05). But there was no significant difference between maxillary and mandibular groups. In the bone to metal contact analysis, there was a significant difference between 4 weeks and 12 weeks(p<0.05). On the contrary, there was no significant difference between maxilla and mandible. The bone area showed significantly higher values in 12 weeks compared to 4 weeks(p<0.05). Histologically mineralization began at the host bone margins. At 12 weeks, increasing accumulation of $Ca^{++}$ element was confirmed. Conclusion: From the results above, the new bone formation was increased according to consolidation period. Especially there was significant difference between 4 weeks and 12 weeks(p<0.05). Implant type distractors used in this study to augment vertical ridge defect may prove to be a clinically useful treatment option in selected cases.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제30권1호
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• pp.92-99
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• 2008

The purpose of this study was to evaluate maxillay distraction for the cleft and other patients who were treated with RED $system^{(R)}$(Martin, Tuttlingen Germany). Eleven patients with severe maxillary hypoplasia who were treated between 2002 and 2007 in the Department of Oral and Maxillofacial surgery, Pusan National University Hospital, are reviewed for this study. Their age at the time of surgery ranged from 7 to 22 years(mean age=15.36 years). Distraction was started at 5 days after Le Fort I or III osteotomy at a rate of 1mm per day for 10 to 20days. All patients used the Rigid External Distraction II system. After distraction was completed, a 2 to 3 months period of consolidation was undertaken. The follow-up period ranged from 1 to 6 years. The mean amount of advancement of the maxilla was 14.2mm(A-point). Relapse, VPI, and local infection around the halo pin were the most common complications. In adult patients, the relapse of maxilla ranged from 21% to 35%. In the growing child, postoperative stability of the maxilla was unstable and unpredictable.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제29권2호
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• pp.79-85
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• 2003

The purpose of this study is to observe histopathologic changes in the bilateral craniomandibular joints after allowing 6 weeks of consolidation by varying the amount of distraction in rabbit mandible. Eight rabbits weighing about 2 to 3 kg were used. After corticotomy was performed on the left mandibular body between the first premolar and the second premolar region, a unilateral fixation device was placed. Then, a 7-day period was allowed without distraction of the device. The mandible was lengthened 0.5 mm/day. Corticotomy and lengthening of mandible were not performed in control group. After the completion of the lengthening process, a 6-week-consolidation period was allowed. Then, the rabbits were sacrificed, and histologic examination of the craniomandibular joints was performed. Proliferative changes were observed in the craniomandibular joints in all groups. With the increasing amount of distraction, hypertrophy of the cartilage layer became more severe, bone formed was dense and enchondral ossification was clearly shown in subchondral bone. Hypertrophy of the cartilage layer was also seen in the non-distracted side as the distracted side in the experimental group. These results indicate that when physical force is applied constantly to joints, the proliferation of articular cartilage and bone formation are present. When more than 6 weeks of consolidation period is allowed at the time of performing distraction for more than 5 mm, articular changes, especially, in the contralateral side should also be noted.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제34권2호
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• pp.100-105
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• 2012

Purpose: In general, the surgical treatment for mandibular retrognathism is represented by two methods, distraction osteogenesis (DO) and mandibular osteotomy surgery. The DO is mostly preferred when the degree of advancement of mandible is large. However, the postoperative stability of mandibular advancement using DO have not been actively investigated. Therefore, in the present study we have compared the postoperative stability between DO and bilateral sagittal split ramus osteotomy (BSSRO) in mandibular retrognathism. Methods: Seven patients who had been treated by DO and thirteen patients with BSSRO were included in this study. Serial lateral cephalograms were analyzed by manual tracing and the amount of the mandibular elongation was measured. To evaluate the postoperative stability, positional changes of the condylar position and B point were analyzed. Results: Mean amount of mandibular advancement was $6.51{\pm}3.57mm$ for BSSRO group and $12.43{\pm}4.35mm$ for DO group, respectively. There was no significant difference in age between the two groups (P>0.05). Mean follow up periods were 10.77 months for BSSRO group and 11.28 months for DO group, respectively. After mandibular advancement, mean positional changes in the condyle were $0.56{\pm}1.43mm$ horizontally and $0.72{\pm}1.61mm$ vertically for BSSRO group and $0.53{\pm}1.56mm$ horizontally and $0.56{\pm}1.75mm$ vertically for DO group, respectively. Mean change of distance from B point to Y-axis was $-1.76{\pm}0.83mm$ for BSSRO group and $-2.14{\pm}1.82mm$ for DO group, respectively. According to the condylar position and B point, there were no significant differences in postoperative stability between the two groups (P>0.05). Conclusion: There was no significant difference in postoperative stability between DO and BSSRO group according to condylar position and B point. Based on the results of the present study, it is hypothesized that DO would be a good treatment choice for severe mandibular retrognathism because DO could achieve more mandibular advancement and concurrent soft tissue elongation.

• Journal of Trauma and Injury
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• 제31권2호
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• pp.107-111
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• 2018

Segmental bone defects of the tibia present a challenging problem for the orthopedic trauma surgeon. These injuries are often complicated by soft tissue defects and infection. Many techniques are reported, from bone graft to bone transport. To our knowledge, bone transport over the plate in the distraction site has not been described for the treatment of tibial bone defect. We report an instance including procedure and subsequent complications after bone transport over the plate, to restore a tibial bone defect.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제43권6호
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• pp.407-414
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• 2017

Objectives: The study was designed to evaluate the efficacy of performing a second, repeat anterior maxillary distraction (AMD) to treat residual cleft maxillary hypoplasia. Materials and Methods: Five patients between the ages of 12 to 15 years with a history of AMD and with residual cleft maxillary hypoplasia were included in the study. Inclusion was irrespective of gender, type of cleft lip and palate, and the amount of advancement needed. Repeat AMD was executed in these patients 4 to 5 years after the primary AMD procedure to correct the cleft maxillary hypoplasia that had developed since the initial procedure. Orthopantomogram (OPG) and lateral cephalograms were taken for evaluation preoperatively, immediately after distraction, after consolidation, and one year postoperatively. The data obtained was tabulated and a Mann Whitney U-test was used for statistical comparisons. Results: At the time of presentation, a residual maxillary hypoplasia was observed with a well maintained distraction gap on the OPG which ruled out the occurrence of a relapse. Favorable movement of the segments without any resistance was seen in all patients. Mean maxillary advancement of 10.56 mm was achieved at repeat AMD. Statistically significant increases in midfacial length, SNA angle, and nasion perpendicular to point A distance was achieved (P=0.012, P=0.011, and P=0.012, respectively). Good profile was achieved for all patients. Minimal transient complications, for example anterior open bite and bleeding episodes, were managed. Conclusion: Addressing the problem of cleft maxillary hypoplasia at an early age (12-15 years) is beneficial for the child. Residual hypoplasia may develop in some patients, which may require additional corrective procedures. The results of our study show that AMD can be repeated when residual deformity develops with the previous procedure having no negative impact on the results of the repeat procedure.

• 대한구순구개열학회:학술대회논문집
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• 대한구순구개열학회 2003년도 종합학술대회
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• pp.37-37
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• 2003