Distraction osteogenesis in maxillary deficiency using a rigid external distraction device.
Explore the source record for details and available documents.
SEARCH · Search PubMed
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
OBJECTIVE: To evaluate the effect of distraction osteogenesis in correction of mandibular micrognathia accompanying obstructive sleep apnea syndrome (OSAS). METHODS: A total of 15 patients, aged 9 to 43 years, 11 males and 4 females, were treated. 7 patients suffered from bilateral ankylosis of temporo manclibular joint inducing severe mandibular micrognathia and accompanying severe OSAS. 3 cases suffered from unilateral TMJ ankylosis with OSAS. 3 patients suffered from congenital developmental micrognathia with OSAS. 2 cases were caused by trauma. Among the 15 patients, 12 were treated by synchronous bilateral mandibular distraction, 3 patients were distracted unilaterally. Every patient had been evaluated pre- and postoperatively with cephalometry and polysomnography. RESULTS: The minimum distance of distraction was 9 mm, the maximum was 30 mm, with a mean of 20.4 mm, in mandible of 15 patients with 27 sides. The distraction process was smooth in all the cases. The osteogenesis was good, without infection and other complications. Complete curative effect was achieved in 4 severe, 3 moderate, and 4 mild cases. The posterior airway space was increased from averaged 4.5 mm preoperatively to 12.4 mm. The increase of SNB angle was from preoperative 66 degrees to 75 degrees on average postoperatively. The vast majority of the patients had their subjective symptoms alleviated gradually or disappeared completely. The results were stable without relapse during a follow-up period of 12 months. CONCLUSION: The distraction osteogenesis can not only be used to effectively correct severe mandibular micrognathia deformity, but also can cure its accompanying OSAS. The procedure is simple, with low risk, high curative rate, low relapse rate, and stable result. Up to now, it is the most effective method in the treatment of this difficult and complicated kind of disorder.
A girl approximately 2 years old with Pierre Robin sequence had periods of nocturnal respiratory insufficiency as a consequence of micrognathia and a boy nearly 4 years old with Nager syndrome and tracheostomy was retarded in his speech development, had problems swallowing and often had respiratory tract infections. The obstruction of the upper respiratory tract was resolved by performing a distraction osteogenesis of the lower jaw. A tracheostomy was avoided or else removed. The girl became more active and there was an improvement in the boy's speech development. Distraction osteogenesis is a good alternative to the current practice of mandibular reconstruction in micrognathic patients, which involves extensive bone grafts.
Mandibular distraction combining the sagittal split ramus osteotomy and an intraoral curved distractor is efficacious to lengthen the mandibular body and ramus. The sagittal split permits immediate rotation of the proximal segment and lengthening while still providing a large surface interface for regenerative bone. The buried curved distractor enables mandibular lengthening along the normal logarithmic grow spiral as shown by Moss and Rickets. In addition, it is well tolerated by the patient and can remain in place for a long duration to provide support. In summary, this combination of surgical techniques provides certain advantages for distraction of the mandible.
PURPOSE: This study aims to evaluate histologic healing of the new bone and soft tissue in the distraction gap of maxillary alveolus after transport distraction at different consolidation intervals. MATERIALS AND METHODS: In a monkey model, dentoalveolar segment was distracted backward to a surgical defect in the posterior maxilla with an internal distractor at a rate of 1 mm/day for 2 weeks. The distracted dentoalveolar processes were harvested at 1, 2, and 3 months of consolidation after the completion of distraction. Histologic examination included the new bone, gingiva of the distraction gap, and teeth carrying the transport segments. Tartrate-resistant acid phosphatase was used to assess the presence of osteoclasts in the new bone. The collagen type and expression of bone morphogenetic proteins (BMPs) in the new bone were assessed by immunohistochemistry. RESULTS: The histology confirmed new bone bridging the distraction gap at 1 month of consolidation. Woven bone was progressively replaced by mature lamellar bone at the second and third months. The gingiva covering the distraction gap was of normal appearance. There were no pathologic pulpal changes noted in the transport segment. Tartrate-resistant acid phosphatase-positive osteoclasts were minimal in the new bone. The mode of ossification was confirmed as intramembranous, and the fibrous stroma consisted mainly of collagen type I. At 1 month of consolidation, the BMPs were expressed profusely in the fibrous matrix and also inside the fibroblasts and osteoblasts. At 2 and 3 months of consolidation, the BMP expression intensity was reduced significantly in the fibrous stroma. CONCLUSIONS: The study confirmed that the bone regenerate in maxillary transport distraction was formed by intramembranous ossification and teeth in the transport segment remain viable after maxillary transport distraction osteogenesis.
An experimental model of leg lengthening was used to study the morphology of, the collagenous proteins present, and the collagen genes expressed in the regenerating tissue following 20% lengthening at four different distraction rates. At a distraction rate of 0.3 mm/day (8 weeks distraction), the regenerate consists of intramembranous bone and localized areas of fibrocartilage. At rates of 0.7 (4 weeks) and 1.3 mm/day (2 weeks), the bone that grows from the cut ends of the cortical bone is separated by fibrous tissue and cartilage is present. At 2.7 mm/day (1 week), only fibrous tissue and sparse bone are present. Type I collagen is present in the matrices around the cells expressing its mRNA and similarly, type II collagen is located around the chondrocytes. Type I collagen mRNA is expressed predominantly by the fibroblasts in the fibrous tissue, the bone surface cells and to a reduced extent by the osteocytes. Type II collagen mRNA is expressed by chondrocytes. The results suggest that osteoblasts and chondrocytes within the regenerate originate from the same pool of progenitor cells, and the differentiation of these cells and the expression of types I and II collagen genes are altered by different rates of distraction. These observations suggest that the optimal rate of distraction in the model is 0.7 mm/day.
The consolidation period, one of the biological factors participating in the distraction osteogenesis phenomenon, has not been elucidated. Parameters to assess new bone formation and consolidation in craniofacial distraction have been borrowed from the orthopedic experience. Up until now, the decision to discontinue distraction has been based more on personal experience than on objective data. By using Scintigraphy with Tc99 DP a method has been developed to accurately assess the termination of the consolidation phase. Scintigraphic evidence of consolidation was seen between the fourth and the fifth week after terminating distraction in infants (younger than 12 months). Not before the 10th week in children and between the 10th and the 14th week in adolescents and adults. The data roughly correlates with previous reports. It is believed that the consolidation period should be addressed in biologic terms and not in radiologic terms as done up until now. A method is proposed that offers objective qualitative and quantitative data for the noninvasive evaluation of bone consolidation which could have further applications in distraction of the craniofacial skeleton.
INTRODUCTION: Therapeutic angiogenesis, a novel concept in tissue engineering, is neo-formation of blood vessels in a tissue upon delivery of an angiogenic growth factor to the tissue. We hypothesised that therapeutic angiogenesis could enhance bone formation and challenged the hypothesis in an experimental model of distraction osteogenesis. METHODS: Rabbits, divided into three equal groups of 12, had their right tibia lengthened by distraction osteogenesis. A mini-osmotic pump delivered to the osteotomy gap either recombinant human vascular endothelial growth factor (VEGF), VEGF-inhibitor, or vehicle alone during the latency and distraction phase. After consolidation, we assessed bone blood flow by radioactive microsphere entrapment, measured torsional stiffness and bone mineral content, and did histomorphometry. RESULTS: VEGF and VEGF-inhibitor treatment failed to influence bone blood flow, torsional stiffness, bone mineral content and histomorphometric indices of the bone regenerate. However, VEGF treatment increased the blood flow in bone of the distracted limb and VEGF-inhibitor treatment decreased bone blood flow. CONCLUSION: The regenerate was unresponsive to VEGF and VEGF-inhibitor treatment in contrast to the neighbouring bone, which implies different biological properties of the vasculature in native and regenerating bone. VEGF is not recommended for enhancement of bone formation in this setting.
The authors reviewed the clinical results of leg lengthening by distraction osteogenesis, where two different osteotomy techniques were used: classical corticotomy according to Ilizarov or osteoclasis. Evaluation of results of 64 patients were bases on orthopedic examination and detailed X-ray analysis which included criteria assessing osseous regeneration rate. In those cases where osteoclasis was performed bone formation in the distraction gap was faster than in after osteotomy. An accelerated rate of regenerate formation, as well as a more active regenerate remodelling was observed. This allowed to shorten the time of external fixator application and an earlier rehabilitation.
BACKGROUND: Surgical treatment of syndromal craniofacial synostosis consists of combined neurosurgical and maxillofacial reconstructions of the neurocranium and midface. Patients often need several operations if they are to achieve a functionally and cosmetically good result. This is, in part, due to limitations in the amount of "acute" correction possible peroperatively with conventional surgical technique. MATERIAL AND METHODS: In recent years, a new method called distraction osteogenesis has been developed, by which the skeletal elements are gradually advanced. The method is based upon a process whereby the reparative callus formed between the surfaces of two bone segments is subjected to traction. This leads to new bone formation parallel to the vector of distraction. RESULTS: Distraction osteogenesis allows for greater mobilizations, hence the promise of fewer reoperations. INTERPRETATION: The method seems to be a valuable treatment modality in syndromal craniofacial synostosis, where major fronto-orbital, midface or maxillary reconstructions are often called for.
BACKGROUND: Bone matrix metalloproteinases are capable of degrading bone matrix during the remodelling, and their degradation activities can be down regulated by the tissue inhibitors of matrix metalloproteinases. This study evaluated the influence of exogenous tissue inhibitor of matrix metalloproteinase-1 on the expression of matrix metalloproteinases and endogenous tissue inhibitor of matrix metalloproteinases in mandibular distraction osteogenesis. MATERIAL AND METHODS: Fifteen New Zealand white rabbits were assigned to three groups: a negative control; a sham control group implanted with a collagen sheet; and an experimental group implanted with recombinant human tissue inhibitor of matrix metalloproteinase-1 impregnated in a collagen sheet. Rabbits were sacrificed at 6 weeks, 12 weeks and 24 weeks of consolidation. RESULTS: Major expression of matrix metalloproteinases and tissue inhibitors of matrix metalloproteinases was observed at the early stage of consolidation, only positive signals of tissue inhibitors of matrix metalloproteinases were observed at 24 weeks. The addition of recombinant human tissue inhibitor of matrix metalloproteinases-1 did not affect bone maturation and remodelling. CONCLUSIONS: An equilibrium of bone formation and resorption was reached at 24 weeks of consolidation in the rabbit mandible. No obvious influence of recombinant human tissue inhibitor of matrix metalloproteinase-1 on bone remodelling of mandibular distraction osteogenesis was noted.
We performed sliding transport distraction osteogenesis (STDO) of an alveolar segment containing an unerupted third molar in the mandible of a 22-year-old man with a benign cementoblastoma. Marginal mandibulectomy including the tumour and the right mandibular second premolar and first and second molars was done. STDO was performed to horizontally reconstruct the alveolar ridge and to restore occlusion with the use of the third molar. After forward horizontal distraction of the alveolar segment, the third molar spontaneously erupted and was gradually moved to the position previously occupied by the second molar.
A patient with juvenile chronic arthritis presented with a malocclusion characterized by mandibular hypoplasia, symphysial deficiency, and an increased mandibular occlusal plane angle. Correction of the mandibular defect required both the horizontal advancement of the mandible and a counterclockwise rotation of the proximal segment to reduce the mandibular occlusal plane angle. This was achieved by a combination of distraction osteogenesis to horizontally advance the mandible (14 mm), followed by manipulation of the postdistraction regenerate to reduce the mandibular occlusal plane and increase the symphysial projection. The counterclockwise rotation of the mandibular body resulted in the creation of a posterior open bite. After a three-month period to allow consolidation of the mandibular distraction osteogenesis, secondary maxillary surgery at the Le Fort 1 level was performed to reestablish maxillary occlusal contact at the new mandibular occlusal plane. A genioplasty was also performed to improve chin projection.
OBJECTIVE: To evaluate the clinical result of alveolar vertical distraction osteogenesis for implant. METHODS: 19 cases with severe vertical alveolar defects (more than 10 mm defect) underwent vertical distraction procedure before implant placement. 15 cases were male and 4 cases were female. The alveolar bone defects were caused by tumor resection in 10 cases, by trauma in 8 cases, and due to congenital defect in 1 case. The vertical defects in all cases were over 10 mm. X-ray examination were taken prior to operation and in 1 week, 2 week, 4 week, the end of active distraction and before removing distractor. Implants were placed in 17 cases after removing distractors. The prosthesis were finished 6 month later. RESULTS: 11 cases out of 19 had implant prosthesis. 6 cases had implant in the jaw but waiting for the prosthesis. Altogether 65 dental implants were placed, 2 cases did not receive further implant treatment because of cost problem. The study showed that new bone formed after distraction in all 19 cases. Average gained height of new bone was 13 mm. COMPLICATIONS: Unexpected mandible fracture in 2 cases, infection in 1 case. CONCLUSIONS: Alveolar vertical distraction is a good alterative for severe alveolar defects. The distractor should be further developed and modified.
Bone distraction is still on the rise again since McCarthy et al. presented in their clinical investigation new osseous formation in the elongated area while performing the distraction of the mandible in 1992. But at the level of craniofacial skeleton, the initial description to the technique of distraction osteogenesis should be credited to the German craniofacial surgeons Rosenthal for the bone lengthening of the mandible in a microgen patient in 1927. The procedure is described and the original schedules and case are presented.
This study was performed to explore the tissue-level changes in mineralization caused by low-intensity ultrasound stimulation after distraction osteogenesis. Unilateral femoral lengthenings (7 mm) were performed on 34 male Sprague-Dawley rats. Half of the animals received daily ultrasound stimulation for 5 weeks; the remaining animals received sham treatments. Healing was assessed with serial radiographs, quantitative micro-computed tomography, and biomechanical testing. Twenty-one animals were evaluated at the conclusion of the study (9 experimental, 12 control). Radiographically, healing of the ultrasound-treated bones preceded that of the sham-treated bones by approximately 1 week. Bone volume fraction and trabecular bone pattern factor were significantly higher in the ultrasound-treated animals, but there were no significant differences in bone mineral content or bone mineral density. The ultrasound-treated femurs were 20% stiffer and 33% stronger than the control femurs, but the differences were not statistically significant. These findings suggest that pulsed, low-intensity ultrasound matures the regenerate by altering the microarchitecture of the newly formed bone.
BACKGROUND: The goal in this study was to investigate the role of extracellular signal-related kinase (ERK) 1/2, a central regulator of mesenchymal stem cell differentiation, and its temporal relationship to bone morphogenetic protein (BMP) 2/4, a potent osteogenic growth factor, during live model distraction osteogenesis. METHODS: The authors examined histomorphometric expression through the early temporal sequence for both ERK 1/2 and BMP 2/4 during gradual distraction to 5.1 mm (n = 12 net). Comparison groups (group sizes, n = 12) included an acute critical-size defect of 5.1 mm and a subcritical-size defect of 2.1 mm. RESULTS: In the group gradually distracted to 5.1 mm, immunohistochemical analysis demonstrated significant intranuclear expression of ERK 1/2 within mesenchymal precursor cells at the osteotomy edges early in distraction (postoperative days 6 and 9). ERK 1/2 became increasingly localized to hypertrophic chondrocytes within the distraction regenerate during the later stages of distraction (postoperative day 16). Adjacent sections examined for BMP 2/4 expression established a close temporal and spatial correlation with ERK 1/2. BMP 2/4 expression was initially present in the regions surrounding mesenchymal precursor cells expressing ERK 1/2, but then developed most prominently within the cytoplasm of hypertrophic chondrocytes expressing ERK 1/2 late in distraction. Comparison groups consistently demonstrated either fibrous nonunion or bony union typical in fracture healing, depending on defect size. However, even specimens with subcritical-size defects and complete bony union were consistently found to have minimal ERK 1/2 expression. CONCLUSIONS: These data provide evidence that ERK 1/2 expression is present within mesenchymal precursor cells during distraction osteogenesis and that ERK expression correlates closely with BMP 2/4 expression. The presence of ERK 1/2 expression only during gradual distraction strongly implicates the concept that mechanical strain appears to be the key upregulating factor for ERK 1/2 expression, based on comparison with fracture-healing and critical-size defect specimens.
BACKGROUND: Complications of external fixation include loosening of the fixation pins and pin-track infection. Laboratory studies and clinical trials have suggested that hydroxyapatite coating improves the osteointegration of various orthopaedic implants. The purpose of this study was to determine whether the prevalence of pin-related complications can be reduced by the use of hydroxyapatite-coated pins in fixators applied for distraction osteogenesis. METHODS: Forty-six consecutive patients undergoing segmental transport or lengthening of the tibia were randomized to the use of either standard titanium Schanz pins or hydroxyapatite-coated stainless-steel Schanz pins. The fixators were used for an average of thirty-eight weeks (range, fourteen to seventy-two weeks). All patients were closely monitored for pin loosening and infection, and digitized radiographs were assessed for bone resorption around all pins. When the external fixator was removed, the torque required to extract the pins was determined with use of an electronic torque wrench. RESULTS: In the control group (titanium pins), twenty-two pins (13%) loosened and an infection occurred at the site of twenty pins. An extensive infection of the canal developed in one patient. Twenty-two pins were removed or replaced because of these complications. In the hydroxyapatite group, no clinical or radiographic signs of pin loosening or infection were observed and no pins required early removal or exchange. The mean torque (and standard deviation) required to remove the hydroxyapatite-coated pins was 0.43 0.18 N-m compared with 0.10 0.09 N-m for the uncoated pins (p < 0.001). CONCLUSION: Coating pins with hydroxyapatite increases their fixation to bone and reduces the rate of infection and loosening during external fixation for distraction osteogenesis. Use of hydroxyapatite-coated pins should be considered in clinical situations requiring prolonged external fixation.