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PubMed1992

Anaesthesia in a parturient with osteogenesis imperfecta.

A 20-yr-old primigravida at 38 weeks gestation with premature rupture of membranes and evidence of fetal distress required urgent Caesarean section. The diagnosis of osteogenesis imperfecta had been made 4 days earlier. The patient refused a regional anaesthetic. Difficulties in the administration of general anaesthesia to patients with osteogenesis imperfecta were recognized and managed accordingly. These problems are discussed and the importance of early antenatal assessment of such patients by the department of anaesthesia is emphasized.

Adult↗
PubMed2003

Orthodontic and orthognathic management of a patient with osteogenesis imperfecta and dentinogenesis imperfecta: a case report.

This case report describes a patient's severe Class III malocclusion, managed with a combination of orthodontic and orthognathic treatment. The medical history was complicated by osteogenesis imperfecta and dentinogenesis imperfecta. In addition the patient was a Jehovah's Witness. Patients with osteogenesis imperfecta carry an increased risk of perioperative haemorrhage, and this led to bimaxillary surgery being carried out as two discrete surgical episodes for the patient described. In addition, the risk of enamel fracture led to orthodontic bands being cemented on all teeth. In spite of the increased risks a successful outcome was achieved.

Adolescent↗
PubMed1997

Pore size of porous hydroxyapatite as the cell-substratum controls BMP-induced osteogenesis.

To elucidate the biochemical mechanism of osteogenesis, the effect of matrix geometry upon the osteogenesis induced by bone morphogenetic protein (BMP) was studied. A series of five porous hydroxyapatites with different pore sizes, 106-212, 212-300, 300-400, 400-500, and 500-600 microns, was prepared. A block (approximately 5 x 5 x 1 mm, 40.0 mg) of each hydroxyapatite ceramics was combined with 4 micrograms of recombinant human BMP-2 and implanted subcutaneously into the back skin of rat. Osteoinductive ability of each implant was estimated by quantifying osteocalcin content and alkaline phosphatase activity in the implant up to 4 wk after implantation. In the ceramics of 106-212 microns, the highest alkaline phosphatase activity was found 2 wk after implantation, and the highest osteocalcin content 4 wk after implantation, consistent with the results observed with particulate porous hydroxyapatite [Kuboki, Y. et al. (1995) Connect. Tissue Res. 32: 219-226]. Comparison of the alkaline phosphatase activities at 2 wk and the osteocalcin contents at 4 wk after implantation revealed that the highest amount of bone was produced in the ceramics implants with pore size of 300-400 microns. In the ceramics with smaller or larger pore sizes, the amount of bone formation decreased as the pore size deviated from 300-400 microns. The results indicated that the optimal pore size for attachment, differentiation and growth of osteoblasts and vascularization is approximately 300-400 microns. This study using chemically identical but geometrically different cell substrata is the first demonstration that a matrix with a certain geometrical size is most favorable for cell differentiation.

Alkaline Phosphatase↗
PubMed1998

Distraction osteogenesis in craniofacial surgery: a review.

Distraction osteogenesis is a technique of new bone formation by the gradual separation of bony fragments. The method, although initially developed for limb lengthening, is now being applied in the treatment of craniofacial deformities. A number of principles have been established through careful scientific study to guide clinical practice, such as the ideal rate and rhythm of distraction, the need for periosteal preservation during bone division, a "latent period" of neutral fixation before, and a "consolidation period" after distraction. The technique is being applied in craniofacial surgery particularly for mandibular deformities and offers considerable advantages over previous methods such as osteotomy and inlay bone grafting. Donor site morbidity is avoided, the investing soft tissue envelope is concurrently expanded, and the magnitude of the procedure is less. However, the technique is still in its infancy and requires further modification and refinement before widespread acceptance as a treatment in mainstream craniofacial surgery. Problems with cutaneous scarring and socially undesirable external hardware, particularly in the pediatric population, have led to the emergence of intraoral miniature devices, with the ultimate goal of development of a multiplanar internal autodistractor. Furthermore, many principles well established in leg lengthening, such as the rate and rhythm of distraction, need to be reexamined and the parameters redefined with particular reference to the craniofacial skeleton. Distraction osteogenesis has an expanding role in craniofacial surgery.

Animals↗
PubMed1994

Tissue segregation enhances calvarial osteogenesis in adult primates.

Calvarial defects of adult mammals have a limited potential for regeneration. Osteogenesis may be impaired by the intrusion within the defect of nonosteogenic tissues during healing, which inhibits centripetal bone deposition from the margins of the defects. Using a primate model, we evaluated bone regeneration in calvarial defects treated with demineralized bone matrix versus defects treated according to the strategy of guided tissue regeneration. Sixty-four defects, 25 mm in diameter, were prepared in 16 adult male baboons (Papio ursinus). In each animal, 2 contralateral defects were covered with a template of porous polymer, 35 mm in diameter. Templates were positioned over the calvarial margins to prevent penetration of the pericranium and the temporalis muscle within the defects, thus maintaining tissue segregation during healing. The third defect was implanted with allogeneic demineralized bone matrix, as positive control. The fourth defect was left untreated and was used as negative control. Undecalcified bone sections (7 microns thick) were prepared from the harvested specimens 3 and 6 months after surgery. Although untreated defects showed limited osteogenesis after fusion of the pericranium with the dura, defects covered with the polymeric template often showed extensive bone deposition extending centripetally from the margins of the craniotomies. Histomorphometry demonstrated that defects treated with demineralized bone matrix and defects covered with the polymeric template had greater amounts of bone and osteoid when compared with untreated defects (p < 0.01). At 6 months, greater amounts of bone formed in demineralized bone matrix-treated defects when compared with defects covered with the polymeric template (p < 0.01). The results of this study show that calvarial membranous bones of adult primates retain the potential to regenerate when segregation between the different tissue components participating in the healing of the wound is maintained. In the same model, however, implantation of allogeneic demineralized bone matrix, used as a positive control provided the most effective treatment for the defects.

Age Factors↗
PubMed1999

The role of transforming growth factor-beta, insulin-like growth factor I, and basic fibroblast growth factor in distraction osteogenesis of the mandible.

Distraction osteogenesis is a viable method for regenerating large amounts of bone. In contrast to fracture healing, the mode of bone formation in distraction osteogenesis is primarily intramembranous ossification. The basic biology of the process is still not well understood. The growth factor cascade is likely to play an important role in distraction. This study examines the growth factor cascade in a lengthened ovine mandible model. Twenty-four animals were divided into four groups with varying rates of distraction (1, 2, 3, and 4 mm/day). A unilateral distractor at the angle of the mandible was used. The mandibles were lengthened to 24 mm and fixed for a period of 5 weeks, after which the animals were killed. The sections were probed for transforming growth factor-beta, basic fibroblast growth factor, and insulin-like growth factor I. The growth factors studied were present in all four groups. Transforming growth factor-beta, basic fibroblast growth factor, and insulin-like growth factor I were present in both the bony matrix of the sections and the cytoplasm of the cells, osteoblasts, and a small number of mesenchymal cells. The sections obtained from groups distracted at faster rates showed stronger presence of the growth factors examined by more intense staining. In fracture healing, the localization of transforming growth factor-beta in stage I of healing corresponded with the precise region of intramembranous ossification in stage II. Diffuse presence of transforming growth factor-beta throughout the lengthened region corresponded with the process of intramembranous ossification observed in distraction. In fracture healing, insulin-like growth factor I and basic fibroblast growth factor have been shown to promote proliferation and differentiation of osteoblasts from precursor cells. The intense presence of insulin-like growth factor I and basic fibroblast growth factor in the distracted region may account for osteoblast proliferation and formation from precursor mesenchymal cells. Mechanical strain has been shown to increase the expression of transforming growth factor-beta and insulin-like growth factor I. Distraction may serve as a source of mechanical strain, which may explain, in part, the expression of these growth factors, particularly in the faster groups.

Animals↗
PubMed2000

Maxillary distraction osteogenesis: a two-dimensional mathematical model.

Patients with cleft lip and palate with severe maxillary retrusion usually have a mandible with anterior-superior autorotation and subsequent overclosure and loss of the vertical facial dimension. Maxillary distraction osteogenesis can correct the sagittal maxillomandibular relationship and should simultaneously reestablish vertical dimension through maxillary vertical height increase and clockwise rotation of the mandible to restore facial balance. We present a two-dimensional mathematical model in the sagittal plane, which reestablishes sagittal and vertical skeletal deficiencies and proper occlusal alignment for planning maxillary advancement with distraction osteogenesis in patients with cleft lip and palate. The model is illustrated in a case of a 13-year-old boy with a complete bilateral cleft lip and palate and severe maxillary retrusion. The two-dimensional mathematical model described in this article allows the surgeon and orthodontist to calculate in a simple and accurate way the ideal distraction vector to advance the maxilla to its desired position.

Adolescent↗
PubMed2001

Fibrous ankylosis after distraction osteogenesis of a costochondral neomandible in a patient with grade III hemifacial microsomia.

Distraction osteogenesis has recently become a mainstay for treatment of craniofacial syndromes with mandibular hypoplasia. This article presents the difficult case of a patient with a previous costochondral rib graft who underwent mandibular distraction and developed a fibrous pseudoarthrosis at the distraction site. This was attributed in part to an associated temporomandibular joint ankylosis. Resorption of the pseudoarthrosis occurred once the distractor was removed. It appears that distraction osteogenesis of a mandible with an ankylosed temporomandibular joint can result in healing with a fibrous union, presumably because of movement at the distraction site when masticating. This can result in a pseudo "temporomandibular joint" at the distraction site. A temporomandibular joint arthroplasty was performed, followed by repeat distraction. We conclude that if there is an ankylosed temporomandibular joint or a stiff temporomandibular joint that may ankylose during the course of the distraction process, then a temporomandibular joint arthroplasty should be performed before or at the time the distractor is placed.

Adolescent↗
PubMed2001

Closure of an oronasal fistula in an irradiated palate by tissue and bone distraction osteogenesis.

Uses for distraction osteogenesis in the craniofacial skeleton have expanded during the last decade. It has become an important rung in the reconstructive ladder for correction of difficult defects. Distraction of irradiated bone has been successfully performed in an animal model but has not been reported in human subjects. We present a case of distraction osteogenesis in a patient with multiple failed reconstructive attempts to close an irradiated palatal defect. An additional benefit included improvement in support of the upper lip from bone transported and the potential for placing dental implants.

Cranial Irradiation↗
PubMed2002

Experimental mandibular regeneration by distraction osteogenesis with submerged devices: preliminary results of a canine model.

The authors describe a new technique for reconstruction of mandibular body defects. The feasibility of distraction osteogenesis with submerged (internal) devices for reconstruction of segmental mandibular defects is investigated in an experiment with five adult dogs. A segmental mandibulectomy was performed on the horizontal ramus. The bony defect was regenerated using distraction osteogenesis (bone transport) at a rate of 1 mm daily. The animals were killed after the consolidation period. Complete bone regeneration of the surgically created gap was successful in three of five dogs. Two animals failed to create new bone. In these two cases, the screws did not offer proper stability to the bony fragments, and this caused a lack of ossification. This experimental study demonstrates the possibility to use internal distraction devices to reconstruct segmental mandibular defects in a canine model. Internal devices show enormous advantages in comparison with the external ones. This method with no donor-site morbidity may become a very useful option in human mandibular reconstruction.

Animals↗
PubMed2002

Distraction osteogenesis of zygomatic bone grafts in a patient with Treacher Collins syndrome: a case report.

Zygomatic aplasia in patients with Treacher Collins syndrome requires reconstruction with autogenous bone grafts. Serial bone grafting may be required if optimal malar projection is not achieved with the initial procedure. This report demonstrates the use of distraction osteogenesis in repositioning a previously bone-grafted zygoma in an adolescent patient with Treacher Collins syndrome, thus avoiding the need for repeat bone graft harvest. The limitations of this technique include difficulty in achieving the desired vector of distraction and the potential of graft devitalization. Nevertheless, the case report illustrates the versatility of distraction osteogenesis in skeletal augmentation/remodeling.

Bone Transplantation↗
PubMed2002

Clinical application of injectable calcium sulfate on early bony consolidation in distraction osteogenesis for the treatment of craniofacial microsomia.

The purpose of this project was to study the effect of calcium sulfate on early bony consolidation in distraction osteogenesis. A total of eight patients with craniofacial microsomia were treated between April 2000 and February 2001. The age of the patients ranged from 2 to 40 years, and all were male. The follow-up period was 1 to 15 months. The operative procedure in adults was based on Ortiz Monasterio's simultaneous mandibular and maxillary distraction technique. In children, osteotomy of the mandible was performed for distraction. On the fifth day after the operation, distraction was performed at a rate of 1 mm/d in three adults. In children, distraction was performed at a rate of 1 mm/d in one patient and 2 mm/d in four patients without a latent period. On the day of completion of distraction, calcium sulfate was implanted into the distracted zone. Radiographs showed bony consolidation at 4 weeks in one child at a rate of 1 mm/d, at 5 to 7 weeks in four children at a rate of 2 mm/d, and at 5 weeks in three adults after implantation of the calcium sulfate. In conclusion, these findings suggest that calcium sulfate is effective for early bony consolidation in distraction osteogenesis and that it would shorten the whole treatment period.

Adolescent↗
PubMed2003

Complications associated with gradual cranial vault distraction osteogenesis for the treatment of craniofacial synostosis.

Distraction osteogenesis has become a standard technique for craniomaxillofacial reconstruction. The authors performed gradual cranial vault distraction osteogenesis in 19 patients with craniosynostosis to study the outcome and complications of this procedure. Postoperative infections developed around the shaft puncture wounds in four patients, including one who required surgical removal of the device. Advanced bone was deformed in one patient. In another, the expansion device was exposed, resulting in a postoperative scar. Despite these complications, the cranium was successfully expanded in all patients.

Child↗
PubMed2003

Three-dimensional surgical planning for maxillary and midface distraction osteogenesis.

Computerized surgical planning protocols for distraction osteogenesis are still in their rudimentary phase. The authors have developed a system to plan distraction osteogenesis in craniofacial and maxillofacial surgery that uses three-dimensional computed tomography scans and computer simulation in a virtual reality environment. This involves the creation of a three-dimensional bone model of the craniofacial skeleton, which incorporates virtual globes. Virtual osteotomies are performed on the bone model and the movements of the bone segments are simulated. The program generates a recipe for the linear and the angular changes necessary to achieve the desired outcome. The purpose of this article is to present this surgical planning process and discuss its use in maxillary and midface distraction.

Child↗
PubMed2004

The bone regenerative effect of chitosan microsphere-encapsulated growth hormone on bony consolidation in mandibular distraction osteogenesis in a dog model.

The purpose of this project was to study the effect of chitosan microsphere-encapsulated human growth hormone, which causes sustained release of chitosan and human growth hormone after implantation on early bony consolidation in distraction osteogenesis of a canine model. Forty-eight dogs were used for this study. An external distraction device was applied to the mandibular body after a vertical osteotomy, and the mandibular distraction was started 5 days after the operation at a rate of 1 mm/d up to a 10-mm distraction. The experimental group was divided into a control group (I), hyaluronic acid group (II), chitosan microsphere group (III), and chitosan microsphere-encapsulated human growth hormone group (IV). Normal saline was injected in group I. In group II, a 1-ml volume of hyaluronic acid solution was injected into the distracted area. In the group III, powder of chitosan microspheres and hGH were mixed with a 1-ml volume of hyaluronic acid to make an injectable form, and it was implanted into the distracted area. In group IV, powder of chitosan microsphere-encapsulated hGH was mixed with a 1-ml volume of hyaluronic acid. A total of 1-ml volume of the solution mix was implanted into the distracted area. Five dogs in each group (total of 20 dogs) were killed 3 weeks after completion of distraction. Twenty-eight dogs were killed at 6 weeks. Bone mineral density was 13.1% of the contralateral normal mandible at 3 weeks and 29.6% at 6 weeks in group I, 16.4% at 3 weeks and 40.4% at 6 weeks in group II, 16.6% at 3 weeks and 45.95% at 6 weeks in group III, and 29.6% at 3 weeks and 66.7% at 6 weeks in group IV. The mean three-point failure load was 16.1% in the control group, 34.7% in group II, 41.5% in group III, and 52.1% in group IV compared with the intact contralateral mandible, with statistical significance. In the histological findings, new bone was generated in all groups. In group IV, the formation of active woven bone was observed throughout the distracted area at 6 weeks. The amount of new bone formation in the distracted zone was in the order of group IV, group III, group II, and the control group. In conclusion, these findings suggest that chitosan microsphere-encapsulated hGH seems to be quite effective in early bone consolidation in distraction osteogenesis.

Animals↗
PubMed2004

Dove tail osteotomy in distraction osteogenesis of costochondral bone grafts in the mandible: a new concept.

To correct the malocclusion and facial asymmetry in patients with Pruzansky type III hemifacial microsomia after autogenous costochondral grafting during early childhood (two male and three female patients with an average age of 17.8 years), the technique of distraction osteogenesis with a three-dimensional device was used. Because of the missing periosteum of the transplanted rib and its relatively small height compared with the horizontal mandible, a dovetail geometrical pattern osteotomy was introduced to increase the osteotomy surface area, which by itself could enhance the amount of fibrin filaments between 30% and 40% in the hematoma occurring during the initial distraction process. These fibrin filaments are biofunctional guiding structures for the development of the microcallus, followed by enhancement of the bone-healing capacity, which allows optimal bone regeneration. Between 20 and 27 days (mean = 21.5 days) after distraction, complete ossification was noted radiographically in all treated patients. Based on our histological animal studies and clinical investigations, dove tail osteotomy enhances the osteotomized surface area and offers protection to the tension-sensitive structures in the center of the distraction zone. It increases early bone formation and mineralization adjacent to the center zone in the distraction gap. Therefore, the dove tail geometrical pattern in combination with distraction osteogenesis of autologous costochondral grafts in the treatment of congenital Pruzansky type III mandibular hypoplasia is strongly recommended.

Adolescent↗
PubMed2006

Clinical application of distraction osteogenesis for traumatic maxillofacial deformities.

Treatment including occlusal function is important for maxillofacial fractures. Because distraction osteogenesis is now used frequently for the treatment of various types of congenital maxillary hypoplasia, the authors applied this technique to six cases of traumatic maxillofacial deformity caused by old maxillofacial fractures. Several kinds of devices were used for the various deformities associated with severe malocclusion, resulting in extension of both bone and soft tissues. In each case, favorable facial aesthetics and occlusion were achieved. Distraction osteogenesis also appears to be an extremely effective method for repair of traumatic maxillofacial deformities.

Adolescent↗
PubMed1986

Bone scan appearance of osteogenesis imperfecta in an adult.

An adult patient with undiagnosed osteogenesis imperfecta presented with a history of multiple fractures. Radiographs could not definitively diagnose the underlying abnormality. The radionuclide bone image suggested the presence of a skeletal dysplasia, and prompted the histopathologic review of fracture fragments. The scan appearance of osteogenesis imperfecta in the adult and possible underlying mechanisms for the radiopharmaceutical distribution are discussed.

Adult↗