Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Osteogenesis”

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.

At least 415 records · Page 23Linked to original sources
PubMed2001

Histologic and radiographic evidence of vertical ridge augmentation utilizing distraction osteogenesis: 10 consecutively placed distractors.

BACKGROUND: Vertical ridge augmentation for dental implant placement is one of the greatest challenges facing the surgeon. Inadequate vertical bone compromises the implant positioning and resulting restoration. The cleansibility, esthetics, and mechanical properties of the restoration can all be compromised. While the technique of distraction osteogenesis has been successfully employed for long bone applications for over 40 years, it has only recently been introduced as a technique for vertical ridge augmentation prior to dental implant reconstruction. METHODS: In this study, the placement of 10 consecutive distractors in 7 patients was evaluated. The surgical technique, latency period, distraction rate, and consolidation period are reviewed. RESULTS: The technique of distraction osteogenesis resulted in an average vertical augmentation of 7 mm, with a range of 5 to 9 mm. There were no complications affecting the outcome of the distraction procedure. No failures have occurred to date in the 16 implants that were placed and loaded following distraction. CONCLUSIONS: In summary, clinical, histologic, and radiographic evidence of consistent vertical bone augmentation was found with this technique of distraction osteogenesis for vertical ridge augmentation.

Alveolar Ridge Augmentation↗
PubMed1996

Vertebral body shape as a predictor of spinal deformity in osteogenesis imperfecta.

We analyzed forty-four patients who had osteogenesis imperfecta, in order to determine the prevalence of spinal deformities. At the time of the most recent follow-up scoliosis was present in thirty patients (68 per cent) and kyphosis, in eighteen (41 per cent). According to the classification system of Falvo et al., scoliosis progressed rapidly with growth in twelve of fifteen patients who had the congenita type of osteogenesis imperfecta and in four of thirteen who had the tarda-I type. Curves that progressed before puberty did not always continue to progress after cessation of growth. Lateral roentgenograms made at the initial examination revealed four types of vertebral body deformities: biconcave, flattened, wedged, and unclassifiable vertebrae:Biconcave vertebrae were seen characteristically in patients who had the congenita type of osteogenesis imperfecta. The presence of six biconcave vertebrae or more before puberty indicated that severe scoliosis (more than 50 degrees) was likely to develop. Biconcave vertebrae did not appear to affect the severity of kyphosis. The other types of vertebral deformities were not useful for predicting progression of spinal deformity.

Adolescent↗
PubMed2003

Acceleration of regenerate ossification during distraction osteogenesis with recombinant human bone morphogenetic protein-7.

BACKGROUND: Bone-lengthening can be accomplished by means of distraction osteogenesis. In the present study, we examined the effect of a single dose of recombinant human bone morphogenetic protein-7 (rhBMP-7) on the rate of new-bone formation during distraction osteogenesis in the rat. METHODS: Fourteen Long-Evans rats were randomized into two groups of seven rats each. An external fixator was applied to the left femur, and a transverse osteotomy was performed. One group was treated with rhBMP-7 in an aqueous solvent, and the other group received the solvent alone and served as the control. rhBMP-7 was administered on the day of surgery by means of a single injection into the osteotomy gap. Distraction was started seven days after surgery at a rate of 0.25 mm every twelve hours. Distraction was continued for twenty days, resulting in a total of 10 mm of lengthening. The regenerate was monitored with use of radiographs and bone-mineral-density measurements at the conclusion of distraction and at two and four weeks after the cessation of distraction. The lengthened femora were harvested, and biomechanical studies were carried out to determine the stiffness and maximum torque to failure. RESULTS: Radiographs showed accelerated regenerate ossification in the BMP-7 group, with a larger amount of new bone compared with the control group. The bone-mineral-density values were dramatically enhanced on Day 20 in the BMP-7 group (103.6 +/- 12.6 mg/cm (2) ) compared with the control group (26.2 +/- 15.1 mg/cm (2) ). These differences continued to be greater at two and four weeks after the cessation of distraction. Normalized values of stiffness (percent stiffness) reached 76.5% +/- 5.4% in the BMP-7 group, compared with 6.6% +/- 0.5% in the control group. The percent maximum torque at failure was 81.1% +/- 1.2% in the BMP-7 group, compared with 20.8% +/- 0.3% in the control group. CONCLUSION: A single injection of rhBMP-7 at the time of osteotomy surgery stimulated the rate of regenerate ossification and increased bone-mineral density during distraction osteogenesis. The biomechanical properties of the newly formed bone were also increased by BMP-7 injection.

Animals↗
PubMed2006

Osteogenesis imperfecta : current treatment options and future prospects.

Osteogenesis imperfecta is a heritable condition characterized by abnormally brittle bones, with an approximate prevalence of 1/20 000 births. Fractures are the main cause of suffering and disability, but owing to the abundance and wide distribution of the defective type I collagen in the body, a variety of symptoms occur. Several types of osteogenesis imperfecta (I-VII) have been described that vary in severity. For many years, therapy consisted of rehabilitation and orthopedic surgery. Presently, pharmacologic therapies aimed at strengthening bone are available, which decrease the pain and fracture rate associated with this condition, and allow more appropriate rehabilitation programs that will hopefully result in a less marked failure to thrive in affected children. In particular, the bisphosphonates, especially pamidronate, have been used for several years. They have been successful in increasing bone mineral density (BMD) and improving bone resistance, leading to a decrease in the fracture rate. Various regimens have been proposed, but it is the therapeutic regimen first used by Glorieux and co-workers in Montreal that has been the most frequently applied.However, as yet there is no definite consensus regarding the indications for therapy, the osteogenesis imperfecta types that are of the greatest concern, the appropriate age at the outset of therapy, and the treatment duration, without yet speaking about the best bisphosphonate regimen for use. The authors have proposed some personal recommendations for the clinical use of bisphosphonates, based on their own experience with the management of patients with this condition; these include the indications for therapy, based on the clinical status, and the treatment duration. These recommendations will certainly not be unanimously endorsed, but they should help to stimulate discussion. Ameliorating BMD is an important step, but will not prevent all fractures because bisphosphonate therapy does not correct the underlying genetic defect. More recently, stem cell replacement therapy in the child or fetus has been proposed as a therapeutic option.All in all, it is possible that, in order to dramatically decrease the fracture rate, combined therapies aimed at both circumventing the consequences of the gene defect using stem cells and reinforcing bone strength with bisphosphonates will have to be considered. Much work is still necessary before recommending these techniques in clinical practice.

Bone Density↗
PubMed1993

Physical therapy management of patients undergoing limb lengthening by distraction osteogenesis.

Limb lengthening by distraction osteogenesis and external fixation is used increasingly in the United States for a variety of orthopaedic conditions. Maintenance of joint motion, critical for successful outcomes, can be difficult to achieve. The rate of growth needed for distraction osteogenesis is faster than that of normal growing bone. Histogenesis of soft tissues must also occur to maintain the motion in joints above and below the limb being lengthened. Physical therapists in patients' home communities need to be knowledgeable about the aggressive management needed to prevent the loss of joint motion. This article introduces physical therapists to a commonly used external fixator, the procedure of distraction osteogenesis, and the role of functional loading. To assist in treatment planning, a physical therapy management plan is presented. Two case examples illustrate how therapists can assess a patient's status relative to the goals in the management plan and determine intervention priorities.

Adolescent↗
PubMed1995

Prenatal diagnosis of osteogenesis imperfecta.

The lethal perinatal types (II A-C) of osteogenesis imperfecta are reported to occur in approximately 1:55000 births. We here present three cases in three unrelated families, diagnosed by antenatal ultrasound within one year. A reliable diagnosis of the lethal perinatal type of osteogenesis imperfecta can be made by ultrasound examination during the second trimester, by identification of fractures of the long bones. The compression of the fetal head by the ultrasound probe and the low echogeneity of the cranium, should raise the suspicion of skeletal dysplasia, but is not diagnostic for osteogenesis imperfecta. The diagnosis is confirmed by postmortem examination including radiography and biochemical studies of cultivated fibroblasts from the fetus. Although rare, this lethal condition should be recognized when an ultrasound examination is performed, to prevent unnecessary obstetric intervention. In families with a previously affected fetus, prenatal diagnosis by first trimester transvaginal ultrasound investigation or chorionic villus sampling should be discussed.

Adult↗
PubMed1995

OIM and related animal models of osteogenesis imperfecta.

Osteogenesis imperfecta (OI) is characterized by fragile bones, skeletal deformity, and growth retardation. This heritable disorder of connective tissue is the result of mutations affecting the COL1A1 and COL1A2 genes of type I collagen. Progress in OI research has been limited because of dependence on human fibroblast and osteoblast specimens and the absence of a naturally occurring animal model for this genetic disorder. Recent technology in molecular biology has led to the development of transgenic models of OI based on site directed mutagenesis of type I collagen genes. OIM is a naturally occurring model which incorporates both the phenotypic and biochemical defects of moderate to severe osteogenesis imperfecta. This powerful tool permits the development of models based on different type I collagen mutations. The collagen type I mutation in OIM is a C propeptide deletion which impairs the production of normal pro-alpha2(I). Tissues in OIM contain only [pro-alpha1(I)]3 homotrimer. Thus, although several animal models are now available for research in osteogenesis imperfecta few are viable or fully mimic human disease disorders. OIM duplicates the phenotype and biochemistry of human disease and has a normal life span.

Animals↗
PubMed1995

Report on new types of intramedullary rods and treatment effectiveness data for selection of intramedullary rodding in osteogenesis imperfecta.

Major advances in the surgical treatment of fractures of long bones in children with Osteogenesis Imperfecta (O.I.) have been made in the last several years. The current mainstay of treatment is bracing and active rehabilitation. When this fails surgery is indicated. The type of fixation device used is generally some type of stainless steel rod. The rod stabilizes the fracture as well as accepts the load across the fracture site thus enabling the fracture to heal. However, the current rods in use have complications. One such complication is cortical atrophy felt to be secondary to the removal of stress from the bone. This phenomena is called stress shielding. Stress shielding in the current rods prompted the study of two new types of rods which more closely approximate the modulus of elasticity of bone. The use of such rods should eliminate the problems of stress shielding. The following paper describes the effectiveness of the various intramedullary rods in the treatment of Osteogenesis Imperfecta fractures. It also reports on the initial results of two new types of intramedullary rods which more closely approximate the modulus of elasticity of bone and therefore may eliminate stress shielding. These rods may replace the stainless steel rods as the "gold standard" of therapy for surgical fixation of long bone fractures in children with Osteogenesis Imperfecta.

Animals↗
PubMed2001

A case of chondrodysplasia punctata with features of osteogenesis imperfecta type II.

The osteogenesis imperfecta syndromes constitute a group of heterogeneous, heritable skeletal dysplasias. Of the 4 types, type II is the most severe, with an incidence of 1 per 55,000. It is characterized by malformed bones secondary to abnormal collagen type I synthesis. Affected fetuses are divided into 3 groups: A, B, and C. All groups have long bones described as "wrinkled" or "crumpled" secondary to repeated fractures. Many bones also show evidence of demineralization, which is especially evident in the bones of the face and calvaria. In groups A and C, the chest is generally small, with thickened and shortened ribs, and each rib has characteristic "beading" patterns secondary to repeated fracturing. Sonography has traditionally been successful in the diagnosis of osteogenesis imperfecta at an early gestational age. Chondrodysplasia punctata describes a heterogeneous group of skeletal disorders characterized by abnormal mineralization of bones during gestation. There are many different causes of it, but some of the specific subtypes include rhizomelic, X-linked dominant (also known as Conradi-Hünermann syndrome), X-linked recessive, and tibia-metacarpal. We report a case of severe X-linked dominant chondrodysplasia punctata, which sonographically had common features with osteogenesis imperfecta type II.

Adult↗
PubMedDate not supplied

[Osteogenesis imperfecta].

Our clinical files on osteogenesis imperfecta are brought up-to-date reviewing a total of 33,555 cases admitted between 4/XII/48 and 31/VIII/76. From these, 5 clinical cases were found. The extreme rareness of this regional pathology in our Cátedra y Sericio de Pediatría, which is the largest concentration center in Paraguay had led us to make this publication. From our casuistics, we may single out a three-month-old infant which would be a case of congenital osteogenesis imperfecta. The remaining 4 would correspond to cases of late osteogenesis imperfecta. Generalized osteoporosis was present in 3 patients and all of them showed blue sclera the same as fractures of femur. Fractures of radius, tibia and fibula were seen in 2 cases. The humerus was fractured in one patient and the ulna in another one. Three patients were under one year old, another one was on his second year and the last one was a school ager. An audiologic examination was normal in the nine-year-old patient. In the other 4 cases, it was not possible to carry out such test.

Humans↗
PubMed1976

Osteogenesis imperfecta of the stapes: an histological study.

Two cases of Van der Hoeve's Syndrome are presented with histological findings consistent with the diagnosis of osteogenesis imperfecta. These findings support the view that otosclerosis can be clearly differentiated histologically from osteogenesis imperfecta. Pre-operative impedance studies are recommended on each patient with osteogenesis imperfecta as a useful diagnostic adjunct to determine whether the conductive component in the hearing loss is secondary to stapedial crural deformity and/or footplate fixation.

Acoustic Impedance Tests↗
PubMed2000

Limb salvage using distraction osteogenesis.

Distraction osteogenesis is a novel technique for the biological restoration of segmental bone defects. Definitive treatment of musculoskeletal tumors often requires large bony resections that can leave patients with significant osseous defects. Limb salvage using distraction osteogenesis is an attractive reconstructive alternative that may, in fact, offer advantages over other conventional techniques. We present our initial experience with the use of distraction osteogenesis in limb salvage.

Adolescent↗
PubMed1975

The cellular changes during osteogenesis in bone and bone marrow composite autografts.

Osteogenesis in and around autografts has been studied in the hope of identifying the osteoblast precursor. Fresh autografts of cortical bone with its constituent bone marrow were implanted into intramuscular sites in rats. The grafts were removed at intervals over a four week period and examined by light and electron microscopy. A chronological sequence of degenerative, reparative and differentiative events was found and described. The relative contributions of the host and graft components to post-grafting osteogenesis are discussed and the problem of the origin of the osteoblast cells is examined, taking into account present views about the interrelationships between skeletal connective tissue cells and their precursors. It is concluded that, in the investigation described, the presence of host granulation tissue was necessary for osteogenesis and it is postulated that osteoblast progenitor cells can arise from this granulation tissue, their differentiation along the osteogenic line being stimulated in some way by the presence of the graft bone.

Animals↗
PubMedDate not supplied

[Distraction osteogenesis of the cranio-maxillo-facial bones].

Distraction osteogenesis is a surgical technique: its main purpose is to induce a mechanically stimulated bone tissue augmentation. A controlled tension, developed by a slow and gradual separation of the corticotomized/osteotomized bone segments, induces new bone formation and related soft tissue augmentation. In this way, we can observe a more harmonious tissue augmentation, better than with traditional techniques as osteotomies with grafts. This procedure, initially applied in orthopedic field for limb lengthening, is now also applied in the cranio-facial field. The most important features of distraction osteogenesis consist in the simplicity of execution, the lack of donor site morbidity and the simultaneous expansion of bone and related soft tissue. Besides, the technique is still at the beginning and requires further acknowledgements, before being widespread used to treat cranio-facial malformations. Disadvantages in bone distraction are related to the external device and consist in esthetic discomfort during treatment, and cutaneous scars. Recently, to solve these problems an intraoral distraction device was proposed. Distraction osteogenesis has now an expanding role in cranio-facial surgery.

Facial Bones↗
PubMed2000

Distraction osteogenesis in functional reconstruction of mandible--report of 6 cases.

OBJECTIVE: To study the application of distraction osteogenesis in mandibular function reconstruction. METHODS: Three types of mandibular distractors were used in 6 patients with different mandibular defects due to tumor resection. For 2 cases with ramus defects, specially designed distractors were used to restore the normal height of the ramus. In 1 case, the trifoci distraction principle was used and a trifoci distractor was designed. In 3 cases, vertical distractors made in Germany or China were used. The patient average age was 31.5 years old (ages ranged from 8 to 54). RESULTS: In 5 cases the mandibular lengthenings were successful according to the direction and distance chosen before distraction. In 1 case, the trifoci distraction principle was applied and a proximal 23 mm mandibular defect was successfully corrected; however, the 23 mm distal mandibular defect was not corrected because the screws for fixation of the transport block were loosened. Infection and dysosteogenesis did not occur in any cases. CONCLUSION: Distraction osteogenesis can successfully be used in mandibular functional reconstruction and is more advantageous than traditional techniques. The most favorable time for distraction osteogenesis in mandibular reconstruction is at the time of tumor resection.

Adult↗
PubMed2001

Geometry of carriers controlling phenotypic expression in BMP-induced osteogenesis and chondrogenesis.

BACKGROUND: The effect of the geometry of extracellular matrices on bone morphogenetic protein (BMP)-induced osteogenesis has not been systematically studied. Geometry is crucially important for the scaffold in bone and joint tissue engineering. The purpose of this study was to elucidate principles of geometry of matrices in designing new scaffolds and matrices for use in reconstruction of bone and joints. METHODS: More than ten biomaterials with different geometries, including a unique device of honeycomb-shaped hydroxyapatite, were combined with BMPs of recombinant (rhBMP-2) or natural bovine origin (S300 BMP cocktail) and implanted subcutaneously into 4-week-old Wistar-King rats. The implanted pellets were removed at 1-4 weeks and analyzed for bone and cartilage formation by histological and biochemical methods. RESULTS: BMP-induced bone and cartilage induction was highly dependent on the geometric properties of the carrier. Some carriers such as porous particles or blocks of hydroxyapatite induced osteogenesis directly, without detectable chondrogenesis, whereas other carriers such as fibrous glass membrane induced cartilage exclusively. Still other carriers induced mostly cartilage followed by bone formation. Solid particles of hydroxyapatite and fibrous glass membrane with too tight a meshwork did not induce bone or cartilage. The optimal pore size for bone-forming efficacy in porous blocks of hydroxyapatite was a diameter of 300-400 microm. In straight tunnel structures with various diameters in honeycomb-shaped hydroxyapatite, tunnels with smaller diameters (90-120 microm) induced cartilage followed by bone formation, whereas those with larger diameters (350 microm) induced bone formation directly within the tunnels. CONCLUSIONS: BMP carriers were classified into three types: bone-inducing, cartilage-inducing, and cartilage-bone-inducing. From the analysis of causative factors inducing osteogenesis and chondrogenesis in the BMP system, we concluded that the geometry of the carrier is crucially important and vasculature-inducing geometry should be considered in designing effective scaffolds for bone formation. We propose a classification of geometry of the artificial extracellular matrices that is useful for designing a scaffold for tissue engineering of bone and related tissues. CLINICAL RELEVANCE: Conventional requisites of the BMP carriers for clinical use have mainly concerned the affinities of carriers with cells and biomolecules and their mechanical strength. The vasculature-inducing geometry of carriers adds a new criterion in designing systems for effective bone and joint reconstruction. The geometries of porous structures-their sizes, continuity, and straightness as verified by hydroxyapatite in this study-will be applicable for other biomaterials for clinical reconstruction therapy.

Animals↗
PubMed1975

Osteogenesis imperfecta tarda. The morphology of rib biopsies.

Undecalcified bone biopsy specimens from 10 normal individuals and 8 osteogenesis imperfecta patients, 2 to 30 years of age, were analyzed using microradiography as well as ultraviolet, tungsten and polarized light microscope techniques. Biopsies of ribs most reliably reflected the disease process of osteogenesis imperfecta when compared to those biopsies of long bones in the lower extremities deformed enough to require corrective surgery. The rib biopsies consistently revealed that there is a rapid surface turnover of histologically well-organized but osteopenic bone. The high rate of bone turnover is similar to that seen in very young normals but in osteogenesis imperfecta turnover rate does not appear to decline with age. The percentage of surface involved in active new bone formation and in osteoclastic resorption is notably elevated. Excessive osteocyte osteolysis is also characteristic.

Adolescent↗
PubMed2001

[Osteogenesis imperfecta. The effect of intramedullary nails in long tubular bones].

INTRODUCTION: The aim of the study was to describe the clinical, radiological, and functional results of intramedullary nailing of deformities in the lower extremities of children with osteogenesis imperfecta after the use of multiple osteotomies and non-telescoping rods (rush pins). MATERIAL AND METHODS: Eight children with osteogenesis imperfecta, who consecutively underwent surgery during 1991-1994, were entered in the study. RESULTS: Sixteen operations were performed on eight children: 12 on the femur and four on the tibia. Like others, we found a high complication rate, 50%. Radiological correction of angular deformities was good. The functional outcome was satisfactory and the patients were satisfied. CONCLUSION: Correction and stabilisation of deformities in the lower extremities in children with osteogenesis imperfecta with the use of non-telescoping rods is an acceptable method of decreasing fractures and allowing most formerly non-ambulatory children to walk. Furthermore, the cosmetics were improved.

Adolescent↗