Osteogenesis Imperfecta: COLLAGEN DISEASES characterized by brittle, osteoporotic, and easily fractured bones. It may also present with blue sclerae, loose joints, and imperfect dentin formation. Most types are autosomal dominant and are associated with mutations in COLLAGEN TYPE I.Osteogenesis: The process of bone formation. Histogenesis of bone including ossification.Osteogenesis, Distraction: Bone lengthening by gradual mechanical distraction. An external fixation device produces the distraction across the bone plate. The technique was originally applied to long bones but in recent years the method has been adapted for use with mandibular implants in maxillofacial surgery.Osteoblasts: Bone-forming cells which secrete an EXTRACELLULAR MATRIX. HYDROXYAPATITE crystals are then deposited into the matrix to form bone.Bone Regeneration: Renewal or repair of lost bone tissue. It excludes BONY CALLUS formed after BONE FRACTURES but not yet replaced by hard bone.Procollagen: A biosynthetic precursor of collagen containing additional amino acid sequences at the amino-terminal and carboxyl-terminal ends of the polypeptide chains.Calcification, Physiologic: Process by which organic tissue becomes hardened by the physiologic deposit of calcium salts.Bone and Bones: A specialized CONNECTIVE TISSUE that is the main constituent of the SKELETON. The principle cellular component of bone is comprised of OSTEOBLASTS; OSTEOCYTES; and OSTEOCLASTS, while FIBRILLAR COLLAGENS and hydroxyapatite crystals form the BONE MATRIX.Mandible: The largest and strongest bone of the FACE constituting the lower jaw. It supports the lower teeth.Core Binding Factor Alpha 1 Subunit: A transcription factor that dimerizes with CORE BINDING FACTOR BETA SUBUNIT to form core binding factor. It contains a highly conserved DNA-binding domain known as the runt domain and is involved in genetic regulation of skeletal development and CELL DIFFERENTIATION.Skull: The SKELETON of the HEAD including the FACIAL BONES and the bones enclosing the BRAIN.External Fixators: External devices which hold wires or pins that are placed through one or both cortices of bone in order to hold the position of a fracture in proper alignment. These devices allow easy access to wounds, adjustment during the course of healing, and more functional use of the limbs involved.Mesenchymal Stromal Cells: Bone-marrow-derived, non-hematopoietic cells that support HEMATOPOETIC STEM CELLS. They have also been isolated from other organs and tissues such as UMBILICAL CORD BLOOD, umbilical vein subendothelium, and WHARTON JELLY. These cells are considered to be a source of multipotent stem cells because they include subpopulations of mesenchymal stem cells.Alkaline Phosphatase: An enzyme that catalyzes the conversion of an orthophosphoric monoester and water to an alcohol and orthophosphate. EC 3.1.3.1.Bone Matrix: Extracellular substance of bone tissue consisting of COLLAGEN fibers, ground substance, and inorganic crystalline minerals and salts.Bone Morphogenetic Protein 2: A potent osteoinductive protein that plays a critical role in the differentiation of osteoprogenitor cells into OSTEOBLASTS.Bony Callus: The bony deposit formed between and around the broken ends of BONE FRACTURES during normal healing.Tibia: The second longest bone of the skeleton. It is located on the medial side of the lower leg, articulating with the FIBULA laterally, the TALUS distally, and the FEMUR proximally.Collagen: A polypeptide substance comprising about one third of the total protein in mammalian organisms. It is the main constituent of SKIN; CONNECTIVE TISSUE; and the organic substance of bones (BONE AND BONES) and teeth (TOOTH).Collagen Type I: The most common form of fibrillar collagen. It is a major constituent of bone (BONE AND BONES) and SKIN and consists of a heterotrimer of two alpha1(I) and one alpha2(I) chains.X-Ray Microtomography: X-RAY COMPUTERIZED TOMOGRAPHY with resolution in the micrometer range.Ilizarov Technique: A bone fixation technique using an external fixator (FIXATORS, EXTERNAL) for lengthening limbs, correcting pseudarthroses and other deformities, and assisting the healing of otherwise hopeless traumatic or pathological fractures and infections, such as chronic osteomyelitis. The method was devised by the Russian orthopedic surgeon Gavriil Abramovich Ilizarov (1921-1992). (From Bull Hosp Jt Dis 1992 Summer;52(1):1)Periosteum: Thin outer membrane that surrounds a bone. It contains CONNECTIVE TISSUE, CAPILLARIES, nerves, and a number of cell types.Dentinogenesis Imperfecta: An autosomal dominant disorder of tooth development characterized by opalescent dentin resulting in discoloration of the teeth. The dentin develops poorly with low mineral content while the pulp canal is obliterated.Mandibular Osteotomy: Intraoral OSTEOTOMY of the lower jaw usually performed in order to correct MALOCCLUSION.Bone Development: The growth and development of bones from fetus to adult. It includes two principal mechanisms of bone growth: growth in length of long bones at the epiphyseal cartilages and growth in thickness by depositing new bone (OSTEOGENESIS) with the actions of OSTEOBLASTS and OSTEOCLASTS.Cell Differentiation: Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.Fracture Healing: The physiological restoration of bone tissue and function after a fracture. It includes BONY CALLUS formation and normal replacement of bone tissue.Osteocalcin: Vitamin K-dependent calcium-binding protein synthesized by OSTEOBLASTS and found primarily in BONES. Serum osteocalcin measurements provide a noninvasive specific marker of bone metabolism. The protein contains three residues of the amino acid gamma-carboxyglutamic acid (Gla), which, in the presence of CALCIUM, promotes binding to HYDROXYAPATITE and subsequent accumulation in BONE MATRIX.Adipogenesis: The differentiation of pre-adipocytes into mature ADIPOCYTES.Ossification, Heterotopic: The development of bony substance in normally soft structures.Integrin-Binding Sialoprotein: A highly glycosylated and sulfated phosphoprotein that is found almost exclusively in mineralized connective tissues. It is an extracellular matrix protein that binds to hydroxyapatite through polyglutamic acid sequences and mediates cell attachment through an RGD sequence.Osseointegration: The growth action of bone tissue as it assimilates surgically implanted devices or prostheses to be used as either replacement parts (e.g., hip) or as anchors (e.g., endosseous dental implants).Osteocytes: Mature osteoblasts that have become embedded in the BONE MATRIX. They occupy a small cavity, called lacuna, in the matrix and are connected to adjacent osteocytes via protoplasmic projections called canaliculi.Femur: The longest and largest bone of the skeleton, it is situated between the hip and the knee.Chondrogenesis: The formation of cartilage. This process is directed by CHONDROCYTES which continually divide and lay down matrix during development. It is sometimes a precursor to OSTEOGENESIS.Micrognathism: Abnormally small jaw.Glycine: A non-essential amino acid. It is found primarily in gelatin and silk fibroin and used therapeutically as a nutrient. It is also a fast inhibitory neurotransmitter.Mandibular Fractures: Fractures of the lower jaw.Bone Morphogenetic Proteins: Bone-growth regulatory factors that are members of the transforming growth factor-beta superfamily of proteins. They are synthesized as large precursor molecules which are cleaved by proteolytic enzymes. The active form can consist of a dimer of two identical proteins or a heterodimer of two related bone morphogenetic proteins.Osteotomy: The surgical cutting of a bone. (Dorland, 28th ed)Cells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.Jaw Fixation Techniques: The stable placement of surgically induced fractures of the mandible or maxilla through the use of elastics, wire ligatures, arch bars, or other splints. It is used often in the cosmetic surgery of retrognathism and prognathism. (From Dorland, 28th ed, p636)Bone Diseases: Diseases of BONES.Cranial Sutures: A type of fibrous joint between bones of the head.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Bone Substitutes: Synthetic or natural materials for the replacement of bones or bone tissue. They include hard tissue replacement polymers, natural coral, hydroxyapatite, beta-tricalcium phosphate, and various other biomaterials. The bone substitutes as inert materials can be incorporated into surrounding tissue or gradually replaced by original tissue.Bone Lengthening: Increase in the longest dimension of a bone to correct anatomical deficiencies, congenital, traumatic, or as a result of disease. The lengthening is not restricted to long bones. The usual surgical methods are internal fixation and distraction.Alveolar Process: The thickest and spongiest part of the maxilla and mandible hollowed out into deep cavities for the teeth.Cartilage: A non-vascular form of connective tissue composed of CHONDROCYTES embedded in a matrix that includes CHONDROITIN SULFATE and various types of FIBRILLAR COLLAGEN. There are three major types: HYALINE CARTILAGE; FIBROCARTILAGE; and ELASTIC CARTILAGE.Bone Marrow Cells: Cells contained in the bone marrow including fat cells (see ADIPOCYTES); STROMAL CELLS; MEGAKARYOCYTES; and the immediate precursors of most blood cells.Fractures, Bone: Breaks in bones.Stromal Cells: Connective tissue cells of an organ found in the loose connective tissue. These are most often associated with the uterine mucosa and the ovary as well as the hematopoietic system and elsewhere.Genes, Lethal: Genes whose loss of function or gain of function MUTATION leads to the death of the carrier prior to maturity. They may be essential genes (GENES, ESSENTIAL) required for viability, or genes which cause a block of function of an essential gene at a time when the essential gene function is required for viability.Tissue Scaffolds: Cell growth support structures composed of BIOCOMPATIBLE MATERIALS. They are specially designed solid support matrices for cell attachment in TISSUE ENGINEERING and GUIDED TISSUE REGENERATION uses.Bone Remodeling: The continuous turnover of BONE MATRIX and mineral that involves first an increase in BONE RESORPTION (osteoclastic activity) and later, reactive BONE FORMATION (osteoblastic activity). The process of bone remodeling takes place in the adult skeleton at discrete foci. The process ensures the mechanical integrity of the skeleton throughout life and plays an important role in calcium HOMEOSTASIS. An imbalance in the regulation of bone remodeling's two contrasting events, bone resorption and bone formation, results in many of the metabolic bone diseases, such as OSTEOPOROSIS.Bone Density: The amount of mineral per square centimeter of BONE. This is the definition used in clinical practice. Actual bone density would be expressed in grams per milliliter. It is most frequently measured by X-RAY ABSORPTIOMETRY or TOMOGRAPHY, X RAY COMPUTED. Bone density is an important predictor for OSTEOPOROSIS.Bone Transplantation: The grafting of bone from a donor site to a recipient site.Durapatite: The mineral component of bones and teeth; it has been used therapeutically as a prosthetic aid and in the prevention and treatment of osteoporosis.Diphosphonates: Organic compounds which contain P-C-P bonds, where P stands for phosphonates or phosphonic acids. These compounds affect calcium metabolism. They inhibit ectopic calcification and slow down bone resorption and bone turnover. Technetium complexes of diphosphonates have been used successfully as bone scanning agents.Fractures, Spontaneous: Fractures occurring as a result of disease of a bone or from some undiscoverable cause, and not due to trauma. (Dorland, 27th ed)Tissue Engineering: Generating tissue in vitro for clinical applications, such as replacing wounded tissues or impaired organs. The use of TISSUE SCAFFOLDING enables the generation of complex multi-layered tissues and tissue structures.Implants, Experimental: Artificial substitutes for body parts and materials inserted into organisms during experimental studies.Scleral Diseases: General disorders of the sclera or white of the eye. They may include anatomic, embryologic, degenerative, or pigmentation defects.Elaeagnaceae: A plant family of the order Rhamnales, subclass Rosidae class Magnoliopsida. The plants have a characteristic silvery or rusty-colored sheen, caused by tiny distinctive scales. Flowers have a tubular structure of four sepals. Root nodules host the Frankia (ACTINOMYCETES) nitrogen-fixing symbionts.Bone Demineralization Technique: Removal of mineral constituents or salts from bone or bone tissue. Demineralization is used as a method of studying bone strength and bone chemistry.Ulna: The inner and longer bone of the FOREARM.Arthrogryposis: Persistent flexure or contracture of a joint.Leg Length Inequality: A condition in which one of a pair of legs fails to grow as long as the other, which could result from injury or surgery.Alveolar Ridge Augmentation: Preprosthetic surgery involving rib, cartilage, or iliac crest bone grafts, usually autologous, or synthetic implants for rebuilding the alveolar ridge.Fibroblasts: Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.Cyclophilins: A family of peptidyl-prolyl cis-trans isomerases that bind to CYCLOSPORINS and regulate the IMMUNE SYSTEM. EC 5.2.1.-Tropocollagen: The molecular unit of collagen fibrils that consist of repeating three-stranded polypeptide units arranged head to tail in parallel bundles. It is a right-handed triple helix composed of 2 polypeptide chains. It is rich in glycine, proline, hydroxyproline, and hydroxylysine.Osteopontin: A negatively-charged extracellular matrix protein that plays a role in the regulation of BONE metabolism and a variety of other biological functions. Cell signaling by osteopontin may occur through a cell adhesion sequence that recognizes INTEGRIN ALPHA-V BETA-3.Pedigree: The record of descent or ancestry, particularly of a particular condition or trait, indicating individual family members, their relationships, and their status with respect to the trait or condition.Skin: The outer covering of the body that protects it from the environment. It is composed of the DERMIS and the EPIDERMIS.Chondrodysplasia Punctata: A heterogeneous group of bone dysplasias, the common character of which is stippling of the epiphyses in infancy. The group includes a severe autosomal recessive form (CHONDRODYSPLASIA PUNCTATA, RHIZOMELIC), an autosomal dominant form (Conradi-Hunermann syndrome), and a milder X-linked form. Metabolic defects associated with impaired peroxisomes are present only in the rhizomelic form.Ehlers-Danlos Syndrome: A heterogeneous group of autosomally inherited COLLAGEN DISEASES caused by defects in the synthesis or structure of FIBRILLAR COLLAGEN. There are numerous subtypes: classical, hypermobility, vascular, and others. Common clinical features include hyperextensible skin and joints, skin fragility and reduced wound healing capability.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Procollagen N-Endopeptidase: An extracellular endopeptidase which excises a block of peptides at the amino terminal, nonhelical region of the procollagen molecule with the formation of collagen. Absence or deficiency of the enzyme causes accumulation of procollagen which results in the inherited connective tissue disorder--dermatosparaxis. EC 3.4.24.14.Tibial FracturesOral Surgical Procedures: Surgical procedures used to treat disease, injuries, and defects of the oral and maxillofacial region.Bone Diseases, DevelopmentalCalcium Phosphates: Calcium salts of phosphoric acid. These compounds are frequently used as calcium supplements.Extracellular Matrix Proteins: Macromolecular organic compounds that contain carbon, hydrogen, oxygen, nitrogen, and usually, sulfur. These macromolecules (proteins) form an intricate meshwork in which cells are embedded to construct tissues. Variations in the relative types of macromolecules and their organization determine the type of extracellular matrix, each adapted to the functional requirements of the tissue. The two main classes of macromolecules that form the extracellular matrix are: glycosaminoglycans, usually linked to proteins (proteoglycans), and fibrous proteins (e.g., COLLAGEN; ELASTIN; FIBRONECTINS; and LAMININ).Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Growth Plate: The area between the EPIPHYSIS and the DIAPHYSIS within which bone growth occurs.Dental Implants: Biocompatible materials placed into (endosseous) or onto (subperiosteal) the jawbone to support a crown, bridge, or artificial tooth, or to stabilize a diseased tooth.Alendronate: A nonhormonal medication for the treatment of postmenopausal osteoporosis in women. This drug builds healthy bone, restoring some of the bone loss as a result of osteoporosis.Bone Density Conservation Agents: Agents that inhibit BONE RESORPTION and/or favor BONE MINERALIZATION and BONE REGENERATION. They are used to heal BONE FRACTURES and to treat METABOLIC BONE DISEASES such as OSTEOPOROSIS.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Biomechanical Phenomena: The properties, processes, and behavior of biological systems under the action of mechanical forces.Musculoskeletal Abnormalities: Congenital structural abnormalities and deformities of the musculoskeletal system.Ribs: A set of twelve curved bones which connect to the vertebral column posteriorly, and terminate anteriorly as costal cartilage. Together, they form a protective cage around the internal thoracic organs.Craniosynostoses: Premature closure of one or more CRANIAL SUTURES. It often results in plagiocephaly. Craniosynostoses that involve multiple sutures are sometimes associated with congenital syndromes such as ACROCEPHALOSYNDACTYLIA; and CRANIOFACIAL DYSOSTOSIS.Ear Ossicles: A mobile chain of three small bones (INCUS; MALLEUS; STAPES) in the TYMPANIC CAVITY between the TYMPANIC MEMBRANE and the oval window on the wall of INNER EAR. Sound waves are converted to vibration by the tympanic membrane then transmitted via these ear ossicles to the inner ear.Genes, Dominant: Genes that influence the PHENOTYPE both in the homozygous and the heterozygous state.Bone Morphogenetic Protein 7: A bone morphogenetic protein that is widely expressed during EMBRYONIC DEVELOPMENT. It is both a potent osteogenic factor and a specific regulator of nephrogenesis.Titanium: A dark-gray, metallic element of widespread distribution but occurring in small amounts; atomic number, 22; atomic weight, 47.90; symbol, Ti; specific gravity, 4.5; used for fixation of fractures. (Dorland, 28th ed)Bone Morphogenetic Protein 4: A bone morphogenetic protein that is a potent inducer of bone formation. It also functions as a regulator of MESODERM formation during EMBRYONIC DEVELOPMENT.Polyglycolic Acid: A biocompatible polymer used as a surgical suture material.Genes, Recessive: Genes that influence the PHENOTYPE only in the homozygous state.Femoral Fractures: Fractures of the femur.Stress, Mechanical: A purely physical condition which exists within any material because of strain or deformation by external forces or by non-uniform thermal expansion; expressed quantitatively in units of force per unit area.Cyanogen Bromide: Cyanogen bromide (CNBr). A compound used in molecular biology to digest some proteins and as a coupling reagent for phosphoroamidate or pyrophosphate internucleotide bonds in DNA duplexes.Osteoporosis: Reduction of bone mass without alteration in the composition of bone, leading to fractures. Primary osteoporosis can be of two major types: postmenopausal osteoporosis (OSTEOPOROSIS, POSTMENOPAUSAL) and age-related or senile osteoporosis.Jaw Abnormalities: Congenital absence of or defects in structures of the jaw.Cell Shape: The quality of surface form or outline of CELLS.Bone Nails: Rods of bone, metal, or other material used for fixation of the fragments or ends of fractured bones.Sialoglycoproteins: Glycoproteins which contain sialic acid as one of their carbohydrates. They are often found on or in the cell or tissue membranes and participate in a variety of biological activities.Elastic Modulus: Numerical expression indicating the measure of stiffness in a material. It is defined by the ratio of stress in a unit area of substance to the resulting deformation (strain). This allows the behavior of a material under load (such as bone) to be calculated.Fractures, Ununited: A fracture in which union fails to occur, the ends of the bone becoming rounded and eburnated, and a false joint occurs. (Stedman, 25th ed)Signal Transduction: The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.RNA, Messenger: RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.Spine: The spinal or vertebral column.Goldenhar Syndrome: Mandibulofacial dysostosis with congenital eyelid dermoids.Osteoclasts: A large multinuclear cell associated with the BONE RESORPTION. An odontoclast, also called cementoclast, is cytomorphologically the same as an osteoclast and is involved in CEMENTUM resorption.Thanatophoric Dysplasia: A severe form of neonatal dwarfism with very short limbs. All cases have died at birth or later in the neonatal period.Cell Proliferation: All of the processes involved in increasing CELL NUMBER including CELL DIVISION.Mandibular Prosthesis Implantation: Surgical insertion of an appliance for the replacement of areas of the mandible.Infant, Newborn: An infant during the first month after birth.Mandibular Prosthesis: A prosthetic appliance for the replacement of areas of the mandible missing or defective as a result of deformity, disease, injury, or surgery.Stem Cells: Relatively undifferentiated cells that retain the ability to divide and proliferate throughout postnatal life to provide progenitor cells that can differentiate into specialized cells.Periodontal Ligament: The fibrous CONNECTIVE TISSUE surrounding the TOOTH ROOT, separating it from and attaching it to the alveolar bone (ALVEOLAR PROCESS).Soft Tissue Injuries: Injuries of tissue other than bone. The concept is usually general and does not customarily refer to internal organs or viscera. It is meaningful with reference to regions or organs where soft tissue (muscle, fat, skin) should be differentiated from bones or bone tissue, as "soft tissue injuries of the hand".Fibrillar Collagens: A family of structurally related collagens that form the characteristic collagen fibril bundles seen in CONNECTIVE TISSUE.Ankylosis: Fixation and immobility of a joint.Biocompatible Materials: Synthetic or natural materials, other than DRUGS, that are used to replace or repair any body TISSUES or bodily function.Femoral NeoplasmsGene Expression Regulation: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.Bone Resorption: Bone loss due to osteoclastic activity.Sclera: The white, opaque, fibrous, outer tunic of the eyeball, covering it entirely excepting the segment covered anteriorly by the cornea. It is essentially avascular but contains apertures for vessels, lymphatics, and nerves. It receives the tendons of insertion of the extraocular muscles and at the corneoscleral junction contains the canal of Schlemm. (From Cline et al., Dictionary of Visual Science, 4th ed)Capillary Fragility: The susceptibility of CAPILLARIES, under conditions of increased stress, to leakage.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Facial Asymmetry: Congenital or acquired asymmetry of the face.Chondrocytes: Polymorphic cells that form cartilage.Bone Morphogenetic Protein 1: A bone morphogenetic protein family member that includes an active tolloid-like metalloproteinase domain. The metalloproteinase activity of bone morphogenetic protein 1 is specific for the removal of the C-propeptide of PROCOLLAGEN and may act as a regulator of EXTRACELLULAR MATRIX deposition. Alternative splicing of MRNA for bone morphogenetic protein 1 results in the production of several PROTEIN ISOFORMS.Homozygote: An individual in which both alleles at a given locus are identical.Dental Prosthesis, Implant-Supported: A prosthesis that gains its support, stability, and retention from a substructure that is implanted under the soft tissues of the basal seat of the device and is in contact with bone. (From Boucher's Clinical Dental Terminology, 4th ed)BenzothiepinsMetacarpus: The region of the HAND between the WRIST and the FINGERS.Heterozygote: An individual having different alleles at one or more loci regarding a specific character.Oval Window, Ear: Fenestra or oval opening on the lateral wall of the vestibular labyrinth adjacent to the MIDDLE EAR. It is located above the cochlear round window and normally covered by the base of the STAPES.Dental Sac: Dense fibrous layer formed from mesodermal tissue that surrounds the epithelial enamel organ. The cells eventually migrate to the external surface of the newly formed root dentin and give rise to the cementoblasts that deposit cementum on the developing root, fibroblasts of the developing periodontal ligament, and osteoblasts of the developing alveolar bone.Palate, Hard: The anteriorly located rigid section of the PALATE.Disease Models, Animal: Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.Silk: A continuous protein fiber consisting primarily of FIBROINS. It is synthesized by a variety of INSECTS and ARACHNIDS.Dental Arch: The curve formed by the row of TEETH in their normal position in the JAW. The inferior dental arch is formed by the mandibular teeth, and the superior dental arch by the maxillary teeth.Alleles: Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.Extracellular Matrix: A meshwork-like substance found within the extracellular space and in association with the basement membrane of the cell surface. It promotes cellular proliferation and provides a supporting structure to which cells or cell lysates in culture dishes adhere.Eye Manifestations: Ocular disorders attendant upon non-ocular disease or injury.Wound Healing: Restoration of integrity to traumatized tissue.Neovascularization, Physiologic: The development of new BLOOD VESSELS during the restoration of BLOOD CIRCULATION during the healing process.Mice, Mutant Strains: Mice bearing mutant genes which are phenotypically expressed in the animals.Sotos Syndrome: Congenital or postnatal overgrowth syndrome most often in height and occipitofrontal circumference with variable delayed motor and cognitive development. Other associated features include advanced bone age, seizures, NEONATAL JAUNDICE; HYPOTONIA; and SCOLIOSIS. It is also associated with increased risk of developing neoplasms in adulthood. Mutations in the NSD1 protein and its HAPLOINSUFFICIENCY are associated with the syndrome.Cell Lineage: The developmental history of specific differentiated cell types as traced back to the original STEM CELLS in the embryo.HSP47 Heat-Shock Proteins: Basic glycoprotein members of the SERPIN SUPERFAMILY that function as COLLAGEN-specific MOLECULAR CHAPERONES in the ENDOPLASMIC RETICULUM.Chin: The anatomical frontal portion of the mandible, also known as the mentum, that contains the line of fusion of the two separate halves of the mandible (symphysis menti). This line of fusion divides inferiorly to enclose a triangular area called the mental protuberance. On each side, inferior to the second premolar tooth, is the mental foramen for the passage of blood vessels and a nerve.Prostheses and Implants: Artificial substitutes for body parts, and materials inserted into tissue for functional, cosmetic, or therapeutic purposes. Prostheses can be functional, as in the case of artificial arms and legs, or cosmetic, as in the case of an artificial eye. Implants, all surgically inserted or grafted into the body, tend to be used therapeutically. IMPLANTS, EXPERIMENTAL is available for those used experimentally.Mandibular DiseasesCore Binding Factor alpha Subunits: A family of transcription factors that bind to the cofactor CORE BINDING FACTOR BETA SUBUNIT to form core binding factor. Family members contain a highly conserved DNA-binding domain known as the runt domain. They can act as both activators and repressors of expression of GENES involved in CELL DIFFERENTIATION and CELL CYCLE progression.Fetal Research: Experimentation on, or using the organs or tissues from, a human or other mammalian conceptus in the postembryonic period, after the major structures have been outlined. In humans, this corresponds to the period from the third month after fertilization until birth.Scoliosis: An appreciable lateral deviation in the normally straight vertical line of the spine. (Dorland, 27th ed)Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Dental Implantation, Endosseous: Insertion of an implant into the bone of the mandible or maxilla. The implant has an exposed head which protrudes through the mucosa and is a prosthodontic abutment.Gene Expression Regulation, Developmental: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action during the developmental stages of an organism.Retrognathia: A physical misalignment of the upper (maxilla) and lower (mandibular) jaw bones in which either or both recede relative to the frontal plane of the forehead.Hydroxylysine: A hydroxylated derivative of the amino acid LYSINE that is present in certain collagens.Tooth Extraction: The surgical removal of a tooth. (Dorland, 28th ed)Maxilla: One of a pair of irregularly shaped bones that form the upper jaw. A maxillary bone provides tooth sockets for the superior teeth, forms part of the ORBIT, and contains the MAXILLARY SINUS.Dentinogenesis: The formation of dentin. Dentin first appears in the layer between the ameloblasts and odontoblasts and becomes calcified immediately. Formation progresses from the tip of the papilla over its slope to form a calcified cap becoming thicker by the apposition of new layers pulpward. A layer of uncalcified dentin intervenes between the calcified tissue and the odontoblast and its processes. (From Jablonski, Dictionary of Dentistry, 1992)Tensile Strength: The maximum stress a material subjected to a stretching load can withstand without tearing. (McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed, p2001)Coated Materials, Biocompatible: Biocompatible materials usually used in dental and bone implants that enhance biologic fixation, thereby increasing the bond strength between the coated material and bone, and minimize possible biological effects that may result from the implant itself.Osteochondrodysplasias: Abnormal development of cartilage and bone.

The use of variable lactate/malic dehydrogenase ratios to distinguish between progenitor cells of cartilage and bone in the embryonic chick. (1/3582)

The activities of LDH and MDH have been studied, both in differentiated cartilage and bone from the embryonic chick, and in the pool of mixed osteogenic and chondrogenic stem cells found on the quadratojugal, a membrane bone. In confirmation of the model proposed by Reddi & Huggins (1971) we found that the LDH/MDH ratio was greater than 1 in cartilage and less than 1 in bone. Furthermore we established, for the first time, that ratios occurred in the chondrogenic and osteogenic stem cells, similar to the ratios in their differentiated counterparts. Alteration in LDH/MDH resulted from variations in the level of LDH/mug protein. MDH/mug protein remained constant, even when LDH/MDH was changing. We interpret these results in terms of adaptation of chondrogenic progenitor cells for anaerobic metabolism and anticipate that our model will be applicable to other skeletal systems where stem cells are being studied.  (+info)

Tumor necrosis factor receptor family member RANK mediates osteoclast differentiation and activation induced by osteoprotegerin ligand. (2/3582)

A receptor that mediates osteoprotegerin ligand (OPGL)-induced osteoclast differentiation and activation has been identified via genomic analysis of a primary osteoclast precursor cell cDNA library and is identical to the tumor necrosis factor receptor (TNFR) family member RANK. The RANK mRNA was highly expressed by isolated bone marrow-derived osteoclast progenitors and by mature osteoclasts in vivo. Recombinant OPGL binds specifically to RANK expressed by transfected cell lines and purified osteoclast progenitors. Transgenic mice expressing a soluble RANK-Fc fusion protein have severe osteopetrosis because of a reduction in osteoclasts, similar to OPG transgenic mice. Recombinant RANK-Fc binds with high affinity to OPGL in vitro and blocks osteoclast differentiation and activation in vitro and in vivo. Furthermore, polyclonal Ab against the RANK extracellular domain promotes osteoclastogenesis in bone marrow cultures suggesting that RANK activation mediates the effects of OPGL on the osteoclast pathway. These data indicate that OPGL-induced osteoclastogenesis is directly mediated through RANK on osteoclast precursor cells.  (+info)

Hindlimb patterning and mandible development require the Ptx1 gene. (3/3582)

The restricted expression of the Ptx1 (Pitx1) gene in the posterior half of the lateral plate mesoderm has suggested that it may play a role in specification of posterior structures, in particular, specification of hindlimb identity. Ptx1 is also expressed in the most anterior ectoderm, the stomodeum, and in the first branchial arch. Ptx1 expression overlaps with that of Ptx2 in stomodeum and in posterior left lateral plate mesoderm. We now show that targeted inactivation of the mouse Ptx1 gene severely impairs hindlimb development: the ilium and knee cartilage are absent and the long bones are underdeveloped. Greater reduction of the right femur size in Ptx1 null mice suggests partial compensation by Ptx2 on the left side. The similarly sized tibia and fibula of mutant hindlimbs may be taken to resemble forelimb bones: however, the mutant limb buds appear to have retained their molecular identity as assessed by forelimb expression of Tbx5 and by hindlimb expression of Tbx4, even though Tbx4 expression is decreased in Ptx1 null mice. The hindlimb defects appear to be, at least partly, due to abnormal chondrogenesis. Since the most affected structures derive from the dorsal side of hindlimb buds, the data suggest that Ptx1 is responsible for patterning of these dorsal structures and that as such it may control development of hindlimb-specific features. Ptx1 inactivation also leads to loss of bones derived from the proximal part of the mandibular mesenchyme. The dual role of Ptx1 revealed by the gene knockout may reflect features of the mammalian jaw and hindlimbs that were acquired at a similar time during tetrapod evolution.  (+info)

The development of the fetal sternum: a cross-sectional sonographic study. (4/3582)

OBJECTIVE: To assess the relationship between gestational age and sonographic appearance of the various sternal components and establish growth during human gestation. DESIGN: A prospective cross-sectional study. METHODS: The study was performed on 252 consecutive normal singleton pregnancies from 19 weeks of gestation until term, using transabdominal high-resolution ultrasound techniques. The sternal length, as well as the number of ossification centers at each gestational age, were recorded. RESULTS: The first occasion at which a fetal human sternum could be visualized with two to three ossification centers was at 19 weeks' gestational age. The fifth ossification center was first visualized at 29 weeks' gestation. The mean +/- SE of sternal length varied from 15 +/- 0.98 mm (95% confidence interval (CI) 12.79-17.21) at 19-20 weeks, to 36.50 +/- 0.29 mm (95% CI 35.58-37.42) at 37-38 weeks' gestation. Sternal length as a function of gestational age was expressed by the regression equation: sternal length (mm) = -11.06 + 1.39 x gestational age (weeks). The correlation coefficient, r = 0.924 for sternal length, was found to be highly statistically significant (p < 0.0001). CONCLUSIONS: The presented data offer normative measurements of the fetal sternum which may be helpful in the prenatal diagnosis of congenital syndromes that include, among other manifestations, abnormalities of sternal development.  (+info)

Effect of strontium on the epiphyseal cartilage plate of rat tibiae-histological and radiographic studies. (5/3582)

Following dietary administration of strontium carbonate, histological and radiographic changes in the epiphyseal cartilage plate of the rat tibiae were examined in the present study. The weight gain of the rat fed a strontium diet was less than that of the control rats. Longitudinal growth of tibiae and endochondral ossification were inhibited by strontium administration. The widths of both proximal and distal cartilage plates increased enormously as has also been shown by other investigators. Sizes of chondroblasts in columns of proximal cartilage plate in rats fed a strontium diet were smaller than those of the control rats and were not different between upper and lower parts. It is suggested that strontium inhibits bone growth through the inhibitory action on the maturation process of chondroblasts and the succeeding endochondral ossification.  (+info)

A quantitative assessment of the healing of intramembranous and endochondral autogenous bone grafts. (6/3582)

The aim of the study was to assess quantitatively the amount of new bone formed in the early stages of healing of intramembranous and endochondral autogenous bone grafts so as to gain further insight into their integration with host bone. Eighteen critical size defects were created in the parietal bone of nine New Zealand White rabbits. In the experimental group (five rabbits), each rabbit was grafted with intramembranous bone in one defect and with endochondral bone in the other. In the control group (four rabbits), one defect was left empty (passive control) and the other was grafted with rabbit skin collagen (active control). After 14 days, the rabbits were killed and the defects were prepared for histological analysis. Serial sections were made across the whole defect. Each defect was divided into five regions spaced 1500 microns apart. Two sections were randomly drawn from each region. Quantitative analysis was performed on 100 sections using an image analyser computer software system to assess the amount of new bone formed in each defect. No bone was detected across the defect in either the active or passive controls. One-hundred-and-sixty-six per cent more new bone was formed in defects grafted with intramembranous bone than those grafted with endochondral bone. This represented an extremely significant difference (P < 0.0001, unpaired t-test) between the two groups. The results show that intramembranous autogenous bone produced more bone than the endochondral bone when grafted in the skull. Clinically, it is recommended that intramembranous bone is used to replace lost membranous bone in the oral cavity, as well as in skull defects, whenever possible.  (+info)

Differential patterns of altered bone formation in different bone compartments in established osteoporosis. (7/3582)

AIM: To investigate the level of bone formation in the different bone compartments in cases of established osteoporosis, as previous work has concentrated on trabecular bone alone. METHODS: Bone formation rates were measured histomorphometrically, in the periosteal (P), cortical (C), subcortical (SC), and trabecular (T) compartments in iliac crest biopsies from 159 patients with established osteoporosis. The values were standardised using age and sex matched control data and patterns of differential change determined by analysis of parametric status (increased, normal, reduced). RESULTS: Mean bone formation was reduced in all four compartments. This was more marked (4.4/4.1 standard deviations below the mean in C/T, v 2.3/0.9 in P/SC) and more frequent (reduced in 81.5%/78.3% in T/C, v 43.3%/44% in P/SC) in the trabecular and cortical compartments than in the periosteal or subcortical bone. Parametric status was equal in trabecular and cortical bone in 85.4% of cases, and in periosteal and subcortical bone in 65.7%, but in all four compartments in only 35.1%, indicating differential alteration of bone formation in the two sets of compartments (T/C v P/SC). CONCLUSIONS: Altered trabecular bone formation is important in osteoporosis, but there are differential patterns of alteration in the other three compartments, emphasising the presence of different microenvironments in bone; thus the effect on the cortical compartment was similar to that on the trabecular, while the subcortical and periosteal compartments also showed linkage. The linkage between the two pairs was divergent, indicating different control of bone formation, with resultant different patterns of perturbation in osteoporosis.  (+info)

Effects of XT-44, a phosphodiesterase 4 inhibitor, in osteoblastgenesis and osteoclastgenesis in culture and its therapeutic effects in rat osteopenia models. (8/3582)

We have reported that denbufylline, a phosphodiesterase 4 (PDE4) inhibitor, inhibits bone loss in Walker256/S tumor-bearing rats, suggesting therapeutic potentiality of a PDE4 inhibitor in osteopenia. In the present study, effects of a new PDE4 inhibitor, 1-n-butyl-3-n-propylxanthine (XT-44), in bone were evaluated in cell cultures and animal experiments. In rat bone marrow culture, XT-44 stimulated mineralized-nodule formation, whereas it inhibited osteoclast-like cell formation in mouse bone marrow culture. In Walker256/S-bearing rats (6-week-old female Wistar Imamichi rats), rapid decrease in bone mineral density (BMD) was prominent, and oral administration of XT-44 (0.3 mg/kg, every 2 days) inhibited the decrease in BMD. In the second animal experiment, female Wistar rats (6-week-old) were sciatic neurectomized, and XT-44 was orally administered to these rats every 2 days for 4 weeks. XT-44 administration (0.3 mg/kg) recovered BMD in these neurectomized animals. Furthermore, 19-week-old, female Wistar rats were ovariectomized (OVX), and 15 weeks after surgery, these rats were orally administered XT-44 every 2 days for 8 weeks. XT-44 treatment (1 mg/kg) increased the BMD of OVX rats. These results indicate that XT-44 could be a candidate as a therapeutic drug for treating osteopenia including osteoporosis.  (+info)

  • Mesenchymal stem cells derived from mouse or human iPS cells (iPS-MSCs) have been reported by several groups 10 , 11 and used for osteogenesis both in vitro and in vivo 12 , which makes iPS-MSCs a promising cell source for studying orthopedic diseases, regenerative orthopedic therapy and patient-specific cell therapy. (nature.com)
  • We studied the effect of OA on osteogenesis of bone marrow-derived mesenchymal stem cells (BMSCs). (mdpi.com)
  • Dr. V. Reid Sutton , professor of molecular and human genetics at Baylor, will discuss the causes of osteogenesis imperfecta, the prognosis for those living with the disorder and the newest treatments being tested in clinical trials. (bcm.edu)
  • Distraction osteogenesis (DO), also called callus distraction, callotasis and osteodistraction, is a process used in orthopedic surgery and oral and maxillofacial surgery to repair skeletal deformities and in reconstructive surgery. (wikipedia.org)
  • Blood vessel growth in the skeletal system and osteogenesis seem to be coupled, suggesting the existence of molecular crosstalk between endothelial and osteoblastic cells. (nih.gov)
  • While osteogenic supplementation or exogenous BMP-2 could enhance some markers of hMSC osteogenesis in the mineralized scaffold, we found the mineralized scaffold was itself sufficient to induce osteogenic gene expression, matrix remodeling, and mineral formation. (rsc.org)
  • Analyzing the expression, regulation, and sequence of osteogenesis genes can help determine their relative importance to the biology of the cellular or disease processes under study. (qiagen.com)
  • Makareeva E, Aviles NA, Leikin S. Chaperoning osteogenesis: new protein-folding disease paradigms. (springermedizin.at)
  • Osteogenesis imperfecta tarda is listed as a " rare disease " by the Office of Rare Diseases (ORD) of the National Institutes of Health (NIH). (rightdiagnosis.com)
  • Based on the fact that aging is associated with a reciprocal decrease of osteogenesis and an increase of adipogenesis in bone marrow and that osteoblasts and adipocytes share a common progenitor, this study investigated the role of PPARγ, a key regulator of adipocyte differentiation, in bone metabolism. (jci.org)
  • Adipogenesis and osteogenesis in the mouse ES cell cultures of homozygous PPARγ -deficient ( PPARγ -/- ) and WT genotypes. (jci.org)
  • We observe differential sensitivities of hMSCs to Wnt inhibition of osteogenesis versus adipogenesis, which favors osteoblastic commitment under binary in vitro differentiation conditions. (rupress.org)
  • This study investigated the potential of NAC as an osteogenesis-enhancing molecule in vitro and in vivo. (nih.gov)
  • In this study, we evaluated in vitro and in vivo functional characteristics of BMPs of different dimerization types, with the aim of determining osteoinductive efficiency of heterodimeric BMP-2/7 on osteogenesis of hASCs. (uva.nl)
  • Heterodimeric BMP-2/7 significantly promoted osteogenesis of hASCs in vitro and in vivo. (uva.nl)