骨形成　　　　　

WordNet

the calcification of soft tissue into a bonelike material
the developmental process of bone formation
the process of becoming rigidly fixed in a conventional pattern of thought or behavior
hardened conventionality (同)conformity
become bony; "The tissue ossified"
cause to become hard and bony; "The disease ossified the tissue"

PrepTutorEJDIC

〈U〉骨化 / 〈C〉骨化して部分
…‘を'骨化させる / (骨のように)…‘を'硬化させる / 骨化する / (人・考え方が)がん固になる,融通がきかなくなる

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2016/03/14 20:52:35」(JST)

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Bone is broken down by osteoclasts, and rebuilt by osteoblasts, both of which communicate through cytokine (TGF-β, IGF) signalling.

Ossification (or osteogenesis) in bone remodeling is the process of laying down new bone material by cells called osteoblasts. It is synonymous with bone tissue formation. There are two processes resulting in the formation of normal, healthy bone tissue:^[1] Intramembranous ossification is the direct laying down of bone into the primitive connective tissue (mesenchyme), while endochondral ossification involves cartilage as a precursor. In fracture healing, endochondral osteogenesis is the most commonly occurring process, for example in fractures of long bones treated by plaster of Paris, whereas fractures treated by open reduction and internal fixation with metal plates, screws, pins, rods and nails may heal by intramembranous osteogenesis.

Heterotopic ossification is a process resulting in the formation of bone tissue that is often atypical, at an extraskeletal location. Calcification is often confused with ossification. Calcification is synonymous with the formation of calcium-based salts and crystals within cells and tissue. It is a process that occurs during ossification, but not vice versa.

The exact mechanisms by which bone development is triggered remains unclear, but it involves growth factors and cytokines in some way.

Timetable for human ossification

Time period^[2]	Bones affected^[2]
Second month of fetal development	Ossification in long bones beginning
Fourth month	Most primary ossification centers have appeared in the diaphyses of bone.
Birth to 5 years	Secondary ossification centers appear in the epiphyses
5 years to 12 years in females, 5 to 14 years in males	Ossification is spreading rapidly from the ossification centers and various bones are becoming ossified
17 to 20 years	Bone of upper limbs and scapulae becoming completely ossified
18 to 23 years	Bone of the lower limbs and os coxae become completely ossified
23 to 25 years	Bone of the sternum, clavicles, and vertebrae become completely ossified
By 25 years	Nearly all bones are completely ossified

Intramembranous ossification

Intramembranous ossification forms the flat bones of the skull, clavicle, and mandible.

Endochondral ossification

Endochondral ossification is the formation of long bones and other bones. This requires a hyaline cartilage precursor. There are two centres of ossification for endochondral ossification.

The primary centre

In long bones, bone tissue first appears in the diaphysis (middle of shaft). Chondrocytes multiply and form trebeculae. Cartilage is progressively eroded and replaced by hardened bone, extending towards the epiphysis. A perichondrium layer surrounding the cartilage forms the periosteum, which generates osteogenic cells that then go on to make a collar that encircles the outside of the bone and remodels the medullary cavity on the inside.

The nutrient artery enters via the nutrient foramen from a small opening in the diaphysis. It invades the primary centre of ossification, bringing osteogenic cells (osteoblasts on the outside, osteoclasts on the inside.) The canal of the nutrient foramen is directed away from more active end of bone when one end grows more than the other. When bone grows at same rate at both ends, the nutrient artery is perpendicular to the bone.

Most other bones (e.g. vertebrae) also have primary ossification centres, and bone is laid down in a similar manner.

Secondary centres

The secondary centres generally appear at the epiphysis. Secondary ossification mostly occurs after birth (except for distal femur and proximal tibia which occurs during fetal development). The epiphyseal arteries and osteogenic cells invade the epiphysis, depositing osteoblasts and osteoclasts which erode the cartilage and build bone. This occurs at both ends of long bones but only one end of digits and ribs.

Primary center of ossification, or Growth Plate.

Evolution

A spotted gar larva at 22 days stained for cartilage (blue) and bone (red).

Several hypotheses have been proposed for how bone evolved as a structural element in vertebrates. One hypothesis is that bone developed from tissues that evolved to store minerals. Specifically, calcium-based minerals were stored in cartilage and bone was an exaptation development from this calcified cartilage.^[3] However, other possibilities include bony tissue evolving as an osmotic barrier, or as a protective structure.

References

^ Caetano-Lopes J, Canhão H, Fonseca JE (2007). "Osteoblasts and bone formation". Acta reumatológica portuguesa 32 (2): 103–10. PMID 17572649.
^ ^a ^b Predicting Height from the Length of Limb Bones Part of: Examining Effects of Space Flight on the Skeletal System. Emily Morey-Holton. NASA Ames Research Center. Moffett Field, California
^ Donoghue PC, Sansom IJ (2002). "Origin and early evolution of vertebrate skeletonization". Microsc. Res. Tech. 59 (5): 352–72. doi:10.1002/jemt.10217. PMID 12430166.

UpToDate Contents

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English Journal

Sequential treatment for a patient with hemifacial microsomia: 10 year-long term follow up.

Seo JS1, Roh YC1, Song JM1, Song WW1, Seong HS1, Kim SY1, Hwang DS1, Kim UK1.
Maxillofacial plastic and reconstructive surgery.Maxillofac Plast Reconstr Surg.2015 Feb 5;37(1):3. eCollection 2015.
Hemifacial microsomia (HFM) is the most common craniofacial anomaly after cleft lip and cleft palate; this deformity primarily involves the facial skeleton and ear, with either underdevelopment or absence of both components. In patients with HFM, the management of the asymmetries requires a series o
PMID 25664313

Osteogenic differentiation of human mesenchymal stem cells in freeze-gelled chitosan/nano β-tricalcium phosphate porous scaffolds crosslinked with genipin.

Siddiqui N1, Pramanik K1, Jabbari E2.
Materials science & engineering. C, Materials for biological applications.Mater Sci Eng C Mater Biol Appl.2015 Sep 1;54:76-83. doi: 10.1016/j.msec.2015.05.005. Epub 2015 May 6.
The objective of this work was to investigate material properties and osteogenic differentiation of human mesenchymal stem cells (hMSCs) in genipin (GN) crosslinked chitosan/nano β-tricalcium phosphate (CS/nano β-TCP) scaffolds, and compare the results with tripolyphosphate (TPP) crosslinked scaff
PMID 26046270

Effect of Capparis spinosa extract on sutural ossification: A stereological study.

Erdogan MS1, Babacan H2, Kara MI2, Gurler B2, Akgul H2, Soyler DA2.
Archives of oral biology.Arch Oral Biol.2015 Aug;60(8):1146-52. doi: 10.1016/j.archoralbio.2015.04.012. Epub 2015 May 21.
OBJECTIVE: To investigate the effects of systemically administered Capparis spinosa extract (CSE) on expanded sutures in rats via three dimensionally morphometric method (stereological method).MATERIALS AND METHODS: Thirty-two Wistar rats were used. Subjects were divided into four groups, each with
PMID 26043444

Phytomolecule icaritin incorporated PLGA/TCP scaffold for steroid-associated osteonecrosis: Proof-of-concept for prevention of hip joint collapse in bipedal emus and mechanistic study in quadrupedal rabbits.

Qin L1, Yao D2, Zheng L2, Liu WC2, Liu Z2, Lei M3, Huang L2, Xie X2, Wang X4, Chen Y5, Yao X6, Peng J7, Gong H8, Griffith JF9, Huang Y10, Zheng Y10, Feng JQ11, Liu Y11, Chen S2, Xiao D3, Wang D5, Xiong J5, Pei D12, Zhang P13, Pan X14, Wang X15, Lee KM16, Cheng CY2.
Biomaterials.Biomaterials.2015 Aug;59:125-43. doi: 10.1016/j.biomaterials.2015.04.038. Epub 2015 May 15.
Steroid-associated osteonecrosis (SAON) may lead to joint collapse and subsequent joint replacement. Poly lactic-co-glycolic acid/tricalcium phosphate (P/T) scaffold providing sustained release of icaritin (a metabolite of Epimedium-derived flavonoids) was investigated as a bone defect filler after
PMID 25968462

Japanese Journal

頸椎後縦靭帯骨化症に対する手術治療成績の検討

貞升彩,宮本敬,田中健一郎,細江英夫,清水克時
岐阜大学医学部紀要 57(1/2), 5-14, 2012-06
NAID 110009422604

重度胸椎後縦靱帯骨化症に対する前方除圧固定法 (シンポジウム重度後縦靱帯骨化症に対する術式選択と合併症)

進藤重雄
臨床整形外科 47(5), 437-445, 2012-05
NAID 40019309522

胸椎後縦靱帯骨化症に対する一期的後方除圧矯正固定術の手術成績 (シンポジウム重度後縦靱帯骨化症に対する術式選択と合併症)

今釜史郎,松山幸弘,石黒直樹
臨床整形外科 47(5), 431-436, 2012-05
NAID 40019309505

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★リンクテーブル★

リンク元	「osteogenic」「osteoplastic」「bone formation」「bone morphogenetic」「骨形成」
拡張検索	「ossification of ligamentum flavum」「ossification of posterior longitudinal ligament」