Bone Formationand

Bone Remodeling

S.K. KimNovember 16, 2009

46HE (H & E) 46HE (H & E)

Intramembranous bone formation of maxilla (flat bone) Intramembranous bone formation of maxilla (flat bone)

Nasal septum (hyaline cartilage)

Nasal septum (hyaline cartilage)

TongueTongue

Oral cavityOral cavity

Nasal cavityNasal cavityNasal cavityNasal cavity

46M (Masson or Trichrome)

46M (Masson or Trichrome)

Rotate 180oRotate 180o

Forming mandibular bone

Forming mandibular bone

Forming toothForming tooth

Meckel’s cartilage (hyaline)Meckel’s cartilage (hyaline)

Tongue

(skeletal muscle)

Tongue

(skeletal muscle)

Genioglossus muscle (skeletal muscle)

Genioglossus muscle (skeletal muscle)

Lower jawLower jaw

Mandibular bone (flat) formation: Intramembranous ossification

Mandibular bone (flat) formation: Intramembranous ossification

#120-N

#120 Developing face (frontal section)#120 Developing face (frontal section)

Forming facial (maxillary) bone: Intramembranous ossification Forming facial (maxillary) bone: Intramembranous ossification

Oral cavityOral cavity

TongueTongue

Nasal cavityNasal cavity Orbit: eye

ballOrbit: eye ball

Nasal septum: (hyaline cartilage)

Nasal septum: (hyaline cartilage)

Intramembranous bone formation. #46-HE; #46-M; #120Intramembranous bone formation. #46-HE; #46-M; #120

PeriosteumPeriosteum

Bone trabecula(e) or spicules

Bone trabecula(e) or spicules

Bone CellsBone Cells

PeriosteumPeriosteum

Osteoblasts Osteoblasts

OsteocytesOsteocytes

OsteoclastsOsteoclasts

OsteoidOsteoid

? #1? #1

? #2? #2

? #3? #3

? #4? #4

? #5? #5

115N (H&E)Sagital section of the

palate

115N (H&E)Sagital section of the

palate

Intramembranous, palatal and maxillary bone formation

Intramembranous, palatal and maxillary bone formation

Nasal cavityNasal cavity

Oral cavityOral cavityUpper lipUpper lip

Gingiva (gum)Gingiva (gum)

Developing toothDeveloping toothRotate 180oRotate 180o

115-M (Masson)115-M (Masson)

Trabecular bone before conversion to compact bone #115N

Immature (woven/mottled) bone; #115N

Highly cellular: aggregation of Highly cellular: aggregation of osteocytesosteocytes

Basophilic: high concentration of Basophilic: high concentration of GAGsGAGs

Sharpey’s fibersSharpey’s fibers #115N#115N

Beginning of osteon formation; #115N

Growth in diameter of a long bone #48 (H&E) and 48b (Masson)

Growth in diameter of a long bone #48 (H&E) and 48b (Masson)

PeriosteumPeriosteum

Long bone shaft:growth in diameter #48 (tibia and fibula)

Long bone shaft:growth in diameter #48 (tibia and fibula)

OsteoblastsOsteoblasts

OsteoidOsteoid

Perioste

um

Perioste

um

(cellu

l

ar)(c

ellul

ar)(F

ibro

us

)(F

ibro

us

)

TibiaTibia

FibulaFibula

Epiphyseal plateEpiphyseal plate

EpiphysisEpiphysis

MetaphysisMetaphysis

DiaphysisDiaphysis

Endochondral Bone formationEndochondral Bone formation

#110 (finger, H&E)#110 (finger, H&E)

Epiphyseal plate and endochondral bone formation #108Epiphyseal plate and endochondral bone formation #108

Resting cartilageResting cartilage

Chondrocyte proliferationChondrocyte proliferation

Chondrocyte hypertrophy

Chondrocyte hypertrophy

Cartilage calcification

Cartilage calcification

Erosion of calicified cartilage and bone deposition (ossification)

Erosion of calicified cartilage and bone deposition (ossification)

Tide markTide mark

(1)(1)

(2)(2)

(3)(3)(4)(4)

(5)(5)

Epiphyseal plate and endochondral bone formation #49

Calcified cartilage core in trabecular bone #49

Calcified cartilage core in trabecular bone #49

Bone Remodeling Erosion (resorption) Tunnel