D618 - Exam 1
pharyngeal arch 1
Meckel's cartilage
water
component of extracellular matrix of cartilage that is responsible for its strength and resiliency
buccopharyngeal membrane
composed of ectodermal and endodermal tissue
lamellae
concentric tubes
development of TMJ
condylar cartilage forms: -band is reduced to dense strip of mesenchyme
costal cartilage
connecting ribs to sternum
endoderm
liver
cleavage stages
movement through the fallopian tubes - 4 days
mesoderm
muscles
bone movement
muscles attach by tendons and use bones as levers to move the body
development of tongue
muscles form occipital mytomes also contribute
branchial arch 2
muscles of facial expression
branchial arch 1
muscles of mastication
ingrowth of mesoderm
muscles of tongue
pharyngeal arch 1
mylohyoid
epiphysis
name for the ends of long bones
34 day old embryo
nasal pit surrounded by lateral and medial nasal processes
27 day old embryo
nasal placode is about to develop and odontogenic epithelium can be identified
face at 5 weeks
nasal placodes form and recess to become pits (nostrils)
ontogeny
recapitulates phylogeny
pharyngeal arch 6
recurrent laryngeal branch
frontal prominence
red
treacher collins
reduced number of neural crest cells
periosteum
two sublayers: -outer fibrous layer -inner (deep) cellular osteogenic layer
skeletal unit
two types: -microskeletal -macroskeletal
functional matrix
two types: -periosteal -capsular
1st groove and pouch
tympanic membrane (eardrum)
1st groove and pouch
tympanic or mastoid antrum
pharyngeal arch 5
ultimobranchial body
development of the TMJ
undifferentiated mesenchyme between: -developing ramus of mandible -developing squamous tympanic bone
70%
unilateral cleft lips will also have cleft palate
fetal stage
until birth
reichert's
upper part of the body and lesser horns of the hyoid bone
endoderm
urinary bladder
servosystem theory
uses cybernetics to describe the growth of the craniofacial complex
palatal fusion failure
usually four incisors form in premaxilla and canine in secondary palate
hemifacial microsomia
usually unilateral
cleft palate
uvula only american indians > orientals > whites > blacks
midline cleft
variation in amount of fusion
treacher collins
varying facial bone underdevelopment: -small jaw -downsloping eyes -some cleft palate -often small ears -usually hearing impairment
intramembranous ossification 3.
vascularized mesenchyme condenses on the external face of the woven bone and becomes the periosteum
3rd groove and pouch
ventral component: -thymus
neural crest cells
ventral migration from distinct rhombomeres
irregular bone
vertebra
bone protection
vertebrae - spinal cord
face at 7 weeks
vertical growth occurs
genomic paradigm
viewed craniofacial growth as primarily genetically predetermined and immutable
larynx
voice box
bone and cartilage formation
week 20: endochondral bone replaces cartilage
mandible
week 6: mesenchyme condensation
mandible
week 6: on lateral aspect of cartilage
mandible
week 7: intramembranous ossification
sutural theory
weinmann and sicher in the 40s
cleft lip
when bilateral = 85% have CP
cleft lip
when unilateral = 70% have CP
treacher collins
TCOF1 gene
pharyngeal arch 1
anterior belly of digastric
pharyngeal arch 2
buccinator
pharyngeal arch 3
common carotid
cleft palate
female > male
cartilage in the adult skeleton
"articular" - covering the ends of most bones and movable joints
cartilage in the adult skeleton
"costal" - connecting ribs to sternum
cleavage stages
"sticky" sugar-like molecules of embryo adhere to sugar-like molecules of uterus
mesoderm
*dentin, pulp, and cementum technically neural crest cells which are of ectodermal origin but require signaling from surrounding mesenchyme to differentiate
mineral crystals
-primarily calcium phosphate -lie in and around the collagen fibrils in extracellular matrix -contribute to bone hardness
types of loose connective tissue
-areolar -adipose -reticular
cartilage formation
-axial skeleton -base of cranium -appendages
cartilage composition
-chondrocytes -abundant extracellular matrix ---fibers ---jelly-like ground substance of complex sugar molecules ---60-80% water ---no nerves or vessels
treacher collins
-coloboma of lower lid -cilia absent medial to coloboma -abnormal hair growth on cheek -malformed ear -micrognathism -hypoplastic zygomatic arches -ptosis of upper eyelid
types of bone
-compact -spongy (cancellous)
anatomy of bones
-compact bone -spongy bone -blood vessels -medullary cavity -membranes ---periosteum ---endosteum
types of connective tissue
-connective tissue proper -cartilage -bone -blood
types of measurements
-craniometry -anthropometry -cephalometric radiology
types of tissue
-epithelial -connective -muscle -nervous
types of cartilage
-hyaline -fibrocartilage -elastic
formation of tongue
-inholding of ectodermal tissue -ingrowth of mesoderm
classification of bones
-long bones -short bones -flat bones -irregular bones -sesmoid bones (short bones include these)
types of dense connective tissue
-regular -irregular -elastic
factors regulating bone growth
-vit D -parathyroid hormone -calcitonin -growth hormone -thyroid hormone -sex hormones
endochondral ossification
1. formation of bone collar around hyaline cartilage model
three synchondroses of the cranial base
1. intersphenoid (birth) 2. spheno-ethmoidal (6 years) 3. spheno-occipital (12-15 years)
palatal shelves
1. oriented in a downward direction with tongue in between them
intramembranous ossification
1. ossification center appears in the fibrous connective tissue membrane
secondary (growth) cartilages
1. the condylar cartilage, which is most important 12 weeks, endochondral ossification
cleft lip/palate
1/1000
meckel's cartilage
10 weeks: rudimentary mandible is formed
cleft lip
10% bilateral
intramembranous ossification
2. bone matrix (osteoid) is secreted within the fibrous membrane
endochondral ossification
2. cavitation of the hyaline cartilage within the cartilage model
secondary (growth) cartilages
2. the coronoid cartilage 4 months, disappears before birth
palatal shelves
2. the tongue drops out from in between the __________________ allowing them to rotate up and together to eventually fuse with the nasal septum
human chromosomes
23 pairs: 22 autosome pairs 1 sex pair
cleft lip/palate
3 stages of ortho: -prior to alveolar graft -mixed dentition -late adolescence (orthognathic surgery)
endochondral ossification
3. invasion of internal cavities by the periosteal bud and spongy bone formation
intramembranous ossification
3. woven bone and periosteum form
facial muscle formation
4 pairs of somites contribute to skin dermis and some orofacial muscles
pharyngeal arches
4 weeks along with the frontonasal process
neural tube formation
4 weeks anteriorly and continues posteriorly
endochondral ossification
4. appearance of secondary ossification centers in the epiphyses in preparation for stage 5
intramembranous ossification
4. bone collar of compact bone forms and red marrow appears
endochondral ossification
4. formation of the medullary cavity as ossification continues
cleft lip/palate
40-60% have associated anomalies
endochondral ossification
5. ossification of the epiphyses
endochondral ossification
5. when completed, hyaline cartilage remains only in the epiphyseal plates and articular cartilages
formation of the secondary palate
7 weeks - tongue withdrawn
facial muscle formation
8-10 weeks
cleft lip
90% unilateral
cleft lip/palate
CLP 2M:1F
branchial arch 3
CN IX - glossopharyngeal
pharyngeal arch 3
CN IX - glossopharyngeal
branchial arch 1
CN V - trigeminal
pharyngeal arch 1
CN V - trigeminal
branchial arch 2
CN VII - facial
pharyngeal arch 2
CN VII - facial
branchial arch 4
CN X - vagus
pharyngeal arch 4-6
CN X - vagus
cleft lip/palate
CP 1.5M:1F
endoderm
GI tract and associated glands
nasal septum theory
James Scott, 50s
primary nerves
V, VII, IX, X, XII
functional matrix hypothesis
a new way of looking at craniofacial growth which became known as the functional paradigm
intramembranous ossification 3.
accumulating osteoid is laid down between embryonic blood vessels, which form a random network - the result is a network (instead of lamellae) of trabeculae
mechanism of action of mandibular growth in the servosystem theory
activation of jaw protrusion muscle act directly on the cartilage of the mandibular condyle and indirectly through vascular supply to the TMJ -add appropriate hormones -stimulates condylar growth
capsular matrix
affects macroskeletal units
periosteal matrix
affects microskeletal units
fertilization
after division, all cells have the same genetic material
servosystem theory
alexandre petrovic, 70s
functional matrix
all the soft tissues and spaces that perform a given function
infolding of ectodermal tissue
allow mobility
infolding of epithelium
allows tongue mobility
compact bone
alternating direction of collagen fibers increases resistance to twisting forces
cleft lip/palate
american indiana > japanese > chinese > whites > blacks
hyaline cartilage
amorphous but firm matrix
CN V
anterior 2/3 of tongue
CN VII
anterior 2/3 of tongue
servosystem theory
anterior growth of the midface results in a slight occlusal deviation between the maxillary and mandibular dentition
pharyngeal arch 1
anterior ligament of malleus
nerve formation in cranial area
anterior portion of neural tube enlarges and bends and forms the brain
endochondral ossification
anterior portion of occipital
palatal fusion
anterior portion of palate develops from fusion of maxillary processes and medial nasal processes
mesoderm migration
anteriorly and laterally between ectoderm and endoderm except at the future area of the mouth (prochordal plate) and the anus (cloacal membrane)
cartilage formation
appears throughout body about 4-5 weeks
genes
areas within the chromosome
cartilage in the adult skeleton
articular discs such as meniscus in knee joint
pharyngeal arch 4-6
arytenoid
spina bifida
associated with genetics and folate (B9) deficiency
pharyngeal arch 2
auricularis
development of tongue pharyngeal arch 3
base of tongue
remodeling theory
based on Brash's research
nasal septum theory
based on the work of anatomists
sutural theory
based on the work of anatomists
85%
bilateral cleft lips will also have cleft palate
ontogeny recapitulates phylogeny
biogenetic law theorizes that the stages an animal embryo undergoes during development are a chronological replay of that species past evolutionary forms
nasal pit
black hole
hematopoietic stem cell
blood cells and macrophages come from...
branchial arch 3
blood vessels -common carotid -internal carotid
long bone
blood vessels - nutrient arteries and veins through nutrient foramen
mandibular process
blue
osteoblasts
bone depositing cells
bone blood cell formation
bone marrow - red makes blood, yellow stores fat
remodeling theory
bone only grows appositionally at surfaces
osteoclasts
bone resorbing cells
osteogenesis
bone tissue first appears during the 8th week (embryo)
mesoderm
bone, cartilage, blood
reichert's
bony process
skeletal unit
bony structures that support the functional matrix and are thus necessary or permissive for that function
cranial growth
brain grows causing frontonasal process to curve downward
spinal cord closing
brain starts to close
ingrowth of mesoderm
bring XII nerve - glossopharyngeal
endochondral ossification
calcification in the center of the diaphysis
bone mineral storage
calcium and phosphorus
remodeling theory
calvarial growth occurs via deposition of bone on the ectocranial surface of the cranial vault and resorption of bone endocranially
genes
can be: -dominant (AA) -recessive (aa) -heterozygous (Aa)
multiple sperm
can penetrate egg shell
short bones
carpal bones
chondrocyte
cartilage comes from...
neural crest cells
cartilage of pharyngeal arches
4th cartilage arch
cartilages of the larynx
hyaline cartilage
cartilages of the nose, trachea, and larynx
cartilage in the adult skeleton
cartilaginous rings holding open the air tubes of the respiratory system (trachea and bronchi)
tetracycline
causes dental staining
meiosis
cells that are formed are NOT the same as each other
meiosis
cells that are formed do NOT have same DNA as parent
chemical composition of bones
cells, matrix of collagen fibers, and ground substance (organic: 35%)
acrosome
chemical reaction causes removal and sperm is able to penetrate egg
mesenchyme
chondroblasts come from...
hyaline cartilage
chondroblasts produce the matrix and when mature (chondrocytes) lie in lacunae
hyaline cartilage
chondrocytes appear spherical
chondroblast
chondrocytes come from...
interstitial growth
chondrocytes within the matrix divide by mitosis and produce additional matrix that causes internal expansion of cartilage
meiosis
chromosomes do strange things: -become rings with deletions -deletions of part of a chromosome -mixup within each chromosome -refuse to let their partner leave -mutations
intramembranous ossification
clavicles
fibers in cartilage
collagen and elastin
hyaline cartilage
collagen fibers form an imperceptible network
hyaline cartilage
collagen is the only fiber
sutural theory
connective tissue and cartilaginous joints of the craniofacial skeleton are the principal locations at which intrinsic, genetically regulated, primary growth of bones takes place
periosteum
connective tissue membrane
nasal and primary palate
connective tissue moves between areas of fusion and bind fused area
fibrocyte
connective tissue proper comes from...
pharyngeal arch 4-6
constrictors of pharynx
neural crest cells
contribute to embryonic connective tissue of face (pulp, dentin, cementum)
migration of neural crest cells
controlled by homeobox genes mediating facial and cranial patterning
homeobox genes
coordinate the development of complex craniofacial structures
pharyngeal arch 4-6
corniculate
periosteal matrix
corresponds to the immediate local environment, typically muscles, blood vessels, and nerves
long bone
covered with articular (joint) cartilage
articular cartilage
covering the ends of most bones and movable joints
periosteum
covers entire outer surface of bone except at epiphyses
hyaline cartilage
covers the ends of long bones in joint cavities
endosteum
covers the internal bone surfaces
nerve formation in cranial area
cranial nerves grow from neural tube and into the face
neural tube formation
crest cells break off from neural fold area
pharyngeal arch 4-6
cricoid
pharyngeal arch 4-6
cricothyroid
pharyngeal arch 4-6
cuneiform
hemifacial microsomia
currently thought to be caused by early loss of neural cells
calcitonin
decreases blood calcium
spina bifida
degrees of severity
Brash
demonstrated that bone only grows appositionally at its surfaces and not interstitially through mitotic activity
periosteum outer fibrous layer
dense irregular connective tissue
incus
derived from meckel's cartilage
malleus
derived from meckel's cartilage
intramembranous ossification
dermal ossicification
cleavage stages
development of nonpermeable membrane around egg
opitz syndrome
developmental delays
fibrocartilage
discs of knee joint
cleavage stages
division of cells into multicelled morula then blastocyst 70-100 cells
3rd groove and pouch
dorsal component: -inferior parathyroid gland
chromosomes
each pair = one maternal + one paternal
pharyngeal grooves
ear canal
neural tube formation
ectodermal cells multiply and folding occurs
cleft lip/palate
familial tendency
cleavage stages
embryo adheres to surface of uterus
1-2 weeks after fertilization
embryo may not be as susceptible as from week 2-12
functional matrix hypothesis
emphasized the plasticity of development and growth of the craniofacial skeleton
homeobox genes
encode important transcription factors that specify cell fate and identify the embryonic patter along the primary and secondary axes
20th week
endochondral bone has replaced cartilage
cleft lip/palate
environmental risk factors: -maternal smoking (inconsistent) -maternal drinking -maternal epilepsy -benzodiazepines -corticosteroids -organic solvents/pesticides
ectoderm
epidermis, hair, nails
cartilage in the adult skeleton
epiglottis - flap keeping food out of the lungs
elastic cartilage
epiglottis, larynx, and outer ear
children
epiphyseal growth plate (disc of hyaline cartilage that grows to lengthen the bone)
endochondral ossification
epiphyseal growth plates close at the end of adolescence -diaphysis and epiphysis fuse -no more bone lengthening
long bone
epiphyseal line in adults
long bone
epiphyses at the ends
ectoderm
epithelium of sinuses, oral and nasal cavities, intraoral glands
face
essentially formed by 7th week
endochondral ossification
ethmoid
pneumatized bones
ethmoid
1st groove and pouch
external auditory meatus
cartilage in the adult skeleton
external ear
pharyngeal arch 2
facial expression: -buccinator -auricularis -frontalis -platysma -orbicularis oris -orbicularis oculi
opitz syndrome
failure of brain growth to bring eyes closer
cleft lip/palate
failure of medial nasal process and maxillary process to fuse unilaterally/bilaterally
midline cleft
failure of medial nasal processes to fuse
face at 6 weeks
failure to fuse causes cleft lip
embryonic stage
fertilization and about 4-8 weeks postfertilization
cleavage stages
fertilization of the egg by the sperm and the union of the nuclei
one sperm
fertilizes the egg
mesenchyme
fibroblasts come from...
appositional growth
fibroblasts of the cellular layer of the perichondrium differentiate into chondroblasts that produce matrix and become chondrocytes when embedded in matrix
fibroblast
fibrocytes come from...
meiosis
first division: DNA replicated and diploid cells produced
epiglottis
flap keeping food out of the lungs
hyaline cartilage
flexible and resilient
nasal and primary palate
floor of nostril fuses front to back
mechanism of action of mandibular growth in the servosystem theory
focused on hormone related cartilage growth of the mandibular condyle
servosystem theory
focused on the nature of cartilage growth in the craniofacial complex, particularly the secondary cartilage of the mandibular condyle
spina bifida
folate (B9) deficiency
rostral fold
folding of the embryo
pharyngeal arch 2
foramen cecum
somites
form muscle sheets of mesoderm between GI tube and neural tube
osteogenesis
formation of bone
neural tube
formed from neural fold (ectoderm)
heart
forms about the same time that the face is forming
maxillary process
forms both sides of upper lip
medial nasal process
forms central portion of nose and philtrum
hyaline cartilage
forms costal cartilages of the ribs
intramembranous ossification
forms directly from mesenchyme (not modeled first in cartilage)
heart
forms in area near head
infolding of ectodermal tissue
forms lingual sulcus
mandibular process
forms lower lip and chin
hyaline cartilage
forms most of the embryonic skeleton
lateral nasal process
forms side of nose
development of tongue
from 1, 2, and 3 pharyngeal arches
osteogenesis
from osteoblasts
membranous bone
frontal
pharyngeal arch 2
frontalis
bones
function: -support -movement -protection -mineral storage -blood cell formation and energy storage
melvin moss
functional matrix hypothesis on ________'s work
38 day old embryo
fusion of various facial processes is complete
homeobox genes
genes are responsible for the genetic initiation, regulation, and coordination of craniofacial growth and development
pharyngeal arch 3
greater horn and lower portion of body of hyoid bone
maxillary process
green
microskeletal units
growth in size and shape is associated with transformation from an embryonic cell type to an osteoblast-osteocyte associated with periosteal deposition
sutural theory
growth of the cranial vault is caused by the intrinsic pattern of expansive proliferative growth by sutural connective tissue that forces the bones of the vault away from each other
functional matrix theory
growth of the face occurs as a response to functional needs and is mediated by the soft tissue in which the jaws are embedded
remodeling theory
growth of the jaws is characterized by deposition of bone at the posterior surfaces of the maxilla and mandible Hunterian growth
remodeling theory
growth of the jaws takes place principally via deposition of bone on the posterior surface of the maxillary complex and mandibular ramus
sutural theory
growth of the midface takes place via intrinsically determined sutural expansion of the circummaxillary suture system, which forces the midface downward and forward
nasal septum theory
growth of the nasal septal cartilage pushes the midface downward and forward relative to the anterior cranial base
sex hormones
growth spurt at adolescence and closure of epiphyses
development of tongue pharyngeal arch 2
gustatory innervation by CN VII
haploid cells
has half the number of chromosomes and one sex chromosome
hyaline cartilage
has resilient cushioning properties
flat bone
have bone marrow but no marrow cavity
compact bone
haversian canals
one sperm
head will swell and become a distinct nucleus
22 day old embryo
head with beginning of forebrain
mesenchyme
hematopoietic stem cells come from...
functional matrix hypothesis
heredity and genes initiate the process of development but do NOT play a continuing role in the growth of the craniofacial skeleton
elastic cartilage
highly bendable
midline cleft
holoprosencephaly
long bone
humerus
pharyngeal arch 2
hyoid
cleft lip/palate
if both parents affected = 25-38% of children will have CL/CP
fertilization - 4 weeks postfertilization
if disturbances are severe, embryo is lost
cleft lip/palate
if parent is affected = 2-18% of children will have CL/CP
sutural theory
importance of cartilaginous structures and skeletal joints in the development and postnatal growth of bones
spina bifida
incomplete closure of neural tube
treacher collins
incomplete formation of facial bones
remodeling theory
increase in the size of the cranial vault occurs by adding bone via periosteal deposition on the outer, ectocranial surface and resorption of bone on the inner, endocranial surface of the vault
sutural theory
increase in the size of the cranial vault takes place via primary growth of bone at the sutures, which forces the bones of the vault away from each other
embryo
increase in weight is exponential until birth
parathyroid hormone
increases blood calcium some of this comes out of bone
vitamin D
increases calcium from gut
pharyngeal arch 1
incus
pharyngeal arch 3
inferior parathyroid
skeleton
initially mostly cartilage
hormonal factors
initiator of mandibular growth in the servosystem
occlusal deviation due to anterior growth of the midface
initiator of mandibular growth in the servosystem theory
development of tongue more caudal area
innervation by CN XII
development of tongue
innervation from V, VII, IX, X and XII
pharyngeal arch 3
internal carotid
cartilage in the adult skeleton
intervertebral discs
fibrocartilage
intervertebral discs
meckel's cartilage
intramembranous ossification
development of tongue more caudal area
intrinsic muscles
pharyngeal arch 4-6
intrinsic muscles of larynx
fibrocartilage
knee menisci and annulus fibrous of intervertebral discs
opitz syndrome
lack of nasal development
hyaline cartilage
lacuna - cavity in matrix holding chondrocyte
compact bone
lamellae: concentric tubes
pharyngeal arch 4-6
laryngeal cartilages
lateral plate mesoderm
laryngeals
cartilage in the adult skeleton
larynx - voice box
face at 6 weeks
lateral brain growth brings eyes closer together
development of tongue pharyngeal arch 1
lateral lingual swellings
facial formation
lateral nasal process fused to maxillary process
pharyngeal arch 1
lateral pterygoid
tissue differentiation
layers of ectoderm and endoderm form
cranial growht
leg buds starting to protrude
embryo
length increases before weight
pharyngeal arch 2
less horn and upper portion of body of hyoid bone
pharyngeal arch 4-6
levator palatine
sutures and cartilages
locations of centers of bone growth at which the inherited pattern of craniofacial from and facial type was expressed
connective tissue proper
loose and dense connective tissue come from...
one sperm
loses its tail
3rd cartilage arch
lower part of the body and greater horns of the hyoid bone
endoderm
lungs
elastic cartilage
maintains the shape of a structure while allowing great flexibility
red bone marrow
makes blood
cleft lip/palate
male > female
ectoderm
mammary and cutaneous glands
1st cartilage arch
mandible
membranous bone
mandible
pharyngeal arch 1
mandible malieus
pharyngeal arch 1
mandibular (maxillary and mandibular processes)
pharyngeal arch 1
mandibular arch grows toward midline and fuses
sutural theory
mandibular growth takes place via intrinsically determined growth of the cartilage of the mandibular condyle, which pushes the mandible downward and forward
pharyngeal arch 1
mastication: -temporal -masseter -medial pterygoid -lateral pterygoid
fibrocartilage
matrix similar to but less firm than that in hyaline cartilage
elastic cartilage
matrix with elastic as well as collagen fibers
membranous bone
maxilla
pharyngeal arch 1
maxilla
branchial arch 1
maxilla and mandible
face at 6 weeks
maxillary and medial nasal processes fuse to form lip
pharyngeal arch 1
maxillary process forms from mandibular arch
1st cartilage arch
meckel's
face at 5 weeks
medial and lateral nasal processes form
facial formation
medial nasal process fusing to maxillary process
nasal and primary palate
medial nasal processes and maxillary processes fuse externally
facial formation
medial nasal processes fusing to each other
pharyngeal arch 1
medial pterygoid
development of the tongue
mesenchyme proliferates and swellings grow
somatomeres
mesoderm units in head and neck region that turn into muscles
hemifacial microsomia
midline structures (palate) not affected as much as distal structures
chemical composition of bones
mineral crystals (inorganic: 65%)
endochondral ossification
modeled in hyaline cartilage then replaced by bone tissue
endochondral ossification
modeled in hyaline cartilage, gradually replaced by bone
growth hormone
modulate bone growth
thyroid hormone
modulate bone growth
cleft lip/palate
more common on left side
cartilage
more prevalent in the embryo than in an adult
intramembranous ossification
most skull bones except a few at the base
CN XII
motor
nasal septum theory
nasal septum is most active and important for craniofacial skeletal growth late prenatally and early postnatally, through approximately 3-4 years of age in humans
functional matrix hypothesis
neither bone nor cartilage determines growth; the control lies in the adjacent soft tissues
spinal cord closing
nerve cells are apparent
ectoderm
nervous system
22 day old embryo
neural tube closing over torso - skin on outside
meckel's cartilage
no contribution to bone development
cleft lip
no extraordinary orthodontic needs
cartilage in the adult skeleton
nose
early chordates
notochord and gill slits
fertilization
nucleus of sperm and nucleus of egg move toward each other, touch, and unite
compact bone
nutrients diffuse from vessels in central canal
2nd, 3rd, and 4th grooves
obliterated by overgrowth of the second arch forming a cervical sinus
palatal fusion
occurs from front to back
periosteum inner (deep) cellular osteogenic layer
on the compact bone containing osteoprogenitor cells
spina bifida
one form is hydrocephalus
calcitonin
opposes parathyroid hormone
medial nasal process
orange
medial nasal process
orange - inside
lateral nasal process
orange - outside
pharyngeal arch 2
orbicularis oculi
pharyngeal arch 2
orbicularis oris
acrosome
organelle protecting head of sperm
acrosome
organelle responsible for allowing the sperm to penetrate the egg and cause fertilization
capsular matrix
organs and spaces that occupy a broader anatomical complex such as the brain, globes of the eyes, nasopharynx, and oropharynx
osteocyte
osseous (bone) comes from...
intramembranous ossification 2.
osteoblasts being to secrete osteoid, which is mineralized within a few days
mesenchyme
osteoblasts come from...
endochondral ossification
osteoblasts in periosteum lay down a collar of bone around the diaphysis
compact bone
osteocytes
osteoblast
osteocytes come from...
endosteum
osteogenic
compact bone
osteons: pillars
ultimobranchial body
outpocketing of the fourth pharyngeal pouch that fuses with the thyroid diverticulum
ovulation
ovarian follicale bursts -> egg is released -> fallopian tubes "catch" egg and propel it forward -> egg enveloped in nutrient cells
somites
paired blocks of mesoderm just lateral to the notochord of a vertebrate embryo
somites
paired segments of tissue next to the neural tube
endoderm
pancreas
membranous bone
parietal
paraxial mesoderm
parietal
flat bone
parietal bone
pharyngeal arch 1
part of temporal bone
branchial arch 1
parts of ear
branchial arch 1
parts of teeth
branchial arch 3
parts of the hyoid
sesamoid bone
patella
servosystem theory
perception of the occlusal deviation by proprioceptors triggers the protruder muscles of the mandible to become more active to reposition the mandible anteriorly
Sharpey's fibers
perforating fibers that secure periosteum to bone
endochondral ossification
perichondrium is invaded by vessels and becomes periosteum
remodeling theory
periosteal bone remodeling being under strong local influences by the functional environment, and not under intrinsic, hereditary controll
development of the tongue
pharyngeal arches meet in midline beneath the stomodeum
1st groove and pouch
pharyngotympani tube (eustachian)
meckel's cartilage
physically close
neural crest cells
pigment cells
osteon
pillars
pharyngeal arch 2
platysma
treacher collins
possible increases apoptosis
CN IX
posterior 1/3 of tongue
branchial arch 2
posterior belly of digastric
pharyngeal arch 2
posterior belly of digastric
membranous bone
posterior portion of occipital
monocytes
precursor cells of osteoclasts
pre-osteoclasts
precursor cells of osteoclasts
pharyngeal arch 1
premaxilla
fertilization - 4 weeks postfertilization
primarily cellular proliferation and migration
4-8 weeks postfertilization
primarily differentiation of all major external and internal structures morphodifferentiation
fetal stage
primarily growth and maturation
capsular matrix
primary growth results in a stimulus for secondary growth of the sutures and synchondroses, leading to overall enlargement of the neurocranium
calcium phosphate
primary inorganic material in bone
endochondral ossification
primary ossification centers
22 day old embryo
primitive heart
stomatodeum
primitive oral cavity
midline cleft
probably failure of brain to form properly
palatal fusion
process required: -growth of tissue required -fusion and breakdown of epithelium -ingrowth of connective tissue & capillaries -bone development
fibroblasts
progenitor cells for connective tissue
apoptosis
programmed cell death
cartilage in the adult skeleton
pubic symphysis
fibrocartilage
pubic symphysis
homeobox genes
regulation of normal and abnormal craniofacial growth and development is dependent on a cascade of overlapping activity from these
2nd cartilage arch
reichert's: -bony process -stylohyoid ligament -upper part of the body and lesser horns of the hyoid bone
calcium and phosphorus
released as ions into blood as needed
bone
replaces cartilage during growth and development
fibrocartilage
resists compression and tension
hyaline cartilage
resists compressive stress
water in cartilage
responsible for the resilience
gametes
result of meiosis
nasal septum theory
results in a separation of the midfacial suture system, which then fills in via secondary, compensatory sutural bone growth
lack of infolding of ectodermal tissue
results in forms of ankyloses of tongue
John Hunter and others
revealed the nature of bone growth in general
bone protection
rib cage - thoracic organs
fibrocartilage
row of thick collagen fibers alternating with rows of chondrocytes (in matrix)
meiosis
second division: DNA not replicated and haploid cells produced
pharyngeal grooves
second pouch overgrows the other grooves to form the external covering of the neck
endochondral ossification
secondary ossification in the epiphyses
periosteum
secured to bone by perforating fibers (Sharpey's fibers)
intramembranous ossification 1.
selected centrally located mesenchymal cells cluster and differentiate into osteoblasts, forming an ossification center
CN V
sensory
CN IX
sensory and taste
neural crest cells
sensory ganglia
development of tongue pharyngeal arch 3
sensory innervation of mucosa by CN IX
development of tongue pharyngeal arch 4
sensory innervation of mucosa by CN X
ectoderm
sensory portion of eye, ear, nose
buccopharyngeal membrane
separates the stomatodeum (primitive mouth) and the foregut
implantation of blastocoele
separation into inner embryonic cell mass and outer covering
intramembranous ossification
sesmoid bones
cleft lip
severity: -notched lip -into nostril -through various portions of palate
cleft palate
severity: -primary -secondary -soft palate only -uvula only -submucous
meiosis
sex cells (gametes) production
tubular diaphysis
shaft of long bone
elastic cartilage
similar to hyaline cartilage, but more elastic fibers in matrix
susceptibility
since body portions form at different times, it's temporal
bone protection
skull - brain
chemical composition of bones
small amount of water
functional matrix theory
soft tissues grow, and both both and cartilage react to this control mechanism
fertilization - 4 weeks postfertilization
some differentiation
endochondral ossification
sphenoid
pharyngeal arch 1
sphenomandibular ligament
cranial growth
spine closes
intramembranous ossification 4.
spongy bone (diploe), consisting of distinct trabeculae, persists internally and its vascular tissue becomes red marrow
diploe
spongy bone in flat bone
endochondral ossification
stage 4 is just before birth
endochondral ossification
stage 5 is the process of long bone growth during childhood and adolescence
endochondral ossification
stages 1-3 during fetal week 9 through the 9th month
branchial arch 2
stapedial artery
pharyngeal arch 2
stapedial artery
pharyngeal arch 2
stapedius
pharyngeal arch 2
stapes
development of the tongue
starts about 4 weeks in utero
osteoprogenitor cells
stem cells that give rise to osteoblasts
face at 4 weeks
stomodeum to GI tract opens
yellow bone marrow
stores fat
pharyngeal arch 2
stylohyoid
pharyngeal arch 2
stylohyoid ligament
reichert's
stylohyoid ligament
pharyngeal arch 2
styloid process
pharyngeal arch 3
stylopharyngeus
macroskeletal units
such as neurocranium and maxillo-mandibular complex, translational growth of associated skeletal structures
pharyngeal arch 4
superior laryngeal branch
pharyngeal arch 4
superior parathyroid
functional matrix hypothesis
supported consideration of the use of dentofacial orthopedic techniques to correct a developing malocclusion or facial deformity
hyaline cartilage
supports and reinforces
elastic cartilage
supports the external ear (pinna), epiglottis
facial growth
surface remodeling of a bone in the opposite direction to that in which it is being translated by growth of adjacent structures creates a situation analogous to a wall being rebuilt to move it backward at the same time the platform on which it is mounted is being moved forward
remodeling theory
sutures and cartilages play no role in the growth of the craniofacial complex
nasal septum theory
sutures play little or no direct role in the growth of the craniofacial skeleton but are secondary/compensatory sites of bone formation and growth
neural crest cells
sympathetic neurons
servosystem theory
the growth of the mandibular condyle is highly adaptive and responsive to both extrinsic systemic factors and local biomechanical and functional factors
development of tongue pharyngeal arch 1
tactile innvervation by CN V of mucosa
CN VII
taste
membranous bone
temporal
pharyngeal arch 1
temporal
fibrocartilage
tensile strength with the ability to absorb compressive shock
pharyngeal arch 1
tensor palatine
pharyngeal arch 1
tensor tympani
hemifacial microsomia
the farther the cells have to migrate, the more the damage is seen
36 day old embryo
the fusion of various facial processes
servosystem theory
the hormonally regulated growth of the midface and anterior cranial base provides a constantly changing reference input via the occlusion
servosystem theory
the muscle activity and the protrusion in the presence of appropriate hormonal factors stimulate growth at the mandibular condyle
servosystem theory
the rate-limited effect of this midfacial growth on the growth of the mandible
endochondral ossification
the rest of the skeleton
development of tongue pharyngeal arch 1
tuberculum impar
long bone
tubular diaphysis or shaft
face at 6 weeks
two medial nasal processes form intermaxillary portion of lip (philtrum)
meiosis
two sets of cell division
secondary (growth) cartilages
the symphyseal cartilage
fibrocartilage
thick collagen fibers predominate
pharyngeal arch 4
thymus
pharyngeal arch 4-6
thyroid
alizarin red
timing of dental mineralization
goal of early orthodontists
to place teeth in the most harmonious position possible for a given facial type, thus compensating for an unchangeable facial form
ossification
to turn into bone
ectoderm
tooth enamel
intramembranous ossification 4.
trabeculae just deep to the periosteum thicken, forming a woven bone collar that is later replaced with mature lamellar bone
rhombomeres
transiently divided segment of the developing neural tube
intramembranous ossification 2.
trapped osteoblasts become osteocytes
implantation of blastocoele
trophoblast layer produces enzymes to break down uterine wall - day 6
odontogenic epithelium
white bars
egg
x chromosome
sperm
x or y chromosome
lateral nasal process
yellow
tissue differentiation
yolk sac forms and provides food source until capillaries form
pharyngeal arch 1
zygomatic bone
day 6
zygote attach to the uterine wall
