craniofacial complex - chu Flashcards
growth
increase in size and number of cells, quantitative, anatomic
development
increase in organizationi, complexity, differentiation and specialization as a consequence of the environment; qualitative, behavioral
head to body ratio at 3 month in utero, at birth, in adulthood
50%, 30%, 12%
cephalocaudal growth gradient in the head and face
cranium grows, then maxilla, then mandible
t/f. the mandible grows at later time and greater amount development than the maxilla
true
scammons growth curve
shows that different tissues exhibit peak growth during different times
growth in length of mandible correlates with what
growth in height and onset of puberty
which curve is an easier assessment of whether acceleration of deceleration in growth rate occured (distance or velocity)
velocity curve = height gain per year over time
distance = change in height over time
why are growth charts good
can establish growth of child in relation to peers; allow you to evaluate if theres an unexpected change in growth pattern
what can contribute to the variability in population at a given point in time
biological clocks/individual variability
what determines biological age
onset of menarche (females first menstrual cycle)
biological age is a good predictor of what
growth and sexual maturity
completion of facial width
onset of puberty
time of greatest change in facial length
puberty then declines rapidly
t/f completion of facial height occurs at puberty
false. has a steady rate and continues into adulthood
cephalometrics
can evaluate soft and hard tissue longitudinally; use to study effects of growth and orthodontic treatment
what can you see with cone-beam computed tomography
a 3D reconstruction of cranium and face
what do you see with vital staining
dye marks location of active growth at the time of injection and is removed during bone resoption
implant radiology
best method of studying dental facial growth pattern by placing metal pins into bones which allows you to superimpose cephalograms from two different time points for a longitudinal study
interstitial growth
growth of soft tissue/cartilagenous precursor
appositional growth
growth of bone (activity of cells in the periosteum leads to direct addition of new bone to surface of existing bone
endochondral ossification
calcification of cartilage into bone at centers of ossificaiton
remnants of endochondral ossification
synchondroses
sites of endochondral ossification
cranial base and mandibular condyle
intramembraneous ossificaiton
bone formation directle within mesenchyme, NO intermediate formation of cartilage
site of intramembraneous ossificaiton
cranial vault, maxilla, mandible (not the condyle)
locations of craniofacial growth
cranial sutures, synchondroses, bone surface
cortical shift
deposition of bone on the periosteal surface and resporption of bone on the endosteal surface = relocation of bone
primary displacement
movement of bone to a new location as a result of bone growth
secondary displacement
movement of bone to a new location as a result of displacement of other bones or soft tissue
ex: growth in the cranial fossa pushes the nasomaxillary complex anteriorly and inferiorly
describe the majority of growth of the cranial vault
apposition of bone along edges
3 synchondroses found in the cranial base
spheno-occipital, inter-sphenoid, spheno-ethmoid
passive growth of the nasomaxillary complex
growth of the cranial base pushes the maxilla forward
active growth of the nasomaxillary complex
bone apposition at the sutures that connect the maxilla to the cranium and cranial base and growth of soft tissue and sinus spaces
anterior surface of the maxilla undergoes what type of surface remodeling
resorption
why is there bone apposition at the maxillary tuberosity
to provide bone for permanent molars
at what age does displacement of the maxilla due to growth of the cranial base stop?
- after 6, growth is due to the ossificaiton of the synchondroses
t/f. bone is added in the direction of movement (down = palate) and resorbed in the direction of movement (forward = anterior maxilla
true.
growth of bone in the mandible
endochondral - back and up to maintain contact with the skull (growth in height)
remodeling in post ramus (growth in length)
major mechanism of mandibular growth
bone apposition in posterior ramus
growth site
where growth occurs with no innate growth potential
growth center
independent, genetically controlled growth
t/f. all growth centers are also growth sites
true
cartilage in the cranial base
synchondrosis
cartilage in the maxilla
nasal septum
cartilage in the mandible
condylar cartilage
growth centers in the craniofacial complex
synchondrosis (cranial base) and maxilla (nasal septum) NOT condylar cartilage
functional matrix theory
soft tissue is the epigenetic control by which bone and cartilage respond
