Mercado Flashcards
what is growth?
an anatomical phenomenon which involves an increase in size or number
what is development?
a physiological phenomenon which involves an increase in organization, complexity or specialization, at the expense of a loss in potential
what happens to the mandible through out life?
mandible does not merely grow
develops by changing positions and shape via translation and remodling
what is the result of how the mandible is developed?
higher specialization for the functions of mastication and speech
according to scammon’s growth curve, what is the maxillary growth similar to? mandibular?
neural for maxillary
general for mandibular
what is the normal percentile of growth?
5-95
what is the timing of growth?
same events may happen at different times
variations in growth due to timing are more evident during adolescence
what is craniometry?
take dry skulls and fixate them and get precise measurement of dimensions
what is anthropometry?
measuring over soft tissues ex head circumference
what is intersitial growth?
growth that occurs by a combination of hyperplasia, hypertrophy and secretion of extracellular matrix
occurs at all points within the tissue
what structures do intersitital growth?
all soft tissues
cartilage
cranial base
what is hyperplasia?
proliferating cells (cell division)
what is hypertrophy?
increase in cell size
what are the steps of interstitial growth?
resting cells in cartilage -> hyperplasia -> hypertrophy -> extracellular matrix
what happens if extracellular matrix is not mineralized?
interstitial growth may continue in soft tissues and cartilages
what is appositional growth?
growth that occurs by a combo of hyperplasia, hypertrophy and secretion of extracellular matrix but ONLY OCCUR AT SURFACE OF BONES
addition of new bone to the surface of existing bone
occurs through the activity of cells in the periosteum
what structures go through appositional growth?
bony surfaces of cranial vault
bony surfaces of maxilla and mandible
what are the steps of appositional growth?
resting cells in periosteum->hyperplasia->hypertrophy->extracellular matrix->bone
what happens when extracellular matrix is mineralized?
bone is formed
interstitial growth cannot occur within bone
what is the connection between interstitial growth and appositional?
cartilage can grow interstitially but bone can;t
once cartilage is transformed into bone, it continues to grow only by apposition
what are the types of skeletal growth?
interstitial vs. appositional
endochondral vs. intramembranous
remodeling
what is endochondral bone formation?
bone growth within cartilage
ossification centers occcur within cartilage
cartilage is transformed into bone