OCB02-1007 Mechanisms of post-natal growth Flashcards
What age does the 1st permanent molar erupt?
7
What age does the 2nd permanent molar erupt?
12
When does the 3rd molar erupt?
Maturity
What are the 3 parts of the craniofacial complex?
Cranial vault
Cranial Base
Face
How many fontanelles are present in the head?
6
What path does the face growth take?
The face follows the somatic growth curve excepts the skeleton around the eyes, middle and inner ear which follows neural growth pattern
What organs develop faster than the face?
Brain and sense organs
At what age does the cranial vault completely expand?
10
What is facial growth completed with?
Eruption of 3rd molars
What parts of the body does the cranial base link?
brain and face
What are the two kinds of bone in the head?
Endochondral and membrane
Where are skeletal structures in head derived from?
Neural crest cells
Where is the cranial vault derived from?
Cranial mesodermal cells
What bones are endochondral?
Cranial base, pharyngeal arch cartilages, otic and nasal capsule
Where is there primary cartilage?
Synchondrosis between the basi-occipital and basi-sphenoid and the nasal septum
Where does interstitial growth occur?
Between growth plates
Where does appositional growth occur?
during remodelling
Where are membrane bones found?
facial and cranial vault
What cartilage is secondary cartilage?
Condylar cartilage
What happens to the intersphenoid bone during cranial base growth?
The inter sphenoid bone is fused between two bones so it cant contribute to post natal growth
What happens to the sphene-ethmoidal bone during cranial base development?
It fuses at 3-5 years
What happens to the sphene-occiputal bone during cranial base development?
It is found between the basiocciputal bone and basinphenoid and contributes to post natal growth at 12-16 years
What growth occurs in the spheno-occiptal joint?
Bilateral growth
What direction does remodelling of the cranial base move the face?
Anteriorly and inferiorly
What age does the cranial base stop growing?
14 years in girls
16 years in boys
What changes does the mandible undergo from birth until adult?
Increases in length, height and width
The angle becomes smaller
The relative sizes of the condylar and coronoid processes is the same and the condylar cartilage acts as a growth centre
The position of the mental foramen changes
What age does condylar cartilage grow?
peaks at adolescence and ceases at 20 years
What is the purpose of symphysial cartilage?
It unites the mandible
How is the height of the mandible increased?
by developing the alveolar bone
How is the length of the mandible increased?
Adding to the chin
How is the width of the mandible increased?
By increasing condylar growth
Which pharyngeal arch gives rise to the lower jaw?
first
At birth, what is present in the maxilla?
Large frontal process and no alveolar bone or any anterior nasal spine is present
What does pressure for the developing eyeball and brain cause to the maxilla?
Put pressure on the maxilla to grow downward
How long does it take the septal cartilage to fully increase in width?
2 years
How long does it take the septal cartilage to fully increase in length?
7 years
How does thumb sucking affect arch development in palatal shelves?
Thumb sucking is thought to impact the growth of palatal shelves
By lowering the palatal shelves, you increase the size of the nasal cavity so more air can enter to increase respiration
What happens to the cartilage between the great wings and body of sphenoid?
It ossifies so growth no longer comes from cartilage and can only come from remodelling
How long is the suture growth of the upper jaw?
10 years
How long is the endochondral growth of the ethmoid and nasal septum?
until 7th year
