mandible and TMJ Flashcards
meckel’s cartilage
in each mandibular process of BA 1
what are the roles of meckel’s cartilage
- temp skeleton of man. processes of BA 1
- temp attachment for mm that eventually attach to the mandible
- cartilage models/OSSIFICATION CENTERS for the malleus and incus
- appearance site of 2 ligaments (anterior mallelar and sphenomandibular)
- temp anterior lingual plate of forming mandible halves
- serve as enclosed GROWTH SITES at the chin end of the mandible
fate of meckels cartilage
- endochondral ossification centers for the 2 ossicles
- retrogressive changes to become the 2 ligaments
- undergo growth, mineralization and resorption while serving as an ANTERIOR GROWTH SITE and replaced as temporary anterior lingual plate by the encroaching bone tissue of the growing mandible halve
what is an ossification center
initial appearances of bone tissue in the area where each of the bone organs of the body form
where can ossification centers appear
- w/in mesenchyme
2. on or w/in cartilage model
if ossification centers appear w/in mesenchyme it is called
intramembranous bone organ development
if ossification centers appear on or w/in a cartilage model it is called
endochondral bone organ development
do the # of ossification centers vary from bone to bone
yes
how many o.cs does the mandible have
1 for each half
how many o.cs does the maxilla have
2 in each bone…so 4
mandible and maxilla development are examples of
intramembranous ossification
what are growth sites
addition of bone tissue to a bone organ
intramembranous bone tissue
bone tissue always forms in a highly vascular c.t called intramembranous bone tissue
the PDL is a
growth site
when does the mandible begin development
6th embryonic week
where does the mandible arise from
from 2 bilateral ossification centers within mesenchymal tissue (intramembranous) lateral to meckel’s