Growth development of craniofacial structure 2

Question 1

describe how the maxilla grows in width (before 7 years of age)

Answer 1

by the process of secondary displacement following brain and cranium (median palatine suture)

Question 2

how does the presence of a cleft palate affect the growth of the maxilla?

Answer 2

there will be no growing madial palatine suture therefore the maxilla will be narrow

Question 3

describe the growth of the maxilla (width ) after 7 years of age.

Answer 3

=occurs by bone drift (bone deposition on outer surface and resorption on inner surface [zygoma , zygomatic archs , orbits , nasal walls , lateral maxillary surface ])

=remodeling also plays a role as

orbit:
bone is resorbed from the lateral surfaces and deposited on the medial surfaces

zygomatic bone :
resorption on anterior surface and deposition on posterior surface casues posterior movement of zygomatic bone (drift )
+ deposition on lateral surface and resorbtion of medial surface

Question 4

what is the most prominent growth of the maxilla?

Answer 4

growth in height

Question 5

describe the growth in maxillary height before 7 years of age .

Answer 5

growth due to secondary displacement downwards to anterior cranial base and nasal cartilage

Question 6

describe maxillary growth in height after 7 years of age :

Answer 6

growth by drift : resorption of nasal floor and deposition on palate and alveolar process ( V principle )–inverted V–

Question 7

what direction does the alveolar process grow in ?

Answer 7

downward forward and lateral

Question 8

how are the alveolar ridges affected as teeth erupt ?

Answer 8

apposition [+] that’s why when some teeth don’t erupt , the alveolar ridges aren’t developed enough and the maxilla lacks in height

Question 9

describe the growth in depth of the maxilla before 7 years of age :

Answer 9

bone deposition at zygomatico maxillary(zygomatico temporal), frontomaxillary (frontonasal) and pterygo palatine sutures —> allows maxilla to grow downward and forwards

all these sutures are oblique and parallel to each other

Question 10

describe growth in depth of maxilla after 7 years of age :

Answer 10

drift: resorbtion of anterior border and deposition of posterior border—-> primary displacement causing maxilla to move forward due to growth of tuberosity and antrum

Question 11

primary displacement of maxilla causing increase in depth is due to :

Answer 11

-growth of tuberosity
-enlargement of maxillary antrum

resorption occurs on entire wall of maxillary sinus except medial wall and outer surface deposition causing increase in antrum size

Question 12

which brachial arch is the mandible derived from ?

Answer 12

1st brachial arch ( mandibular arch)

Question 13

the majority of mandible ossification is :

Answer 13

intramembranous ossification adjacent to Meckel’s cartilage . endochondral ossification is also present tho

Question 14

what are the 3 cartilages that are ossified by endochondral ossification ?

Answer 14

-condylar cartilage
-coronoid cartilage
-symphyseal cartilage

Question 15

which cartilage is involved in mandibular growth up until the 20th year of life?

Answer 15

condylar

Question 16

which cartilage converts into the mental ossicles in the symphysis region of mandible ?

Answer 16

symphyseal cartilage

Question 17

what is the fate of the meckels cartilage ?

Answer 17

-malus and incus of middle ear
-Sphenomandibular ligament
-lingula as bony specule at entrance of inferior alveolar canal
-mental ossicles

Question 18

describe the mandible at birth :

Answer 18

ill defined body
-no alveolar process
-short rami
-condyles are not well developed
-175 degree angle

Question 19

angle of mandible at birth ?

Answer 19

175 degrees

Question 20

how does the mandible grow in width ?

Answer 20

-through symphysial cartilage growth

-increase in inter-ramial width by resorption of its outer surfaces and deposition at inner surface (V principle)

-growth of mandibular condyles in a posterior, superior, and lateral direction by ENDOCHONDRAL bone formation (V-principle)

Question 21

which type of bone formation allows mandibular condyles to grow?

Answer 21

endochondral

Question 22

APPOSITION [+] - In the lingual side the border between the ramus & body forms Lingual tuberosity

RESORPTION [-]- Below the lingual tuberosity forms Lingual fossa

Question 23

how does the mandible grow in length ?

Answer 23

secondary displacement downwards and forwards by action of brain and cranial base

primary displacement downwards and anterior by condylar growth in upward and posterior direction

Question 24

what are the 3 mechanisms involved in condyle growth ?

Answer 24

-deposition above the condyle head

-deposition within the articular fossa

-due to soft tissue growth around the mandible

Question 25

angle of mandible at adolescence , adulthood , and old age:

Answer 25

140–>110/120—>140

Question 26

growth of ramus happens through :

Answer 26

APPOSITION [+] - Posterior border
RESORPTION  [-] -Anterior border

The Ramus drifts posteriorly the entire length of the mandible body increases to accommodate posterior teeth.

Question 27

growth of coronoid process :

Answer 27

Apposition [+] Posterior border ,apex & medial aspect
Resorption [-]  Anterior border
Due to above events the Coronoid process attains shape like ‘PROPELLAR TWIST’

Question 28

growth of the chin :

Answer 28

Develops as a separate sub unit.
APPOSITION[+] -Anterior & inferior most part forms the chin.
RESORPTION[-]-Anterior superior part of the symphysis

Downward & Forward Growth of the Mandible also contributes to increase CHIN PROMINANCE

Question 29

how does the mandible grow in height?

Answer 29

Alveolar bone growth along the superior border of the mandibular body in the vertical direction allowing eruption of teeth.

Bone is deposited along the entire inferior surface of the mandibular body.

Chin : bone deposition at periosteal bone and resorption above mental protuberance

Question 30

parts of mandible derived from intramembranous ossification:

Answer 30

Whole of body except anterior part

Ramus as far as mandibular foramen

Question 31

describe the differential growth of the mandible :

Answer 31

in fetal life:
-at 8 weeks , the mandible grows faster thean maxilla

-at 11 weeks they are equal

-at 13-20 weeks the maxilla grows faster than mandible

at birth the mandible is retrognathic— early postnatal life becomes orthognathic