Lesson 3&4 Flashcards
During this stage the mandible is bigger than the maxilla
During fetal life
In what week during the fetal life, the maxilla overlaps the madible?
8th week
In what week ( during the fetal life) the upper is equal to the lower jaws
11th week
During the fetal life, in what week does the mandibular growth lags behind maxilla?
13th & 20 week
True or false
At birth. the mandible tends to be retrognathic relative to the maxilla
True
Underdeveloped; with tooth buds
Alveolar bone
large; projects over the condyle
Coronoid process
minimal develooment
Condyle
short/ low/wide
Rami
Main sites of postnatal growth of mandible
- condylar cartilage
• 2. posterior border of rami
• 3. alveolar ridges
What month or year:
symphyseal cartilage Is replaced by bone
4 months-1 year
What month or year:
growth is selective
4 months - 1 year
What year?
appositional growth bone remodelling
1st year
> Overall Increase in size
> Selective growth
Changes in the mandible after 1 year
growth:
downward and forward
Changes in the mandible after 1 year:
Bone deposition:
lingual surface
»> growth superiorly, posteriorly and medially
Development of the mandible according to the V principle
True or false
Growth in height is completed first
False
Growth in WIDTH is completed first
What is completed first up to the last?
Height
Width
Lenght
1.width
2. Length
3. Height
Completed before adolescent growth spurt
Growth in Width
• Little change in intercanine width increase after ________.
12 years
(Growth in Width)
In Growth in Width, where is the Deposition, and resorption:
Deposition: Outer surface of the
mandible
resorption:
inside
Continues through puberty
Growth in Length of mandible
Growth in Length of mandible
age of girl:
14-15years
Growth in Length of mandible
age of boys:
18-19 years
Posterior drift along ramus
Growth in Length of mandible
Growth in Height and Thickness of Mandible
Depostion:
alveolar process with the developing dentition and condyle
Alveolar process grows in a ______ and ______
upward, outward
Alveolar process grows in a upward and outward
Growth in Height and Thickness of Mandible
To accommodate the permanent teeth
Growth in Height and Thickness of Mandible
Peaks at puberty
Growth at the Condyle
Stops at 20 years old
Growth at the Condyle
Endochondral growth
Growth at the Condyle
Growth by expanding V principle : Outward, backward
Growth at the Condyle
lengthens vertically
Growth at the Coronoid Process
Growth at the Coronoid Process
Lingual:
Buccal:
• Lingual:
Deposition (medial, superior posterior growth)
• Buccal:
resorption
medial, superior posterior growth
Lingual (deposition)
In Ramus uprighting
Posterior border:
Anterior border:
Posterior border: deposition
• Anterior border: resorption
At what age the greatest increase in size of the mandible occur
6
After age 6, the greatest increase in size of the mandible occur ______ to the _____
distal, first molars
> created by resorption of the anterior border of the ramus
Arch length space for the permanent 6’s and 7’s
Four dimensions of facial growth
- vertical growth
- length
- width
- time
In facial growth, Vertical growth means?
Height
In facial growth, length means?
antero-posterior; depth; sagittal
In FACIAL GROWTH, width means?
(transverse)
Completed before ( 9-10 years) adolescent growth spurt
Transverse growth
Minimally affected by adolescent growth changes
Transverse growth
•Ex 13 year old girl with Class Ill skeletal malocclusion»_space; interception is ruled out but maxillary expansion after suture closure is possible
Transverse growth
True or false
In Transverse growth it is Completed after ( 9-10 years)
False
Transverse growth Completed BEFORE( 9-10 years)
True or false
Direction of growth has to be considered
True
True or false
•Sometimes growth is expected downward and forward movement
False
•Sometimes growth is not in the expected downward and forward movement
True or false
Direction of growth has to be considered
•Can be redirected with extraoral appliances
True
All dimensions of growth occur in different orders (Hellman)
Face:
Cranium: height > width > depth
4th dimension:
Face: width > depth > height
Cranium: height > width > depth
4th dimension: time
Terms RELATED TO GROWTH
GROWTH FIELDS
GROWTH SITE
GROWTH CENTER
REMODELLING
CORTICAL DRIFT
DISPLACEMENT (TRANSLATION)
first 20 years of growth after birth
POSTNATAL GROWTH
→ outside and inside surfaces of bone
→ covered by soft tissues, cartilage, and osteogenic membrane
GROWTH FIELDS
more specific than growth fields
GROWTH SITE
areas of specific bone that have strong impact in overall growth
GROWTH SITE
→ special growth site which controls the overall growth of the bone
→ ex.: condyle which will influence the growth of the maxilla and
mandible
GROWTH CENTER
→ reshaping of bone
→ deposition (apposition) and resorption in some areas
o wherever there is deposition, that is the direction of growth
REMODELLING
→ growth movement or relocation of bone towards area of deposition
→ result of remodeling
CORTICAL DRIFT
→ movement of bone as a whole from a certain position or place
→ can be:
o primary
o secondary
DISPLACEMENT (TRANSLATION)
→ movement of bone because of growth that occurs on a specific part of the bone
→ ex.: maxillary tuberosity
o maxilla moves forward because of growth in
this area
Primary
→ growth on adjacent bone of another structure influences the overall growth of another bone
→ ex.: cranial base
o influences the growth of
the maxilla
Secondary
Remodeling, cortical drift, and displacement are mechanisms of ____
bone growth
only two structures that undergo this mechanism of
formation
cranial base and condyle
a cartilage matrix (template) is filled with blood vessels and
there is formation of osteoblasts which will cause the bone to mature, elongate, or grow
ENDOCHONDRAL BONE FORMATION
→ cranial vault, maxilla, body of the mandible
→ mesenchymal cells create fibrous connective tissue framework
for ossification
INTRAMEMBRANOUS BONE FORMATIO
some undifferentiated mesenchymal cells differentiate into
osteoblasts in an ossification center
INTRAMEMBRANOUS BONE FORMATIO
→ axis of continued growth extending from head to the feet
→ structures of the upper end growth faster or mature earlier
→ later on, there is lesser growth at the head and more maturation
at the lower area of the body such as the limbs
CEPHALOCAUDAL GRADIENT OF GROWTH
(4) major body tissue systems of the body and percentage of adult attainment at 20 years of age:
lymphoid tissues
o neural tissues
o general body tissue
o genital tissues
mature early and rise high for immunity of the child and will decrease later on in adulthood. It peaks at 10 years of age.
Lymphoid tissues
rise suddenly at a young age and slow down at the ages of 6-7 (its peak) and there is gradual or consistent growth from there on.
Neural tissues
follow a steady course that is slightly delayed compared to other tissues.
General tissues
peak suddenly during puberty.
Genital tissues
The maxilla follows the growth of neural tissues, while the mandible follows general tissues.
True or false
True
for bones with a “V” or funnel shape
ENLOW’S EXPANDING “V” PRINCIPLE
→ fast and intense increase in the rate of growth in height and weight during adolescence
→ earlier in girls and later in boys
GROWTH SPURT
THEORIES OF CRANIOFACIAL GROWTH
NASAL SEPTUM
SUTURE DOMINANCE THEORY
FUNCTIONAL MATRIX
→ Scott
→ area around the nasal septum is the primordium where it all
starts
→ displaces maxilla anteriorly and inferiorly
→ genetic control
NASAL SEPTUM
. → Melvin Moss
→ most accepted
→ bone grows in response to functional relationships established
by the sum of all the soft tissue matrix associated with that bone
→ genetic factors are not part
FUNCTIONAL MATRIX
→ intramembranous growth (replaces fontanels) → remodeling due to brain growth
GROWTH OF CRANIAL VAULT
Age where mostly secondary to pneumatization of frontal sinuses and thickening of anterior part of the frontal bone
15 years and adulthood (GROWTH OF CRANIAL VAULT)
→ Skeletal Class II relationship
→ excessive midface growth
Large/Long Cranial Base
→ Skeletal Class III relationship
→ decreased midface growth
Low/Short Cranial Base
→ displacement of maxillary complex
→ growth at sutures
POSTNATAL GROWTH OF THE MAXILLA
→ intramembranous ossification
→ strong influence of the cranial base (up to 6 years)
→ surface remodeling (7 years and beyond)
GROWTH OF MAXILLA
bone deposition at posterior portion of maxillary tuberosity
GROWTH OF LENGTH OF MAXILLA
→ bone deposition of alveolar process as teeth erupt
→ palatal remodeling
GROWTH IN HEIGHT OF MAXILLA
→ the downward and forward displacement of maxilla allows for the enlargement of the nasal and oral pharynx
GROWTH OF NASAL AIRWAY
→ 16th week
→ rapid downward growth
→ everything is resorptive except the medial part
GROWTH OF MAXILLARY SINUS
→ with its growth, the nasal region is enlarging anteriorly,
affecting the nose and making the face deeper anterior-posteriorly
GROWTH OF THE CHEEK BONE & ZYGOMATIC ARCH
