MIDTERMS Flashcards
Combinations of deposition and resorption result in growth movement toward the depository surface
Drift
Ramus movement
Results in drift of ramus in posterior direction
Region of the craniofacial complex that holds the greatest potential for adaptive changes.
Oral apparatus
Chondrocranium and Splanchnocranium or Viscerocranium under _
Face
growth in this of both jaws continues through the period of puberty
Length and height
Viewed at the tip or end wires maybe half round, oval square, or rectangle
Design
primary factors influencing from the late embryonic period, throughout fetal period and postnatal juvenile period are:
- expansion of the brain and cranial vault
- Growth of anterior cranial base
- Expansion of nasal cavity and oropharynx
Completion of growth in the maxilla in mandible is achieved in definite sequences
- Width
- Length
- Height
Is primarily structural and contributes little to the overall growth, possibly expresses growth factors that support the facial sutures
Nasal Capsule
Buccal side of mandible deposition
Postero-inferior
Cells responsible for resorption
Osteoclasts
5 metals used in orthodontics
- Gold
- stainless steel
- Elgiloy
- Nickel silver
- Nitinol or nickel titanium
this growth mechanism involves sutures, endosteal and periosteal surfaces, and alveolar processes
Nasomaxillary growth
Lip thickness reaches maximum during __ then decreases throughout __
Adolescence, adulthood
begins when neural crest-derived mesenchymal cells differentiate into specialized, bone forming cells called osteoblasts
Intramembranous ossification
Mandibular arch perimeter
+2mm during early mixed dentition
-4-6mm during late mixed dentition
-3.5mm (male) or 4.5mm (female)between 8-15 y.o
Premaxillary/ Maxillary sutures close at
3-5 years
Midface or nasomaxillary complex
- Maxilla, nasal, Zygomatic, Lacrimal, Palatine, Vomer, turbinates
Mandibular Intermolar width
+2-3mm between 6-16 years of age
it trails behind growth of the jaws before adolescence
lips
Ramus anterior part movement
Resorption
this experiences a small and variable degree of rotation, forward or backward
Maxilla
Buccal side of mandible resorption
Antero-superior
flat bones are formed via
Intramembranous ossification
a force or system of forces tending to cause rotation
Torque
combining gold to other metals like palladium benefit
Widening the melting range of gold
growth of this follows the enlarging V principle
Coronoid process
Growth in maxillary height sequence
- Sutural growth in frontal and zygomatic bones
- Bone apposition in the floor of orbit
- Resorption of nasal floor and apposition oin hard palate
- Maxillary alveolar process while in late adolescence
Mandibular arch depth
decreases slightly during transition to early mixed dentition
maintains dimension most of mixed dentition
-2-3mm with loss of deciduous 1st and 2nd molars
It can cause lower incisor crowding when there is tight occlusion
Late mandibular growth
It tips the maxillary incisor forward, increasing their prominence
Forward rotation of maxilla
Maxilla develops postnatally by
Intramembranous ossification
Involves both dissolution of bone mineral and degradation of organic bone matrix
Resorption
Growth sites in the nasomaxillary complex
- Sutures
- nasal septum
- Periosteal/ Endosteal Surface
- Alveolar processes
Angle of mandible at birth
(-) or 175 degrees
It can occur in the late teenage years or adulthood (18-20). Most often seen in Asians and males
Late mandibular growth
Growth in this of both jaws and dental arches is usually completed before adolescent growth changes
Width
These form the red marrow
Blood vessles
Growth of cranial base moves maxilla __
Foward
An unmineralized organic tissue secreted by osteoblast that eventually undergo calcification and is deposite as lamellae or layers in the bone matrix
Osteoid
This differentiate into osteoblasts and group into ossification centers
Mesenchymal cells
It is ductile and easily workable, and more corrosion resistant than SS
Elgiloy
Prominence of tuberosity is increased by
Large resorption field just below it
the process by which bone forms, or by which tissue changes into bone
ossification
Lingual side of mandible deposition
Antero-superior
nose becomes much more prominent at __ especially in __
Adolescence, boys
which forward decrease in the arch length is greater, maxilla or mandible?
Mandibular arch
Foundation of all orthodontic appliance
Wire/ orthodontic wire
greater or lesser degree of rotation of the jaws can occur and result in __ variation of jaw orientation even in individuals with normal face proportions
Moderate
Movement of the whole bone as a unit
Displacement
Steps in endochondral ossification
- Mesenchymal cells differentiate into chondrocytes and form the cartilage model for bone
- Chondrocytes near center of the cartilage model undergo hypertrophy and alter the contents of the matrix they secrete, enabling mineralization
- Chondrocytes undergo apoptosis due to decreased nutrient availability; blood vessels invade and bring osteogenic cells
- Primary ossification center forms in the diaphyseal region of the periosteum called the periosteal collar
- Secondary ossification centers develop in the epiphyseal region after birth
Mandible shows opposite backward rotation
Long -face type / Dolichofacial
Overall growth directions in a ___ and ___ displacement with most of growth occuring in the ramus
Downward and forward
not easily divided into a core of bone and a series of functional processes
Maxilla
intramatrix rotation or rotation centered within body of mandible
75%
Large gonial angle
Short-face type / Brachyfacial
Maxillary intercanine width during transition to early mixed dentition
+3mm
results from failure of normal lengthening of cranial base
Midface deficiency
Connects the midface to the neurocranium
Circummaxillary suture system
Cells in the cartilage that secrete extracellular matrix to form the cartilage model for bone
Chondrocytes
It undergoes the larges amount of growth postnatally
Mandible
Excessive forward rotation of mandible during growth
Short-face type / Brachyfacial
Loosely organized undifferentiated mostly mesodermal cells that give rise to such structures such as connective tissues, blood, lymphatics, bone, and cartilage
Mesenchymal celss
it indicates the amount of material used
Cross sectional design of wire
Displacement from cranial base growth is an important part of maxilla’s forward growth until the age of
6 years
ramus height: 1-2mm per year
body length: 2-3 mm per year
what age range
7-16 years of age
this rotation makes mandibular incisor erupt upward and somewhat forward
Internal rotation of mandible
Mandibular symphysis is closed by age of
1 year
there are important parts of growth and shape change in the mandibular growth
Areas of muscle and tooth attachment
matrix rotation or rotation around condyle
25%
Not affected by oral fluids
Gold
combining gold to other metals like platinum benefit
Increase hardness and strength, contributes to resistance to tarnish and oral fluids
Deep bite malocclusion and crowded incisors usually seen
Short-face type / Brachyfacial
Increase in the diameter of bones by the addition of bony tissue at the surface of bones
Apposition
In orthodontics, these are used regarding design of wire
Principle of the rod and tube
Process that involves direct conversion of mesenchyme to bone
Intramembranous ossification
Steps in intramembranous ossification
- Mesenchymal cells differentiate into osteoblasts and group into ossification centers
- Osteoblasts become entrapped by the osteoid they secrete, transforming them to osteocytes
- Trabecular bone and periosteum form
- Cortical bone forms superficially to the trabecular bone
- Blood vessels form the red marrow
Palatal plane rotated posteriorly
Long -face type / Dolichofacial
Maxillary arch perimeter
+4-5 mm during early mixed dentition
-4mm during late mixed dentition
- minimal overall increase between 8-15 y.o
The process whereby a new bone is formed
Deposition
Two mechanism involved in the growth of the nasomaxillary complex
- Growth in cranial base pushes maxilla forward
- Active growth of maxillary structures and nose
more usual pattern of rotation of maxilla
Forward
In mixed dentition, it causes lip incompetence which decreases during adolescence
Short lip
It entails the resorption of old or damaged bone, followed by the deposition of new bone material
Remodeling
Circummaxillary sutures closed later than
Intermaxillary sutures
Splanchnocranium or Viscerocranium and dentition under
Oral apparatus
Short anterior lower face height
Short-face type / Brachyfacial
Maxilla postnatal development
Apposition of bone at sutures
Surface modelling and remodelling
variation in this contributes to most malocclusions
Variations in mandibular morphology
angle of mandible Natal
115 degrees
Body of mandible: Anterior border
Remodeling
Bimolar width of the 6’s correlates with
- Vertical growth of maxilla
- Growth in the midpalatal suture
- growth in height
Lingual side of mandible resorption
Posterior - inferior
Nasomaxillary complex arise from neural crest cells within the maxillary process of the __
First branchial arch
Maxillary arch depth
decreases slightly during transition to early mixed dentition
+1-2mm with emergence of permanent incisors
-2mm - with loss of deciduous 1st and 2nd molars
Located below and between roots of first and second premolar
Mental foramen
Ramus posterior region movement
Deposition
Major centers of ossification within the midface can be seen at
7-8 weeks AOG
Structures that arise from mesenchymal cells
connective tissues, blood, lymphatics, bone, and cartilage
rotational pattern of jaw growth influences __, __, and ___ position of tooth eruption
Magnitude, direction, and anteroposterior
Clavicle is formed via
Intramembranous ossification
Anatomic regions of the craniofacial skeleton
Desmocranium
Chondrocranium
Splanchnocranium or Viscerocranium
Dentition
Its prominence is accentuated by bone resorption that occurs in the alveolar region above it creating a concavity
Mental protuberance
the appendicular skeleton (limbs) are formed via
Endochondral ossification
Increased mandibular plane angle
Long -face type / Dolichofacial
natural controlling factors of craniofacial bone growth include
Genetics, function, and general bodily growth
When in pure state, is soft malleable and ductile
Gold
These increase in height due to bone deposition at the margins
Alveolar process
The resorption filed produces a sizeable depression called
lingual fossa
it can freely move in the tube and creates a “play” where it lessens its influence on the movement of the tubes direction
rod of lesser size
Not a stainless steel but a cobalt nickel spring alloy
Elgiloy
different vertical facial developments
- short face/ brachyfacial
- Normal/ Mesofacial
- Long face/ Dolicofacial
this rotation directs maxillary incisor posteriorly and uprights them
Backward rotation of maxilla
It plays a special role in mandibular growth and translation
Condylar region
It forms superficially to the trabecular bone
Cortical bone
left and right premaxillary bones present in human fetuses with with maxilla within
3-5 years after birth
Midpalatal and transpalatal sutures close between
15-18 yrs up to 20-25
lingual tuberosity moves __ for deposition
Posteriorly
The two rami diverge __ from below to aove so that additive growth at __, ___, and __ also increases the superior inter-ramus dimension
outward, coronoid notch, coronoid process, condyle
Nearly horizontal plane
Short-face type / Brachyfacial
Cells responsible for the synthesis and mineralization of bone during both bone formation and bone remodeling
Osteoblast
Mandibular intercanine width with eruption of permanent canines
little of none
this contributes significantly to height, width, and length increases correlated with eruption
Nasomaxillary growth
Responsible for the increase in thickness in the body of mandible
Generalized surface apposition on the outer surface of mandible
Develops in response to the presence of tooth buds
- Alveolar process
Corrosion resistant iron
Stainless steel
Mandibular intercanine width
+3mm during transition to early mixed dentition
little to none with eruption of permanent canines
Mandibular intercanine width during transition to early mixed dentition
+3mm
most of cranial bones are formed via
Intramembranous ossification
Advantages of stainless steel
- Resistant to corrosion in presence of oral fluids
- Strength in small diameters
Desmocranium and chondrocranium under _
Neurocranium
It can be revolved without resistance from the tube, thus can move vertically or horizontally or tip the tooth
Rod of exact size
nasomaxillary complex bone ossification
Intramembranous ossification
Composition of elgiloy
Cobalt - 40% for toughness
Chromium - 20% as mordant to fix color
Nickel - 15% for hardness, malleability, and ductility
Manganese
Molybdenum - 7% for hardness
Carbon - 15% combining element
Iron - firmness and strength
Remodeling process and a combination of deposition and resorption resulting in bone movements towards the depository side
drift
Process that involves the replacement of hyaline cartilage with bone
Endochondral ossification
Maxillary intercanine width
+3mm during transition to early mixed dentition
+2mm with eruption of permanent canines
Growth of condyle occurs at the surface of __ by __
Condylar cartilage by bone deposition
this migrate further mesially during growth
Molars
This growth mode and mechanism are mostly intramembranously rather than endochondrally determined
Mandibular growth
Maxillary Intermolar width
+4-5mm between 6-16 years of age
Step 3 in Intramembranous ossification
Trabecular bone and periosteum form
Classification of wires
- Design or cross section form
- Diameter
- Composition
The cells for the formation of new bone
Osteoblasts
It moves prominent in males which is concave
Chin
its normal rotation in the mandible alters the eruption of the incisors somewhat posteriorly
Internal rotation of mandible
Growth in maxillary width sequence
- primarily by growth in median palatal suture
- Sutural growth increase mimics the general growth curve of body
- maximum pubertal growth in median suture coincides with that in facial sutures
Its purpose is to produce controlled forces to move teeth
Orthodontic appliance
Arise from neural crest cells within the maxillary process of the first branchial arch
Nasomaxillary complex embryology
how is diameter expressed in orthodontics
Thousandth of an inch
It is inserted into the anterior and medial border of the coronoid process and it seems that the tension exerted by this muscle during function stimulates growth of bone at the alveolar margins with the eruption of teeth contributes to most of the increase in height
Temporal muscle
Body of mandible: Posterior border
Bone deposition
all long bones of the axial skeleton (vertebrae and ribs) are formed via
Endochondral ossification
Maxillary intercanine width with eruption of permanent canines
+2mm
Excessive lower anterior face height
Long -face type / Dolichofacial
By late adolescence dental arch in the maxilla drifts forward by ___ in the __ and __ in the +__, thus shortening the dental arch perimeter
5mm in the molar region
2.5mm in the incisor region
Nasal bone growth completed at age__ then only by __ thereafter
10, cartilage
Anterior open bite malocclusion and mandibular deficiency happens
Long -face type / Dolichofacial
Growth in maxillary length sequence
- Occurs by apposition on maxillary tuberosity and by sutural growth toward palatine bone
- Labial surface of maxilla moves away from largely inferior direction of growth
Apposition of bone on the upper and posterior surfaces of the coronoid process will lead to increase in size in an __ and ___ direction
Upward and backward
Skeletal sub-units of mandible
Coronoid process, Alveolar process, Condylar process, Angular process, Body of mandible, Chin unit
from 7-16 years of age:
ramus height increase:
body length increase:
ramus height: 1-2mm per year
body length: 2-3 mm per year
Involves correct amount of force directed to stimulate the histologic process that must accompany tooth movement
Controlled force
rotation of mandible experiences __ of ___ and is associated with __ facial development
internal rotation, 10-15 degrees, vertical
Low mandibular plane angle
Short-face type / Brachyfacial
Sutures attaching the maxilla allow its __ and __ repositioning
Downward and forward
which forward internal rotation is greater, maxilla or mandible?
Mandible
Growth of the brain and eyes is essentially completed resulting in a stable anterior cranial base, but nasomaxillary complex continues throughout childhood to adolescence
7 years of age
This become entrapped by the osteoid they secrete, transforming them to osteocytes
Osteoblast