Ortho - Lecture 4: Growth and Development Flashcards
Increase in size
Growth
Increase in complexity
Development
Combo of growth and development over time
Maturation
Patterns of growth are determined by the ____________ relationships between structures. A normal growth pattern is marked by changes in these proportional relationships over time
proportional
Patterns imply _____________
predictability
Tissue systems of the body grow at ___________ rates
different
The maxilla follows the ___________ growth curve
neural
The mandible follows the ___________ growth curve
general
During the adolescent growth spurt, which jaw grows more than the other?
Mandible grows more than maxilla
What are the 1st, 2nd, and 3rd directions of growth of the skull?
1st: Transverse
2nd: A-P
3rd: Vertical
Used to evaluate if a patient’s pattern of growth falls outside normal range acceptable for a population
Standard growth chart
A child’s growth should plot along the same _____________ at all ages
percentile
Normally developing patients undergo specific changes at _____________ times
different
How can timing variability be reduced?
By using developmental age instead of chronological age
When is the adolescent growth spurt for females?
11-13
When is the adolescent growth spurt for males?
13-15
What is the peak of adolescent growth spurt for females?
Breast development
What is the peak of adolescent growth spurt for males?
Pigmented hair on lip
Age determination measured in years
Chronological age
Age determination measured by stage of dental development (which teeth are absent/present)
Dental age
Age determination measured by bone maturation (size/shape of vertebrae determines growth status)
Skeletal age
Why do we monitor growth?
Determine normal vs abnormal
Determine specific growth pattern
Assess amount of growth remaining
Determine tx timing of ortho
Changes in proportions of head and face during growth
Craniofacial growth
Postnatally, there is much more growth of __________ structures compared to cranial structures
facial
At birth, the face and jaws are _______________ compared to the adult
underdeveloped
Formed by intramembranous ossification (no cartilage precursor!)
Cranial vault
Nasomaxillary complex
Formed by endochondral ossification (starts as cartilage!)
Cranial base
What is the major mechanism for growth of the cranial vault?
Apposition of new bone at sutures
What growth curve does the cranial vault follow?
Neural
As ossification of the cranial base proceeds, bands of cartilage called _____________ remain btwn the centers of ossification
synchondroses
In the cranial base, where does growth occur? What is the cartilage eventually replaced by?
Growth occurs at synchondroses in both directions
Cartilage is replaced by bone
Growth of the nasomaxillary complex occurs by apposition of bone at the sutures connecting the ___________ to the cranium and cranial base, and __________ remodeling
maxilla; surface
What direction does the maxilla grow?
Downward + forward
Why does the midpalatal suture fuse early?
Transverse growth is completed 1st
Apposition of bone in the maxillary molar area accounts for space for which teeth?
Maxillary 3rd molars
As the maxilla grows downward + forward, its anterior surface tends to resorb through ______________, except for which part?
remodeling; except for small area around anterior nasal spine
Remodeling of the palatal vault moves it in the same direction as it is being translated. Bone is removed from the floor of the ________ and added to the roof of the _________
nose; mouth
As the palatal vault moves downward, bone remodeling also _________ it
widens
Which direction is the mandible translated? How does it grow?
Translated downward + forward
Grows upward + backward
What are the 3 principle sites of growth for the mandible?
Posterior surface of ramus
Condylar process
Coronoid process
As the mandible grows in length, the ramus is extensively remodeled. What happens to the anterior and posterior surface of the mandible?
Anterior surface = resorption
Posterior surface = apposition of new bone
What age do centrals erupt?
Upper: 7
Lower: 6
What age do laterals erupt?
Upper: 8
Lower: 7
What age do canines erupt?
Upper: 12
Lower: 11
What age do 1st premolars erupt?
Upper and lower: 11
What age do 2nd premolars erupt?
Upper and lower: 12
What age do 1st molars erupt?
Upper and lower: 6
What age do 2nd molars erupt?
Upper and lower: 12
Caused by maxillary protrusion or mandibular retrusion, or a combo of both
Class II
Caused by maxillary retrusion or mandibular protrusion, or a combo of both
Class III
What part of class II tx planning?
Done early to prevent maxillary growth/allow mandible to catch up
Headgear
What part of class II tx planning?
Attempt during late mixed/early permanent dentition and during adolescent growth spurt
Growth modification
What part of class II tx planning?
Ext during permanent dentition to hid mild/moderate skeletal problem
Camouflage
What part of class II tx planning?
Done after all growth is complete
Surgery
What part of class III tx planning?
Protraction facemask (reverse pull headgear) done early before sutures fuse
Growth modification
What part of class III tx planning?
Ext after growth is complete so pt does not outgrow tx
Camouflage
What part of class III tx planning?
Done after growth is complete
Surgery
What does tx timing depend on? (4)
Degree of severity
Amount of growth left
Tx objectives
Facial profile
When are teeth extracted for ortho tx?
Not enough room
Camouflage a skeletal discrepancy
What is treatment timing based on for dental problems?
Dentition
What is treatment timing based on for skeletal problems?
Skeletal maturation
Appliances that affect growth
Which jaw?
Protraction facemask (reverse pull headgear)
Mandible (class III)
Which jaw?
Headgear
Maxilla (class II)
Ap skeletal pattern chart
transverse/vertical chart
