theories of craniofacial growth Flashcards
Heredity/Genetics of craniofacial growth
based on DNA/ influenced by environment= epigenetics, are genes expressed/ to what degree?
orthodontics can influence the environment
approaches to fix malocclusions/ craniofacial abnormalities
surgical, functional appliance, othro
Equilibrium Theory
duration or magnitude?
- Balance of forces keep the teeth and jaws in their position: mm/ tongue
- Duration of force more important than magnitude
soft tissue forming with bone/ functional matrix
bone forms first then soft tissue, however, forces provided by the soft tissue with function can influence bone growth= functional matrix (balance between cheek and tongue)
Mouth breathing and sleep apnea
can be due to?
can be due to unfavorable dentoalveolar growth: over eruption, lack of transverse development,
tongue may also push incisors forward
all of this can lead to mouth breathing and sleep apnea
Dental Effects of Mouth breathing bite? max incisors? man incisors? wide or narrow maxilla? man protrusion or retrusion? result of?
- Anterior open bite
- Maxillary incisor protrusion
- Mandibular incisor retrusion
- Narrowing of the maxilla
- Mandibular retrusion: can be genetic/functional matrix not optimized
tongue creation of anterior open bite
may provide a protrusive force on the incisors with lack of counter from masticory mm= anterior open bite formation
Skeletal-Dentoalveolar issues, result?
can have super-eruption of the maxilla dentoalveolar process= can lead to ant open bite
can also have lack of ramus development
Growth centers
- Epiphysis of long bones and at cranial base
- Responsible for growth of long bones
- Cells are layered in a precise manner
- Transplanted cell will continue to grow (chemical mediators?)
- Do not respond to tension or pressure
Growth sites places? cells? function with a transplant? sensitive to?
•Mandibular condyles, sutures, tuberosity
•Immature fibrocartilaginous cells (not layered)
•Stop functioning if transplanted (mediators)
•Growth sites are sensitive to mechanical stimulations ( tension=growth/pressure=stops, orthodontic uses)
forms less bone than a growth center
Differences of growth sites and centers for Orthodontics
sites respond to?
amount of growth?
programming of centers?
- Growth site responds to mechanical stimulation (pull on PDL, stimulates bone)
- Amount of growth is much lower in a growth site
- Growth centers are genetically programmed and less affected by the environment (epigenetics, how much expressed?)