Theories of craniofacial growth- Final Flashcards
In orthodontics they feel that by changing the environment/manipulating the growth patterns, they are positively influencing the:
epigenetic patterns of genes
The concept of the genes that you express or don’t express and to what degree:
epigenetics
Epigenetic are considered very:
unpredictable
In orthodontics they feel that by changing the environment/manipulating the growth patterns, they are positively influencing the epigenetic patterns of genes resulting in:
correction of malocclusion
The lower incisors and upper incisors DO meet with w/ 25% overbite and they are in balance:
incerincisal cupping
For the male patient seen with 12mm of overjet (full class II malocclusion), the treatment required:
orthognathic surgery
Although the man who required orthognathic surgery son came in with the same genetics as his father (and some from his mother), what treatment was decided and why?
A functional appliance to reposition the lower jaw forward (avoiding surgery) due to young age and not being done with growth
What was the hope with treating the boy with a functional appliance?
we hope to have a 50% U and L correction of vertical dimension and that the dental alveolar processes respond to this new position
The growth theory of proffitt=
Equilibrium
Theory that states, not only should you make inferences from the hard tissue but also consider the balance of forces that keep the jaws in their position & the duration of force is more important than the magnitude:
Equilibrium theory of proffitt
The Equilibrium Theory of Proffitt states that in addition to looking at the hard tissues, you should also consider: (2)
- balance of forces keep the teeth and Jaws in their position
- duration of force more important than magnitude
The Equilibrium Theory of Proffitt states that the ___ of force is more important than the ___
duration; magnitude
The Equilibrium Theory of Proffitt states that the balance of ____ keeps the teeth and jaws in their position
forces
The Equilibrium Theory of Proffitt considers the balance of what muscles:
- muscles of mastication
- lingual muscles
- orofacial muscles
What does the The Equilibrium Theory of Proffitt state should be in balance?
- bone
- soft tissue
- pharynx/nasal cavity/airway
means that the function requirements (breathing, eating, mastication, etc.) is very relevant to the development of your craniofacial complex:
functional matrix
The theory of functional matrix reverse the theory that:
the theory that that we first have bone, bone grows, and tissues accomodate
Functional matrix theory considers the balance between:
cheek pressure & tongue posture
What positions does the tongue push on the teeth?
- AP position
- transverse position
(does NOT have massive influence on the vertical dimension)
Discuss the relationship between bone growth and soft tissues portrayed by the functional matrix theory:
Bone growth <—->soft tissue accomodation (we just don’t know to what degree)
Orthodontics has the capacity to influence growth thanks to:
functional matrix
Mouth breathing and sleep apnea may be due to:
anterior open bite
Enhancing dental alveolar growth has an influence on the ___ but we do not know to what degree:
muscles
Malocclusion that is 100% related to functional alterations
open bite
- over eruption of alveolar processes
- no equilibrium
- jaws not developing enough in the transverse direction
- everything is too small
- tongue pushes on teeth
open bite
What condition may be correlated to the open bite?
sleep apnea
Dental affects on mouth breathing include: (5)
- anterior open bite
- maxillary incisor protrusion
- mandibular incisor protrusion
- narrowing of the maxilla
- mandibular retrusion
Mandibular recursion (a component of open bite malocclusion) may be due to:
- mandible is genetically too small
- mandible may not be growing because functional matrix is not optimized
(likely a combination of these two)
For the case of the patient with skeletal-dentoalveolar malocclusion, what was wrong with the maxilla and what was wrong with the mandible?
maxilla= dental alveolar (excessive vertical growth)
mandible= short ramus
What treatment was used for the skeletal-dentoalveolar malocclusion patient?
a combination of dental alveolar treatment with orthodontics, extractions, and a sagittal segment osteotomy
What bone and where do growth CENTERS occur:
epiphysis of long bones
Where would we NOT find growth CENTERS?
No growth centers in the craniofacial complex except for cranial-base
Growth centers are responsible for growth of:
long bones
In growth centers, how are cells organized?
cells are layered in a precise manner
What happens with a cell that is transplanted from a growth center and why?
It will continue to grow (maybe due to chemical mediators or genetics)
Do growth centers respond to tension or pressure?
NO
(tightly genetically controlled)
Because growth CENTERS are tights genetically controlled, this means:
there is no place for functional adaptation
Where do we find growth SITES?
- mandibular condyles
- maxillary sutures
- maxillary tuberosity
Discuss the cell organization of growth SITES:
Immature fibrocartlaginous cells that are NOT layered
What happens to cells that are transplanted from a growth SITE?
They stop functioning (genetic mediators basically stop working)
Are growth SITES sensitive to mechanical stimulation such as tension and pressure?
YES- tension makes bone & pressure resorbs bone
Discuss the amount of bone formed at growth SITES via mechanical stimulation:
amount of bone formed is small
Growth sites respond to:
mechanical stimulation
The amount of growth is much ___ in a growth site
lower
____ are genetically programmed and less affected by the environment
growth centers
