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 & to what degree:
Epigenetics
Epigenetics 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 & upper incisors DO meet with 25% overbite & they are in balance:
Interincisal cupping
For the male patient seen with the 12 mm of overate (full class II malocclusion) the treatment required:
Orthognathic surgery
Although the man who required orthognathic surgery’s son came in with the same genetics as his father (and some from his mother)- what treatment was decided and why?
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% upper & lower correction of vertical dimension & that the dental alveolar processes respond to this new position
Growth theory of Proffitt=
Equilibrium
Theory that states not only should you look at the hard tissues & make inferences from this, but also the balance of forces that keep the jaws in their position & the duration of force (that is more important than the magnitude)
Equilibrium theory of proffitt
The Equilibrium Theory of Profitt states that in addition to looking at the hard tissues you should also consider (2):
- Balance of forces keep the teeth & jaws in their position
- Duration of force more important than magnitude
The Equilibrium Theory of Profitt states that the ____ of force is more important than the _____
Duration; magnitude
The Equilibrium Theory of Profitt states that the balance of _____ keeps the teeth & jaws in their position
Forces
The Equilibrium Theory of Profitt states considers the balance of what muscles?
- Muscles of mastication
- Lingual muscles
- Orofacial muscles
What does the Equilibrium Theory of Profitt state should be in balance? (3)
- 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 reverses the theory that:
The theory that we first have bone, bone grows, & tissues accomodate
The 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 & soft tissues portrayed by the functional matrix theory:
Bone growth <—-> soft tissue accommodation
(we just don’t know to what degree)
Orthodontics has the capacity to influence growth thanks to:
Functional matrix
Mouth breathing & sleep apnea may be due to:
Anterior open bite
Enhancing dentoalveolar growth has an influence on the ________ but we do not know to what degree
Muscles
Malocclusion that is 100% related yo functional alterations:
Open bite
-Overeruption of alveolar processes
-no equilibrium
-jaws not developing enough in the transverse direction
-everything is too small
-tongue pushes on teeth
All of this contributes to:
Open bite
What condition may be correlated to an 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 retrusion (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 opsonized
(likely lies somewhere in between!!)
For the case of the patient with skeletal-dentoalveolar malocclusion, what was wrong with the maxilla & what was wrong with the mandible?
Maxilla= dentoalveolar (excessive vertical growth)
Mandible= short ramus
What treatment was used for the case of the patient with skeletal-dentoalveolar malocclusion?
Combination of dentoalveolar treatment with orthodontics, extractions & sagittal segment osteotomy
What bones & 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
How are cells organized in growth CENTERS?
Cells are layered in a precise manner
What happens with a cell that is transplanted from a growth CENTER?
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 tightly genetically controlled, this means:
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 fibro-cartilagenous cells that are NOT layered
What happens to a cell transplanted from a growth SITE?
They stop functioning (genetic mediators basically stop working)
Are growth SITES sensitive to mechanical stimulation such as temperature 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 minimal
Growth SITES respond to:
Mechanical stimualtion
The amount of growth that occurs at a growth SITE is:
Minimal
______ are genetically programed and less affected by the environment
Growth CENTERs
