Pt 2 - biomechanics Flashcards
growth modification uses what force vs tooth movement
orthopedic force (growth modification) and orthodontic = tooth movement
orthopedic forces
heavier
over 500 gmf
orthodontic
lighter is 10-150 gmf
gmf - gram of force
orthopedic forces application and sutures?
maxilla and mandible and forces of tension and pressure are on the SUTURES
example use of restraint of growth in maxilla
class II - due to maxillary
Sand A angle will be larger
augmentation of growith
when there is lack of growth
for example in patient class III- maxilla underdeveloping
mandible restraint in
class III
restraint or augmentation occurs in what view
sagital
maxillary dental expansion
correct DENTAL crossbites
tipping the teeth BUCCALY
NOT orthopedic effect (single light forces)
maxillary DENTAL expansion devices
TPA
- trans palatal arch
Quad helix
maxillary PALATAL expansion
two examples?
correct skeletal crossbites
NO tipping
OPEN paltal suture
HEAVY orthopedic forces
Hass appliance
rapid palatal expander
Hyrax appliance
- Hygenic rapid expander
bonded expander
prevents any molar extrusion
- covers all posterior teeth
- important in patients with longer faces
Microfractures with?
RPE’s
- rapid palatal expanders
in early adolescence and late mixed dentition there is a complex interdigitation on palat
but after do this – more complex configuration and bony bridging
overall for the max palatal expansion
suture opening that is NON PARALLEL
type of opening in palatal expansion
triangular in two dimensins
- horixontal and frontal planes
occlusally opening is more pronounced anterior – (interincisal diestema)
base – occlusally - opens more on occlusal than at the nasal level
BASE ANTERIOR AND BASE OCCLUSAL
maxilla stops growing around what age
10
ggrows down and forward so if want to restrain it – needs to go back and up
describe restraint of max growth
excesssive max growth (Class II)
prognathic maxilla
will compress maxillary sutures
- forces oppose natural growth direction
- allow others to ‘catch up’
corrects MX/MD discrepencies
ex- HEADGEARS
types of headgear
- cervical pull – one strap around back of head
- simplest design and produces slight extrusion of the molars
- EXTRUDE MOLARS - high pull
- USED when you need maximum vertical control- Open bite tendency
Back and up
- INTRUDE MOLARS
- Open bite tendency
- straight pull
-Much more horizontal force
Without intrusion or extrusion
- GOES THROUGH CENTER OF ROTATION
inner bows and outer bows
force prescription of headhears
500-1000 gmf
direction : slightly above occlusal plane
application - molar
12/hr day (growth hormone release)
12-18 months
overview of augmentaion of max grwoth
when insufficient max growth (class III) - retrognathic maxilla
TENSION ON MAX SUTURES
forces follow natural growth directions: down and forward
*very controversal / reverse headgears - “face mask”
patient compliance is extremely important factor
petite face mask
rod in center
support for forehead and chin
outer bow
worn 24/7
gets hooked to elastics
face mask - delaire
wireage come on the sides
tx prior to face mask?
an RPE is recommended
face mask prescription
force 500-1000 gmf
direction - slightly above occlusal plane
application – intraoral hooks
18-24 hours / a day
12-18 months
sideeffects of face mask
proclination of upper incisors
retroclination of lower incisors
chin soft tissue irritation
