ORTHO functional appliances Flashcards
list the general ortho tx options?
removable appliance
fixed appliance
orthognathic surgery
grown modification
how do we assess if a functional appliance has met our goals?
pre and post tx lat ceph
what is intramembranous bone formation?
mesenchymal cells aggravate and differentiate into osteoblasts, laying down a matrix which becomes calcified
where in the jaws do you get intramembranous bone formation?
whole maxilla
mandible except condylar cartilage
what is endochondral bone formation?
cartilage cells increase in size, matrix is calcified by invasion of osteoblasts and converted to bone
where do you find endochondral bone formation in the jaws?
condylar cartilage
nasal septal cartilage
what are the skeletal effects of a functional appliance?
causes forward displacement of the mandible
places a backwards force on the maxillary arch
accelerates condylar growth
redirects condylar growth
what are the dentoalveolar effects of functional appliances?
retracts upper teeth
proclines lower teeth
different rates of tooth eruption
how do functional appliances work?
stretch the muscles of mastication
posture mandible
how is a functional appliance made?
wax bite instructing pt to protrude mandible when biting
what is a functional appliance?
an appliance that utilises/ redirects the forces of the masticatory and/ or circum-oral muscles to produce or permit tooth movement and may modify facial growth
indications for a functional appliance?
motivated pt
pre adolescent growth phase
skeletal discrepancy mild or moderate
increased overjet/ overbite (if class II)
proclined maxillary incisors (if class II)
well aligned arches
how do functional appliances cause less damage to tooth tissue?
less root resorption
less chance of decalcification
less effect on bone levels
advantages of functional appliance?
removable - easy to clean
may avoid xla
accelerates skeletal growth
reduces incidence of trauma
early tx
economical
less damage to tooth tissue
contraindications of functional appliances?
poor motivation
age >14
poor dental health
condylar disease
proclined lower incisors
what are the disadvantages of functional appliances?
compliance - it is bulky, speech issues, soft tissue trauma
lack of detailed tooth movements
candidosis with removable appliances
what is remodeling?
a process involving deposition and resorption occurring on opposite ends
- progressively change the size of whole bone
- sequentially relocate each component of the whole bone
what are the sutures of the naso-maxillary complex?
zygomatico-frontal
fronto-maxillary
naso-maxillary
zygomatico-maxillary
zygomatico-temporal
palato-maxillary
what is a class II maxillary excess?
lowering of the palatal plane
supra eruption of dentition
tx for a class II maxillary excess?
headgear
what is a problem class III maxillary deficiency?
reduced lowering of palatal plane
over closing of mandible
tx for class III maxillary deficiency?
face mask
what does a functional appliance depend on?
part of cartilage that hasnt converted to bone
depends on the calcification of condylar cartilage
- postures the mandible forward to activate condylar cartilage to produce more bone and stabilise the glenoid fossa
when is the pre pubertal growth spurt?
male: 12-14
female: 11-13
