Cranio (Distration, TMJ, Migraine) Flashcards
What factors influence the success of osteodistraction
- vascularity and quality of soft tissue
- stability of distraction device
- Latency period
- Rate and frequency of distraction
How are the collagen fibers organized in the generate in osteodistraction
parallel to the vector of the distraction
Describe the zones of present during the activation phase of OD
Central zone: cellular proliferation
Transition zone of vasculogenesis
Paracentral zone: parallel collagen and osteoid production
Transitional mineralization front: bone spicule formation
Mature bone zone: calcification and formation of cancellous and cortical elements
What are some advantages of OD
- less blood loss
- decreased infection rate
- reduction of dead space
- lower incidence and degree or relapse than single stage
Describe the distraction process (5)
- Osteotomy
- Application of distraction device
- Latency
- Activation phase
- Consolidation phase
What is the latency period in OD and how long should it last?
period between osteotomy and start of distraction
newborns: 0-72hrs
older: 5-7 days
What is the rate in OD
of mm per day
neonates: 2-4mm
older 1mm/day
What is the rythm in OD
times the distractor is activated daily
usually 2-4x/day
List 5 indications for OD
Mandibular lenghtening
- hemifacial microsomia
- micrognathia
- airway compromise in newborn
LeFort 1 advancement
- large anterior movement >1cm
- clefts with significant class III
Lefort 3/Monobloc
- syndromic craniosynostosis
- severe midface hypoplasia/exorbitism
Posterior cranial vault distraction
- syndromic bicoronal craniosynostosis
List advantages and disadvantages of external OD devices
Advantages
- easier to apply and remove
- multiple vectors
Disadvantages
- social stigma
- increased risk of being disloged
- pin-site scars
List advantages and disadvantages of internal OD devices
Advantages
- less social stigma
- minimal scars
- less risk of dislodgment
Disadvantages
- single vector
- more difficult to apply
- need GA to remove
What are the goals of mandibular OD
- achieve proper occlusion
- restore normal dimensions of the mandible
- normalize relationship of tongue base to the airway
In mandibular distraction, what direction of advancement will you get with a L-shaped or vertical osteotomy
horizontal advancement
In mandibular distraction, what direction of advancement will you get with a oblique osteotomy
horizontal and vertical advancement
In mandibular distraction, what direction of advancement will you get with a horizontal osteotomy
vertical lengthening
