Cranio 1 (Distraction, skull base) Flashcards
(33 cards)
What factors influence the success of osteodistraction (4)
- vascularity and quality of soft tissue
- stability of distraction device
- Latency period (entre corticotomie et début distraction)
- 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 5 zones of present during the activation phase of OD
Central: cellular proliferation
Transitionzone of vasculogenesis
Paracentral: parallel collagen and osteoid production
Transition: mineralization, bone spicule formation
Os mature: calcification and formation of cancellous and cortical elements
OD: qu’est-ce que la période d’activation
période de distraction active et de production du ‘‘generate’’
What are some advantages of OD (compared to regular osteotomies)
- less blood loss
- decreased infection rate
- reduction of dead space
- lower incidence and degree or relapse than single stage
- permet d’obtenir plus d’avancement
Describe the distraction process (5)
- Osteotomy
- Application of distraction device
- Latency
- Activation phase
- Consolidation phase (quand longueur voulu est obtenue)
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
nombre de distraction par jour
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
Name 5 complications of OD
OD: qu’arrive-t-il si distraction trop lente
ossification prématurée
OD: qu’arrive-t-il si distraction trop rapide
Union fibreuse
Quels sont les 3 types d’OD
Unifocal : 1 ostéotomie avec vis de chaque côté
Bifocal : 1 segment de transport (1 ostéotomie pour 1 déficit osseux)
Trifocal : 2 segments de transports (2 ostéotomies dans 1 déficit osseux)
3 compartiments de la base du crâne?
antérieur
middle
postérieur
5 os qui forment la base du crâne
ethmoid
sphenoid
occipital
paired frontal
and paired temporal bone
skull base: 2 structures qui délimite compartiment antérieur
Ant: Portion postérieur du sinus frontal
Post: planum sphénoidal
en latéral délimité par os frontal
skull base: 4 foramen de la fosse antérieur
- Foramen olfactif de la lame criblée
- Foramen ethmoid antérieur
- Foramen ethmoid postérieur
- Foramen cécum
