FINAL Flashcards
Osteoinduction is _ from _, derived from _
New bone formation from differentiation of osteoprogenitor cells derived from mesenchymal cells into osteoblasts
Differentiation is induced by _ from _
Bone inductive proteins from bone matrix
BMP does what
Initiates osteoinduction. Acts on progenitor cells to induce diff into osteoblasts
BMP is higher in _ than _
Cortical bone than cancellous
Osteoconduction is formation of new bone from _ or _ along a _
Host derived or transplanted osteoprogenitor cells
Along a biologic framework
T/F osteoconduction produces new bone
FALSE, conducts bone forming cells from host into the scaffolding
Osteogenesis is formation of new bone from _
Osteoprogenitor cells. It’s both inductive and conductive
Two phase theory of osteogenesis.
Phase I is what:
What does it determine
Transplanted cellular bone produces new osteoid.
Determines QUANTITY of bone that the graft will form
Two phase theory of osteogenesis.
Phase II is what
Determines what
Fiber and blood vessel proliferation, then osteogenesis. Woven bone replaced by lamellar. Graft resorbed, BMP released.
Determines QUALITY
5 types of grafts and definition
Autograft - tissue from yourself Allograft - other human Xenograft - animal graft Alloplast - synthetic (HA) Recombinate graft - BMP
How do Allografts and xenografts work
Osteoconduction
1 reason BMP is not effective
Cost
Tough issue when putting implants into grafted bone
Crown to root ratio
Osteoclasts come from _
Osteoblasts come from _
Hematopoietic stem cells
Mesenchymal stem cells
4 reasons for poor wound healing
Medications
Radiotherapy
Infection
Systemic disease
3 types of drugs associated with MRONJ
Bisphosphonates
Anti-resorptive agents
Anti-angiogenic medications
How do bisphosphonates work
Inhibit osteoclasts by binding to Ca2+
Who would take bisphosphonates
Osteoporosis/osteopenia
Paget’s disease
Osteogenesis imperfecta
Solid tumors with bone metastasis
Hypercalcemia of malignancy
Multiple myeloma
What makes the jaws unique for bone remodeling
Increased turnover (10 x long bones) Thin overlying oral mucosa
MRONJ
Stage 1
Stage 2
Stage 3
1: asymptomatic exposed bone, no infection
2: exposed bone, pain, infection
3: exposed/necrotic bone, pain, infection
Osseus surgery if on IV BP
Avoid if at all possible
PO BPs needing EXT
Informed consent, medical consult to see about drug holiday
Three hypos of ORN
Hypoxia
Hypovascularity
Hypocellularity
Osteomyelitis:
Bone infection.
Inflammation of bone marrow involving cancellous and cortical bone that tends to progress.
Steps of osteomyelitis
Bacteria Inflammation Vascular compression Ischemia Necrosis
Osteomyelitis is found more in the _ than the _
Mandible
Why is osteomyelitis more common in mandible
Cortical bone more prone to damage on ext
Blood supply of max is better
Radiographic findings of osteomyelitis
Moth eaten
Islands of non-resorbed bone
Antibiotic for osteomyelitis
Clindamycin
How long does dry socket last
A week
3 ways to restore lost tissue volume
Grafting
Distraction
Ortho eruption
GBR
Horizontal augmentation, flap, prepare site, place bone, membrane, primary closure
Block grafting:
Horizontal alveolar graft, shaped like a block
Cortical w or w/o cancellous
Block maintains space while remodeling
Pros/Cons of iliac crest donor site
P: lots of bone, no rejection
C: need gen anesthesia, two surgeons, scar on hip
Diet modification after block graft
Non chew (scrambled eggs at most) for 12 days
T/F vertical augmentation is easily achieved
FALSE. No got way to do it currently
3 reasons not to do grafts for vertical gain
Risk of graft exposure
Bad adaptation of graft to ridge
Higher resorption rates
Advantages to distraction for vertical gain
Controlled
New bone in gap
Soft tissue envelope expands
Phases of distraction and length of each
Latency (4-7 d)
Distraction (1 mm/day)
Consolidation (2-3 months)
Two disadvantages of distraction
Distractor arm
Long consolidation phase
Sinus augmentation timeline for autograft vs allograft
Autograft in 4 months
Also in 6-8 months
Post op for sinus augmentation with perf
Nasal decongestant
Mucolytic
4 requirements for good implants
Healthy gingival collar
Thick biotype gingiva
No perio
Adequate bone
T/F immediate implant should fill socket
FALSE
T/F Most people have enough bone for mand ant implants
True
Patient wants max ant implants, not a lot of bone, can’t do sinus augmentation
Angle implants/implants in nasal bones
Why are long angled implants usually not done
If patient can’t do sinus augmentation, they can rarely do general anesthesia
_ is needed before definitive removal of a pathological condition
Histological diagnosis
Reconstruction should be planned when
While planning excisional surgery
A true cyst contains a _
An epithelial lining
4 ways to manage cysts
Enucleation
Enucleation and curettage
Marsupialization
Staged marsupialization and enucleation
When to do E&C
Removing known aggressive cyst like OKC
Or 2nd surgery after the first was supposed to cure it
When to do marsupialization
Adjacent vital structures at risk
Difficult surgical access to all portions of cyst
Medical compromise
T/F marsupialization alone is done more frequently than other treatments
FALSE. Staged marsupialization and enucleation is done more
Advantages of marsupialization and enucleation
Thickened cystic lining
Reduces morbidity
Same as marsupialization
Cysts that probably require extraction
Dentigerous
OKC (potentially)
Management of jaw tumors depends on what 3 things
Lesion behavior
An atomic location
Desired reconstruction results
E&C indications
Slow growing, non-aggressive
Most odontogenic tumors
Medically compromised
Jaw tumor resection indications
Aggressive lesions either path or clinically
Difficult to remove by E&C alone
Most important part of workup
History
Pain history
Location Intensity Quality Onset Radiation Associated symptoms Alleviating factors Aggravating factors
Pts that will benefit from TMJ surgery
Mechanical or inflammatory joint disease
Failed non-surgical therapy
Muscle disorders are not only problem
Invasive treatment will correct mechanical dysfunction
Why do arthroscopy instead of arthrocentesis
Long duration of symptoms History of failed steroid injection Long history of late, hard, painful pop Can’t get MRI Obesity
Pros/cons of arthroscopy
P: minimally invasive, excellent success
C: not for advanced disease, failure requires open surgery, can injure middle ear or nerve
Arthrotomy:
Incision into joint
Arthroplasty
Repair, revision and or reconstruction of joint tissues
Meniscectomy or discectomy
Removal of disk
Main reason for arthrocentesis
Acute closed lock
Arthrocentesis affects _ space
Superior joint space
Arthroscopy benefits
Allows examination under anesthesia
Doesn’t reposition disk
T/F a healthy joint should be avascular and show bone and fibrocartilage
FALSE. Should be avascular and no bone, with fibrocartilage
Most common graft material for discectomy
Temporal fascia
Best material for condyle graft
Rib
Most common joint reconstruction for kids?
Costochondral rib, grows with patient
Indications for total joint replacement
Severe degeneration of condyle
Recurrent fibrous or bony ankylosis
Failure of other reconstructive procedure
Why not do total joint replacement
Expensive
May not improve pain
Treatment of last resort
