s10-Ridge atrophy Flashcards
What is the primary cause of ridge atrophy after tooth extraction?
Alveolar bone remodeling and resorption due to loss of functional stimulation.
What % of bone loss occurs within 2–3 years post-extraction?
40–60%.
Name the 3 types of ridge defects in Allen Classification.
Type A (apico-coronal loss), Type B (bucco-lingual loss), Type C (combined loss).
Which Atwood stage describes a “knife-edge” ridge?
Stage 4.
In Lekholm & Zarb, what does Bone Quality “1” indicate?
Almost homogenous compact bone.
Name two patient-related factors affecting ridge atrophy management.
Smoking, poor oral hygiene, medical conditions (e.g., diabetes).
What defect-related factor determines graft selection?
Size/site of defect, hard/soft tissue involvement, inter-arch space.
Why are autografts considered the gold standard?
Live cells, no immune reaction, high success rates.
Name two intraoral autograft harvest sites.
Chin, lateral ramus, maxillary tuberosity.
What is the main disadvantage of autografts?
Donor site morbidity (secondary surgery).
How do allografts differ from xenografts?
Allografts: human cadavers; Xenografts: cross-species (e.g., bovine).
What is the role of hydroxyapatite in alloplasts?
Acts as a synthetic osteoconductive scaffold.
What are the three biological mechanisms of GBR?
Osteogenesis, osteoconduction, osteoinduction.
What is the success rate of GBR at 12.5 years?
0.93
What is the key disadvantage of GBR?
Membrane instability causing fibrous tissue formation.
When is the ridge split technique indicated?
Horizontal augmentation of narrow ridges (esthetic zone/posterior mandible).
Why is ridge split technique avoided in single-tooth defects?
Technically sensitive, risk of fracture.
Name two advantages of onlay bone grafts.
Addresses large horizontal/vertical defects, high graft survival.
What fixation method is used for onlay grafts?
Titanium mini-screws.
Which bone graft is harvested via “reverse Olympic sign”?
Chin graft.
What are the four phases of distraction osteogenesis?
Osteotomy, latency, activation, consolidation.
What is the purpose of perforating recipient site cortex in grafting?
Enhance vascularity for graft integration.
What are the two main sinus lift techniques?
Lateral window (open) vs. internal (closed) approach.
How does the tenting technique differ from traditional sinus lift?
Uses implants to elevate membrane without bone graft.
