ABP ABP Occlusion and Biomechanics 2 — Questions and Answers
Question 1: Which tooth movement pattern places the greatest lateral stress on the periodontium, predisposing to angular bone defects?
- Pure intrusive axial loading
- Lateral/tipping forces creating tension and pressure zones (Correct answer)
- Rotational forces around the tooth's long axis
- Extrusive vertical forces from occlusal contacts
Correct answer: Lateral/tipping forces creating tension and pressure zones
Lateral and tipping forces create alternating zones of tension and pressure within the PDL, leading to angular (infrabony) bone loss patterns when combined with inflammation.
Question 2: In the concept of 'jiggling' occlusal forces, how does this type of loading affect a periodontally compromised tooth?
- Stimulates bone regeneration through piezoelectric effect
- Causes irreversible tooth mobility and accelerated bone loss (Correct answer)
- Has no clinical significance in treated periodontitis
- Promotes PDL fiber realignment and stability
Correct answer: Causes irreversible tooth mobility and accelerated bone loss
Jiggling forces (alternating pressures from multiple directions) on a compromised periodontium cause progressive bone resorption and increasing mobility that does not resolve without intervention.
Question 3: What is the primary purpose of occlusal splint therapy prior to definitive periodontal treatment?
- Permanently redistribute occlusal forces to reduce bone loss
- Diagnose and stabilize occlusal relationships before irreversible treatment (Correct answer)
- Replace missing teeth during healing phases
- Provide antibiotic depot delivery to the periodontium
Correct answer: Diagnose and stabilize occlusal relationships before irreversible treatment
Occlusal splints allow clinicians to diagnose centric relation discrepancies and distribute forces evenly before committing to irreversible occlusal adjustments or restorations.
Question 4: Bruxism is considered a risk factor in periodontal prognosis primarily because it does which of the following?
- Directly causes periodontal pocket deepening through tissue trauma
- Increases parafunctional forces that can accelerate bone loss in inflamed tissues (Correct answer)
- Prevents adequate plaque control by causing tooth wear
- Initiates inflammatory cytokine release independent of bacteria
Correct answer: Increases parafunctional forces that can accelerate bone loss in inflamed tissues
Bruxism generates excessive parafunctional forces that, when superimposed on inflamed periodontal tissues, can significantly accelerate alveolar bone destruction.
Question 5: When evaluating furcation involvement radiographically, which projection provides the most accurate view of mandibular molar furcations?
- Standard periapical with parallel technique
- Bitewing radiograph
- Panoramic radiograph
- CBCT cross-sectional view (Correct answer)
Correct answer: CBCT cross-sectional view
CBCT provides three-dimensional visualization of furcation morphology and bone levels that cannot be accurately assessed with two-dimensional conventional radiographs.
Question 6: The Glickman co-destruction theory proposes that occlusal trauma affects the 'zone of irritation' by doing which of the following?
- Eliminating bacterial plaque through increased crevicular fluid flow
- Altering the pathway of inflammation extension from the gingiva into the supporting bone (Correct answer)
- Creating a physical barrier preventing apical migration of the junctional epithelium
- Causing direct mechanical tearing of the gingival fiber apparatus
Correct answer: Altering the pathway of inflammation extension from the gingiva into the supporting bone
Glickman proposed that occlusal trauma alters the transseptal fiber pathway so that gingival inflammation extends through vascular channels into the alveolar crest, creating angular bone defects.
ABP ABP Occlusion and Biomechanics 2
Which tooth movement pattern places the greatest lateral stress on the periodontium, predisposing to angular bone defects?