IMPORTANCE OF CONE BEAM CT

Why CBCT? (3)

Provides desired diagnostic yield

Low pt risk (lower than MDCT)

Low cost (lower than MDCT)

Pans and PA radiography are useful for what

Initial and post op assessment

T or F:

CBCTs should be used routinely as post op assessment

CBCT is the modality of choice for presurgical implant planning

F - should NOT

T

Imaging protocol for CBCT should include what

Smallest field of view necessary

What are the four components of CBCT image acquisition

X ray generation

Image detection system

Image reconstruction

Image display

What are the two principles of CBCT

X ray source and detector move synchronously

X ray beam is usually pulsed to reduce exposure

What are the three planes of CBCT

Axial (up and down)

Coronal (back to front)

Sagittal (side to side)

What are the appropriate field of view (FOV) mainly used for implants

S(50x50)

S + (50x100)

M (80x100)

Large FOV (>15 cm) is used for what four things

Ortho

Surgery

Pathology

TMJ

Medium FOV (10-15cm) is used for what two things

General dx

Guided surgery

Small FOV (4-10cm) is used for what three things

Single implant

Endo

Periodontology

Most important source of image degredation for CBCT scans

Patient motion

Likely hood of patient movement is inversely related to what

Stability

What are the three patient positions?

Which is traditional dental model?

Medical model?

Which has largest footprint

Standing - dental model

Seated

Supine - medical model (larger footprint)

Rank standing, seated and supine in terms of stability

Most = Supine

Middle = Seated

Least = Standing

Indications for CBCT (6)

Implant planning

Endo

Ortho planning

OS cases

Pathology

TMJ

Stochastic Effects:

Main effect:

Risk is proportional to what?

Threshold dose?

Severity is ______ of dose

Cancer

Dose

NO

Independent

Deterministic effects:

Includes (3)

Threshold dose?

Severity is proportional to what

Utero birth defects, skin erythema, cataracts

Yes

Dose

Primary role of CBCT

Full knowledge of oral-bone anatomy and detection of hidden/subte pathologies

What area of the dental alveolas has the most complexities?

Maxillary anterior (esthetic zone)

What region of dental alveolus has the highest implant failure rate?

Why?

Maxillary posterior

Lowest bone density