Orthodontic Biomechanics Flashcards
7 cards from real ABO practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Orthodontic Biomechanics flashcards as text
Frontal (direct) bone resorption during tooth movement occurs when applied force is:
Answer: Light and preserves PDL vitality
Light forces maintain PDL vitality, allowing osteoclasts to resorb bone directly on the pressure side.
Undermining (indirect) resorption is associated with:
Answer: Hyalinization of the PDL from excessive force
Excessive force causes PDL hyalinization, and resorption proceeds indirectly from adjacent marrow spaces, delaying movement.
During tooth movement, cells responsible for bone formation on the tension side are:
Answer: Osteoblasts
On the tension side, stretched PDL fibers stimulate osteoblasts to deposit new bone.
A longer lag phase in the tooth-movement timeline is typically caused by:
Answer: Areas of hyalinization requiring undermining resorption
Hyalinized zones must be removed by undermining resorption before movement resumes, creating a lag phase.
Which structure primarily transmits orthodontic force signals into cellular bone remodeling?
Answer: The periodontal ligament
The PDL senses mechanical strain and mediates the biological remodeling of surrounding alveolar bone.
Root resorption during orthodontic treatment is most strongly linked to:
Answer: Heavy prolonged forces and excessive torque
Heavy, prolonged forces—especially with root torque—increase the risk of orthodontically induced root resorption.
The initial displacement of a tooth immediately after force application is due to:
Answer: Compression and viscoelastic response of the PDL
The first movement reflects PDL compression and fluid displacement before biologic remodeling begins.