Bio of Tooth Movement

Question 1

How do teeth move

Answer 1

• Bone remodeling (apposition and resorption)
  
  • Mediated by PDL when force is applied at local sites
    
    • Fluid is displaced in PDL space
    • PDL compressed against bone
  • At local and distant sites
    
    • Teeth
    • Maxillary and mandibular condyle (growth sites
• Sustained force causes remodeling of adjacent bone

Question 2

Bioelectric Theory

Answer 2

• Light pressure on teeth leads to bending of alveolar bone
• Piezoelectric currents (movement of electrons in a crystalline structure) lead to bone regeneration if force is prolonged
• Signals are produced with onset and release of force only. No bone activity with sustained force
• Stress generated signals (bending of alveolar bone under function) important for maintaining bone around teeth
  
  • Vibrational application of pressure to produce stress generating signals to elicit tooth movement

Question 3

Pressure Tension Theory

Answer 3

• Diameter of blood vessels is increased (tension side) and reduced (pressure/compression side) when a force is felt within the PDL
• Blood flow is altered in the PDL Space
  
  • More blood flow on tension side (increase O2 Decrease CO2)
  • Less blood flow on compression side (dec O2, Increase CO2)
• Mechanical compression of tissue and changes in blood flow cause release of chemical messenger cAMP to elicit response