Orthodontics · single question
What is the orthodontic force magnitude recommended for forced (surgical) extrusion of a tooth?
Show answer and explanation
Correct answer: B. 1 mm per month
1 mm per month is the recommended rate for orthodontic/forced extrusion. This controlled slow rate allows bone and soft tissue to follow the tooth as it extrudes, preventing ankylosis and maintaining periodontal support. Faster extrusion rates risk bone loss and tissue complications. This rate applies to both orthodontic extrusion (for biologic width establishment before crown) and forced eruption of impacted teeth.
- A. ❌ 3 mm per month would cause the tooth to outpace bone remodeling, resulting in inadequate bony support.
- B. ✅ CORRECT – 1 mm per month is the recommended rate for orthodontic/forced tooth extrusion.
- C. ❌ 0.5 mm per month is too slow and not the standard recommendation.
- D. ❌ 2 mm per month is too rapid and risks losing the bony support that should follow the tooth.