Orthodontics · single question
When performing orthodontic extrusion of a tooth, what is the MOST important clinical feature to evaluate?
Show answer and explanation
Correct answer: D. Crown-to-root ratio
Crown-to-root ratio is the primary concern during orthodontic extrusion because the procedure shortens the root's bony support while lengthening the clinical crown.
- A. Overjet is an orthodontic measurement not directly related to the safety of extrusion procedures.
- B. Interproximal contacts may need management post-extrusion but are not the primary evaluative concern.
- C. Overbite is important in occlusal analysis but is not the primary concern during extrusion.
- D. CORRECT. Crown-to-root ratio is the most critical factor. Orthodontic extrusion reduces alveolar bone support, increasing the clinical crown. If the ratio becomes unfavorable (<1:1), the tooth's long-term prognosis is severely compromised.