Tooth #9 was intruded 3 mm and will be orthodontically extruded. What should be carefully considered?

Orthodontic extrusion decreases the root within bone while increasing the clinical crown length, thereby worsening the crown-to-root ratio. A final ratio of 1:1 or better is needed for long-term prognosis. If the ratio becomes unfavorable, surgical crown lengthening or extraction and implant may be required.