Orthodontics · single question
A patient is missing tooth #19, and tooth #18 is mesialized. What would happen if a coil spring is used?
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Correct answer: C. Extrusion and distalization of #18
A coil spring applies force to reposition teeth. In this case, it would exert distal force on #18, causing distalization. Due to the angulation of the root and force application, extrusion (movement outward from the socket) may also occur. Proper orthodontic planning is essential to prevent unintended movements.