# If the permanent canines are lost prematurely, the permanent incisors may drift:
A. Labially
B. Distally
C. Medially
D. Lingually
The correct answer is B. Distally.
When a primary first molar or canine is lost prematurely, there is also a tendency for the space to close. This occurs primarily by distal drift of incisors, not by mesial drift of posterior teeth. The impetus for distal drift appears to have two sources: force from active contraction of transseptal fibers in the gingiva, and pressures from the lips and cheeks.
Reference: Contemporary Orthodontics, 4th Edition, Profitt, Page no. 140
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