However, there are many factors
to be considered before interceptive
treatment can be done. A classic study
from Ericson and Kurol35 showed that
extraction of the primary canines
between the ages of 10 and 13 years
will obtain a favorable result with
most palatally erupted canines. If the
cusp tip of a permanent maxillary
canine in the panoramic radiograph
does not exceed the midline of the lateral
incisor, the chance of the canine
erupting normally is 91%; if the cusp
tip does exceed the midline of the lateral
incisor, the chance for normally
erupting drops to 64%.