Question

Mild crowding of the permanent mandibular incisors may resolve after the age of 10 for which of the following reasons?A. The permanent mandibular incisors are only slightly larger in size than the primary mandibular incisors. Normal growth of the anterior region of the mandible provides more than adequate room for the permanent incisors by the age of 12.B. The presence of primate space distal to the mandibular canines allows space for the mandibular canines to move distally, creating more room for the mandibular incisors and alleviating mild crowding problems.C. The tongue will force the permanent incisors facially, creating adequate room to resolve any problems of crowding.D. It is not possible for even mild crowding of the permanent mandibular anterior teeth to resolve at this time because adequate growth of the anterior region of the mandible has not occurred.

Answer 1

The correct answer is B. The presence of primate space distal to the mandibular canines allows space for the mandibular canines to move distally, creating more room for the mandibular incisors and alleviating mild crowding problems. Primate space is the space between the primary and permanent mandibular canines. As the permanent mandibular canines erupt, they displace the primary canines distally, creating more space for the permanent mandibular incisors and resolving the mild crowding.

A is incorrect because the size of the permanent mandibular incisors is only slightly larger than the primary mandibular incisors, so normal growth of the anterior region of the mandible is not enough to provide adequate room for the permanent incisors by the age of 12.

C is incorrect because the tongue does not force the permanent incisors facially, but instead can cause them to be pushed distally.

D is incorrect because mild crowding of the permanent mandibular anterior teeth can resolve at this time due to the presence of primate space.