An 11-year-old child presents with wide spaces between mandibular second premolars and permanent first molars. These spaces are typical of
A) Mesial step
B) Distal step
C) Leeway space
D) Flush terminal plane

Question

Quizplus · Accepted Answer

Leeway spaces literally provide leeway, or additional space, between the deciduous canines and the first molars. In an arch that is not fully grown, leeway spaces allow an extra margin of space for the eruption of the permanent canine and the premolars. It is typical to see leeway spaces in an 11-year-old child. Note that leeway spaces also exist between the first and second molars. Mesial step, closely related to leeway spaces, is the chain reaction that occurs as the permanent molars close spaces by pushing against deciduous molars. In mesial step the mandibular molars are situated more mesially than their maxillary counterparts, thereby forming a mesial step. In a distal step the mandibular molars are situated more distally than their maxillary counterparts. In flush terminal plane the distal surfaces of the deciduous molars are even with each other.

An 11-Year-Old Child Presents with Wide Spaces Between Mandibular Second