Effect of serial extraction alone on crowding: relationship between closure of residual extraction space and changes in dentition

Mandibular dentitions from 33 subjects who had undergone serial extraction without appliances were analyzed at three stages: before extraction of deciduous canines (T1), after extraction of first premolars (T2), and at the end of the observation (T3). It was suggest that the mesial movement or tipping of the second premolars was associated with most of the space closure from T2 to T3, although the distal movement or tipping of canines might also contribute space closure.