treatment, as proclining the upper incisors is a form of expansion which itself creates
more space.
Clearly, where active orthodontic treatment is planned the loss of a lower first molar
is not automatically compensated by the extraction of the opposing upper first molar.
The broad principles of the management of enforced extraction of first molars are
summarized in 912HTable 14.3.
913H
Fig. 14.5 Spaces between the lower first and second premolars resulting from very
early extraction of the lower first molars.
914H
Fig. 14.6 (a) and (b) Loss of the lower first molar after eruption of the second molars
causes severe tipping of the lower second molar and overeruption of the upper first
molar.
915H
Fig. 14.7 (a) and (b) Extraction of the upper first molar as well as the lower prevents