[The second primary molar in the lower jaw in cases of agenesis of the second premolar; use it or break it?].

In cases of agenesis of the mandibular second premolar, a choice can be made from among several treatment options. Besides preserving the second primary molar, it can be decided to close the diastema orthodontically, following extraction of the primary molar. This can be done in several ways: full or partial (hemisection) removal of the primary molar. The procedure for a hemisection initially consists of removing only the distal part of the relevant primary molar, in order to preserve the breadth of the alveolar process and to enable spontaneous mesialization of the first permanent molar. Secondly, the mesial part of the primary molar is removed.