Although only over half the patients had FPMs extracted at the "ideal time", this did not appear to influence successful positioning of the upper or lower SPM. More research is required to investigate and confirm which predictive parameters have a significant effect on post-extraction orthodontic development, especially in the lower arch.

ICDAS should be the index of choice when detecting and assessing occlusal caries in the primary dentition, and in vitro data can be safely extrapolated in vivo. The DIAGNOdent pen must be employed with caution. Currently, the CarieScan PRO is unsuitable for use in the primary dentition.

Apart from extraction timing of the FPM, consideration must also be given to the presence of the third permanent molar and angulation of the SPM in order to ensure a reliable degree of spontaneous space closure of the lower SPM.