A bushier top - means more stems ... with more stem tips, you will see more flowers ...
to get more stems, need to "encourage" new growth
Cutting out, or pruning off stems on adenium encourages 1, to 5 new shoots to form just below the pruning cut ..
Use a pair of pruning shears - or razor blade to make the cuts - adenium stems are soft, and easy to cut through (don't use a saw)
Try to keep the exposed cut as dry as possible, or until it hardens over
It may take several weeks for new stems to appear .... but once established, new stems will take off
Be patient - adeniums seem to take forever to respond to changes
These initial cuts will heal over in 3-to-5 years -
Have made a copy of one of your pictures and added drawn lines of where I might make the cuts ....
where you make the cuts is up to you