Oracle Database Discussions

According to my information truncate command by default will release all the allocated space for the truncated table and delete its contains as well ,that means it will deallocate all it's extents .But with truncate table_name reuse ,it will delete all the data in this table but it will not release it's extents ,they can by used again by this table .My question is when I queried dba_segment view for this table in both cases it return some extents still allocated even after truncate table_name drop command .

Can someone clear it up for me?

Thanks in advance.