Young man trumpeted about his head having incisive issues (4-7)

'having incisive issues' is the definition.
I can't judge whether this definition defines the answer.

'young man trumpeted about his head' is the wordplay.
'young man' becomes 'buck' (old-fashioned term for a young man).
'trumpeted' becomes 'tooted' (I can't explain this - if you can you should believe this answer much more).
'about' is an insertion indicator.
'head' indicates taking the first letters.
The initial letter of 'his' is 'h'.
'tooted' placed around 'h' is 'toothed'.
'buck'+'toothed'='BUCK-TOOTHED'

Can you help me to learn more?