The same model conceals new facial twitch (9)
I believe the answer is:
identical
'the same' is the definition.
(thesaurus)
'model conceals new facial twitch' is the wordplay.
'model' becomes 'ideal' (ideal is a kind of model**).
'conceals' is an insertion indicator.
'new' becomes 'n'.
'facial twitch' becomes 'tic' (I've seen this before).
'n'+'tic'='ntic'
'ideal' placed around 'ntic' is 'IDENTICAL'.
(Other definitions for identical that I've seen before include "Exactly alike, the same in every detail" , "lacking distinction" , "Aid client to be the very same" , "uniform" , "Duplicate" .)