little, slight, small
pained, painful (esp. AmE)
wry
facial

give (sb), make
She made a wry grimace.

twist into
His face twisted into a grimace.

twist sth
An ugly grimace twisted her face.

with a grimace
He acknowledged his mistake with a wry grimace.

grimace of
a grimace of disgust/pain

slightly
inwardly

at
He grimaced slightly at the pain.
She grimaced at him.

in, with
She grimaced in disgust.