The pterygoid can close the jaw and pull it sideways.

The medial pterygoid can close the jaw it sideways .

Explanation:

The medial pterygoid muscle, is square - shaped muscle which is present on both the sides of the inner jaw.  

The location of medial pterygoid muscle is in inner of the lateral pterygoid muscle , it is closer to mid - line of the human body.  

The function of these muscle is to open , close the mouth , move lower jaw side - to - side.

Hence the answer is -

The medial pterygoid can close the jaw it sideways .