Good Morning lybrate-user
Thanks for the query
As per your words it seems you are not able to open the mouth
post surgery, it can be because of trauma or infection
in that area.
Need not to worry ,For the same you yourself can do the exercises by forcefully opening and closing your mouth.
Under your Dentist
supervising you can take Mussle relaxtant tabelts also.
Do Hot Fermentation and warm saline gargles.