Acute Neck sprain/spasm in 2yr 9mnth kid

Hi last evening I was trying to apply candid mouth paint in my toddler's mouth while she was being very difficult, refused to cooperate.I applied pressure on the side of her cheeks just to get her to open her mouth, but she started to throw her head vigorously from side to side while lying on the bed refusing to cooperate.I stopped trying to apply the mouth paint as it was pointless However my toddler almost instantly started to cry badly when she got up n said pain in ear.Actually she started to experience pain in right side of her neck ,the place where the ear meets the jaw.immediately rushed her to the doctor fearing she could have got injured.The doctor checked her n mentioned it's a spasm of the muscles and put her on ibugesic 5ml three times a day, Phenergan 5ml if pain is severe at night n goldbar gel I'm worried n paranoid cos she's still unable to lie down n can't move her neck to the right.I want to know if I should ask for an X-ray n if this is common wth kids under 3yrs