You answered it. Bruise! A bruise can take some time to develop and eventually does develop. The are can become tender and swollen then eventually hut when moved. If you gums star to swell, please consult your doctor!
Hi!
If there is jaw pain on opening your mouth, it could just be the trauma causing a temporomandibular joint disorder. To get some relief you can try massaging the sore muscles. You have to press on muscles of your face to look for sore points. Then massage these points with short strokes. To massage the masseter muscles on each side of your jaw, place your thumb inside your mouth and squeeze the thick muscle in your cheek with your fingers. To massage the jaw muscles inside your mouth, use your index finger to probe and massage these spots. Massaging the muscles does not help every one. Also if the procedure is nor correct, then it can further aggravate the problem.
Moist heat or cold packs on the face, vitamin supplements, or biofeedback are useful for some people. Usually people find a method that brings relief by trial and error. Also taking a mild pain killer for a day or two may help. Consult an ENT specialist if you do not get relief in a day or two. Take care!
The medical advice given should not be considered a substitute for medical care provided by a doctor who can examine you. The advice may not be completely correct for you as the doctor cannot examine you and does not know your complete medical history. Hence this reply to your post should only be considered as a guiding line and you must consult your doctor at the earliest for your medical problem.