The tooth visible outside is what we call the crown. Within the gums the tooth is attached to the jaw by the root. If the tooth was hit in the accident you mentioned then mostly the tooth will have hit the bone causing an infection to develop. This infection will not be visible on the outside but will usually present as a sharp pain whenever you bite down on the tooth.
Next Steps
Firstly get a pain killer from a nearby medical. Aceclofenac will work well or an ibuprofen - paracetamol will also work provided you are not an asthmatic . Secondly get a dental X-ray of the paining tooth and consult a dentist. Most probably it may require a root canal treatment for the infection to subside.
Health Tips
In case the tooth root is infected it will be best to attend to immediately otherwise the infection will fester and cause the tooth to literally die, causing surrounding bone destruction.