Could an ear infection be the cause of locking jaw, congestion, and a toothache?

Tmd or tmj dysfuncti. Tmj dysfunction can often manifest in similar ways . The symptoms can include an itchy feeling in the ear to painful symptoms in the ear due to clenching and or grinding. The large muscle in front of the ear that is responsible for chewing and clenching can become tender due to overuse. If you touch the muscle body it can be painful and may radiate into the jaw or temples. Locking can occur.
See OFP doctor. Orofacial Pain provides diagnosis and management of pain in the face, TMJ disorders, locking jaw as well as, associated headaches and neck pain. They are the experts in this field. Good luck.
NO. No. Likely a TMJ problem. See oral surgeon or ENT doc for confirmation. If TMJ, see TMJ-orofacial pain expert.