Why is my jaw locking daily?

TMJ problem. This is due to dysfunction of the temporal mandibular joint just below the ear. The cartilage catches on the other side of the joint and clicks as the joint moves. Sometimes the cartilage catches the other side and the jaw locks. If this starts to happen, do not try to close the morth - but keep it open, rock the joint from side to side and yawn and usually the jaw will snap into place.
Disk displacemunt. Advanced jaw joint (TMJ) dysfunction in which the cartilagenous disk between the upper and lower bones has become displaced. Ask your Dentist to evaluate your occlusion. Orthodontic treatment may be helpful. If damage intractable, Oral Surgeon may be required.
Jaw joint idisk. Jaw joint disk likely out of position. Advanced problem with joint. May totally lock with increased pain and dysfunction. See TMJ expert for advice. Any dentist can be a TMJ expert with the proper training and experience. Most commonly, oral surgeons, prosthodontists, and orofacial pain specialists. Ask your MD, your dentist and your dental society for referrals.
Very possible. Your jaw may be locked, which means that the articular disk that joins the upper and lower jaws (maxilla and mandible,) may be out of place. It may be displaced forward and does not allow the mandible to get back to its comfortable position and the lower teeth therefore do not come together.
TMJ Disorder. Although it is not the most common of TMJ problems, jaw locking daily is very frightening for those who have it. I do think that seeing your dentist or orthodontist, is the next best step.