When yawning, if there is a jaw rattle, this situation is mainly due to two reasons: First, there is a degeneration of the temporomandibular joint area, osteoarthritis, there will be abnormal friction of the cartilage of the temporomandibular joint area when yawning, which usually triggers the appearance of the rattle; Second, see the case of temporomandibular arthritis, related to the injury and degeneration of the temporomandibular joint area, it will lead to the temporomandibular area has This can lead to significant cartilage degeneration and spasm of the surrounding ligaments and joint capsule, which can cause abnormal friction inside the joint when yawning and opening the mouth, thus causing a rattling sound, and can seriously lead to significant pain in the jaw area and difficulty in opening the mouth.