A deep overbite or deep bite occurs when the lower incisor (front) teeth bite too close or into the gum tissue behind the upper front teeth. When the lower front teeth bite into the palate or gum tissue behind the upper front teeth, significant bone damage and discomfort can occur.
A deep bite can also contribute to excessive wear of the incisor teeth, as well as headaches and often TMJ problems because the jaw joints are forced too far back into the sockets (against the middle ear) and the auriculotemporal nerves. This causes the disks to become displaced forward of their normal positions over the tops of the jaw joints, which can result in jaw joint noises. The patient will try to avoid the nerve by thrusting the lower jaw forward off of the disk until the front teeth are edge-to-edge.
If they are under stress, the patient will grind (brux) their teeth when they are edge-to-edge during the night, causing excessive stretching and overloading of the jaw muscles, the teeth, and the jaw joints. This latter situation can cause severe pain, frontal headaches, eye pain, sinus pain, excessive and abnormal wear on the biting (incisal) edges of the front teeth, as well as excessive wear and flattening of the jaw joints, referred to as osteoarthritic degeneration.