If you're experiencing the sensation that your teeth are moving when you bite down, it can be quite concerning. Several factors could contribute to this sensation, including:   - Mouth or jaw trauma - A previous mouth or jaw injury can compromise the stability of your teeth, giving the impression that they are moving when you bite. - Teeth clenching or grinding - Persistently clenching or grinding your teeth, often while you're asleep or under stress, can cause tooth looseness and discomfort. - TMJ dysfunction - Problems with the TMJ, which is a joint connecting your jaw to your skull, can lead to jaw misalignment and instability. This instability can cause a shifting sensation when you bite down. - Periodontal disease - Severe gum disease can cause bone loss and gum recession, which makes your teeth feel looser and more mobile.