Bruxism is not part of normal chewing movement and is not a healthy action. It can lead to excessive wear on teeth and nerve exposure, leading to permanent damage to teeth and the jaw joint. Clenching and grinding may occur during the day or night. During sleep, you have no conscious control over the abnormal movements.
Three major muscle groups are associated with bruxism. These include the temporalis and masseter muscles, which close the jaw; and the lateral pterygoid muscles, which move the jaw side to side. Accessory muscles of the neck may also be involved, leading to head and neck aches, especially in the morning.