Occlusion refers to the relationship between the upper and lower teeth and how they come together. When the teeth bite in an ideal position, this lessens the stress on the periodontium, or the supporting structures around the teeth or the TMJ (temporomandibular joint), which guides and allows the movement of your lower jaw, and the muscles of mastication that support the jaws during any kind of movement.
Occlusal adjustment is when the dentist deliberately grinds down certain areas on the biting surface of your teeth with a drill to help the teeth bite in a more ideal position. This helps to distribute pressure evenly across the dentition, reducing the likelihood of TMJ disorders, localized periodontal disease, pain in the muscles of mastication, and uneven unintentional wearing of the teeth. The dentist may recommend a protective mouthguard for you to wear at night to keep your teeth protected from wear and to relax the jaw muscles.