Patient-friendly definition from the DentistsDirectory.org dental glossary.
Occlusion refers to the contact relationship between the upper and lower teeth when the jaw closes or during chewing movements. In its most basic sense, it simply means "how your teeth bite together." In dentistry, occlusion is a central concept because the way teeth contact each other directly affects the distribution of forces through the teeth, jaw joints, and muscles of the face — with implications for everything from tooth wear to headaches.
In ideal occlusion, each upper tooth contacts the corresponding lower teeth in a specific, biomechanically favourable pattern that distributes chewing forces evenly and guides the jaw smoothly through all movements. When occlusion deviates significantly from this ideal — whether due to malocclusion, missing teeth, poorly fitted restorations, or worn teeth — certain teeth or regions bear disproportionate force. This can lead to accelerated wear on specific teeth, sensitivity, cracking, and strain on the temporomandibular joint and jaw muscles, sometimes manifesting as pain, clicking, or headaches.
Virtually every dental restoration affects occlusion and must be carefully designed to harmonise with it. A crown or filling that sits even slightly too high (creating what dentists call a "high bite") puts excessive force on that tooth and the opposing tooth with every bite. Your dentist will use articulating paper — carbon paper that marks where the teeth contact — to verify the bite after every restoration. Major restorative work, orthodontics, and TMJ treatment all require careful occlusal analysis. If you experience pain after a new crown or filling, a bite adjustment is usually a quick in-office fix.