occlusal surface of tooth

The occlusal surface of a tooth is the chewing surface of the premolar and molar teeth. It is the flat or ridged surface that contacts the opposing teeth during biting and chewing. This surface bears the cusps, fissures, pits, and ridges that are characteristic of each tooth type and that function together to break down food.

The occlusal surface is located on the coronal portion of posterior teeth—premolars and molars—facing the opposing arch. In the upper dentition, it faces downward; in the lower dentition, it faces upward. This surface is the most superior aspect of lower posterior teeth and the most inferior aspect of upper posterior teeth when viewed from the biting perspective.

The occlusal surface is involved in the mechanical breakdown of food during mastication. Its cusps and ridges are designed to chew and grind food particles, increasing the surface area for enzymatic digestion. The interdigitation of upper and lower occlusal surfaces during biting provides the force needed to fracture food items of varying hardness.

Dental caries (tooth decay) may initiate in the pits and fissures of the occlusal surface, as these areas can trap plaque and food debris. Bruxism (teeth grinding) may be associated with attrition—the wearing away of the occlusal surface enamel and dentine. Malocclusion may be associated with abnormal wear patterns or uneven loading of occlusal surfaces.

The occlusal surface is examined clinically by visual inspection using a dental mirror and probe under good illumination. Tactile exploration with a sharp probe assesses pit and fissure integrity. Dental radiographs can reveal interproximal caries extending toward the occlusal surface. Digital photography and intraoral scanners document surface morphology and wear patterns.