Dental Assistant Practice Exam

What is the term for a small liner depression on the surface of a tooth?

1. Fossa

2. Groove

3. Cusp

4. Fracture

The correct answer is: Groove

The correct term for a small liner depression on the surface of a tooth is a fossa. A fossa refers to a small, shallow depression or pit on a tooth, typically found on the occlusal surface of molars and premolars. These depressions can help in the chewing process by allowing the tooth to interdigitate with opposing teeth and contributing to the overall occlusion. Grooves, while they may also represent linear indentations on the tooth's surface, are deeper and typically run along the length of the tooth, serving as pathways for the dental roots or facilitating movement of food during chewing. They aren't classified as small depressions but rather as more pronounced linear features. Cusps are the pointed or elevated portions of a tooth that help in slicing or grinding food. They are more about the shape and function of the tooth surfaces rather than existing as depressions. Fractures refer to breaks or cracks in the tooth structure, which indicates damage rather than a natural anatomical feature. Thus, a fossa correctly identifies the small liner depression in tooth anatomy.