HOSA Dental Terminology Test 2026 – 400 Free Practice Questions to Pass the Exam

A cleft lip refers to a congenital condition characterized by an opening or gap in the upper lip that results from incomplete fusion during fetal development. This condition can range from a small notch in the lip to a significant opening that extends up into the nose. The development of a cleft lip occurs when the tissues that form the lip do not fully come together, which typically happens in the early stages of pregnancy.

The other options address different conditions or structures. A gap in the lower lip is not recognized as cleft lip but could refer to an entirely different type of lip defect. The separation of palate structures pertains specifically to cleft palate, which is a distinct condition that affects the roof of the mouth, whereas full closure of the lip would indicate a normal anatomical structure without any pathological opening. Thus, the defining characteristic of cleft lip is specifically the gap or opening in the upper lip due to developmental anomalies.