What is the most common facial anomaly presenting as a defect of the upper lip?

• A. Facial cleft
• B. Cleft palate
• C. Cleft lip with palate
• D. Macrostomia

Answer: (A)

The most common presentation of an upper lip defect is a cleft lip, a type of facial cleft. This occurs when the facial prominences that form the upper lip fail to fuse properly during early development, usually between weeks 4 and 7 of gestation. The result is a gap in the upper lip that can be on one side (unilateral) or both sides (bilateral) and can occur with or without involvement of the palate. The reason this best fits the question is that it specifically describes the lip defect; a palate-only cleft affects the palate rather than the lip, a cleft lip with palate includes both lip and palate but centers on the lip defect for the presentation, and macrostomia is an abnormally wide mouth, which is not the typical upper lip defect. A facial cleft is a broader term that can include various craniofacial clefts, but the upper lip-specific anomaly is cleft lip.