Which nasal structure lies at the profile's right angle to the upper lip?

• A. Ala nasi
• B. Dorsum nasi
• C. Columna Nasi
• D. Septum

Answer: (C)

Understanding how the upper lip meets the nose in profile comes down to the nasolabial angle, formed at the junction of the columella and the upper lip. The Columna Nasi sits at that boundary and defines the right-angle relationship with the upper lip when this angle is around 90 degrees. The other nasal structures don’t form this boundary: the ala nasi are the side walls of the nostrils, the dorsum nasi is the nasal bridge along the top, and the septum is the internal partition. So the structure that lies at the profile’s right angle to the upper lip is Columna Nasi.