A patient presents with a convex profile, competent lip closure and a deviated nose. All of the following are true of this facial pattern EXCEPT one. Which is the EXCEPTION?

Correct answer: C. The nasolabial angle is straight

• A. This IS true and is given in the case. Competent lips meet at rest without strain — the significant finding in a convex profile, because it distinguishes a purely skeletal pattern from one with soft-tissue strain and a hyperactive mentalis.
• B. This IS true and is given in the case: a convex profile indicates a skeletal Class II tendency, from maxillary protrusion, mandibular retrusion, or both.
• C. CORRECT — this is the EXCEPTION. A 'STRAIGHT' NASOLABIAL ANGLE is not a valid descriptor: the nasolabial angle is the angle between the columella of the nose and the upper lip, and it is described as normal (roughly 90–110°), acute (obtuse maxillary protrusion) or obtuse (maxillary retrusion) — never 'straight'. In a convex profile with maxillary protrusion the angle is characteristically ACUTE.
• D. This IS true and is given in the case. Nasal deviation is a component of facial ASYMMETRY and is recorded in the frontal analysis.

Note: The orthodontic facial examination separates into the FRONTAL analysis (symmetry, facial thirds, transverse widths, midlines, smile arc, incisal display) and the PROFILE analysis (convexity, nasolabial angle, lip position to the E-line, chin projection, mandibular plane angle, lip competence).