Orthodontics · single question
On a cephalometric film, landmarks are labeled: A=9, ANS=10, B=11, N=12. Which pair gives the maxillomandibular jaw relationship?
Show answer and explanation
Correct answer: B. 9 and 11 (A and B)
- A. Points A and ANS are both maxillary landmarks — they do not compare the two jaws.
- B. Point A (subspinale, maxillary) and Point B (supramentale, mandibular) yield the ANB angle — the standard cephalometric measurement of the maxillomandibular (jaw-to-jaw) relationship. Normal ANB = 2°±2°.
- C. B and N describe the mandible-to-cranial base relationship (SNB), not maxilla-to-mandible.
- D. ANS-B is not a standard jaw relationship measurement.