ABO Study Guide 2026
Everything you need to pass the ABO exam in one place: the exam format, every topic to study, real practice questions with explanations, flashcards, and full-length practice tests. Free, no sign-up needed.
📋 ABO Exam Format at a Glance
📚 ABO Topics to Study (38)
✍️ Sample ABO Questions & Answers
1. Root resorption during orthodontic treatment is most commonly detected using:
Periapical radiographs reveal root length changes due to resorption, and CBCT provides three-dimensional detail of root morphology and resorption extent.
2. Which of the following is a primary indication for extraction in orthodontic treatment planning?
Severe crowding combined with dental protrusion often requires extraction to relieve the discrepancy.
3. The cephalometric landmark Articulare (Ar) is located at the intersection of which anatomical structures?
Articulare is defined as the intersection of the posterior border of the mandibular ramus (or condylar neck) with the inferior border of the cranial base, used when the condyle is not well visualized.
4. Which record is essential for evaluating the transverse dimension and posterior crossbite?
A posteroanterior cephalogram and study models assess transverse width and posterior crossbites.
5. Frictionless (loop) mechanics differ from sliding mechanics because they:
Loop mechanics activate bends/loops to move teeth without the tooth sliding along the archwire, avoiding friction.
6. Placing a reverse curve of Spee in the lower archwire is intended to:
A reverse curve of Spee creates intrusive forces on the anteriors and molars while extruding the premolars to level a deep curve of Spee.