Free ABO MCQ Questions and Answers 2026 October
Free ABO MCQ Questions and Answers practice test with questions and answer explanations. 🗨️ Prepare for the 2026 October exam with instant scoring.

ABO Practice Test Questions
Prepare for the ABO - American Board of Orthodontics exam with our free practice test modules. Each quiz covers key topics to help you pass on your first try.
ABO Dentofacial Orthopedics
ABO Exam Questions covering ABO Dentofacial Orthopedics. Master ABO Test concepts for certification prep.
ABO Growth and Development
Free ABO Practice Test featuring ABO Growth and Development. Improve your ABO Exam score with mock test prep.
ABO Orthodontic Appliances and Mechanics
ABO Mock Exam on ABO Orthodontic Appliances and Mechanics. ABO Study Guide questions to pass on your first try.
ABO Periodontics and Interdisciplinary Tre...
ABO Test Prep for ABO Periodontics and Interdisciplinary Treatment. Practice ABO Quiz questions and boost your score.
ABO Retention and Stability
ABO Questions and Answers on ABO Retention and Stability. Free ABO practice for exam readiness.
ABO Orthodontic Biomechanics
ABO Mock Test covering Orthodontic Biomechanics. Online ABO Test practice with instant feedback.
ABO Orthodontic Diagnosis and Treatment Pl...
Free ABO Quiz on Orthodontic Diagnosis and Treatment Planning. ABO Exam prep questions with detailed explanations.
Sample American Board of Orthodontics (ABO) Practice Questions
Try these questions from our free American Board of Orthodontics (ABO) practice tests. The correct answer and an explanation follow each question.
Cervical vertebral maturation (CVM) stage CS3 indicates:
- A. Pre-adolescent growth; no pubertal peak yet
- B. Approximately 1 year before the pubertal growth peak
- C. The peak of the pubertal growth spurt
- D. Post-pubertal; growth is nearly complete
Answer: C. The peak of the pubertal growth spurt
CVM stage CS3, characterized by concavities on the lower borders of C2 and C3, corresponds to the onset and peak of the pubertal growth spurt.
The Wits appraisal is measured by projecting points A and B onto which plane?
- A. Frankfort horizontal plane
- B. Functional occlusal plane
- C. Mandibular plane
- D. Palatal plane
Answer: B. Functional occlusal plane
The Wits appraisal drops perpendiculars from points A and B onto the functional occlusal plane.
What factors are considered when deciding between extraction and non-extraction orthodontic treatment?
- A. Crowding severity, facial profile, lip position, skeletal pattern, age, and anchorage requirements
- B. Only the patient's preference
- C. Cost of treatment only
- D. The orthodontist's schedule
Answer: A. Crowding severity, facial profile, lip position, skeletal pattern, age, and anchorage requirements
Extraction decisions consider arch length discrepancy, facial profile and lip position, skeletal pattern, growth potential, anchorage requirements, periodontal status, and treatment objectives.
What is the discrepancy index in ABO case assessment?
- A. A scoring system measuring the complexity of a malocclusion based on multiple criteria including overjet, overbite, crowding, and skeletal pattern
- B. The difference between estimated and actual treatment time
- C. A measure of patient satisfaction
- D. The gap between upper and lower teeth
Answer: A. A scoring system measuring the complexity of a malocclusion based on multiple criteria including overjet, overbite, crowding, and skeletal pattern
The ABO Discrepancy Index quantifies malocclusion complexity by scoring criteria including overjet, overbite, anterior open bite, crowding, occlusal relationships, lingual posterior crossbite, and cephalometric measurements.
Take the full American Board of Orthodontics (ABO) practice test
About the Author

Dentist & Dental Licensing Exam Specialist
University of Michigan School of DentistryDr. Patricia Chen is a licensed dentist with a DDS and a Master of Science in Periodontics from the University of Michigan School of Dentistry. She has 14 years of clinical practice and academic instruction experience, specializing in helping dental school graduates prepare for the NBDE, INBDE, regional clinical boards, and dental hygiene licensure examinations.
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