Question Submission for Written Exam
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The ABO Written Examination is a comprehensive exam that assesses the examinee's knowledge of basic sciences and clinical concepts. It is administered only at computerized testing centers throughout the United States, U.S. Territories and Canada.

The written examination is available to any educationally qualified practicing orthodontist who has never taken the written exam or was unsuccessful on a prior written exam. Residents in an orthodontic program accredited by the Commission on Dental Accreditation (CODA) may take the written exam in the year of their graduation or if they have completed 18 months of their program at the time of the exam.

There is no time limitation nor expiration date for the written examination. In other words, a successfully completed written examination will never need to be retaken. Anyone who has successfully completed the written examination is eligible for the ABO Clinical Examination.

The written examination consists of 240 multiple-choice questions related to the basic sciences, applied biomedical sciences, orthodontic theory, orthodontic practice, related dental disciplines and orthodontic literature. Questions are developed from the recommended reading list and referenced journals, textbooks and clinical case reports. Questions are also submitted from educators and residents across the country. To that extent, the ABO has provided an entry page for question submission on this website. All questions are refined by the ABO Written Examination Committee and added to a question bank.

The examination is based on subject areas outlined by CODA and includes the following subjects:

  1. Embryology and Genetics
  2. Growth and Development
  3. Head and Neck Anatomy
  4. Histology
  5. Oral Physiology and Biochemistry
  6. Pathology
  7. Research Methodology and Biostatistics
  8. Adjunctive Orthodontic Procedures as related to integrated disciplines
  9. Biomechanical Principles
  10. Cephalometrics and Radiography
  11. Clinical Orthodontics (adults and children)
  12. Clinical Photography
  13. Craniofacial Deformities
  14. Dentofacial Orthopedics
  15. Infection and Hazard Control
  16. Interdisciplinary Comprehensive Care
  17. Risk Management
  18. Literature Review
  19. Principles of Occlusion
  20. Orthodontic and Orthopedic Appliance Design
  21. Orthodontic Dental Materials
  22. Orthodontic Diagnosis and Treatment Planning
  23. Orthodontic Technique
  24. Radiographic and Imaging Techniques
  25. Surgical Orthodontics (Diagnosis, Treatment Planning and Presurgical and Postsurgical Orthodontic Treatment for Orthognathic Surgery)
  26. Temporomandibular Disorders
  27. Cardiopulmonary Resuscitation

Test Specifications

The ABO Written Examination is based on criterion-referenced testing, which is the concept that examinees should be measured against the skill and knowledge represented by each test item. The difficulty of each item for the minimally-competent examinee is the basis for setting the Criterion Standard, one that is represented as an absolute standard on a Benchmark Scale. The Benchmark Scale and Criterion Standard for the ABO Written Examination were first established in 2003 and updated every five years.

The Written Examination Guide will give you a breakdown of the percentage of questions to total exam by topic.

Reading List

The objective of this reading list is to offer a list of references which may serve as a source of knowledge in preparing for board certification. This reading list includes papers of historical as well as scientific interest. It is intended to give the orthodontist a broad perspective of the changing world of orthodontic theory and practice. It should be clearly understood that a bibliography such as this is not all encompassing and will be continuously subject to additions and deletions. The American Board of Orthodontics does not consider any of the texts and/or articles to contain the indisputable answer to any questions within the field of orthodontics.

ABO Written Examination Guide and Reading List