RHS, ICE, GC< DANB, Dental assisting bords

Q: The radiolucency in the image is a(n):

A. Oral ulcer
B. Mandibular foramen
C. Mental foramen
D. Incisive foramen

In order to solve this, we have to examine the location of the radiolucency. In this image, the lucency is below the second premolar but detached from the root. Because it is detached from the roots, we already know that it is NOT a lesion associated with the tooth (lesion is not even available as an answer choice). Now we must know the 3 other foramina to solve this question and prepare for the Dental Assisting Board Exams (RHS® Exam, GC Exam, NELDA® Exam, CDA® Exam, etc.).

  • Mental foramen is an opening for the mental nerve and vessels and is located below the mandibular premolar It appears as a round radiolucent area that is sometimes mistaken for a periapical lesion.
  • Incisive foramen is the passageway for the nasopalatine nerves and vessels. It appears as a small radiolucent oval between the roots of the maxillary central incisors.
  • Mandibular foramen is an opening on the inner side of the ramus above the occlusal plane. It usually does not appear on radiographs as the placement of the receptor/film will not capture this foramen.

Oral ulcers and herpes do not appear on radiographs since they are lesions of the oral mucosa.


Answer: (C). Mental foramen


Where is the mental foramen most commonly located? Generally, between the two mandibular premolars. But as you can see in the image today, there can be some slight variations. I hope your day is just little better knowing that you gained some knowledge for the dental assisting board exams.

Keep up the amazing work like always and share this important knowledge with your friends! The world needs more amazing dental assistants like you!

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Author: Claire RDH, MS

Claire is the founder of StudentRDH and SmarterDA – exams prep solutions for the dental hygiene and dental assisting students. The exam review online solutions quickly became the #1 choice among students. Studying is now “addictive!”Prior to her career in the dental field, Claire was an education specialist at Boston Children’s Museum. Claire is licensed to practice in the United States and Canada.

Disclaimer: CDA®, NELDA®, and RHS®  are registered trademarks of the Dental Assisting National Board, Inc. (“DANB”). This article is not sponsored or endorsed by or affiliated with the DANB.