RHS, ICE, GC< DANB, Dental assisting bords

Q: The receptor size usually required for a full-mouth series on a six-year-old patient is: 

(A). Size 1
(B). Size 0
(C). Size 3
(D). Size 4

Keywords: six-year-old

  • Size 0 is the smallest receptor and is used for children
  • Size 1 is larger than size 0 and is used for children’s dentition and adult anterior teeth
  • Size 2 is larger than size 1 and is used on adults (BWX and PA)
  • Size 4 is used for occlusal exposure

A six-year-old child is usually bigger than a small child. Therefore size 0 may be too small. Also at this age, the first molars begin to erupt. Therefore, between the two sizes of receptors indicated for children, the larger one is more appropriate.


Answer: (A). Size 1


Since we are talking about the Prep Course for DANB’s RHS® (Radiology and Health Safety) Exam, should we learn a little more? What about the different intraoral imaging techniques?

There are 4 main types of intraoral imaging that we can take, namely: periapical, bitewing, occlusal, and full-mouth-series.

  • Periapical (PA): captures the crown, CEJ, root, and surrounding areas. Used mainly for diagnosis of periodontal disease, pathology, endodontic therapy, and implants.
  • Bitewing (BW): captures crowns, contacts, and height of alveolar bone. Used mainly for diagnosis of dental caries (only interproximal). Vertical bitewings can detect early periodontal disease because the bone level can be detected.
  • Occlusal: captures bone surrounding the teeth, the floor of the mouth, sialolith (stone), supernumerary teeth, etc. Useful when the patient has limited jaw opening.
  • Full-mouth series (FMX): represent the entire dentition using a combination of PAs and BWs. The total number of images may vary according to the patient.


Do you want FREE mini-reviews like this one, delivered to you? 


As mentioned in the explanations, it is important to understand that bitewings are usually indicated for the detection of caries while periapicals are indicated for the detection of periodontal diseases. This is not clear-cut science, but some basic information that can help us navigate through the dental assisting board exams (RHS® Exam, NELDA® Exam, CDA® Exam, etc.) more easily. And of course, knowing this can help you become an excellent clinician!

We have a fantastic Prep Course for DANB’s RHS® (Radiology and Health Safety) Exam that you will love. It offers a STEP-BY-STEP process. You get everything you need!

If you have any questions about the dental assisting exams, I am always here at ClaireJ@SmarterDA.com and support@SmarterDA.com. I have taken the CDA® Exam and CPFDA® Exam, so I know what you are going through! Hang in there and keep pushing for “SUCCESS and NOTHING LESS!”


Start Your FREE Trial Today! 

Prep Course for DANB’s RHS® (Radiology and Health Safety) Exam


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 Jeong was an education specialist at Boston Children’s Museum. Claire is licensed to practice in the United States and Canada. She can be reached at ClaireJ@SmarterDA.com and support@SmarterDA.com.

Disclaimer: DANB®, CPFDA®, CDA® 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.