You are here:

Dentistry/Fixed expanders


Dear Dr Myerson

My son 6 year old was diagnosed with posterior cross bite and crowding.
I have visited 2 orthodontists. One of them offered "butterfly" expander with a key, another quad helix.
I will be very grateful, if you could help me to compare this options, using your knowledge and experience.

Thank you very much

In my practice there is a fundamental difference between these two appliances.  The quad helix is used to simply widen the upper dental arch.  The butterfly expander is a rapid palatal expander which is used to expand not only the width of the dental arch but also the maxillary bone or palate. These two appliances are not interchangeable since they each are used to correct slightly different problems.  


All Answers

Answers by Expert:

Ask Experts


Dr. Randolph Myerson


Please limit your inquiry to questions about orthodontics (braces) and children's dentistry. I am both an Orthodontist and a Pediatric Dentist, having been trained in both of these dental specialty fields. Orthodontics is the dental specialty that treats problems of tooth, bite and jaw alignment using braces and removable appliances. Pediatric Dentistry is the dental specialty also known as dentistry for children, which deals specifically with the dental problems of this special age group from infants to adolescents. I am also experienced in Forensic Dentistry, the application of dentistry to law enforcement and identification using dental records.


I have been in the private practice of orthodontics and pediatric dentistry for over 20 years. Prior to that I served for three years on the Cleft Palate and Cranio-facial Reconstruction team at Children''s Hospital of Philadelphia and was an Assistant Professor of Dentistry at University of Pennsylvania School of Dental Medicine. I also served as a dentist in the U.S.Air Force, stationed at Andrews AFB in Washington, DC.

I am a Fellow in the American Academy of Pediatric Dentistry, and a member of the American Association of Orthodontics, as well as a member of the American Dental Association and the Dental Society of the State of New York.

I received my BA in Biology from Frankin & Marshall College in 1969, and my dental degree from University of Pennsylvania School of Dental Medicine in 1973. In 1978 I received both my Certificate in Orthodontics from University of Pennsylvania School of Dental Medicine, and my Certificate in Pediatric Dentistry from Children''s Hospital of Philadelphia after completing a three year Teaching Fellowship in Orthodontics and Pediatric Dentistry in 1978.

©2016 All rights reserved.