Both Hawley and Essix type retainers are commonly used by orthodontists. The traditional type is the Hawley retainer, which includes a metal wire that surrounds the teeth and keeps them in place. Named for its inventor, Dr. Charles Hawley, the wire is anchored in an acrylic arch that sits in the palate (roof of the mouth). The advantage of this type of retainer is that the metal wires can be adjusted to finish treatment and continue moving teeth as needed. The Essix retainer is a vacuum formed retainer. This is a polypropylene or polyvinylchloride material, typically .020" or .030" thick. Essix is a brand name many dental offices are familiar with. This clear or transparent retainer fits over the entire arch of teeth and is produced from a dental mold. Is there any difference between these two type of retainers related to stability and patient acceptance?
A recent prospective study by Kumar and Bansal (2011) compared the effectiveness and acceptability of Essix and Hawley retainers. The study consisted of 224 patients who had undergone comprehensive orthodontic treatment. The results showed that there was, no clinically significant differences in stability and irregularity, when the two types of retainers were compared. They also found that Hawley retainers were more acceptable for biting and Essix retainers were more acceptable for appearance and comfort.So what can we take away from this? Basically, that your Essix retainers work just as well as traditional retainers but they are more comfortable and you will probably be more pleased with your appearance as well!
Kumar AG, Bansal A. Effectiveness and Acceptability of Essix and Begg Retainers: A Prospective Study. Aust Orthod J 2011; 27 (May):52-56.