ADH appliance: an alternative for patients allergic to acrylic

Retention is an integral part of successful orthodontics. It can be defined as ‘maintaining newly moved teeth in position long enough to aid in stabilizing their correction and to permit reorganization of the periodontium, as well as the alveolar bone, around the teeth.’1

The Hawley removable retainer2 is used widely as it permits the patient to perform optimal oral hygiene care. The major disadvantage of such a retainer is the effect of the acrylic baseplate on speech and the possibility of an allergic reaction to the monomer. To overcome these shortcomings of the traditional acrylic retainer, a new non-acrylic based retainer is suggested that has all the features of the traditional retainer but with reduced bulk, better tissue adaptability and enhanced patient comfort.

A 23-year-old girl presented with relapse of previous orthodontic treatment resulting in a midline diastema in the maxillary arch and opening of the extraction spaces in all quadrants (Figure 1). The patient reported that she developed swollen lips and palate on wearing the retainer, which resolved uneventfully when the appliance was discontinued. The allergy to acrylic was the culprit in lack of sufficient wear of the retainer, which resulted in relapse. As the patient was not willing to undergo retreatment with fixed appliances, it was necessary to design an acrylic-free appliance.