Lingual retention and the elimination of the visible clasp arm

The modern removable partial denture (RPD), in response to the increased esthetic demands of our patients, is no longer acceptable if it requires visible buccal and facial clasp arms for retention. By eliminating the bracing arm and having its functions taken by paralleled guide planes and precise, positive rests, the retentive element, a lingual circumferential wire clasp arm, will provide the same amount of retentive force as if it were placed on the buccal surface and will not be visible. Designs for the major connector either plate the lingual surface of the abutment or, as in a lingual bar, leave that surface open. Both of these situations are adaptable to the lingual retentive clasp and are illustrated in this article.

Design features such as metal clasps needed for the retention of RPDs can be very unsightly, creating an esthetic problem. This article reviews the concepts for creating lingual clasp arms that enhance the esthetic quality of prostheses.