Recording 'sublingual crescents' in lower complete dentures: a technique so effective but still esoteric and arcane

To achieve retention in severely resorbed mandibular ridges during impression making and to maintain the retention and stability of these dentures during function.

No good method with adequate clinical photographs that will empower the dentist with the necessary skill has been reported in the literature.

The technique involves making a preliminary impression in alginate to record the denture bearing area clearly, doing a border moulding procedure with excess width to fill the wide sulcus present; except in the area of anterior lingual flange from second premolar to second premolar area. The anterior lingual border of the impression is then extended sublingually without interfering with the tongue function or blocking the opening of the ducts of the sublingual gland; to maintain contact with the surrounding sublingual tissue in both protruded and retruded positions of the tongue, thereby creating good peripheral seal in the most vulnerable area in the lower denture, where the seal is easily broken during tongue movements.

This impression technique, combined with arrangement of teeth on the center of the ridge in the posterior part, use of flattened cusp posterior teeth and contoured polish surface of denture base (Fisch concept) provide sufficient retention and stability to the dentures made on these severely resorbed ridges.

Patients with severely resorbed ridges cannot be rehabilitated with implants also and so normally suffer with loose lower denture fabricated with normal border moulding procedures. These patients can be rehabilitated to a great extent properly.