Influence of the thickness of the resin palatal vault on the closest speaking space with complete dentures.

The closest speaking space (CSS) has been considered stable over time, and therefore useful to determine the vertical dimension of occlusion (VDO) in edentulous patients. Clemençon affirms that, in complete denture wearers, CSS is not constant but depends on the thickness of the resin palatal vault, and that is the air volume needed to pronounce words to remain constant. The aim of this study was to evaluate Clemençon hypothesis in a group of edentulous patients rehabilitated with traditional maxillary denture and mandibular implant anchored overdenture. The CSS was determined by means of a kinematics method using the Elite System(R) at 30, 60, 90, 180, 360 days from delivery. The CSS was assessed twice at each stage: with the unmodified denture and a second time after thickening the resin palatal vault by 2 mm with a calibrated wax layer. The CSS after thickening the resin palatal vault was wider. The wider CSS observed can be because of oro-sensory feedback excited by contact between tongue and palatal vault. As hypothesized by Clemençon thickening the resin palatal vault could be a useful procedure to increase the VDO, in cases in which it is too low from the aesthetic stand point.