Denture wearers often claim an alteration of taste and oral senses. There are many sensory spots on the hard palate but not taste receptors, so a palatal appliance does not cover taste receptors. Thus, the causes of these claims are not fully understood. In this experiment, we examined the effects of an experimental palatal appliance on taste and form discrimination ability. We took maxillary impressions and made a palatal appliance of acrylic resin. The subjects were seven healthy women (aged 21 to 25). They were divided randomly into two groups and the following two experiments were performed. Experiment 1: we checked the taste threshold for four basic taste stimuli (sucrose, NaCl, acetic acid, and hydrochloric acid quinine) by means of the whole mouth test and filter paper-disk method. Experiment 2: we examined their form discrimination ability. For form discrimination ability, we prepared test blocks of four forms of different sizes. Volunteers were asked to put one of the blocks into their mouth, and to identify the form of the block. There was no significant difference in the taste threshold whether they were wearing a palatal appliance or not. In form discrimination ability, there was no significant difference between subjects with and without a palatal appliance. The insertion of a palatal appliance causes few, if any, changes in oral senses. This study suggests that the alteration of oral senses after wearing dentures may be due to mental factors, the contact of food and oral mucosa, and the flow, flavor, and temperature of food and so on.