[The problem of taking dental impressions in acquired microstomia].

Two cases of severe cicatricial atresia of the oral rima with total edentia are reported. These patients present considerable problems when impressions of the dental arches have to be obtained. To make the labial tissues more elastic and in the attempt to increase rimal space, a perilabial collar of resin is made. Using the normal silicon-based synthetic elastomers, a first mould can be obtained directly in the mouth. This in its turn is filled with a more fluid elastic material and set in the mouth. From this initial impression, a chalk model can be obtained and from this an individual silicon mould is made from which a more accurate final impression is possible. In order to adjust the occlusion and test the teeth, a resin plate is prepared. This can be detached from the wax and fitted into the mouth. The standard methods are then employed to make the body of the prosthesis.