Functional impression and bite registration: a single session procedure for the construction of complete dentures

The closed‐mouth technique for the construction of complete dentures provides in the first session both impressions and a rough idea of the jaw relation in habitual intercuspation. The aim of this study was to apply this methodological advantage to the open‐mouth technique and to assess whether the arbitrary moulding of tooth position‐analogue plastic rims on functional impression trays facilitates a subsequent preliminary bite registration. Therefore, 104 complete dentures, manufactured by students during their final exams, were surveyed at 22 different test points using the Gutowski–Meyding gauge. Furthermore, the position of the front teeth, the lip support and the vertical dimension were assessed clinically. The results were as follows Upper complete denture vertical distance: middle of ridge – incisal edge of central incisor: 13 ± 3 mm (5–21) vertical distance: middle of ridge – tip of cusp of first molar: 9 ± 2 mm (2–16) sagittal distance: middle of ridge – incisal edge of central incisor 7 ± 2 mm (3–14) Lower complete denture vertical distance: middle of ridge – incisal edge of central incisor: 12 ± 3 mm (7–19) vertical distance: middle of ridge – tip of cusp of first molar: 13 ± 3 mm (5–20) sagittal distance: middle of ridge – incisal edge of central incisor: 3 ± 2 mm (0–6) Complete dentures in maximum intercuspation vertical distance upper to lower ridge region central incisor 20 ± 4 mm (12–33) vertical distance upper to lower ridge region first molar 21 ± 4 mm (9–34) Because of the interindividual variance the arbitrary moulding of the tooth position‐analogue plastic rims seems not ideal. However, a functional and aesthetically pleasing existing denture should be surveyed to pre‐shape functional impression trays. Such individualized trays proved clinically a valuable tool for functional impressions and an immediate preliminary bite registration.