Determining approximate size of maxillary anterior artificial teeth when mandibular anterior teeth are present. Part I: Size relationship.

Three methods were used to obtain a ratio of the maxillary to the mandibular anterior teeth, with results of 1.29, 1.30, and 1.31. It can be concluded that a ratio of 1.30 is sufficient to determine the approximate width of the six maxillary anterior teeth when given the size of the mandibular natural anterior teeth. This ratio should be valid to select a maxillary denture mold of sufficient width mesiodistally to obtain a Class I canine relationship. However, the ratio may need a slight adjustment to compensate for the intentional disocclusion of the maxillary denture teeth with the natural mandibular teeth. In Fig. 1 the canine to canine measurement of the mandibular anterior teeth was 35 mm; when multiplied by a factor of 1.30, a maxillary measurement of 45.5 mm is obtained. The denture teeth were to be set with approximately 1 mm of horizontal overjet and 1 mm of vertical overlap (Fig. 2), therefore a slightly larger mold of 48.5 mm was chosen (Fig. 3). This maxillary mold produced a Class I canine relationship (Fig. 4). The 48.5 mm ratio of the chosen maxillary mold to the mandibular measurement of 35 mm yielded a ratio of 1.38. When this ratio of 1.38 is applied, the desired prosthetic mold is not always available. There is a range of acceptability above and below the desired ratio.(ABSTRACT TRUNCATED AT 250 WORDS)