Determination of approximate size of maxillary anterior denture teeth when mandibular anterior teeth are present. Part III: Relationship of maxillary to mandibular central incisor widths.

The average width of a natural maxillary central incisor is 8.92 mm. This value is determined from the results of three studies of natural dentitions. The average width of a mandibular central incisor is 5.5 mm. The average ratio produced by dividing the average maxillary central incisor width by the average mandibular incisor width is 1.62. The factor of 1.5 times the width of a mandibular central incisor produces a maxillary central incisor width that is too narrow. The width of a mandibular central incisor plus half the width of the mandibular lateral incisor also produces a maxillary central incisor width that is too narrow. There may be a tendency to undersize the maxillary prosthetic dentition. The ratio of 1.62 can be used to select the appropriate width for a missing maxillary central incisor when given the width of the mandibular central incisor. This ratio of 1.62 is also valuable to verify the dimension of a selected artificial maxillary central incisor when the patient complains that the tooth is too large. If substitutions or adjustments are made in the mold, the desired canine-to-canine measurement produced by the ratio range of 1.3 to 1.38 reported in Parts I and II of this study should be maintained.