A method of mixed dentition analysis in the mandible.

We developed a method of space analysis based on the fact that the measurement between the distal surfaces of the mandibular permanent lateral incisors was approximately equal to that of the combined widths of the mandibular permanent canine and premolars. This method is referred to as Interlateral Incisor Width (I.L.I.W.) Analysis. One hundred and nineteen Japanese children, without malocclusion, were selected for the study. Various measurements of teeth were taken in their mouths with a modified, fine-tipped, electrical, digital caliper and recorded in a Handheld Computer by connecting it to the caliper. Statistical analyses were conducted to compare the accuracy of the I.L.I.W., Ono, Moyers, and Ballard and Wylie analyses in the mandibular arch. The summary of the results were: Correlation coefficients for the sum of the actual mesiodistal dimensions of the canine and premolars with their predicted values obtained by each of the four analyses revealed r = 0.63 for I.L.I.W., r = 0.55 for Ono, r = 0.57 for Moyers, and r - 0.55 for Ballard and Wylie. Our I.L.I.W. method presented the best correlation of the four analyses, although each indicated a relatively low correlation. This method does appear to be clinically valid, since it is simple enough to enable the practitioner to estimate the combined dimension of the unerupted canine and premolars by measurement, in the mouth, of the distance between the distal surfaces of both mandibular permanent lateral incisors, instead of on study casts. It is recommended that a radiographic method be used in conjunction with our method to obtain a more accurate estimate.(ABSTRACT TRUNCATED AT 250 WORDS)