This study was undertaken to examine the interrelationship between tooth size and arch dimension in patients with dental crowding and spacing. Three groups of dental casts were selected on the basis of dental crowding and spacing. One group, consisting of 60 pairs of dental casts (30 male and 30 female), exhibited remarkable dental crow-ding. A second group, consisting of 60 pairs of dental casts (30 male and 30 female),
exhibited remarkable dental spacing. A third group, consisting of 60 pairs of dental_ casts (30 male and 30 female), exhibited little or no dental crowding and spacing.
Mean, standard deviation, t-test, and F-test of the following parameters were used to compare three groups : individual and collective mesiodistal tooth diameters, buccal and lingual arch widths and arch area.
The following results were obtained.
1) The major etiology of crowding was small dentak arch dimension in the male except lingual arch width at maxillary canine region and in the female was both large tooth size and small dental arch dimension except lingual arch width at maxillary canine region and buccal arch width at mandibular canine region.
2) The major etiology of spacing was small 4 anterior teeth size and large lingual arch widths at canine and 1st premolar region.
3) The crowded group revealed larger tooth size and smaller dental arch dimension than the spaced group.
4) In three groups, the largest arch area was revealed in the spaced group, the second in the normal group, and the last in the crowed group.
|