Deciduous dental arch widths and widths of the face in early childhood

Abstract

The data for this investigation were obtained from one hundred thirty white children (67 males, 63 females) who are enrolled in the Facial Growth Study being conducted at the University of Iowa. Approximately 95 per cent of the parents were of northwest European ancestry, and resided in or near Iowa City. Socioeconomically they were above average. The records of 86 per cent of the children were utilized at more than one age. Of this group 32 per cent appear in the study at two ages, 38 per cent at three ages, and 16 per cent at four ages. Materials used included casts of the deciduous dental arches for determining arch widths, standardized posteroanterior cephalometric x-rays for obtaining bigonial diameter, and direct measurements of bizygomatic diameter. All were provided by the files of the Study. Three widths of the upper and lower deciduous dental arches (intercuspid, intermolar I, and intermolar II) were employed. Central tendency and variability findings for these three interlingual widths were tabulated for boys and girls for the maxillary deciduous arch from 4 to 7 years and for the mandibular deciduous arch at the age of 5 years. Growth in arch width of the maxillary deciduous arch during the period from 5 to 7 years was determined by the three interlingual dimensions and arranged to show central tendency and variability values. The bigonial and bizygomatic diameters of boys and girls of 5 years of age were analyzed for central tendency and variability. Face and arch widths of boys and girls at the age of 5 years were studied for degree of relationship. Major findings are: 1. 1. The typical boy has a wider maxillary deciduous dental arch in the cuspid and molar areas than the typical girl at the ages of 4 to 7 years. 2. 2. The mandibular deciduous dental arch of the typical boy is wider in the cuspid and molar regions than that of the typical girl at the age of 5 years. 3. 3. The means for boys and girls indicate a steady increase in maxillary deciduous dental arch widths from 4 to 7 years. The increase in the means is greater for boys than for girls over the three-year period. 4. 4. Measurements on the same children at 5 and 7 years show that during this biennium the typical child increases about 1.5 mm. in maxillary intercuspid width and about 1.0 mm. in maxillary width between the first and second deciduous molars. The increase in both intermolar dimensions is almost identical for boys and girls, but the girls show a 20 per cent greater increment in intercuspid width. There is a decrease in maxillary deciduous dental arch width in a few children of both sexes from the ages of 5 to 7 years. 5. 5. The bigonial and bizygomatic dimensions for the typical boy are larger than those for the typical girl at the age of 5 years. No clinically useful relationship exists between the bigonial and bizygomatic diameters and their respective deciduous dental arch widths for boys or girls at the age of 5 years.