Semi-longitudinal study of growth and development of children aged 6 to 17 Part I : Growth and development of arch form

Sohn, Byung Wha; Lee, Jung Goo; Kim, Hyun Suk; Kim, Hyung Soon

Abstract

This study was carried out as a part of the semi-longitudinal study on growth and development of Korean children, with purpose of observing the growth change in arch form, 736 pairs of study models were taken for 3 years. Mesio-distal diameter of each tooth, intercanine width, intermolar width, canine arch depth, molar arch depth and arch perimeters were measured. Afterwards, mean value and each standard deviation of each age group and each gender were obtained, and corresponding graphs were drawn. The following conclusions were obtained: 1. Mesio-distal diameters of maxillary central incisor, maxillary 2nd molar, mandibular canine, and mandibular 2nd molar showed statistical differences between boys and girls. 2. Intercanine width shows a gradual increase until age of 11. 3. Intennolar width in maxilla shows continuous increase, and the tendency of increase is more apparent between age of 9 and 14. In mandible, various pattern was shown until age of 9, and after, a slight increase. 4. Canine arch depth shows the increasing tendency until age of 13 in maxilla and 11 in mandible. 5. Molar arch depth shows the pattern of increase until age of 10 in male and 9 in female, which is more apparent in maxilla. After age of 9 or 10, dereasing pattern was significantly shown until age of 15 in maxilla and age of 12 in mandible. 6. Arch perimeters in maxilla and mandible showed gradual increase until age of 10, and the tendency of increase was more apparent in maxilla; however, between the age of 10 and 14, arch perimeters of maxilla and mandible showed gradual decrease which was more apparent in mandible.