Semi-longitudinal study on growth and development of children aged 6 to 17 Part III : Growth change of craniofacial hard tissue

Orthodontic patients are individuals that grow and develop; therefore selection of the proper time for orthodontic treatment is considered to be one of most difficult and yet difficult factor. Since the development of cephalometric X -ray, amount and pattern of craniofacial growth change with aging could be predicted and be came useful in the process of orthodontic treatment. The relationship between the mean values of cephalometric measurements and body height and weight was studied among the groupstboys and girls) of Korean children from the ages 6--years to 17-years. 409 boys and 437 girls with no abnormality in growth and development and no history of orthodontic treatment from the ages of 6 years to 17 years were chosen as subjects: Cephaloment X -ray were taken for 3 years and hard tissue analysis based on Burstone´s COGS, which was devided into measurements of 6 parts(Cranial base, Maxillar and Mandible, Dental measurements). The relationship between craniofacial growth and height & weight was studied. The following conclusions were obtained: 1. The maximum growth in the measurements of cranial base, N-Ar(FH), N-Ba(FH) corresponded with the age with the maximum increase in body height & weight in both boys and girls. 2. Gonial angle gradually decreased with aging in both boys and girls. 3. N-ANS(L) showed greater amount of growth than ANS-Ne(L), and this had greater influence on facial profile. 4. N-A-Pog ° decreased with aging, and mandibular growth exceeded maxillary growth in amount and rate. 5. Length of Y-axis increased, but Y-axis to FH plane remained constant. This show that mandible grows at a constant angulation to cranial base. 6. As permanent teeth erupt, interincisal angle deceased.ope