Abstract
Occlusal force was measured and bone salt was also measured by photodensiometry from dental films. The subjects consisted of a total of 48 children,24boys and 24 girls, from 8 to 10 years old, who were examined at the outpatients of Department of Pediatric Dentistry, Attached Hospital, Kyushu Dental College.
These children had normal occlusion and had practically no caries or defects in the mandibular molar region from the clinical standpoint.
The results were as follows:
1. The averages of the occusal force for boys were 23.64±3.74 kg for age 8,29.25±4.63 kg for age 9, and 32.63±5.19 kg for age 10, and for girls were 24.75±4.68 kg for age 8,26.38±5.19 kg for age 9, and 32.38±6.22 kg for age 10. In the t-test taken by the boys and girls, nosignificant difference was found from ages 8 to 10. In the t-test between ages, age 9 gorup showed significantly greater values than age 8 group (p<0.05) between ages 8 and 9; age 10 group showed greater values than age 8 group (p<0.05) between ages 8 and 10; and age 10 group showed significantly greater values than age 9group (p<0.05) between ages 9 and 10.
2. In the measurements of bone salt, the averages for boys were 3.74±0.74 mm Al fbrage 8,4.36±0.80 mm Al for age 9, and 4.44±0.73 mm Al for age 10, and for girls were 3.54±0.70 mm Al for age 8,4.18±0.82 mm Al for age 9, and 4.59±0.73 mm Al forage10. No significant difference was found between boys and girls. In the t-test between ages, between age 8 and 9, and between ages 8 and 10, the latter who were older showed significantly higher values than the former, but no significant difference was found between ages 9 and 10.
3. Correlative coefficients of occlusal force and bone salt's were r=0.816 for age 8, r=0.860 for age 9, and r=0.730 for age 10, and r=0.820 for the whole. A strong correlation was found between occlusal force which is the physical simulation to the jaw bone and bone salt which reflects the internal structure of the bone.
