Abstract
Ossification of the costal cartilage was investigated by the appearance of thoracic X-ray pictures of 633 normal persons ranging in the age from 0 to 73 (370 male and 263 females), and 42 stutterers ranging in the age from 0 to 52 (39 males and 3 females) . Capacity of lungs was also compared between the stutterers (ranging in the age from 4 to 54, 149 males and 23 females) and normal persons. Further, external appearance of the clavicle was examined on 93 stutterers.
The results obtained were as follows:
1. No significant difference was seen in the ossification between stutterers and normal individuals.
2. No sign of the ossification was detected in both male and female children under 6 years of age.
3. Ossification of the first costal cartilage appears ealier among females, however, the completion of ossification was seen in 100% in both sexes over the age 51 to 60.
4. The lower third, fourth and fifth costal cartilages showed the sign of ossification earlier than other costal cartilages in both sexes, however, the ossification was completed in 100% among the females ranging in the age from 41 to 50 which was 10 years earlier than in males.
5. No distinction was seen in the in the ossifiation of costal cartilages between the left and the right.
6. Difference of the ossification between males and . females suggests the presence of some relationship between the ossification and the respiratory movements, but as the individual difference is so great further considerations are necessary.
7. The capacity of lungs of stuutterers did not differ from that of normal individuals.
8. Malformation of the clavicle is not necessarily high among stutterers.
