The present study was conducted to produce the latest cephalometric standards of Japanese children. Materials consisted of 329 lateral cephalograms and 274frontal chphalograms taken from Japanese children with clinically normal occulusion, supplied from the Departments of Pediatric Dentistry of dental colleges and universities in Japan. Variations of angular and linear measurements, and XY coordinates calculated from the laterl cephalograms were compared with the past data, Iizuka, Sakamoto and Ono, taken in the 1950s.
Environmental factors which brought about a remarkable increase in the height of Japanese children, also influenced many parts of the maxillofacial cranium in two ways, i. e. the increase in length and the phenomenon of accelerated development. The increase in length was observed more clearly in boys, however, the phenomena of accelerated development was observed more clearly in girls.
Dividing the maxillofacial cranium into depth and height, the increase in length was more marked in height. The increase in depth was more than the corrected values, which were estimated using the allometry between the standing height and lengths of the maxillofacial cranium, at the anterior cranial base in all of the observation periods. Also at the nasomaxillary complex, the increase in depth was more than the corrected values only after the mid mixed dentition periods. However, at the mandible in most periods, the increase in depth was less than the corrected values. On the other hand, the increase in height was more remarkable in the posterior facial height than in the anterior facial height. The morphological changes to adults, concerning both the axes of the upper and lower central incisors and the outer frame of mandible, as phenomena of accelerated development, were observed after the mid mixed dentition period.
With the results calculated from the frontal cephalogram, the growth patterns of the neighboring parts were compared between width and depth at the neurocranium, the upper face and the lower face. Their growth patterns were almost the same, but the growth in width preceded the growth in depth. The increase in width were especially prominent in the lower face.