[Soft X-ray study on fetal cranio-facial growth and development].

This study was undertaken to ascertain the changes of fetuses in craniofacial dimension and to evaluate the growth and development during fetal period. Lateral cephalograms by soft X-ray were taken from 64 fetuses and were measured in linear and angular aspects. The following conclusions were obtained. 1. The linear increase rates of anterior cranial base length exceeded those of the posterior cranial base length. 2. Growth increments on horizontal dimension were greater than vertical dimension in the maxilla. 3. The cranial base angle was almost constant after fetal period 13 weeks with the average angle of 130 degrees. 4. The angle between anterior cranial base and palatal plane was decreased gently during fetal period.