An analysis was made about the roentgenographic findings of 122 cases with enamel hypoplasia from 400, 000 routine dental roentogenograms at Department of Oral Radiology, Osaka Dental Hospital.
The results were obtained as follows:
1. The mean age was 11.9 years.
2. The affected sex-ratio did not reveal apparent differences.
3. The affected percentage of enamel hypoplasia was 1.1 % of patients under 20 years old age.
4. The incisors, cuspids and first molars were involved most frequently.
5. Seven cases in four families revealed hereditary amelogenesis imperfecta and three cases in a family were described.6. First molars were a relatively common in some of which were performed restorative preparations for enamel hypoplasia.
7. Enamel hypoplasia among 101 cases have almost occurred during two years after birth.
8. The etiology of enamel hypoplasia is possibly caused by nutritional, vitamin deficiencies and infectious fever.
