Nolla.docx

Nolla’s Stages of Tooth Development

Nolla arbitrarily divide the development of each tooth into ten stages:

1. Presence of crypt 2. Initial calcification 3. One third of crown completed 4. Two thirds of crown completed 5. Crown almost completed 6. Crown completed 7. One third of root completed 8. Two thirds of root completed 9. Root almost completed, open apex 10. Apical end of root completed

Important stages to remember are stage 2 and 6. Girls are more advanced in calcification than boys at each stage and more so in the later stages. Sex differences for tooth calcification are less than bone development. Since girls are well ahead of boys by 10 years of age, the differences cannot be result of the timing of the secretion of sex hormone. The variability in calcification of the permanent teeth is much greater than usually is assumed, probably because the most popular standards of tooth development is similar to that eruption, sexual maturity, and other similar growth indicator.

Nolla’s Stages of Tooth Development