Primary dentition

Why this matters

Twenty teeth carry a child from about six months to about twelve years, and almost every clinical problem in that decade is an anatomy problem first. The enamel is roughly 45 per cent of the thickness of permanent enamel, the mesiobuccal pulp horn can sit about 1.5 mm below the dentine surface, the pulp chamber floor is 0.8 to 1.8 mm from the furcation, and the roots arch around a developing premolar that a careless extraction can bring with them. You will also be examined on two dimension tables that between them contain no measured human teeth.

The big picture

One set of twenty teeth built small, built fast and built to be destroyed. Everything on this list follows from those three facts: thin enamel and a short crown because formation time was short, a pulp close to the surface because the tooth is small, and thin flared roots that resorb because a successor is growing inside the furcation.

The 15 cards in this lesson

1. 01Twenty teeth, five per quadrant, and one permanent molar that replaces nothing
2. 02Ten tooth types on one plate, and three features you can read straight off it
3. 03The two primary-tooth dimension tables you will be examined on contain no measured human teeth between them
4. 04Three size relationships run backwards from the permanent dentition, and one identification rule has to be deleted
5. 05The five anterior primary teeth, and the canine that breaks the canine rule
6. 06The two primary FIRST molars resemble nothing else in either dentition
7. 07The second primary molars mimic the permanent first molars, and each mimicry has one reliable tell
8. 08Primary molar roots are thin, flared, and arched over a premolar that is growing inside the furcation
9. 09Root count and canal count are two different counts, and both move between countries
10. 10Every primary root you will ever measure is a resorption-state statement unless the paper says otherwise
11. 11The pulp is about eight per cent of the crown, and the danger is one corner of it
12. 12About 45 per cent of the enamel, and a line inside it that records the day of birth
13. 13The classical list of differences, item by item, against whether anyone measured it
14. 14Clinical alert — in the lesson
15. 15What to carry out of the primary dentition, and what this lesson could not source

You have got it when

You can (1) name all twenty primary teeth and say why there is no primary premolar; (2) separate an upper D from a lower D, an upper E from a permanent upper 6 and a lower E from a permanent lower 6 on crown form, not on width; (3) say why the mesiobuccal corner of a primary molar concentrates the tallest pulp horn, the cervical ridge and the deepest proximal box; (4) say which primary-tooth numbers are measured and…