Foundations of occlusion

Why this matters

Occlusion is the part of dentistry where the vocabulary is least settled and the stakes are most ordinary. Every crown you cement, every extraction that leaves a space, every orthodontic referral you write is a statement about how these teeth meet. Two of the measurements on this page change what happens to a child's front teeth: overjet in millimetres, and which side a crossbite is on.

The big picture

Two jaw positions defined by two different things - one by the condyles, one by the teeth - and almost nobody's coincide. Everything else here describes that gap: overjet and overbite in millimetres, two curves and a sphere in three dimensions, one cusp against one groove for Angle, and marks on paper for the contacts themselves.

The 15 cards in this lesson

1. 01Centric relation is defined by the condyles; maximum intercuspation is defined by the teeth
2. 02Four names, two positions, and one word that inverts between specialties
3. 03Almost everyone has a CR-to-MIP difference, so finding one tells you almost nothing
4. 04A record can be repeatable and still not be valid, and centric relation is the textbook case
5. 05Whether a CR-to-MIP discrepancy causes disease sits in three different states of evidence
6. 06Overjet is horizontal and overbite is vertical, and neither means anything without the position and the convention
7. 07There is no normal overjet - there is a distribution, and it moves with age and with the survey
8. 08Clinical alert — in the lesson
9. 09A deep-bite prevalence is a statement about a criterion, not about a population
10. 10Clinical alert — in the lesson
11. 11Angle's classification is a statement about one cusp and one groove, and nothing else
12. 12The same mouth gets classified two ways, and the photograph is one of the reasons
13. 13Two curves in two planes, and the sphere that is supposed to contain them both
14. 14Occlusal contacts, and the two words that decide whether you can read the literature
15. 15An articulating-paper mark is not the same thing as an occlusal contact

You have got it when

You can now (1) define centric relation and maximal intercuspal position in the current glossary's own words and say what each is independent of; (2) translate between CR/MIP and RCP/ICP; (3) measure overjet and overbite in millimetres and state the position and convention; (4) quote the overjet-trauma odds for each dentition stage; (5) record a crossbite with its direction and side; (6) assign an Angle class and…