As for the teeth, there are thirty-two of them. Sometimes some people have missing wisdom teeth, that is, the outer four, and then there are twenty-eight teeth. The teeth include two external incisors and two internal incisors at the top and the same teeth at the bottom to cut food, as well as two fangs at the top and two fangs at the bottom to crush it, and also molars to grind, on each side, the upper and lower, four or five teeth. This makes a total of thirty-two teeth or twenty-eight teeth. The extreme teeth most often grow in the middle of the developmental period, that is, after reaching maturity and before growth stops. And growth stops around the age of thirty, which is why these teeth are called wisdom teeth.
The teeth have roots and pointed heads that wedge into the sockets of the bones that support them in both jaws. At the edge of each hole, a round bone process grows, which surrounds the tooth and holds it, and there are strong ligaments there. Each tooth, except the molars, has one head. As for the molars stuck into the lower jaw, the smallest number of their heads is two, and sometimes, in particular for two wisdom teeth, there are three. As for the molars inserted into the upper jaw, each of them has at least three heads, and sometimes, in particular for wisdom teeth, there are four. Molars have many roots because they are large and work harder. The upper teeth have more roots because they are suspended and their weight causes them to deviate in the direction opposite to the roots. As for the lower teeth, the heaviness does not resist their wedging into the bone.
No bone has any sensitivity at all except the teeth. Galen says: “On the contrary, experience shows that the teeth are sensitive. This is also facilitated by the ability passing to them from the brain, which also serves to distinguish between warm and cold.”