 Each pair of tusks has a depression for two teeth on each side of the jaw with only one tooth present at a time.It was one thought that the empty depression was fit for the teeth of the lower jaw in order to close the mouth, but upon further inspection small bits of tooth could be seen in the empty depressions showing that there was a tooth there once.The size of the teeth varies on the upper and the lower jaw, the larger teeth being more anchored into the mandible than the smaller ones on the lower jaw.