All of the following cells of periodontal ligament are of mesenchymal origin except________?

HLA – B27 histocompatbility antigen is seen in________?

Cyst arising from dental lamina:________?

Megnesium is needed for the activity of which enzymes?

Main arterial supply of the tonsil is from________?

Hertwig’s epithelial root sheath is made up of________?