Helictites are, perhaps, the most delicate of cave formations. They are usually made of needle-form calcite and aragonite. Forms of helictites have been described in several types: ribbon helictites, saws, rods, butterflies, hands, curly-fries, and clumps of worms.. They typically have radial symmetry.
The temporomandibular joint (TMJ) is the joint where the mandible articulates with the cranium (Fig 8.1). The following characteristics make the TMJ a complex and unique joint: 1  It is classified as a compound joint even though it does not include three bone structures in the articulation.
3D-printed prosthetic jaw Learn about a titanium 3D-printed prosthetic jaw. Â© University of Melbourne, Victoria, Australia The mandible consists of a horizontal arch, which holds the teeth and contains blood vessels and nerves. Two vertical portions form movable hinge joints on either side of the head, articulating with the glenoid cavity of the temporal bone of the skull.