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.
The primary bones of the face are the mandible, maxilla, frontal bone, nasal bones, and zygoma. Facial bone anatomy is complex, yet elegant, in its suitability to serve a multitude of functions.ust lateral to the symphysis on the inner surface of the mandible are 2 paired protuberances termed the superior and inferior mental spines. The genioglossus muscle attaches to the superior mental spines, and the geniohyoid muscle attaches to the inferior mental spines.