Found in near equal frequencies in both maxilla and mandible. Mandible and maxilla osteotomies date to the 1940s. The dentary is the main bone that forms the lower jaw (mandible). The lower lip covers the anterior body of the mandible. It inserts into the posterior half of the lateral surface of the mandible. The culmen is the dorsal ridge of the upper mandible. There was a diastema (gap) between the incisors and molars of the mandible. The temporomandibular joints are the dual articulation of the mandible with the skull. Intramembranous ossification forms the flat bones of the skull, mandible and hip bone. Sebaceous glands are present on the angle of the jaw and mandible. The skull is composed of two parts&colon; the cranium and the mandible. These crests anchor the powerful temporalis muscles, which attach to the lower jaw (mandible). They are located in the premaxilla above and on the mandible below. Its action is the elevation of the mandible (closing of the jaw). The suspensorium includes several bones and articulates with the snout, brain case, and the mandible.