gnatho-, gnath-, -gnatha, -gnathan, -gnath, -gnathia, -gnathic, -gnathous
(Greek: jaw)
The jaw is the name applied to the bones which contain the teeth.
The two upper jaw-bones, the maxillae, are firmly attached to the other bones of the face.
The lower jaw, the mandible, is shaped in a form similar to that of a horseshoe, and, after the first year of life, it consists of a single bone.
It forms a hinge-joint with the squamous part (thin, plate-like section) of the temporal bone, immediately in front of the ear.
Both the upper and the lower jaw-bones include deep sockets known as alveoli, which contain the roots of the teeth.
It may be real or imaginary, depending on anatomic or physical and developmental factors.
Real prognathism may exist when both the mandible (lower jawbone) and the maxilla (upper jawbone) increase in length or when the maxillary length is normal and the mandibular length increases excessively.
Imaginary prognathism may exist when the maxilla is underdeveloped and the mandibular length is normal
2. Jaws that project beyond the upper part of the face; opposed to orthognathous.
It serves as a pumping organ to draw the water through the gill cavity.
2. Referring to the mouth and jaws collectively.