The anatomical structures of gnathological concern are (in a nutshell) the mandibula, the articular disk, the cranic base (fossa and tubercule), muscles and ligaments (see pictures).
The mandibula has two articulating heads called "condyles" that move into two grossly bowl shaped spaces under the cranic base. In between these two bone structures there is a cartylage disk having functions of surface adaptation and shock absorber of the mastication weight. The disk is situated inside an articuar capsule and held into position and driven while in movement by ligaments connecting it to the neighboring structures.
The muscular structures are made of muscles elevating and lowering the mandibula. Without too much details, the main elevating muscles are the masseter and the temporal, while the lowering muscles are those of the mouth pavement and the digastric.
When opening the mouth, the condyles slide forward and downward following the glenoid fossa and, at maximum aperture, they practically reach the top of the articular tubercle (sometimes even passing it). The disk follows the condyle in this movement, staying constantly interposed thanks to its ligaments. Just in asimilar way, the mandibula performs its lateral movements always with the articular disks accompanying the condyles.