The theory of Posterior Guided Occlusion (PGO) has a static and dynamic component. The static component is a position where the mandible is in a braced, neuromuscular position at which the posterior teeth touch stable, non-deflecting surfaces on opposing teeth. It allows the antero-medial aspect of the head of the mandibular condyle to be firmly braced on the medial aspect of the glenoid fossa. This anatomical position allows for the maximal coordinated contraction of the major muscles of closure of the mandible.
PGO also has a dynamic component. From the static position, direct lateral excursive movements can be made without limitation or reduction of muscular coordination or effort. The temporomandibular joint is stabilized with harmonious bi-laterally balanced tooth contacts.
The dynamic range of motion is within a small area, defined as a “centrum”, which is about 1-1.5mm in diameter. The lengths of the contacts on these simultaneously contacting teeth vary, but are generally about 1.5-2mm of glide on the opposing maxillary cuspid. This coordinates with a stroke length of about 0.5mm on the facial (buccal) aspect on the lingual cusp of the ipsilateral, balancing guide on the most posterior teeth possible. The variation in length is relative to the differing distances from the gliding condyle.