The gnathologic concept is useful in restoring teeth as well as eliminating occlusal problems. The mandibular movements can occur in either of the three planes; frontal, horizontal and sagittal. The movements in either of the planes are guided by the proprioceptive impulses. In dentulous patients, the impulses are obtained from the periodontal ligament whereas in edentulous patients, the impulses are generated from the temporomandibular joint. While mandibular movements cannot be reproduced with complete accuracy on an articulator, we should reproduce them with as much accuracy as possible to minimize damage to supporting structures from occlusal disharmony.This book aims at describing the importance of the maxilla-mandibular relations in maintaining the harmony of the stomatognathic system.