Is Centric Relation and Centric Occlusion Discrepancy an Enigma? An Orthodontic Perspective

Abstract

Centric Relation (CR) and Centric Occlusion (CO) are commonly used references in clinical dentistry. CR represents bone-tobone contact independent of teeth contact, while CO refers to occlusal contact between the maxillary and mandibular teeth. The coincidence or discrepancy between CR and CO has been the subject of many challenging debates. These reference positions of the mandible typically do not align in natural dentition. When a discrepancy exists, the mandible slides from CR to CO to stabilise the occlusion. Such functional interferences can result in occlusal wear, excessive tooth mobility, poor periodontal health, temporomandibular joint dysfunction, and myofascial pain. Orthodontists who follow gnathologic occlusion recommend using study models mounted on articulators in the CR position to coincide with the treatment of CR-ICP (Maximal Intercuspal Position - ICP). Generally, a discrepancy of 1.5 mm in the vertical and horizontal planes and 0.5 mm in the transverse plane is considered acceptable as it does not cause significant pathology. In the present article authors, we discuss the discrepancy between CR and CO, the dentofacial characteristics of patients with CR-CO discrepancy, its relationship with TMJ dysfunction, and its impact on cephalometric analysis and deprogramming. A clear understanding of CO and CR allows clinicians to approach treatment planning in an organised manner.