Effects of CO-CR discrepancy in daily orthodontic treatment planning

Nowadays centric relation is defined as a musculoskeletal stable position, with the condyles forward, as far upward as possible, centered transversely and with the articular disc properly interposed. On the other hand, centric occlusion or maximum intercuspidation is a dental determined position. The purpose of this pilot study is to evaluate the direction, frequency and magnitude of the discrepancy between centric occlusion and centric relation in all three axial directions, in a muscular non-deprogrammed population, before the beginning of orthodontic treatment.

The study group was represented by 40 symptomatic and asymptomatic patients seeking orthodontic treatment in a private dental office in Cluj-Napoca, Romania between 2014 and 2015. All patients had full records and articulator mounted models. All measurements were analyzed three-dimensionally.

85% of the patients had vertical and 87.5% had horizontal CO-CR discrepancy for both condyles. 87.5% of the cases have had a significant condylar displacement in at least one of the three planes.

We should be aware of the dental occlusion determined by the dental contacts and the occlusion dictated by the musculoskeletal stable position of the condyles. The bigger the discrepancy between these two positions at the level of the condyles, the greater the chances to have either a patient who will develop a form of TMD before/during or after the orthodontic or prosthetic treatment, or a patient suffering already, but poorly diagnosed.