Understanding Centric Relation: A Key Concept in Dentistry

Centric relation (CR) is a foundational, albeit historically controversial, concept in dentistry. For nearly a century, its precise definition and application have been subjects of extensive discussion among dental professionals. Understanding CR is essential not only for dental practitioners but also for patients seeking to comprehend aspects of their oral health. At its core, centric relation describes a specific spatial relationship between the maxilla (upper jaw) and the mandible (lower jaw). Through various studies and surveys, including one among members of the Academy of Prosthodontics, a consensus definition has emerged. CR is understood as a clinically determined, repeatable, and physiologic jaw position that is independent of tooth contact. The repeatability aspect is crucial; during functions like chewing or speaking, the lower jaw naturally returns to this consistent starting position relative to the upper jaw. It's important to distinguish centric relation from centric occlusion (CO). Centric occlusion refers to the position of your lower jaw when all your teeth are fully meshed together, also known as maximum intercuspation (MIP). Unlike CR, centric occlusion is dictated by the teeth's interdigitation and is independent of the jaw joint's position. While some individuals naturally have their centric occlusion aligning with their centric relation, for many others, these positions differ anatomically. This discrepancy can lead to various dental issues. The significance of centric relation in dentistry is profound. Its accurate determination is paramount in the construction of dentures, as dentures not harmonized with this position are prone to failure. Beyond prosthodontics, CR has become a vital consideration in restorative dentistry, orthodontics, and comprehensive full-mouth reconstructions. Dentists often aim to treat patients to centric relation when signs of occlusal disease are present, when the patient's temporomandibular joints (TMJs) are healthy, and when a stable, repeatable position is needed for restorations. By leveraging the predictable nature of CR, dentists can effectively minimize the progression of occlusal disease. Furthermore, there's a recognized connection between centric relation, centric occlusion, and their potential impact on TMJ health, highlighting the importance of proper mandibular positioning. Dentists employ specific methods to determine centric relation. These typically involve recording the jaw relationship under either minimal pressure to prevent displacement of supporting tissues or under heavy pressure to achieve controlled displacement. Your dentist is the best resource to determine if your jaw and bite alignment are optimal and if any treatment related to centric relation is necessary for your oral health.