Occlusion in dentistry describes how the upper and lower teeth meet and interact. This fundamental relationship is important for chewing efficiency and overall oral function. A harmonious bite ensures that forces generated during chewing are distributed effectively, contributing to the longevity of teeth and surrounding structures.
The Basics of Dental Occlusion
Dental occlusion refers to the way maxillary (upper) and mandibular (lower) teeth align and contact each other. This includes both static contacts, when the jaw is closed and stationary, and dynamic contacts during jaw movement. Centric Occlusion (CO), also known as maximum intercuspation, represents the position where the greatest number of opposing teeth make contact. This is the habitual bite individuals often close into.
Teeth also interact during jaw movements. Lateral excursive movements involve side-to-side motions of the mandible during chewing. Protrusive movement occurs when the lower jaw shifts forward. Harmonious occlusion aims to ensure smooth contact during these dynamic movements, important for efficient chewing, clear speech, and protecting teeth from excessive forces.
What is Group Function Occlusion
Group function occlusion is a specific occlusal scheme where multiple posterior teeth on the working side contact simultaneously during lateral jaw movements. The “working side” refers to the side of the mandible towards which the jaw is moving. In this scheme, occlusal forces are shared among several teeth, distributing the biting load across a broader area rather than concentrating it on a single tooth.
This differs from canine guidance, another occlusal scheme, where only the canine tooth on the working side contacts during lateral excursions, disengaging all other posterior teeth. Canine guidance is a form of mutually protected occlusion, where anterior teeth protect posterior teeth during lateral movements, and posterior teeth protect anterior teeth in centric occlusion by bearing primary chewing forces. In contrast, group function involves the canine along with premolars and sometimes molars in guiding the lateral movement.
Group Function’s Role in Oral Health
Group function spreads occlusal forces over multiple teeth during lateral movements, which can reduce the load on individual teeth and minimize the risk of excessive wear or fracture. It can be considered when canine teeth are compromised due to wear, loss, or malposition, making them unsuitable for guiding the mandible alone. Restorative dentistry, particularly in complex full-mouth reconstructions, may also utilize group function to achieve occlusal stability.
However, group function has considerations for oral health. Excessive or misdirected forces can lead to generalized wear on posterior teeth. Some individuals might experience muscle fatigue or temporomandibular joint (TMJ) issues if the occlusal scheme is not balanced. While both canine guidance and group function are acceptable occlusal schemes, some clinicians may prefer canine guidance for its ability to disengage posterior teeth, potentially protecting them from lateral forces.
Diagnosing and Managing Occlusal Schemes
Dentists assess a patient’s occlusion through a clinical examination. This involves observing how upper and lower teeth meet in various positions and movements. Tools like articulating paper identify specific contact points and force distribution. Occlusal analysis helps determine the existing occlusal scheme and identify any interferences or imbalances.
Managing occlusal schemes aims to achieve a harmonious bite that supports chewing efficiency and protects teeth and jaw joints. While no single “ideal” occlusion exists for everyone, dentists evaluate what works best for each patient. Group function might be intentionally established or modified in cases requiring complex restorative work or to address existing tooth wear or pain. Approaches to occlusal adjustment or restoration involve reshaping tooth surfaces or using dental restorations to create a more balanced and functional bite.