Understanding occlusion in periodontal care: The role of occlusal trauma in periodontal care

Author: Gum Specialist Dr Shray

Occlusion refers to the static and dynamic relationship between the maxillary and mandibular dentition. This plays a pivotal role in both the health and function of the periodontium. When the masticatory muscles generate and apply excessive and/or traumatic occlusal forces to the teeth, the reparative capacity of the periodontal attachment apparatus is exceeded. This results in occlusal trauma and/or tooth wear.

Occlusal trauma results in injury to the periodontium that is classified into primary occlusal trauma or secondary occlusal trauma.

Primary occlusal trauma refers to excessive force applied to teeth with a normal periodontium whereas secondary occlusal trauma refers to normal or excessive force applied to teeth with reduced periodontal support. These forces can be applied to individual teeth or groups of teeth.

Occlusal trauma is a histological term referring to the pathological alterations or adaptive changes in the periodontium caused by traumatic occlusal forces. These histologic changes present as distinct zones of either pressure or tension, which are determined by the direction and magnitude of the traumatic forces applied. The pressure zone may exhibit increased vascularisation and permeability, hyalinisation/necrosis of the periodontal ligament, haemorrhage, thrombosis, bone resorption, cemental tears and root resorption. In contrast, the tension zone may present with elongation of the periodontal ligament fibres and apposition of cementum and bone.

Due to the histologic nature of its definition and diagnosis, without block biopsies, occlusal trauma can only be presumed through assessment of clinical and radiographic surrogate indicators. These clinical and radiographic indicators include progressive tooth mobility, fremitus, occlusal discrepancies, wear facets caused by parafunctional habits, discomfort/pain on chewing, tooth migration/drifting, tooth fracture, thermal sensitivity, root resorption, cemental tears and periodontal ligament widening.

Experimental studies on humans and animals have shown that occlusal trauma within a healthy periodontium does not lead to pocket formation or loss of connective tissue attachment. However, it does lead to alveolar bone resorption and increased tooth mobility. This bone resorption and subsequent increase in tooth mobility is considered a physiologic adaptation of the periodontal ligament and surrounding bone to the traumatic occlusal forces.

However, while occlusal trauma in isolation does not initiate periodontal disease, it can, under certain conditions, act as a co-factor and exacerbate existing periodontitis and its effects by increasing tooth mobility, contributing to attachment loss and altering the bony architecture. It therefore needs to be considered in the management of periodontitis.

The management of occlusal trauma aims to reduce or eliminate the excessive forces applied to the teeth. Treatment options include management of the aetiological factors that contribute to the forces created by the masticatory muscles, and/or management of the dentition. This includes the provision of mouth guards for parafunctional habits, occlusal adjustment, splinting of teeth, prosthetic replacement to redistribute the traumatic occlusal forces or orthodontic treatment.