October 19, 2021
The human teeth bare dome-shaped structures on their biting surface known as cusps. When the upper and lower teeth come together, there is a harmonious closure of the bite. This inter-cuspation of teeth is called an occlusion. Occlusion is any arrangement of teeth when they intercuspate. An improper occlusion is called a malocclusion. A proper occlusion ensures not only proper distribution of biting forces, but also the normal tense and flex of the muscles that are attached to the jaws.
Each tooth is surrounded by a complex tissue system known as the periodontium. This periodontium constitutes the gingiva, the underlying bone (alveolar bone), the ligament (periodontal ligament) connecting the tooth and the bone, and the hard tissue covering the roots (cementum). It is because of the periodontium that each individual tooth is able to bare and resist the various forces acting upon them. However, there are cases when an improper force, arising due to the bite causes damaging changes in the periodontium. This is called occlusal trauma.
Classification of occlusal trauma - primary and secondary
Trauma to the teeth arising as a result of improper occlusion can be grouped into two types: Primary and Secondary.
Primary occlusal trauma is when there is absence of a periodontal disease or condition. It arises because of parafunctional habits like clenching or grinding teeth (bruxism), chewing upon fingernails, pens, pencils, etc. The duration, frequency and magnitude of these habits directly correspond to the damage on the tooth.
Secondary occlusal trauma is when occlusal forces exaggerate the damage on a tooth that is already having a periodontal condition or disease.
Etiology
In primary occlusal trauma, since the involved teeth are in an otherwise healthy state, the reason for the trauma can be due to a malocclusion like a deep bite, where teeth of upper arch contain the teeth of lower arch and lay down heavy forces on normal closure of the mouth.
Occlusal trauma can also arise because of over-eruption of one tooth of the opposing arch.
Recent dental treatments, wherein a tooth is restored with a restorative material can also contribute to occlusal trauma if the restoration is done higher than the normal occlusal level.
Signs and symptoms
Mobile teeth is the most common sign of a tooth that has occlusal trauma. It occurs because of a condition called fremitus. This is basically when the tooth exhibits mobility caused due to widening of the ligament surrounding it that primarily occured because of undue forces of occlusion.
A tooth whose periodontal condition becomes compromised might as well rotate or drift away from its normal position in the oral cavity.
Pain and sensitivity are common findings arising as a result of excessive forces.
Regular and consistent occlusal forces that lead to trauma can also lead to the tooth's surface become gradually chewed away leading to the formation of wear facets.
Diagnosis
Clinically, the patient is asked to close his or her mouth and a suspected occlusal trauma can be diagnosed by observing the intercuspation of teeth. Gingival bleeding around the affected tooth can be seen. The excessive traumatic force can devoid the tooth of blood supply. A radiograph is taken to understand the extent of resorption of the underlying bone and subsequent widening of the periodontal ligament.
What is the difference between primary occlusal trauma and secondary occlusal trauma?
In primary occlusal trauma, since the teeth are otherwise in a normal condition, grinding of the cusps or reducing the height of the restoration can help in reducing the occlusal force. Moreover, in patients with habits like bruxism, a nightguard can be advised to safeguard the patient from further damage.
In secondary occlusal trauma, since the tooth is periodontally weakened, treatment is aimed at both, reducing the occlusal trauma and restricting the mobility of the tooth. Splinting is a procedure where mobile teeth are bound with a flexible sturdy wire. This can be coupled with bone grafting and surgical procedures which help in improving the attachment of the tooth to the underlying bone. In some cases, implants or bridges might need to be placed in areas where no tooth or teeth is present. This can help in better distribution of occlusal forces.
Trauma from occlusion is a condition that needs to be addressed at the moment of diagnosis, since its negative implications can extend deep into the bony areas and have detrimental effects on the oral-health related quality of life.