Periodontology - Occlusal Trauma

Occlusal trauma is when the teeth are damaged after excessive force and they no longer align properly.

When the jaws close, during chewing or at rest, the relationship between the opposing teeth is called an occlusion. When trauma, disease or dental treatment alter the occlusion through the change of the biting surface of any of the teeth, the teeth come together in a different way. As a result, their occlusion changes. When this change in the teeth has a negative effect on how the teeth occlude, it can result in tenderness, pain and even damage the movement of the teeth. This is referred to as a traumatic occlusion.

Traumatic occlusion can cause a thickening of the cervical margin of the alveolar bone in addition to a widening of the periodontal ligament.

There are a number of physiological results which are evidence of occlusal trauma. These symptoms include:

• Tooth mobility
• Fremitus
• Tooth migration
• Pain
• Sensitivity to hot or cold
• Pain while chewing or percussion
• Wear facets

Diagnosis

Microscopically, there are various features which accompany occlusal trauma. These features include the following:

• Hemorrhage
• Necrosis
• Widening of the periodontal ligament
• Bone resorption
• Cementum loss and tears

There are two different types of occlusal trauma, primary and secondary. Primary occlusal trauma occurs when a greater than normal occlusal force is placed on the teeth. This can occur from parafunctional habits, such as bruxism or chewing and biting habits.

The associated excessive forces can be grouped into three categories, duration, frequency and magnitude.

Secondary occlusal trauma occurs when normal or excessive occlusal forces are applied to the teeth with compromised periodontal attachment. This contributes harm to a system which is already damaged. Secondary occlusal trauma typically occurs when there is a pre-existing periodontal condition.

Cause and treatment

The teeth constantly experience both horizontal and vertical occlusal forces. With the center of rotation of the tooth acting as a fulcrum, the surface of bone adjacent to the pressured side of the tooth can undergo resorption and eventually disappear. While the surface of bone adjacent to the tensioned side of the tooth can undergo apposition and eventually increase in size.

In both primary and secondary occlusal trauma, the mobility of the teeth may develop over time. Tooth movement occurs earlier and is more prevalent in secondary occlusal trauma. In order to treat mobility from primary occlusal trauma, the cause of the trauma itself needs to be eliminated.

In cases of primary occlusal trauma, the cause of the mobility was the excessive force being applied to a tooth with a normal attachment apparatus. This is also called a periodontally-uninvolved tooth. The cause of the pain and mobility should be identified and eliminated. The mobile tooth or teeth should soon stop demonstrating any mobility. This could involve adjustments such as removing a high spot from a recently restored tooth. It could also involve altering the patient’s habits, such as chewing on pens or biting fingernails. For a bruxer, the treatment of the patient's primary occlusal trauma could involve selective grinding of certain interarch tooth contacts or using a nightguard to protect the teeth from normal occlusal forces. For patients who are missing teeth, the treatment may include restoration using a removable denture or an implant-supported crown or bridge.