It's essential to have confidence in your examination skills to predictably and effectively treat occlusal problems. Most of our patients will exhibit a shift between CR and ICP – a majority of these patients have a very mild shift and will not need equilibration.
However, for those who have symptoms, it's important to be aware of the complications that the patient may experience when there is a major shift between CR and their ICP.
Muscle issues: Let's take the example of a patient with a significant shift and the first point of contact is on molars. When the mandible moves and the brain recognizes the first point of contact, the lateral pterygoid is triggered to contract and the teeth are moved into interdigitation. Over time this contraction can cause muscle hyperactivity and may cause pain or tenderness.
Tooth sensitivity: Patients with a shift may also experience pulpal sensitivity from repeated contact on the same interference every time the mandible brings the teeth into contact. If your patient has a significant shift from CR, it is important to remember that when evaluating the occlusion on restorations you have just placed, simply asking the patient to bite in ICP does not ensure that there are no occlusal interferences.
Wear and fractures: In almost every severe wear case, patients have a healthy periodontium. A healthy periodontium minimizes tooth mobility and increases the occlusal forces that can be applied to the teeth. These forces not only result in wear, they can cause cracks and fractures.
Not all patients with a CR- ICP shift are going to experience these complications. Keeping the above findings in mind during examination is important. A comprehensive muscle and dental examination on every patient can help them avoid pain, sensitivity and wear.