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| The above image is an EMG recording of maximum clenching intensities of right and left anterior temporalis (LTA and RTA) and the right and left masseter (LMM and RMM). All six recordings are on the same patient, each with a different occlusal scheme: Natural centric occlusion (CO), manipulated centric relation (CR), posteriorly placed cotton rolls, a Myo orthosis, an NTI device, and an Aqualizer. |
| Natural CO: Both temporalis and masseter contracted at maximal intensity (maximum "clench") |
| "CR": While the temporalis contracted at maximum intensity, the masseters were at a significant reduction. CR is that orientation of the condyle when the jaw is closing against resistance (biting down on an object between the teeth) while the elevating (closing) musculature braces the condyle against the eminance. This is when the temporalis is supposed to be able to contract at maximum. The masseter, on the other hand, is designed and oriented for mastication. Its maximum contraction intensity occurs when the teeth are nearly approximated. Assuming the investigators obtained two different condylar positions for these recordings (CO vs. CR), the masseter readings are normal for "CR" and would be higher in CO. |
| Cotton Rolls: As with CO, both sets of muscles can contract at maximum. |
| Myo Orthosis: As with CO, both sets of muscles can contract at maximum. |
| NTI: Both sets of muscles maximum contractions are significantly reduced. The NTI device is designed prevent the maximum nocturnal clenching intensity that is possible with the other occlusal conditions presented here. |
| Aqualizer: As with CO, both sets of muscles can contract at maximum. |