It has been observed that, in patients affected by temporomandibular disorders (TMDs) and edentulism, a left–right asymmetry in electromyographic (EMG) activity of masseter muscles during clenching and in pupil size at rest (anisocoria) is present. Both are greatly reduced by an orthotic-prosthetic correction. In parallel, the correction significantly improves cognitive performance. These effects are possibly due to the recovery of a cortical balance, via Locus Coeruleus (LC) modulation, whose activity is powerfully affected by the sensorimotor trigeminal input. The role of this functional axis was further investigated in subjects without overt occlusal or dental problems.

In these individuals, the EMG asymmetry was significantly correlated to anisocoria at rest, with the dental arches open or in contact. Also in normal subjects, both the EMG and the pupil asymmetry during clenching could be significantly reduced by an orthotic (bite) correction.

Closing the arches without bite increased anisocoria and reduced performance in the Spinnler-Tognoni matrices test, as well as the mydriasis induced by a haptic task. When the bite was interposed, anisocoria was reduced, while both performance and task-related mydriasis were enhanced. Since pupil size is considered a proxy of the LC activity, these results suggest that asymmetric occlusion biases the LC discharge and the hemispheric excitability, possibly via a sensorimotor trigeminal imbalance. Removing the anisocoria through bite correction re-establishes a symmetric LC discharge, improving performance and enhancing task-related mydriasis. Therefore, occlusal balancing may represent a tool for improving subjective performance and may be exploited for training and rehabilitative purposes.

已经观察到，在受颞下颌疾病 (TMD) 和无牙颌影响的患者中，咬肌在咬肌的肌电图 (EMG) 活动中存在左右不对称，而在休息时瞳孔大小不对称（瞳孔不等）。两者都被矫形假肢矫正大大减少。同时，校正显着提高了认知能力。这些影响可能是由于皮质平衡的恢复，通过蓝斑 (LC) 调制，其活动受到感觉运动三叉神经输入的强烈影响。在没有明显咬合或牙齿问题的受试者中进一步研究了该功能轴的作用。

在这些个体中，EMG 不对称性与静息时、牙弓张开或接触时的等距显着相关。同样在正常受试者中，通过矫形（咬合）矫正可以显着减少紧握期间的 EMG 和瞳孔不对称。

在没有咬合的情况下关闭足弓会增加异侧角并降低 Spinnler-Tognoni 矩阵测试的性能，以及由触觉任务引起的瞳孔散大。当咬合被插入时，异瞳症减少，而表现和与任务相关的瞳孔散瞳均得到增强。由于瞳孔大小被认为是 LC 活动的代表，这些结果表明不对称闭塞可能通过感觉运动三叉神经失衡使 LC 放电和半球兴奋性产生偏差。通过咬合矫正去除异瞳重新建立对称 LC 放电，提高性能并增强与任务相关的瞳孔散大。因此，咬合平衡可以代表一种改善主观表现的工具，并且可以用于训练和康复目的。