Obstructive sleep apnea has been known to be associated with sleep related bruxism. This study measuring apnea-hypopnea index (AHI) and sleep bruxism index (SBI) showed no correlation between AHI and SBI. The patients with severe apnea showed a tendency to have higher bruxism index. However, there was no correlation between AHI and SBI.

In the orofacial pain field, traditionally, the masseter muscle has been divided into superficial and deep layers. The possibility of a third layer was mentioned in a few historical texts. This anatomical study is probably the first of its kind that showed a distinct third layer of the masseter muscle. The existence of the third layer is consistent in every human cadaver examined; the muscle layer is attached on the medial surface of the zygomatic process of the temporal bone to the root and posterior margin of the coronoid process. The arrangement of the fibers suggests its involvement in stabilizing the mandible by elevating and retracting the coronoid process.

This narrative review summarizes the data on the effect of light on migraine patients. Light has been reported as a trigger for migraine attacks. This article shows that photophobia being an early manifestation is a false attribution, contrary to this belief. Migraineurs are not equally photophobic to all wave bands of the light spectrum. With regards to this, the suggestion is to use human-centric lighting (“integrative lighting”) that mimics natural daylight, and thereby avoiding harmful light wave bands.