The spectrum of involuntary movements seen in essential tremor (ET) is limited. Jaw tremor is one such movement. The prevalence and clinical correlates of jaw tremor have not been studied in detail.

At the age of 52 years, a man had begun to exhibit jaw tremor, decreased vocal volume, reduced facial expression and muscle pain, all of which suggested a diagnosis of Parkinson disease (PD).

While this tremor can also present in the lower lip, jaw or leg, it's most common in the hands. The sensation is often described as "pill-rolling," where you feel as though you're holding a pill ...