Normal and pathologic radiographic anatomy of the motor innervation of the face.

Facial motor disorders, including facial paralysis, myokymia, dyskinesia, and hemifacial spasm, are common clinical problems in which radiographic evaluation plays a crucial role. Since every segment of the motor innervation of the face from the brain to the parotid gland can now be seen radiographically, radiologists must understand the normal anatomy, the common pathologic lesions at each level, and the clinical findings that help localize the abnormality so that the most sensitive and accurate radiographic approach can be planned. Though computed tomography alone allows for visualization of every segment, other methods such as cisternography, angiography, polytomography, sialography, and magnetic resonance imaging are complementary in specific disorders.