What is the name of the machine used to take a lateral skull radiograph?

The appropriate choice for the machine used to take a lateral skull radiograph is the cephalostat. A cephalostat is a specialized radiographic device designed specifically for obtaining standardized cephalometric radiographs, which include lateral skull views. This machine ensures precise positioning of the patient's head and facilitates reproducibility, which is critical for diagnostic assessment and treatment planning in orthodontics and various other dental specialties.

In contrast, while a radiographic unit (an umbrella term) encompasses various types of imaging equipment, it does not specifically denote a machine designed for lateral skull imaging. An X-ray machine is a broad category of equipment used to produce X-ray images and can be used for many purposes but is not specialized for the standardization required in cephalometric analysis. Lastly, a tomography machine utilizes a different imaging technique that focuses on specific layers or sections of anatomy and is not typically used for lateral skull radiographs. Therefore, the cephalostat is the most accurate and contextually appropriate choice.