Certified Instrument Specialist (CIS) Practice Exam 2026 - Free CIS Practice Questions and Study Guide

The instrument that is specifically designed to keep the mouth open during dental procedures is the Molt mouth gag. This tool is crucial for providing the dentist with access to the oral cavity without the patient unintentionally closing their mouth, which can hinder procedures such as extractions, cleanings, or other surgeries. The Molt mouth gag gently holds the jaws apart, allowing for better visibility and maneuverability, thus enhancing the overall efficiency and effectiveness of dental treatment.

In contrast, the other instruments listed serve different purposes. The Henahan retractor is typically used to hold back soft tissues during surgical procedures but is not specifically designed for the mouth. Rongeurs are used for cutting and removing bone and are more commonly utilized in surgical contexts rather than for maintaining mouth openness. Periotomes are specialized instruments used for cutting periodontal ligaments during tooth extractions, rather than for holding the mouth open.