General anesthesia has been developed in dentistry as a type of management technique to sedate patients who may be uncontrollable or require medical consideration. However, emergency treatment for controlling pain before general anesthesia could be required due to the time for medical evaluation for general anesthesia. There is a greater possibility of developing complications under extended waiting period. A disabled patient who needs dental treatment under general anesthesia underwent pretreatment with intramuscular injection of midazolam and N₂O-O₂ inhalation sedation in these cases report.