Oral care is easily neglected in patients in an intensive care unit (ICU) because they are often intubated or have altered mental status. Although care workers pay careful attention to the mouth, tooth loss often occurs in the ICU. Here we report 3 cases of dental bridge loss undetected by the ICU staff. One patient was under mechanical ventilation via an endotracheal tube after emergency intubation, whilst 2 patients were drowsy but not intubated. Consecutive chest X-rays revealed dental bridge loss in all 3 cases, but this was not identified immediately. Along with other critical management approaches, these cases demonstrate how an initial evaluation of the oral cavity, with special attention to the number of teeth, and the existence of dental prosthetics is essential to preventing potential deleterious complications. The number of teeth and the existence of dental prosthetics must be documented in ICU patients.