What are the two most common causes ofâ¦. What are two types of preventatives forâ¦. A patient choking on a temporary crownâ¦. small objects that we place in the mouth, and the supine positâ¦. food and the second is dental appliances. a rubber dam and/or a gauze curtain placed in the anterior porâ¦. partial obstruction because the patient is still able to cough. What two things about dental treatmentâ¦. small objects that we place in the mouth, and the supine positâ¦. What are the two most common causes ofâ¦.