As dentists, we frequently encounter people who hate having things in their mouth. This doesn't constitute a full phobia, but extreme anxieties are generally grounds for a phobia, such as these verified medical ones (and some that may just be urban legends). The mind is a strange and wonderful thing.
The most common oral phobia in the world: a fear of dentists. For most people, this means they just don't like going to the dentist or it causes anxiety, but it prevents some from seeking medical treatment at all.
Odontarruphobia is the fear of toothbrushes. This might sound innocuous enough; people often don't like putting things in their mouth. But the history shows how extreme this phobia can be, including a 1969 book that was going to be titled The Evils of Toothbrushes.
Probably the strangest and most niche oral phobia in the world: the fear of peanut butter sticking to the roof of your mouth. Where this comes from, we have no idea, but apparently this is a real phobia … of peanut butter.
Queunliskanphobia is the fear of saliva (usually other people's). This is one of the most extreme oral phobias, because it prevents many forms of intimate contact. It also makes it difficult for sufferers to eat and drink, or to brush their teeth.
Cibophobia (also called sitophobia) is the fear of food—more specifically, choking while eating food. Usually caused by the experience of choking on food, it can last a long time and cause bulimia or anorexia, or eating disorders such as overcooking meat or liquidizing all your food.
Touloungeaphobia is the fear of tongues—commonly, the fear of swallowing your tongue, particularly while sleeping.
We'll end with one that many of us likely can't fathom easily: dipsophobia, the fear of drinking alcohol. This control-oriented phobia can be very severe; some dipsophobes suffer to such extremes they can't drink in public places or if they haven't bought and poured the liquid themselves.