I have a question for you about a client. He is a six year old boy who has a significant Class III underbite. He has had expanders. The dentist is now recommending a gate, but his mother is against this and has contacted us. On top of his significant underbite, he also has a very long tongue. His productions of /s, z/ are pretty good, but his resting posture is not. While he tries very hard to keep his tongue up and behind his top teeth, he needs to curl his tongue backwards to make it fit. Any suggestions you have would be great.
It is good that his mother and you are investigating the alternatives and exploring the pros and cons of habit appliance. Let me direct you to a position page regarding habit appliances such as rakes, cribs, and gates. Here is the link https://orofacialmyology.com/wp-content/uploads/2018/10/orofacial-myology-position-statement-regarding-appliance-use-for-oral-habit-patterns.pdf
Quite often therapy cannot be effective with a Class III underbite. I’m going to ask you to visualize the jaw/mandible as it literally “carries” the tongue with it. The tongue is attached to the floor of the mouth so if the jaw is forward, then the tongue has to be forward along with it. Now if the tongue and jaw are forward, one would have to curl the tongue awkwardly backwards in order to try to use the “spot” where others naturally rest their tongues. But for someone with a Class III, especially a substantial one, it is totally unnatural to rest on the spot and thus cannot be habituated to the spot. All of this can make the tongue appear to be too long, but it is very unlikely that it is so. Hopefully, this will help you see the connections of the Class III, the appearance of a long tongue, and the frequent negative results associated with habit appliances.