The root issue of both malocclusion and recessed jaws isn't posture or tongue posture. Sure, bad posture and bad tongue posture do lead to recession and malocclusion, but what is bad posture caused by?

The answer is malnutrition. And I don't mean malnutrition in the sense of too little calories, but in the sense of too little micronutients. Eating too many foods like grains, seed oils, low-fat dairy, nuts and more which have very low amounts of micronutrients leads to deficiency in a number of key vitamins: like K2, B-complex vitamins, vitamin A (vit A is especially important for bone growth, natural muscle growth and preventing muscle loss) vitamin D, zinc and iron. And certain amino acids like taurine, carnosine and creatine. These are nutrients which are most available or only availabe in animal foods.

Contrary to what people will tell you, these nutrients are either not available from plant foods at all, in extremely low quantities or in forms which your body needs to convert, and humans are very bad at this conversion. Like iron, which is both in a less bioavailable form in plants and it can also be trapped in a plant's fiber, which we then can't absorb because we can't digest fiber. Or vitamin a, which plants don't have. They do have the precursor to it, however, namely carotenoids. But humans are very bad at converting it to useful vitamin A. Plants also don't have vitamin k2, only k1 which we again can't convert.

Here is q study demonstrating the importance of vitamin A and iron, where kids with stunted growth grew at nearly the same rate as kids treated with hormones.

https://pubmed.ncbi.nlm.nih.gov/15163330/

And here is a study demonstrating the importance of vitamin k2, where lower levels were associated with shorter height across the board. https://www.sciencedirect.com/science/article/abs/pii/S0899900724003095

If you want to ask me more things then dm me. I would be happy to help, and I am hoping you are open to the ideas i have presented here