Is it permissible to supplicate for the jaw to become flexible so that it returns to its natural position with orthodontics after the age of 18, by analogy with the issue of supplicating for an increase in height after puberty?

The questioner is advised not to preoccupy themselves too much with superficial matters, for a person's perfection lies in their faith and character. As for the question regarding the change in jaw shape after a certain age, if it is scientifically proven to be impossible, then asking Allah Almighty for it is considered a forbidden transgression, based on the statement of Shaykh al-Islam Ibn Taymiyyah: "Transgression in supplication: sometimes by asking for what one is not allowed to ask for... and sometimes by asking for what Allah does not do... and similar matters whose asking is a transgression that Allah does not love, nor does He love the one who asks it." Similar is the statement of Ibn Abidin in Radd al-Muhtar: "It is forbidden to ask for continuous health for eternity, or the good of both worlds, and the دفع of their evil, or for customary impossibilities, such as the descent of a table [of food from heaven]."