Pedipalp, if you're afraid to open his mouth (or afraid to hurt him by doing so), you might hold him gently & just run his face back & forth a few times under
gently running cool water...that may be enough to dislodge whatever is stuck in his jaw? If not, it's no big deal...also dipping his face into his water bowl may
get him to drink also. This would be less invasive than forcibly opening his mouth.