Oftentimes when exporting a part with bones, especially mouths, one of the joints will explode outwards in the game. This seems to be an issue with the exporter, as when the model is re-imported, it also appears screwed up. the easiest way to test this is with the .blend file I have linked below, or even just by importing and then re-exporting any maxis-made mouth and using it as a part ingame.
Oftentimes when exporting a part with bones, especially mouths, one of the joints will explode outwards in the game. This seems to be an issue with the exporter, as when the model is re-imported, it also appears screwed up. the easiest way to test this is with the .blend file I have linked below, or even just by importing and then re-exporting any maxis-made mouth and using it as a part ingame.
blend file: https://www.mediafire.com/file/ofdu2ek4myjchep/ce_mouth_tusks_01.blend/file