I would like to know what does 歯が欠ける mean: Lacking teeth? Broken teeth?
Context: 人の幸せを素直に喜べないやつ理解出来なさすぎて、また歯が欠けた。
My translation:
I can't barely understand people who cannot honestly be glad for other's happiness, 「???」.
How would you translate the expression 歯が欠ける?
Thank you so much in advance for your help!