Yes, the sentence is grammatically correct.
The meaning of the sentence is that the speaker is reflecting on the possibility that they might look more attractive without their diastema, which is the space between two teeth, often referring to the gap between the front teeth.
Here are some possible rephrasings:
1. "I occasionally think about whether I'd look more beautiful if I didn’t have my diastema."
2. "At times, I find myself


