A panoramic radiograph (similar to the one shown, with a tiny finding on the right side) — what is wrong?

When a small, subtle radiographic finding is localized to one side only (asymmetric) rather than appearing as an expected bilateral/midline normal structure, a fracture line is the more likely explanation than a normal anatomic airspace, which would typically be a symmetric or centrally located finding rather than an isolated unilateral abnormality.