William Cullen Bryant

Truth gets well if she is run over by a locomotive, while error dies of lockjaw if she scratches her finger.

American Poet

The person whose face is between your legs is gonna get lockjaw.

Lockjaw refers to a specific health issue, not just any kind of jaw pain or stiffness.

Using 'lockjaw' implies a severe medical problem that usually requires immediate attention.

Lockjaw is a formal medical term, so it is appropriate in medical or serious discussions.