Trismus, also sometimes called lockjaw, is a painful condition in which the chewing muscles of the jaw become contracted and sometimes inflamed, preventing the mouth from fully opening.
For most people, fully opening the mouth means opening it beyond 35 millimeters (mm) wideTrusted Source — a little greater than the width of two fingers.
When the mouth’s opening movement is restricted, a number of problems can arise.
These include feeding and swallowing problems, oral hygiene issues, and even difficulty speaking.
► See also: DENTAL ANESTHESIA : Mandibular Anesthesia : Gow-Gates technique
Trismus is not the same condition as tetanus, which is also sometimes called lockjaw. Tetanus is an infection caused by the bacterium Clostridium tetani.
Because there’s a vaccine for preventing tetanus, it’s a rare infection in the United States. However, when tetanus does occur, one will have muscle stiffness and spasms that are painful and could occur anywhere in the body.
° Author : healthline.com