X-ray - OPG and mandible x-rays
What is trismus?
Reduced range of motion of the TMJ, i.e. inability to fully open the mouth. It has many causes.
Which extraction cavity is abnormal?
The left mandibular extraction cavity has indistinct margins compared to the others.
Extraction cavities of the wisdom teeth can be seen. Note how the outline of the left cavity is blurred compared to that on the right.