Pathology · patient case with 2 questions
Restricted opening with pain only on passive stretch
Patient: Female, 33 years old
Chief Complaint: “My jaw feels tight and I cannot open as wide as I used to.”
Background: Reports a stressful year and daytime clenching. No trauma, no locking episodes, no previous treatment.
Vital Signs: BP 116/72 mmHg · HR 76 bpm
Findings: Maximum comfortable opening 32 mm. On gentle PASSIVE STRETCH the jaw opens a further 5 mm, at which point the patient reports pain. NO pain on lateral or protrusive movements. NO joint noise. Palpation of the masseter and temporalis reproduces her familiar discomfort. Radiographs show no degenerative change.
Question 1
What does the additional 5 mm of opening on passive stretch, with pain at the end of that range, indicate?
Show answer and explanation
Correct answer: B. A MUSCULAR restriction — the soft end feel of muscle guarding
- A. The same reasoning applies whichever side is proposed. The end feel is soft, so the block is not intracapsular.
- B. CORRECT. The END FEEL is what the test is for. If gentle passive stretch gains a further 4–5 mm before pain, the restriction is SOFT and springy — muscle, which stretches under load. That points to MYALGIA or protective guarding, and it fits the rest of the picture: palpation reproduces her familiar pain, there is no joint noise, and lateral and protrusive movements are painless.
- C. Degenerative joint disease produces crepitus, radiographic flattening, erosion or osteophyte formation, and pain on loading. None is present.
- D. A disc displaced without reduction gives a HARD end feel — passive stretch gains little or nothing, because the displaced disc mechanically blocks translation. It also produces persistent deviation toward the affected side and pain on contralateral excursion.
Note: The bedside distinction to carry: a SOFT end feel with several extra millimetres on stretch means MUSCLE; a HARD end feel with no give means DISC or bony ankylosis. Normal maximum opening is 40–55 mm, and translation contributes the portion beyond roughly 25 mm — which is why muscular and disc restrictions both show up in the 25–35 mm range.
Question 2
What is the appropriate FIRST line of treatment?
Show answer and explanation
Correct answer: D. Occlusal splint therapy with patient education and jaw exercises
- A. Arthrocentesis is an INTRACAPSULAR procedure for a joint problem that has failed conservative care. This patient's restriction is muscular, and nothing has been tried yet.
- B. Occlusal equilibration is IRREVERSIBLE. There is no good evidence that grinding teeth treats temporomandibular disorders, and once enamel is removed it cannot be returned.
- C. Orthognathic surgery addresses skeletal discrepancy. It is not a treatment for masticatory myalgia and sits at the very end of any escalation, if at all.
- D. CORRECT. Management of temporomandibular disorders begins with what is REVERSIBLE and CONSERVATIVE: patient education and reassurance, a soft diet and jaw rest, moist heat, gentle stretching exercises, stress and parafunction awareness, and a flat-plane STABILISATION SPLINT worn at night. The great majority of patients improve on this alone. Pharmacotherapy — an NSAID or a short course of a muscle relaxant — is an adjunct, not the foundation.
Note: Sequence every temporomandibular case the same way: reversible first — education, self-care, physiotherapy, splint — then reassess at six to eight weeks; then adjunctive pharmacotherapy or trigger point injection; and only after documented failure of conservative care does anything irreversible come into the conversation. The condition is largely self-limiting, which is precisely why irreversible treatment is so hard to justify early.