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These are the case findings in their original reveal order, moving from the broader presentation to the most discriminating evidence.
Clue 1
A 58-year-old has had a deep, unrelenting ache in the right side of his lower jaw for seven months. It began after a back tooth was taken out eight months ago, and the socket has simply never closed over. He has smoked for decades and his mouth has not met a toothbrush as often as it should.
Clue 2
Three years ago he finished a course of radiotherapy for a cancer of the oropharynx: 66 Gy, with the lower jaw sitting inside the treated field. The molar came out eight months ago — which is to say, after the radiotherapy rather than before it.
Clue 3
Lift the cheek and the socket has a patch of bare bone sitting in it, dull and plainly dead, the gum edges never quite meeting over the top. A small opening beside it discharges pus. He can no longer open his mouth as wide as he used to.
Clue 4
What is absent matters. There is no mass, no ulcer with rolled, heaped-up margins, and nothing firm or indurated in the tissue around the exposed bone. He has never taken a bisphosphonate or any other antiresorptive drug. Both teeth flanking the gap answer cold and electric testing normally and are vital, so no dead tooth is feeding infection into that site.
Clue 5
Diagnosis
Osteoradionecrosis
Why the diagnosis fits
Radiotherapy leaves bone with a blunted capacity to heal, and this jaw was asked to heal anyway. Three years ago he finished 66 Gy for an oropharyngeal cancer with the mandible in the treated field; risk becomes substantial between 60 and 70 Gy, where the incidence is about 1.8%, rising to 9% above 70 Gy. A lower molar was then extracted after the radiotherapy — the most avoidable risk factor on the list, alongside his smoking and poor oral hygiene — and the socket never closed. What is left is osteoradionecrosis: injured bone tissue with an inadequate healing or remodelling response persisting for at least three to six months, here seven and counting, with exposed necrotic bone, a draining fistula, secondary infection and trismus. Two things make the reveal land. The first is the interval. This typically manifests on average two to four years after radiation therapy is completed, and this bone was laid bare more than two years out. Findings that develop within six months of finishing radiotherapy point the other way, towards persistent or recurrent malignancy — the diagnosis that must not be missed here. There is no mass, no ulcer with rolled margins and no induration, and the timing is wrong for recurrence; but where genuine doubt remains, biopsy is the arbiter, not the radiograph. The second is the direction of the radiographic change: lytic areas with ill-defined, non-sclerotic borders. Medication-related osteonecrosis of the jaw runs the other way — osteosclerotic — and is associated with bisphosphonate exposure rather than radiation, and this man has never taken an antiresorptive drug. Alveolar osteitis, the other obvious candidate after an extraction, begins within days of the procedure and settles; it does not leave dead bone uncovered for seven months. Staging follows Marx, 1 to 3, based on the response to hyperbaric oxygen therapy, and management ranges from conservative wound care and antibiotics to surgical debridement and vascularised bone reconstruction.
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