Pterygomandibular raphe ossification in a patient with severe trismus following trauma: A rare case report and review of the literature

BACKGROUND: Pathological changes of the pterygomandibular raphe (PMR) are rarely reported, and true ossification is particularly uncommon. Severe trismus associated with extensive PMR ossification has not been previously described. CASE PRESENTATION: A 24-year-old man presented with severe, long-standing trismus following treatment of a mandibular fracture sustained at 5 years of age. Maximum interincisal opening (MIO) was 18 mm, and a firm, noncompliant area was palpable in the right pterygomandibular region. Cone-beam computed tomography demonstrated extensive ossification along the expected course of the right PMR toward the pterygoid plates. The ossified structure was surgically excised. Histopathology confirmed mature osseous tissue. MIO increased immediately to 26 mm and reached 33 mm at 6 months with postoperative jaw-opening exercises. CONCLUSION: Extensive PMR ossification should be considered among the uncommon extra-articular causes of persistent trismus. Immediate improvement after excision supports a mechanical contribution, although causality with childhood trauma cannot be established.