Accentuated temporal line on the frontal skull radiograph: a sign of hyperparathyroidism.

Abstract

To determine the importance of a temporal line (the marginal line for the attachment of the temporal muscle to the skull) that is accentuated on frontal skull radiographs of hyperparathyroid patients owing to subligamentous bone resorption under the temporal muscle. Radiographs from skeletal surveys of 134 surgically treated patients with primary (n = 102) or secondary (n = 32) hyperparathyroidism (HPT) and frontal skull radiographs of 63 age-matched control patients were reviewed. An accentuated temporal line was the most frequent finding (29.4% of cases) in primary HPT, followed by subperiosteal bone resorption in the hand (8.6%), salt-and-pepper appearance of the skull (3.5%), and rugger-jersey spine (1.1%). In secondary HPT, an accentuated temporal line became less obvious as subperiosteal bone resorption advanced. This finding was not seen in the control group. An accentuated temporal line is another radiographic indication of bone resorption in HPT.