 The advent of the multichannel autoanalyzer in the 1960s and 70s led to an increase in early diagnosis of primary hyperparathyroidism . This increase led to a sharp decline in the prolonged manifestation of the disease , leading to a drop in the number of cases of OFC due to the early detection of hyperparathyroidism . Before this invention , the diagnosis of primary hyperparathyroidism was generally prolonged until the emergence of severe manifestations , such as OFC . 
