PTH and hypoparathyroidism: At the time of examination (in average 8.2 years after surgery), 20 patients had normal PTH levels (48 %, mean 3.6 ± 1.9 pmol/l), eight patients had a mild hypoparathormonemia (19 %, mean 0.8 ± 0.4 pmol/l) and seven patients had a biochemical hypoparathyroidism (17 %).