Cysts of the nasopalatine duct.

Nasopalatine duct cysts in 70 patients were reexamined clinically and radiographically. 50 of them were also reexamined histopathologically. 20 specimens of normal duct tissue were likewise examined. More than half of the cysts showed clinical symptoms. The form on the radiograph was usually spherical or oval. Only 1 of 5 cysts was heart-shaped; 1 of 10 was unilateral. The mesiodistal width of the cysts ranged from 4-40 mm, with 75% from 6-12 mm. 3 of 4 showed pronounced radiolucency. Every 2nd cyst was completely surrounded by a thin radiopaque border. The histopathological investigation showed small cysts to be present in 1 of 4 clinically and radiographically normal nasopalatine ducts. More than 1 of 4 clinically and radiographically diagnosed cysts lacked histopathological characteristics of a cystic cavity. The type of epithelium in the cysts was independent of the vertical position in the duct.