Twenty cases of nasopalatine duct cyst

We made clinical and statistical analysis on 20 cases of Nasopalatine duct cyst, and the following results were obtained:1) Among 20 cases, 11 were male and 9 were female. No significant differences could be found in frequency by sex distinctions.2) As for the age of patients, they were distributed from twenties to seventies, and mean age was 44.3 years.3) As for the chief complaint, swelling was claimed in 8 cases and pain in 4 cases, while no subjective symptom was recognized in 8 cases.4) Bilateral central incisor was found in 12 cases, and among them only 3 cases showed their central incisors positive on both sides as a result of the electric pulp test.5) Radiogram exams revealed the following:i) 12 cases were round-like, 6 cases oval and 2 gourdshaped in their appearance on occlusal films.ii) The maximal diameter of the cyst on occlusal films measured approximately 20 nuniii) The cases with anterior nasal spine recognized inside of cyst shadow on the radiograms were 13 with occlusal view and 10 with conventional intraoral radiogram. So called heart-shape shadow in intraoral radiogram was seen in 3 cases.iv) The cyst borders were clear in 10 cases and another 10 cases were not. The latter showed a longer mean of maximal diameters than the former.v) The cyst was located in mid-suture region of maxilla in all cases. 11 cases appeared eccentric.6) As for treatment, the procedures were made from labial side in most cases, 2 cases were from the palatal side.7) Histopathological exams revealed the following:i) The kinds of epithelium of cystic wall were as follows: Pseudostratified ciliated columnar epithelium was found in 15 cases, cuboidal epithelium was in 14 cases and squamous epithelium was in 5 cases (counts are duplicated)ii) Cysts which have two kinds of epithelium in their walls were found in 13 cases.iii) Among the cases of pseudostratified ciliated columnar or cuboidal epithelium, partial squamous metaplasia was observed in 6 cases.iv) Relatively larger bundles of nerves and blood vessels were recognized in 10 cases.v) Glandular tissue was observed in 7 cases.