Maxillary sinus floor in edentulous and dentate patients.

To compare the depth of the maxillary sinus floor on panoramic radiographs between the edentulous and dentate patients. Thirty panoramic radiographs of edentulous female patients and 47 panoramic radiographs of female dentate patients were used for the sample. To measure the depth of the maxillary sinus floor, the outline of the maxillary sinus on the panoramic radiograph was traced on transparent paper. An apparent difference in depth of the maxillary sinus floor was recognized only in comparing the left sides of the edentulous and dentate jaws(P < 0.05). However, there was no statistical difference in the depth of the maxillary sinus floor between the right and left sides in the edentulous and dentate jaws. In this study there seems to be no difference in the depth of maxillary sinus floor between the right and left sides of either the edentulous or dentate jaws. It is not clear as to why, on the other hand, there is a statistical difference in between only the left maxillary sinus floor of the edentulous and dentate jaws, this apparent contradiction might be further investigated statistically.

A generational comparison of changes in mandibular third molars.

Due to recent increases in the number of cases of embedded mandibular third molars, the Department of Dental Radiology, Kyushu Dental College decided to investigate generational differences in their occurrence. For the purpose of investigation, 670 panoramic radiographs, obtained from two different generations (1970s and 1999s) of Kyushu Dental College students, wer used. There were significant statistical differences in the angle of eruption of the third molar between the 1970s and 1990s groups. The mandibular third molars in the 1990s group were growing at an abnormal angle (P < 0.05) and were closer to the mandibular canal (P < 0.05) than those in the 1970s group.