Comparison of occurrence of oro-maxillo-facial tumor types in different regions of the People's Republic of China.

The frequencies of oro-maxillo-facial tumors, by type, seen at the Guangxi Medical College Hospital were surveyed in order to compare different regions of the People's Republic of China. Computer analysis was performed on data for all oro-maxillo-facial tumors, as confirmed by the hospital between 1957 and 1987, inclusive. The results were then used in a comparative study with those of five other medical colleges. Among a total of 4,052 cases, there were 1,593 benign tumors, 2,049 malignant tumors and 410 unknown tumors. Tumors derived from the epithelium were the most common type (42.0% of the total), whereas in the other five medical colleges the mean corresponding proportion was 27.8%, the difference being significant (p < 0.05). Epithelial tumors were also the most common type of malignant tumor (70.5% of the total), whereas the corresponding proportion reported by the other five institutions was 60.6%, which was also significantly different (p < 0.05). The proportion of malignant tumors among the total was more than 50.6%, which was higher than that reported by the other five colleges. This study shows that epithelium-derived tumors and malignant tumors were encountered more frequently at Guangxi Medical College than at the other five medical colleges in China.