ReαlITent aphthous stomatitis (RAS) appears to be one of the most common oral diseases. However, the defmitive etiology of RAS is not well established, though many etiologic faαors have been suggested and examined. The present study was petformed to investigate the association between HIA and Korean recurrent aphthous stomatitis pa디ents. πle proportions of class 1 and class II HIA types expressed in 49 Korean subjects affected by recurrent aphthous stomatitis (RAS) and in 50 healthy controls were deteffi1Í11ed by microlymphocytotoxicity test. 까le sig띠ficance of the data was analyzed by chi-square test and Fisher' s exact test. πle proportions of HIA-Cw1 and -DR9 antigens were significantly higher in RAS pa디ents (p(0.05), whereas those of HIA-DR4 and -DQ2 antigens were significantly lower (p(0.05). 까le odds ratio (OR) were 2.8 for HIA-Cw1 and 2.7 for -DR9. πle etiologic fractions (EF) were 0.262 and 0.193, respectively. The results s맹gest that, in Koreans, there Í$ a sig띠ficant relation between HIA antigens and RAS. Genetic faαors ， reflected in the HIA type, may play an in1portant role in the development of RAS.

• Ji Jun Lim(Department of Oral Pathology, College of DentistIy and Dental Research Institute, Seoul National University) | 임지준
• Nan Hi Gwack(Department of Oral Pathology, College of DentistIy and Dental Research Institute, Seoul National University) | 곽난희
• Seong Doo Hong(Department of Oral Pathology, College of DentistIy and Dental Research Institute, Seoul National University) | 홍성두
• Sam Pyo Hong(Department of Oral Pathology, College of DentistIy and Dental Research Institute, Seoul National University) | 홍삼표
• Jae ll Lee(Department of Oral Pathology, College of DentistIy and Dental Research Institute, Seoul National University) | 이재일
• Chang Yun Lim(Department of Oral Pathology, College of DentistIy and Dental Research Institute, Seoul National University) | 임창윤