Abstract: The material on which this report is based was recovered during a series of archaeological excavation carried out from 1993 to 1998, at Lamadong cemetery in Beipiao, Liaoning. The date of this site is estimated to be about 1600 —1700 years ago. Malocclusion is one of oral diseases with high mor- bidity today. This paper described the incidences of the malocclusion of 87 skeletons unearthed from Lamadong cemetery in Beipiao, Liaoning, and discussed the relationship between the frequency of malocclusion, on the one hand, and sex and age on the other. The result is as follows: (1)Among the 87 individuals whose upper and lower dental archers were preserved intact, 57. 43 % had normal occlusion and 42. 53 % had malocclusion ; in Angle' s classification of malocclusion, class Ⅰ occured most fre- quently, which accounts for 70. 27 %. This is different from the occlusal condition of the present people. The most of malocclusions in Lamadong group were due to abnormal positions of individual teeth while most malocclusions of modern people belong to the categories of anomaly of dental arches or jaw bones. (2)The frequency of the malocclusion had no marked sexual difference. (3)Formation of hu- man malocclusion had certain association with the dietary traditions decided by their economic status. (4)The forms of the dental arch of human being are classified as ovoid arch form, square arch form and V-shaped arch. The ovoid types represents the majority,V-shaped arch, or tapering type occurred rarely. Among the dental arches of these ancient individuals ovoid arch form or square arch form oc- curred in 97. 7 % cases. This is also different from modern people. (5)In 54.02 % cases of the Lamadong people the abraded occusal surface looked flatter and even,while in most of the present people it appears very uneven and rocky.

Key words: Malocclusion; Wei-jin period; Lamadong cemetery