A total of 20 individuals with X-chromosome aberrations, 14 45,X/46,XX-women and six 46,Xi(Xq)-women, were examined for occlusal anomalies. The controls were first-degree woman relatives and population women. The results showed that the most common type of malocclusion in both study groups was lateral cross bite. Also distal molar occlusion, increased maxillary overjet and in 45,X/46,XX-women open bite was found. 45,X/46,XX-women's occlusion seems to be more affected than that of 46,Xi(Xq)-women. Compared to 45,X-women, the present study groups show milder expression of malocclusion. One might speculate that enamel genes of the X-chromosome are involved in occlusal development.