The effect of the sex chromosome deficiency on permanent tooth crown height is due to the magnitude of lacking sex chromosome material. The present results regarding the 45,X females are parallel to previous findings in Turner patients regarding reduced mesiodistal and labiolingual dimensions and tooth crown heights in the permanent dentition.

These results with the large pure sample size of the whole dentitions in patients with monosomy X confirm the earlier findings of short tooth roots in 45,X females. The fact that in most instances there were no significant differences in tooth root lengths between 45,X and 45,X/46,XX females comes close to the earlier findings regarding mesio-distal tooth crown sizes.

Based on previous investigations and this work, it is evident that the impact of the extra Y chromosome during tooth crown development is holistic, increasing permanent tooth sizes in three dimensions in a balanced manner.

No abstract