Root lengths in the permanent teeth of 45,X females

Abstract

Objective. Studies in permanent and deciduous tooth crowns and permanent tooth roots in individuals with sex chromosome anomalies and in their relatives have given proof that the X chromosome affects enamel formation, root length and crown and root morphology. The present research studies the effects of sex chromosome deficiency on the development of permanent tooth root. Materials and methods. This research investigated tooth root lengths in a group of 97 45,X females. As controls there were 32 sisters and 28 mothers of the 45,X females, 45 female and 42 male population controls and 15 45,X/46,XX females from the KVANTTI research project. Tooth root lengths on both sides of the jaws were measured from panoramic radiographs in each acceptable instance. Results. The results showed significantly shorter tooth root lengths in the 45,X females than in the female and male controls in all teeth measured, whereas in the female relatives tooth root lengths were shifted towards the aneuploids in relation to that in the general population. The tooth root lengths in the 45,X females differed more from those found in their sisters than in their mothers. Conclusions. 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.

Key Words::

• chromosomes
• human
• X
• sex chromosome
• tooth root
• Turner syndrome

Acknowledgements

The KVANTTI dental research project has been supported by the Emil Aaltonen Foundation, the University of Turku Foundation, the Academy of Finland, the Finnish Dental Society, Apollonia and Tyyne Tani (University of Oulu). We thank the Northern Ostrobothnia Hospital Board for the finance received for this project under the EVO scheme and the Orthodontic section of the Finnish Dental Society Apollonia for a grant towards this research. Professor Erkki Tammisalo contributed to the accomplishment of radiographic examinations. We are also grateful to Ahti Niinimaa for performing the statistical analyses presented here. The research reported here complies with the current law in Finland.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.