Crown heights in the permanent teeth of 45,X and 45,X/46,XX females

Abstract

Objective. Previous results regarding human sex chromosome aneuploidies have shown that the X and Y chromosomes affect tooth size and morphology. This study looked for the effect of sex chromosome deficiency on permanent tooth crown heights. Materials and methods. The material, from the Finnish KVANTTI Research Project, consisted of 97 45,X females and 15 45,X/46,XX females. The controls were 32 sisters and 28 mothers of the 45,X females, eight sisters and two mothers of the 45,X/46,XX females and 35 female population controls. Crown heights of all the available teeth except third molars on both sides of the jaws were measured from panoramic radiographs with a digital calliper according to the defined procedure. Results. The tooth crown heights were significantly smaller in the 45,X females than in the female population controls, except for the incisors and one canine in the maxilla, whereas the tooth crown heights of the 45,X/46,XX females were close to those of the normal control females. The differences between the 45,X and 45,X/46,XX females were statistically significant, excluding the upper incisor area and a few teeth in the mandible. Conclusions. 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.

Key Words::

• sex chromosomes
• tooth crown
• tooth size
• Turner syndrome
• X chromosome

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 performing of the radiographic examinations. 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.