Occlusal morphology in Turner syndrome.

The prevalence of malocclusion in 32 Turner syndrome patients, age 7-16.7 years, was investigated. The sample was subdivided according to karyotype, and 72 normal girls, aged 7.1-16.1 years, served as controls. Compared with normal girls overjet did not differ significantly while overbite was significantly reduced in 45X patients. The prevalence of distal molar occlusion, anterior and lateral open bite and lateral crossbite was significantly increased. Most significant differences were found between 45X patients and controls. Mosaic and isochromosome for the long arm of X karyotypes showed the same pattern of malocclusion, but with greater variation. No significant differences were found comparing 45X patients with mosaic and isochromosome for the long arm of X karyotypes. The results indicate that patients with structural and/or numerical aberration of the X chromosome, develop a specific pattern of malocclusion with deviations in sagittal, vertical and transversal directions.