Journal of Dental Research, Vol 71, 1604-1606, Copyright © 1992 by International & American Associations for Dental Research Online Journals
Effect of 45,X/46,XX mosaicism on root morphology of mandibular premolars
J. Varrela
Institute of Dentistry, University of Turku, Finland.
The effect of X chromosome mosaicism on root morphology of mandibular
premolars was studied in 14 females with 45,X/46,XX chromosome
constitution. Occurrences of two-rooted premolars and the morphology of the
roots were examined from orthopantomograms. Six (43%) of the 45,X/46,XX
mosaics had two-rooted mandibular premolars. Two-rooted first premolars
were found in four (29%) and second premolars in three (21%); in one, all
four mandibular premolars were two-rooted. The results indicate that the
frequency of two-rooted mandibular premolars was similar in 45,X/46,XX
mosaics and in 45,X females, and in both groups significantly higher than
in normal 46,XX females. Compared with 45,X females, the 45,X/46,XX mosaics
showed a slight tendency toward more simplified root morphology in the
first premolars. The findings suggest that the presence of normal 46,XX
cells among the defective 45,X cells does not affect the development of the
mandibular premolar roots. Furthermore, the results do not support the
earlier proposal that the presence of normal 46,XX cells in 45,X/46,XX
mosaic individuals would be reflected in gradual normalization of dental
development.
