nlme (version 3.1-99)

Orthodont: Growth curve data on an orthdontic measurement

Description

The Orthodont data frame has 108 rows and 4 columns of the change in an orthdontic measurement over time for several young subjects.

source

Pinheiro, J. C. and Bates, D. M. (2000), Mixed-Effects Models in S and S-PLUS, Springer, New York. (Appendix A.17)

Potthoff, R. F. and Roy, S. N. (1964), ``A generalized multivariate analysis of variance model useful especially for growth curve problems'', Biometrika, 51, 313--326.

Details

Investigators at the University of North Carolina Dental School followed the growth of 27 children (16 males, 11 females) from age 8 until age 14. Every two years they measured the distance between the pituitary and the pterygomaxillary fissure, two points that are easily identified on x-ray exposures of the side of the head.

Examples

formula(Orthodont)
plot(Orthodont)