# Orthodont

##### Growth curve data on an orthdontic measurement

The `Orthodont`

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

- Keywords
- datasets

##### 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.

##### 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.

##### Examples

```
data(Orthodont)
formula(Orthodont)
plot(Orthodont)
```

*Documentation reproduced from package lme4, version 0.6-6, License: GPL version 2 or later*