A partial least squares model of cephalometric data in obstructive
sleep apnea patients.
Pae, Eung-Kwon, Dds, Msc, Phd, Alan A. Lowe, Dmd, Phd, Frcd(c), John
A. Fleetham, Md, Frcp(c) and Fred L. Bookstein, Phd.
The University of British Columbia, 2199 Wesbrook Mall, Vancouver,
B.C., Canada, V6T 1Z3
APStracts 2:0033L, 1995.
Since Obstructive Sleep Apnea (OSA) has a complex pathophysiology,
studies of this disease demand an analysis of many variables which
are usually interrelated. The analysis requires a large sample size
to ensure an adequate statistical analysis and test of significance.
Furthermore, interrelated variables can often be a source of
multicollinearity. Landmark data for the face and tongue and
interlandmark data for the pharynx obtained from upright and supine
cephalometric measurements of 80 subjects with varying degrees of OSA
were evaluated by means of a Partial Least Squares (PLS) analysis.
PLS analysis is a statistical technique that is intrinsically
insensitive to sample size and multicollinearity. The PLS model of
cephalometric data from OSA subjects displays which part of the
anatomical structure is most associated with OSA severity. The
results show that pharyngeal length was proportionally associated
with OSA indices. The pharynx variables obtained in the upright
cephalograms may be useful in the prediction of OSA severety.
Overall, the statistical tool adopted in this study appears to be
practical for the analysis of complex diseases such as OSA.
Received 18 July 1994; accepted in final form 21 February 1995.
APS Manuscript Number L202-4.
Article publication pending Am. J. Physiol. (Lung Cell. Mol.
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 10 March 1995.