The purpose of this study was to compare the effect of head posture on
occlusion in subjects with craniovertebral fusion to that in normal u
nfused subjects. The experimental group consisted of five subjects (ag
e range 30-76) who have all undergone previous surgical fusion of the
craniovertebral region. The control group consisted of five unfused su
bjects matched by age, race and gender. Each subject's tooth contacts
were recorded with a computerized dental instrument known as the T-sca
n. The tooth contacts were measured several times for each subject wit
h the head tilted backwards (45 degrees) and forwards (30 degrees). A
modification of Wilcoxon's rank sum test was used to compare the locat
ion of the tooth contacts and compare any variations between the crani
overtebral-fused subjects' occlusal contact patterns and those of the
normal nonfused patients. The results indicated that four of the five
fused subjects had occlusal contact patterns that differed from their
matched counterparts, thus suggesting that fusion of the craniovertebr
al region interferes with a normal mechanism that permits changes in h
ead posture to shift tooth contact points. These results suggest that
those who manage problems related to occlusion (craniofacial pain synd
romes) need to consider the influence of the craniovertebral region on
both occlusion and jaw position.