Foot orthoses and dental appliances--is there a relationship?

This investigation was aimed at examining whether subjects who wear a combination of functional foot orthoses and dental appliances have less postural sway and furthermore to study if these changes are direction dependent.

Centre of pressure (CoP) displacement in seven subjects, mean age 49 range (39-58) who met the inclusion criteria were evaluated using a pressure platform. Total displacement of the centre of pressure, the reduction in the displacement about the origin, area of the ellipse, total displacement along the x- and y-axes and frequency of sway along the anterior-posterior and mediolateral axes were estimated under four conditions, namely wearing orthoses and appliances, wearing only orthoses, only appliances and finally wearing neither orthoses nor appliances.

In the six patients who had class II malocclusion there was no significant difference between the displacement (z=0.314 and p=0.753) and the frequency (z=0.680 and p=0.496) of sway along the medio-lateral or anterior-posterior axes. Under control conditions the mean path length was 780 (SD 415) mm, the mean deviation from origin was 4.76 (SD 5.8) mm and the mean area was 0.83 (SD 1.87) mm(2)/cm(2). The mean deviation from origin was seen to reduce under all experimental conditions. Wearing the dental appliance alone was seen to be the most effective although the difference was not statistically significant. The sway area was also seen to reduce under all experimental conditions. The sway was most reduced when participants were wearing orthoses (i.e. conditions 1 and 3) with the reduction being the greatest when the orthoses was worn on its own (i.e. condition 3).

While, foot orthoses have been used for the relief of symptoms either within or extrinsic to the foot, they could have a much wider role in the management of patients with stability problems. Results from this study highlight the need for further research in this exciting and as yet unexplored area.