The determination of freeway space using two different methods.

The aim of this study was to determine the average freeway space of dentate subjects and relate this to recommended ranges for edentulous patients, also to see if any differences were observed between two different methods of measuring freeway space. The freeway space of 72 dentate subjects was measured, first using a Willis gauge, and secondly using a pair of sprung dividers. The intra- and interoperator variability was evaluated as was the reproducibility of the accuracy of both techniques. The mean freeway space using the Willis gauge was 3.3 mm, for both intra and inter operator variability, and with the sprung dividers 3.1 and 2.9 mm, respectively, with no significant difference being seen between any combination of results (P > 0.05). Individual measurements within the two measuring methods being assessed showed significant differences (P < 0.05). The mean measurements of freeway space in dentate subjects found in this study were within the recommended 2-4 mm range, however, 15% of the subjects in the study had freeway space measurements outside this range. This study would suggest that the range for freeway space measurement could more realistically be 2-7 mm.