Reliability and comparison of two facial measurements to detect changes of occlusal vertical dimension in complete denture wearers.

BACKGROUND

Facial measurements are frequently used to determine OVD. However, the reliability of neither the method nor the chosen landmarks has been cleared yet.

OBJECTIVE

This study compares the reliability of two facial measurements, subnasal (SN) to chin (C) and tip of the nose (TN) to C, for determining occlusal vertical dimension (OVD).

MATERIALS AND

METHODS

Thirty edentulous subjects with adequate neuromuscular co-ordination, without signs and symptoms of temporomandibular disorders and who had been wearing complete dentures for at least 5years were enrolled. A modified central bearing device was used to alter the OVD and facial measurements were made with a digital caliper. Student's t-test was used to compare the two measurements. Interobserver and intraobserver reliability were evaluated with Spearman's rho correlation test.

RESULTS

TN-C distance had an improved correlation with the changes in intraoral alterations than SN-C distance. While the means of the changes in facial measurements were in good agreement with the intraoral alterations, the ranges were wide. Both interobserver and intraobserver reliability of the measurements were high.

CONCLUSION

While facial measurement is not a good predictor of OVD, TN-C distance appears to be more reliable than SN-C distance.