A pilot study to determine the potential application of the pressure specified sensory device in the maxillofacial region.

This pilot study was carried out at the Chang-Gung Memorial Hospital in Taiwan. In order to evaluate this instrument, One-point static (IPDS) cutaneous pressure thresholds were estimated in the perioral region utilizing a hand-held pressure specified sensory device (PSSD). Pressure specified two point discrimination (2PDS) could not be estimated due to the extreme sensitivity of the lip. Normative data were collected from 50 adults and a small, further group of 10 persons evaluated on two separate occasions to determine the likely chance of reproducibility and reliability. The normal range for 1PDS as determined using a hand-held technique, lay between 0.01 g/mm2 and 0.08 g/mm2. These results are up to 200 x lower than previously reported by other authors when estimated with Semmes-Weinstein nylon monofilaments. The results obtained suggest that sensitivity may not decline with advancing years, that the upper lip is more sensitive than the lower lip and that there may be a difference in the appreciation of sensation across the mid-line. Re-examination of the smaller group of subjects established values within 0.01 g/mm2 at 82% of points, 0.02 g/mm2 at 90% of points and 0.03 g/mm2 at 100% of points. The results achieved, although highly operator dependent and difficult to reproduce, reflect the exquisite sensitivity of the lip. The instrument, which was designed for assessment of hand sensation, would benefit from modification if its enormous potential as a research tool in the maxillofacial region is to be maximized. Despite a steep operator learning curve the PSSD may well prove itself to be an invaluable clinical tool and this instrument is worthy of further study within individual units.