Reliability of a new technique for intraoral mapping of somatosensory sensitivity

Diagnosis of intraoral pain conditions may be facilitated by assessment of somatosensory sensitivity not only at a single test site but also at multiple test sites, that is, intraoral somatosensory mapping. No standardized mapping techniques are currently available. The aim of this study was to evaluate: (1) spatial variations in somatosensory sensitivity; (2) the reliability of a new technique for mapping of intraoral somatosensory sensitivity. Fifteen healthy volunteers participated in two experimental sessions. In each session, three mechanical stimuli (32 mN and 512 mN von Frey and electronic von Frey (EVF)) were each applied to 15 test sites in a 5 × 3 matrix located at the gingivomucosal area adjacent to the upper premolar region on both sides. A custom-made silicone-based template secured standardization of the test sites. The subjects rated the perceived intensity on a 0-50-100 numerical rating scale (NRS) for tactile (32 mN) and pinprick (512 mN) stimuli and determined the pinprick threshold (PiPT) by EVF by pushing a stop button. Analyses of variance for NRS scores and PiPT for all three stimulus modalities showed no significant differences between sessions or sides (p = 0.077), whereas there were significant site-to-site differences (p < 0.001). Generally, the anterior and apical regions were more sensitive than posterior and cervical regions. Intraclass correlation coefficients for between session reliability ranged between 0.76 and 0.87 for NRS scores and PiPT measures. In conclusion, good test-retest reliability of intraoral somatosensory mapping was found with the help of a new template, which can be used for further studies of intraoral pain mechanisms.