The spatial distribution, intensity and unpleasantness of acute dental pain

The distribution, intensity and unpleasantness of acute dental pain were studied in 196 patients. Dental pain was classified by source according to 7 anatomical sites: dentinal, pulpal, pulpal and periapical, periapical, pericoronal, papillar, and periodontal. The distribution of dental pain was classified by the frequency of pain spread throughout the sample, by the extent of pain spread for a particular pain source, that is, the number of vectors of spread, and by the pain reference locations in the face and head. Pain-intensity and pain-unpleasantness were assessed on Visual Analogue Scales. The frequency and extent of pain spread varied as a function of source. However, specific patterns of pain spread were not associated with particular pain sources. There was considerable overlap in patterns of spread between maxillary and mandibular pain sources. The frequency and extent of pain spread was correlated positively with both pain intensity and pain unpleasantness. The correlation between pain ratings and pain spread may be attributed to central mechanisms and interactions between trigeminothalamic neurons. Spatial overlap of pain from maxillary and mandibular pain sources may be due to the large receptive fields of wide dynamic range neurons, that can extend beyond one trigeminal division. These observations indicate that the spatial distribution of acute dental pain is not sufficient as a diagnostic tool for indentifying pain source.