Tactile threshold and pressure pain threshold during treatment of orofacial pain: an explorative study

The aim of the present study was to evaluate the pressure pain threshold (PPT), tactile threshold (TT) and pain intensity as measured on a Visual Analogue Scale (VAS) in patients with pain in the orofacial region. Twenty-six patients with myogenous pain (7 ss), myogenous and capsular pain (11 ss) or neuropathic pain (8 ss) participated in the study. At baseline, the PPT was evaluated using an algometer and the TT using von Frey hairs. In addition, the pain intensity was rated on a VAS scale and the psychological profile made using the SCL-90 questionnaire. In some of the patients, the measurement procedure was conducted I week later, immediately before active treatment started. As active treatment, patients with myogenous or capsular pain received physical therapy in addition to conscious relaxation of the masticatory system, while patients with neuropathic pain were treated using tricyclic antidepressant medication. After 4 to 6 weeks, the measurements were repeated. Statistical evaluation using a linear mixed model revealed no significant changes in TT. In patients with myogenous and capsular pain, as well as in patients with neuropathic pain, the PPT increased after active treatment, while it decreased in the group with pure myogenous pain. The VAS score decreased in all groups. Regarding psychological profiles, a variety of characteristics were observed and the scale for sleeping problems was especially elevated in a majority of the patients.