Intraoral Sensory Alterations in Myofascial Orofacial Pain Patients: Implications for Clinical Management

This study evaluated differences in intraoral sensitivity to thermal and mechanical stimuli, and pulp sensibility between patients with myofascial orofacial pain (MOP) and healthy controls. We hypothesized that patients would exhibit increased sensitivity to these stimuli.

A controlled study was performed, including 50 MOP patients and 104 controls aged 18-65. Intraoral and extraoral sensitivities were assessed at various sites using simple quantitative sensory testing (numerical ratings of thermal/mechanical stimuli) and qualitative somatosensory testing (side-to-side differences in sensitivity to touch, cold and pinprick as hyper-, hypo- or normal). Pulp sensibility was evaluated using cold stimuli. Statistical analyses included repeated-measures analysis of variance and Fisher's exact test (α = 0.05).

Patients exhibited significantly higher intraoral hypersensitivity at the buccal gingiva to touch (14%), cold (34%), and pinprick stimuli (36%) compared to controls (0%, 14%, 15%). Similar trends were observed at extraoral sites including the masseter, temporalis, and thenar region. Pulp testing revealed significantly longer pain durations in patients (mean: 5.9 seconds) compared to controls (mean: 3.7 seconds), although pain intensity did not differ significantly. While simple quantitative sensory testing showed no significant group differences, qualitative somatosensory testing effectively identified intraoral and extraoral somatosensory abnormalities.

Patients with MOP exhibited heightened intraoral sensitivity and prolonged pain responses. These findings underscore the diagnostic challenge of distinguishing sensitivity associated with MOP from odontogenic pain, such as pulpitis, which may lead to unnecessary dental procedures. Thorough assessments may help clinicians avoid misdiagnosis and improve outcomes, while longitudinal studies are needed to assess the possibility of clinical consequences.