title: [Evaluation of trigeminal somatosensory evoked potential of patients with chronic masticatory muscle pain].
abstract: OBJECTIVE
  To evaluate trigeminal function of patients with chronic masticatory muscle pain (MMP) using trigeminal somatosensory evoked potential (TSEP) and analyze mechanism of changes compared to the controls.
  
  
  METHODS
  Twelve chronic MMP patients and 12 matched controls participated in this study. TSEPs of bilateral masseter regions and inferior alveolar nerves were measured and compared between patient and control groups. The collected waves were concluded and those with appearance rate over 75% - 100% were selected. The latencies of waves were analyzed by use of the paired t test and independent-samples t test.
  
  
  RESULTS
  Five stable-appearing waves were obtained and named P1, N1, P2, N2, P3. The latency of P1 was significant reduced in patients (P < 0.05). The latencies of other waves were prolonged, but only P2 and N2 in left were significantly changed (P < 0.05).
  
  
  CONCLUSIONS
  TSEP latencies of chronic MMP patients changed in certain regular pattern and TSEP could be used as a parameter to disclose the trigeminal system abnormalities of the patients. The reduced latency of P1 might indicate the increasing conductivity of trigeminal nerves under level of ganglion Gasseri and the prolongation of latency of P2 was possibly related to inhibitory effects of the brain stem.
authors.affiliation: Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing 100081, China. xieqiuf@163.com
authors.forename: Qiu-fei
authors.initials: QF
authors.lastname: Xie
authors.forename: Ye
authors.initials: Y
authors.lastname: Cao
authors.forename: Zhao-hui
authors.initials: ZH
authors.lastname: Yang
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002908:Chronic Disease; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008410:Masticatory Muscles / Q000503:physiopathology*; D008875:Middle Aged; D009437:Neuralgia / Q000175:diagnosis / Q000503:physiopathology*; D014276:Trigeminal Nerve / Q000503:physiopathology*; D055815:Young Adult