ABSTRACT
BACKGROUND: Quantitative Sensory Testing (QST) has been used in clinical and experimental settings to establish sensory assessment for different types of pains, and may be a useful tool for the assessment of orofacial pain, but this premise needs to be tested. OBJECTIVE: The aim of the study was to evaluate responses to thermal stimuli between painful and non-painful facial sites in subjects with orofacial pain using QST. METHODS: A total of 60 participants (5o females: 28-83 years; 10 males: 44-81 years) with unilateral orofacial pain were recruited from the Orofacial Pain Clinic at the Pain Management and Research Centre, Royal North Shore Hospital, Sydney, Australia. The study followed the methods of limits of the German Research Network testing four modalities of thermal thresholds, the Warm Sensation, the Cold Sensation, the Heat Pain and the Cold Pain using a TSA-II Neurosensory Analyser. The results were compared to the results from the unaffected side of the same patient on the same area and a single t test statistical analysis was performed, where a p value of less than 0.05 was considered significant. RESULTS: The Mean Difference for Cold Sensation between the pain side and the non-pain side was 0.48 °C ± 1.5 (t= 2.466, p=0.017), 0.68 °C ± 2.04 for Warm Sensation (t= -2.573, p= 0.013), 2.56 °C ± 2.74 for Cold Pain (t= 7.238, p<0.001) and -1.21 °C ± 2.59 for Hot Pain (t= -3.639, p=0.001). CONCLUSION: The study showed that QST methods using thermal stimuli could be used to evaluate sensory dysfunction in orofacial pain patients using the specific parameters of cool and warm sensation, and cold and hot pain.
ABSTRACT
STATEMENT OF PROBLEM: Making electromyographic recordings of the lateral pterygoid muscle (LP) is difficult because of potential electrode damage to, for example, the maxillary artery and long buccal nerve, and because of pain and reduced jaw mobility characteristic of many orofacial pain patients. PURPOSE: The purpose of this study was to develop a reliable intraoral placement technique for the inferior head of the lateral pterygoid (IHLP) that minimizes jaw displacement. MATERIAL AND METHODS: In 2 dried skulls and 7 human cadavers, it was estimated that, with the mandible in an ipsilateral closed position, a straight needle could be used to position fine-wire electrodes into the midportion of IHLP by inserting the needle through the mucosa adjacent to the distal root of the maxillary second molar, towards the external auditory meatus and parallel to the buccal alveolar bone of the maxilla. The needle avoided the maxillary artery and long buccal nerve. Using this approach in 5 adults, 2 fine-wire electrodes were placed into the IHLP. Placement was verified by computer tomography (CT) and electromyography. RESULTS: In all subjects, the ideal insertion depth to place the electrodes in the middle of IHLP was 29 mm. CONCLUSIONS: This technique is a reliable method for IHLP electrode placement for patients with impaired jaw function, minimizing risk of damage to major structures.
