Pain is divided into two groups: physiological pain (nociceptive pain) and pathological pain. Although physiological pain is adaptive, transient, and has a protective role as a warning signal of potential tissue damage in response to a noxious stimulus, pathological clinical pain is usually maladaptive, persists, and serves no meaningful defensive or other helpful purpose. Peripheral tissue injury and inflammation are known to alter the properties of somatic sensory pathways, resulting in behavioral hypersensitivity and pathological pain, including increased responses to pain caused by both noxious stimuli (hyperalgesia) and normally innoxious stimuli (allodynia). It has been reported that glia cells in the spinal cord contribute to the maintenance of pathological pain, but recent evidence suggests that activation of satellite glia in sensory ganglia may also plays a significant role in the development of hyperalgesia and allodynia. There is evidence that non-synaptically released chemical mediators derived from both neurons and satellite glia may trigger chronic pain via autocrine and/or paracrine mechanisms and that augmented excitability of primary afferent neurons results in changes in central pain-signaling neurons (central sensitization). The present review focused on the function of satellite glia cells in sensory ganglia to pathological pain. Furthermore, we discuss potential therapeutic targets in satellite glia-neuronal interactions for the prevention of pathological pain.

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Purpose: The purpose of this study was to clarify the sex difference in the perception and pain thresholds to the thermal stimulation in the trigeminal nerve area.
Methods: Subjects were composed of 80 healthy volunteers (40 males and 40 females, mean age: 24.7 years). Thermal perception and pain thresholds of the trigeminal nerve were evaluated with thermal quantitative sensory analyzer (TSA-II®, Medoc). Thermal stimulation was applied to the skin surface of bilateral cheeks. The data were statistically analyzed to evaluate whether the values were influenced by sex and/or laterality with two-way ANOVA using SPSS Statistics® 17.0.
Results: Warm perception thresholds were significantly lower in females than in males (P=.001), while no difference was found in the cold perception thresholds between both sexes (P=.379). No laterality was found both in warm and cold perception thresholds. Heat pain thresholds were significantly lower in females than in males (P=.003), while no difference was found in the cold pain thresholds between both sexes (P=.515). No laterality was found both in heat and cold pain thresholds.
Conclusions: There found a sex difference both in thermal perception and in pain recognition to thermal stimulation of the trigeminal nerve.

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Purpose: The purpose of the present study is to investigate factors related to the analgesic drug use after removal of impacted third molars under general anesthesia.
Methods: Seventy patients who received removal of impacted third molars under general anesthesia participated in this study. Use of analgesic drugs was recorded for assessment of postoperative pain in this surgery. To study the factors related to the postoperative pain, the patients were examined gender, age, number of extracted teeth, operation time, anesthesia time, amount of fentanyl, and CRP level on the next morning of extraction. Multiple regression analysis was used for analysis of the correlation between use of analgesic drugs and conditions of the patients.
Results: After surgery, 94.3% of patients took analgesic drugs. The number of the drug takings within 72 hours after surgery was ten tablets from 0 tablets, with six tablets of medians. No significant correlation was found between use of analgesic drugs and conditions of the patients. Although the relationship between use of analgesic drugs and CRP was no significant (p<.10) , the analysis that assumed CRP 2 variables (<2.0mg/dl and ≥ 2.0mg/dl) was studied again. As a result, use of analgesic drugs was significantly increased in patients with high CRP level (p<.05) .
Conclusions: After removal of impacted third molars, analgesic drugs were taken in most patients (94.3%) . Ten tablets of the drugs were necessary in postoperative 72 hours. Much drugs were required in patients with high CRP level (≥2.0mg/dl) .

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Purpose: Since lack of number of specialists for orofacial pain, as a primary care facilities, general dentists need to have the knowledge of orofacial pain and be able to manage those patients as much as possible.
Orofacial pain is the result of symptom caused by several factors which are related each other. Some of the factors might be able to be removed by general dentists such as inflammation, occlusal trauma or occlusal factors. After the removal of those factors, other problem such as physical symptoms or neuropathic symptoms can be distinguished. Following removal of risk factors, I reevaluate the patient response and transfer the patients to medical specialists. Occasionally the dental treatment may influence other risk factors to improve the symptom. We manage the orofacial pain patients as follows;
1. Listen to the patient narration carefully, take away their anxiety and give them hope.
2. Try to remove inflammation, occulusal trauma and occlusal factor. Controlling bruxism is necessary because occlusal trauma especially bruxism is one of the important factors for orofacial pain.
3. Treating patients with minimal intervention. For controlling bruxism, my treatment is mainly consisting of self instruction method (kind of cognitive behavior therapy) as patient self control. Occlusal splint is used as supplementary.
I introduce my management method for orofacial pain patients by showing three cases.

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Patients: Case 1: 16 year-old girl. Her chief complaint is severe pain due to the soy sauce when eating. A lower right canine was displaced up-downward when tapping the tooth and stomatitis with shapes of oval formation on the buccal and lingual gingivae close to the tooth periapical areas were found. Case 2: 42 year-old male. His chief complaint is inlay loosening. An upper left canine displaced in buccal direction when grinding the tooth and a stomatitis formed on the buccal gingiva from the cervical region of the tooth to the upper left second bicuspid. Case 3: 31 year-old female at her regular medical examinations. A lower left canine was displaced up-downward when tapping the tooth and a stomatitis of oval shape was found on the buccal gingiva close to the periapical area of the tooth. Case 4: 41 year-old female at her regular medical examinations. An upper right second bicuspid displaced in the buccal direction when grinding the tooth, and a stomatitis of oval shape was found on the buccal gingiva close to the periapical area of the tooth. Case 5: 33 year-old female under her orthodontic treatment. An upper right first molar displaced in the buccal direction when grinding the tooth, and a stomatitis of oval shape was found on the buccal gingiva close to the periapical area of the tooth.
Similar symptoms of the stomatitis were edema. There were no erosions or aphthous ulcers and the stomatitis was painless by palpation except for case 1, which had the pain of 1/10(VAS) by palpation. All stomatitis disappeared after we performed occlusal adjustment for the teeth.
Discussion: A displacement of tooth under tapping or grinding generates an external force to the periodontal tissue. It is thought that the stomatitis forms in the areas of force existence. On the other hand, the stomatitis disappeared when the displacement of teeth was alleviated by the occlusal adjustment. When we associated displacement of teeth with occlusal forces, occlusal trauma was responsible for these five cases of stomatitis.

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This report discusses 2 cases of endodontically treated teeth in which intractable pain persisted after root canal treatment. As the treatment of choice, root canal preparation was repeated as far as the apical constriction of each tooth, under local anesthesia. This treatment was followed by disappearance of pain.
Patients: Case 1: A 32-year-old woman with no improvement of pain even after undergoing root canal treatment of right mandibular 1st molar tooth, in another dental clinic 2 years ago. R test of Endodontic Meter revealed presence of residual pulp tissue of this endodontically treated tooth. The pain was disappeared by a diagnostic anesthesia.
Case 2: A 58-year-old man was referred to our hospital from a general practitioner for root canal treatment.
Left maxillary 2nd molar had been root filled. However, there was continuous postoperative pain. When gutta percha was removed from this tooth, residual pulp tissue was found in the apical area and the pain disappeared by a diagnostic anesthesia.
Discussion: The above-mentioned cases suggest that correct measurement of working length and removal of residual pulp are necessary in the differential diagnosis of intractable pain.
Conclusion: It is important that the root canal treatment of the intractable pain set surely the working length.

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