口腔顔面痛の病態と治療

Current treatments for oral and maxillo-facial diseases. Pathophysiology and treatment of orofacial pain.

　“痛み”は生体防御の警告信号であり生命を維持するために極めて重要な感覚であるが，筋・筋膜性疼痛，舌痛症，三叉神経痛などの口腔顔面領域の異常疼痛は生体防御としての役割はなく，治療対象とすべき疾患である。最近の疼痛学の発展に伴い，これらの異常疼痛は末梢から中枢に至るまでの侵害情報伝達経路に存在する神経細胞，グリア細胞あるいは免疫細胞の可塑的変化が原因となることが解明されつつある。実際の口腔顔面痛治療においては，口腔顔面痛の長期化や増悪化を防ぐための適切な治療介入をするために，正確な鑑別診断が最も重要であると考えられる。

“Pain” is one of body defense mechanisms and crucial for the life support. However, orofacial pain such as myofascial pain syndrome, burning mouth syndrome and trigeminal neuralgia plays no part in body defense mechanisms and requires therapeutic intervention. Recent studies have indicated that plastic changes in the activities of trigeminal neurons, satellite glial cells in trigeminal ganglion, secondary neurons, microglia and astrocytes in trigeminal spinal subnucleus following orofacial inflammation and trigeminal nerve injury are responsible for orofacial pain mechanisms. Clinically, it is well known that the etiologic differential diagnosis which consists of careful history-taking and physical examination is essential for therapeutic decision in patients with orofacial pain. This report outlines the current knowledge on the pathophysiology, diagnosis, treatment of orofacial pain.