Lee D K, Kim B J
Taehan Chikkwa Uisa Hyophoe Chi. 1989 Feb;27(2):201-9.
Pericoronitis is the most commonly encountered pathologic condition involving the mandibular third molar. Because of the dangers associated with mandibular third molar pericoronitis, prophylactic extraction of third molar at high risk has been recommended. We studied 411 patients with mandibular third molar pericoronitis by clinical symptoms and radiographic measurement of mandibular third molar height, wideth and angulation. The results were as follows: 1. Mandibular third molar pericoronitis is frequently seen in third decade and there are no sexual difference significantely. 2. In inflammatory type of mandibular third molar pericoronitis, chronic pericoronitis occured more frequently than acute type. 3. In relation to angulation and height, mandibular third molar most likely to be afflicted with pericoronitis is vertical eruption at occlusal plane of the second molar. 4. In relation to angulation and width, it appears that the position of the mandibular third molar most likely to be afflicted with pericoronitis is in a vertically erupted tooth of which the space between the ramus and the distal side of the second molar is less than the mesiodistal diameter of crown. (Class II). 5. In relation to height and width, it appears that the position of the mandibular third molar most likely to be afflicted with pericoronitis is class II width (described above)at occlusal plane of the second molar.
冠周炎是下颌第三磨牙最常见的病理状况。由于下颌第三磨牙冠周炎存在相关风险，因此建议对高危的第三磨牙进行预防性拔除。我们通过临床症状以及对下颌第三磨牙高度、宽度和角度的影像学测量，对411例下颌第三磨牙冠周炎患者进行了研究。结果如下：1. 下颌第三磨牙冠周炎常见于30岁左右人群，且无显著性别差异。2. 在炎症类型方面，下颌第三磨牙冠周炎中慢性冠周炎的发生率高于急性类型。3. 就角度和高度而言，最易患冠周炎的下颌第三磨牙是在第二磨牙咬合平面垂直萌出的牙齿。4. 就角度和宽度而言，似乎最易患冠周炎的下颌第三磨牙位置是在垂直萌出且下颌支与第二磨牙远中侧之间的间隙小于牙冠近远中径的牙齿（II类）。5. 就高度和宽度而言，似乎最易患冠周炎的下颌第三磨牙位置是在第二磨牙咬合平面的II类宽度（如上所述）。
