下颌第三磨牙阻生情况与急性冠周炎发生的关系

目的:研究下颌第三磨牙位置特征与急性冠周炎发生的关系。方法:选择122名临床诊断为下颌第三磨牙急性冠周炎患者(年龄18～31岁),分别记录下颌第三磨牙的萌出角度、软组织覆盖率、有无上颌牙列的咬合创伤及其萌出高度,然后对以上数据分别进行统计学分析。结果:发生急性冠周炎的下颌第三磨牙以垂直阻生最多见(57%),近中阻生次之(34%),水平阻生(7%)和远中阻生最少(2%),各种阻生之间的差别具有统计学意义(P<0.05)。发生急性冠周炎的下颌第三磨牙部分软组织覆盖(以75%的覆盖率最多见)多于全部软组织覆盖,差别具有统计学意义(P<0.05)。有无上颌牙列的咬合创伤与急性冠周炎的发生没有明显的统计学意义(P>0.05)。发生急性冠周炎的下颌第三磨牙萌出高度多数与(?)平面平齐,萌出高度间的差别具有统计学意义(P<0.05)。结论:垂直阻生、软组织部分覆盖、萌出高度平齐于(?)平面的下颌第三磨牙容易发生急性冠周炎,具有这些特征的下颌第三磨牙要高度重视。

Correlation of Acute Pericoronitis and Position of Impacted Mandibular Third Molar

Objective： To study the relationship between the characteristics of mandibular third molar position and incidence of perieoronitis. Methods： A total of 122 （aged 18-31 years old） patients with acute mandibular third-molar pericoronitis were subjected into this study. Variables including the percentage of soft tissue coverage, occlusal trauma of maxillary dentition, the angulation and eruption level of the mandibular third molar were recorded. The data was statistically analyzed. Results： Vertical impaction was the most frequent angulation （57%）, mesioangular impaction （34%） was higher than horizontal impaction （7%）, and distoangular impaction was quite rare （2%）. Difference between type of angulation was statistically significant for all groups （P〈0.05）. The frequency of partial soft tissue coverage, particularly 75% coverage, was much more observed than the full soft tissue coverage. The difference for the amount of soft tissue coverage was statistically significant （P〈0.05）. Occlusal trauma of maxillary dentition did not have a statistically significant（P〉0.05）. Most pericoronitis （49%） was associated with the third molars that erupted at the same level of the adjacent tooth ocelusal plane. The differences among the three levels of eruption were significant （P〈0.05）. Conclusion： Impacted mandibular third molars with partial soft tissue coverage, exhibiting vertical inclination, reach or near to the level of the occlusal plane of the arch were considered with highest risk for developing pericoronitis. Such third molars should be given high priority for prophylactic care.