Celikoglu Mevlut, Miloglu Ozkan, Kazanci Fatih
Department of Orthodontics, Faculty of Dentistry, Ataturk University, Erzurum, Turkey.
J Oral Maxillofac Surg. 2010 May;68(5):990-5. doi: 10.1016/j.joms.2009.07.063. Epub 2010 Jan 22.
The objectives of the present study were to investigate the frequency of impaction, agenesis, angular position, and related pathologic changes of third molar teeth in a group of orthodontic patients.
Our sample included the panoramic radiographs of 351 orthodontic patients aged 20 to 26 years (mean 22.8). The descriptive characteristics of agenesis, impaction, angular position, and pathologic changes of third molars were recorded. The chi(2) test was used for analysis.
The proportion of third molar agenesis was 17.3% with no statistically significant gender differences (18.4% for women and 15.8% for men). The frequency of impacted third molars (ITMs) was 35.9% (24.2% in men and 45.0% in women; P < .05). The frequency of maxillary ITMs was 43.2% (192 of 444 teeth), and the frequency of mandibular ITMs was 56.8% (252 of 444 teeth). The position observed most often was mesioangular inclination, with a frequency of 50.0%. Only 10.4% of the ITM teeth were affected by any pathologic changes, and most of these changes were associated with the horizontal position.
The present results showed that agenesis accounted for 17.3% and impaction for 35.9% of the pathologic features in this group of Turkish orthodontic patients aged 20 to 26 years of age. Mesioangular inclination was seen in 50.0%, and a small proportion (10.4%) had pathologic changes of the ITMs.
本研究的目的是调查一组正畸患者中第三磨牙的阻生、先天缺失、角向位置及相关病理变化的发生率。
我们的样本包括351名年龄在20至26岁（平均22.8岁）的正畸患者的全景X线片。记录第三磨牙先天缺失、阻生、角向位置及病理变化的描述性特征。采用卡方检验进行分析。
第三磨牙先天缺失的比例为17.3%，性别差异无统计学意义（女性为18.4%，男性为15.8%）。阻生第三磨牙（ITM）的发生率为35.9%（男性为24.2%，女性为45.0%；P <.05）。上颌ITM的发生率为43.2%（444颗牙中的192颗），下颌ITM的发生率为56.8%（444颗牙中的252颗）。最常观察到的位置是近中倾斜，发生率为50.0%。只有10.4%的ITM牙齿受到任何病理变化的影响，且这些变化大多与水平位置有关。
目前的结果表明，在这组年龄在20至26岁的土耳其正畸患者中，先天缺失占病理特征的17.3%，阻生占35.9%。近中倾斜占50.0%，一小部分（10.4%）的ITM有病理变化。
