Rajasuo Ari, Peltola Jaakko, Ventä Irja, Murtomaa Heikki
Department of Oral and Maxillofacial Diseases, Mikkeli Central Hospital, Mikkeli, Finland.
Acta Odontol Scand. 2003 Oct;61(5):263-7. doi: 10.1080/00016350310005565.
In this study we assess radiographic findings characteristic of mandibular 3rd molars that had required either routine or surgical extraction. X-ray findings relating to acute pericoronitis were also examined. The material was collected by investigating patient records and rotational panoramic radiographs of 20-year-old Finnish male conscripts (n = 738) treated during military service because of 3rd-molar-related problems. The follicle around the crown of mandibular 3rd molars with acute pericoronitis was enlarged in 19% of cases and in 13% of chronic symptom-free pericoronitis cases (not statistically significant difference). Mandibular 3rd molars extracted surgically were more often mesially inclined than those extracted routinely (61% vs. 23%; P < 0.001), partially or totally intrabony impacted (92% vs. 66%; P < 0.001) and deep situated (on average 4.2 mm vs. 2.5 mm under the occlusal plane). Surgical extraction was also associated with the roots completely developed [92% vs. 84% of the teeth routinely extracted, odds ratio (OR) 2.6, 95% confidence interval (CI) 1.2-5.5] and with the absence of radiographic pericoronitis [around 27% vs. 39% of the teeth routinely extracted (OR 0.5, 95% CI 0.3-0.8)]. In 86% of cases the space between 2nd molar and ramus of the mandible was narrower than the 3rd molar extracted surgically, whereas this was 62% in routine extraction cases (P < 0.001). We conclude that there are some typical 3rd-molar findings in rotational panoramic radiographs that show a need for surgical extraction.
在本研究中，我们评估了需要常规或手术拔除的下颌第三磨牙的影像学特征。还检查了与急性冠周炎相关的X线表现。通过调查芬兰20岁男性应征入伍者（n = 738）因第三磨牙相关问题在服役期间接受治疗的患者记录和旋转全景X线片来收集资料。急性冠周炎患者下颌第三磨牙牙冠周围的牙囊在19%的病例中增大，慢性无症状冠周炎病例中这一比例为13%（无统计学显著差异）。手术拔除的下颌第三磨牙比常规拔除的更常向近中倾斜（61%对23%；P < 0.001），部分或完全骨内阻生（92%对66%；P < 0.001）且位置较深（平均在咬合平面以下4.2 mm对2.5 mm）。手术拔除还与牙根完全发育有关[92%对常规拔除牙齿的84%，优势比（OR）2.6，95%置信区间（CI）1.2 - 5.5]以及无影像学冠周炎有关[约27%对常规拔除牙齿的39%（OR 0.5，95% CI 0.3 - 0.8）]。在86%的病例中，第二磨牙与下颌升支之间的间隙比手术拔除的第三磨牙窄，而在常规拔牙病例中这一比例为62%（P < 0.001）。我们得出结论，旋转全景X线片中存在一些典型的第三磨牙表现，提示需要进行手术拔除。
