Meisami T, Sojat A, Sàndor G K B, Lawrence H P, Clokie C M L
University of Toronto, Faculty of Dentistry, Department of Oral and Maxillofacial Surgery, Ontario, Canada.
Int J Oral Maxillofac Surg. 2002 Apr;31(2):140-4. doi: 10.1054/ijom.2001.0215.
The purpose of this study was to assess the influence of the presence, position, and severity of impaction of the mandibular third molars, on the incidence of mandibular angle fractures. A retrospective cohort study was designed for patients presenting to the Division of Oral and Maxillofacial Surgery, Toronto General Hospital (Toronto, Canada), for treatment of mandibular fractures from January 1995 to June 2000. The independent variables in this study were the presence, position and severity of impaction of third molars. The outcome variable was the incidence of mandibular angle fractures. Hospital charts and panoramic radiographs were used to determine and classify these variables. The demographic data included age, sex, mechanism of injury and number of mandibular fractures. The study sample comprised 413 mandibular fractures in 214 patients. The incidence of angle fractures was found to be significantly higher in the male population and was most commonly seen in the third decade of life. Assault remained the most significant aetiological factor. Patients with third molars had thrice the increased risk of angle fractures when compared to patients without (P<0.001). Impaction of third molars significantly increased the incidence of angle fractures (P<0.001). The severity and angulation of third molar impactions were not significantly associated with angle fractures. This study provides evidence that patients with retained impacted third molars are significantly more susceptible to angle fracture than those without. The risk for angle fracture, however, does not seem to be influenced by the severity of impaction.
本研究的目的是评估下颌第三磨牙阻生的存在、位置和严重程度对下颌角骨折发生率的影响。设计了一项回顾性队列研究，针对1995年1月至2000年6月在加拿大多伦多总医院口腔颌面外科就诊治疗下颌骨折的患者。本研究的自变量是第三磨牙阻生的存在、位置和严重程度。结果变量是下颌角骨折的发生率。利用医院病历和全景X线片来确定和分类这些变量。人口统计学数据包括年龄、性别、损伤机制和下颌骨折的数量。研究样本包括214例患者的413例下颌骨折。发现男性人群中角部骨折的发生率显著更高，且最常见于第三个十年年龄段。袭击仍然是最重要的病因因素。与没有第三磨牙的患者相比，有第三磨牙的患者发生角部骨折的风险增加了两倍（P<0.001）。第三磨牙阻生显著增加了角部骨折的发生率（P<0.001）。第三磨牙阻生的严重程度和角度与角部骨折无显著相关性。本研究提供的证据表明，保留阻生第三磨牙的患者比没有阻生第三磨牙的患者更容易发生角部骨折。然而，角部骨折的风险似乎不受阻生严重程度的影响。
