Ellis Edward
Professor, Division of Oral and Maxillofacial Surgery, University of Texas Southwestern Medical Center, Dallas, TX 75390-9109, USA.
J Oral Maxillofac Surg. 2009 Aug;67(8):1685-90. doi: 10.1016/j.joms.2009.03.062.
The purpose of the present study is to report an intraoperative method of determining which condylar process fractures of the mandible do not require open reduction and internal fixation.
A total of 332 patients with unilateral extracapsular fractures of the mandibular condylar process were retrospectively studied. After any other mandibular fractures had undergone open reduction and internal fixation, the maxillomandibular fixation was released and the occlusion checked to determine whether deviation of the mandible was present toward the side of the condylar fracture. In addition, digital posteriorly directed force was applied to the chin to determine how easily the mandible would deviate. Those cases in which the mandible dropped posteriorly toward the side of fracture, creating a malocclusion ("drop-back"), were treated either closed or by open reduction, according to several factors. Those whose mandibles either did not deviate toward the side of fracture or those in whom the mandible could be pushed posteriorly on the side of fracture but readily regained a midline position on release of pressure (nondrop-back) were treated closed. Displacement of the condylar process was examined using pretreatment Towne's and panoramic radiographs. The relationship between the intraoperative drop-back results and the pretreatment level and displacement of the condylar process fractures was statistically assessed.
Of the 332 fractures, 105 were in the nondrop-back group and 227 were in the drop-back group. The only demographic difference between the 2 groups was the displacement of the condylar process, which was greater in the drop-back group. All patients in the nondrop-back group, except for 1, had good occlusal and functional outcomes, with minimal need for interarch elastic guidance.
Determining which patients would not benefit from open reduction and internal fixation can be assessed clinically during surgery more reliably than using preoperative imaging studies.
本研究的目的是报告一种术中确定哪些下颌骨髁突骨折无需切开复位内固定的方法。
对332例单侧下颌骨髁突囊外骨折患者进行回顾性研究。在其他下颌骨骨折接受切开复位内固定后,松开颌间固定并检查咬合,以确定下颌骨是否向髁突骨折侧偏斜。此外,向后施加手指力量于颏部,以确定下颌骨偏斜的难易程度。根据多种因素,对于下颌骨向骨折侧后方下垂导致错牙合(“后垂”)的病例,采用闭合治疗或切开复位治疗。对于下颌骨不向骨折侧偏斜或下颌骨在骨折侧可被向后推但在压力释放后容易恢复到中线位置(非后垂)的病例,采用闭合治疗。使用术前汤氏位片和全景片检查髁突的移位情况。对术中后垂结果与术前髁突骨折的程度和移位之间的关系进行统计学评估。
在332例骨折中,105例属于非后垂组,227例属于后垂组。两组之间唯一的人口统计学差异是髁突的移位情况,后垂组的移位更大。非后垂组中除1例患者外,所有患者的咬合和功能结果良好,几乎不需要颌间弹性牵引。
与术前影像学检查相比,术中临床评估能更可靠地确定哪些患者无法从切开复位内固定中获益。