Baqain Zaid H, AlHadidi Abeer, AbuKaraky Ashraf, Khader Yousef
Professor in Oral and Maxillofacial Surgery, Department of Oral Surgery, Oral Medicine and Periodontology, School of Dentistry, The University of Jordan, Amman, Jordan, and Hamdan Bin Mohammed College of Dental Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai, United Arab Emirates.
Assistant Professor in Oral and Maxillofacial Radiology, Department of Oral Surgery, Oral Medicine and Periodontology, School of Dentistry, The University of Jordan, Amman, Jordan.
J Oral Maxillofac Surg. 2020 Jul;78(7):1071-1077. doi: 10.1016/j.joms.2020.03.002. Epub 2020 Mar 13.
We aimed to investigate whether cone-beam computed tomography (CBCT) alters the treatment decision for impacted mandibular third molar (M3M) surgery when the third molars show proximity to the inferior alveolar canal (IAC) on panoramic radiography (OPG) and to examine surgeons' confidence in the various treatment options.
We performed a retrospective study evaluating a series of randomized OPG and CBCT images and answering a set of questions regarding impacted M3Ms. The anatomic risk factors studied included the proximity of M3M roots to the IAC, vertical relationship between the M3M and the IAC, and interruption of the IAC cortex by M3M roots. The primary outcome variable was the treatment decision of whether to observe, extract under local anesthesia, extract under general anesthesia, or perform coronectomy. The secondary outcome variable was confidence in the proposed treatment plan. The χ test was used to compare proportions and to test the differences in the treatment plan according to the studied independent variables. Binary logistic regression was used to determine the effect of anatomic factors. P < .05 was considered statistically significant.
The study sample consisted of 132 impacted M3Ms in 71 patients. No significant differences in the proposed treatment plan were found when the imaging modalities (OPG and CBCT) were compared (P > .05). Examination of CBCT enabled detection of anatomic risk factors (P < .001). Binary logistic regression showed the absence of IAC cortex interruption to be the most significant determinant toward planning for extraction on OPG (odds ratio, 3.1; P < .005) and on CBCT (odds ratio, 5.0; P < .001). Surgeons were more confident when planning for extraction (P < .001).
The use of CBCT provides a better understanding of the anatomic relationship between M3M roots and the IAC. However, experienced surgeons dealing with impacted M3Ms with evidence of proximity to the IAC on OPG can decide on the treatment modality without CBCT.
我们旨在研究当第三磨牙在全景X线片（OPG）上显示靠近下牙槽神经管（IAC）时，锥形束计算机断层扫描（CBCT）是否会改变下颌阻生第三磨牙（M3M）手术的治疗决策，并检验外科医生对各种治疗方案的信心。
我们进行了一项回顾性研究，评估一系列随机的OPG和CBCT图像，并回答一组关于阻生M3M的问题。研究的解剖学危险因素包括M3M牙根与IAC的接近程度、M3M与IAC的垂直关系以及M3M牙根对IAC皮质的中断情况。主要结局变量是治疗决策，即选择观察、局部麻醉下拔除、全身麻醉下拔除还是进行牙冠切除术。次要结局变量是对建议治疗方案的信心。采用χ检验比较比例，并根据研究的自变量检验治疗方案的差异。使用二元逻辑回归确定解剖因素的影响。P < 0.05被认为具有统计学意义。
研究样本包括71例患者的132颗阻生M3M。比较成像方式（OPG和CBCT）时，建议的治疗方案未发现显著差异（P > 0.05）。CBCT检查能够检测到解剖学危险因素（P < 0.001）。二元逻辑回归显示，IAC皮质未中断是OPG（优势比，3.1；P < 0.005）和CBCT（优势比，5.0；P < 0.001）上计划拔除的最重要决定因素。外科医生在计划拔除时更有信心（P < 0.001）。
CBCT的使用能更好地了解M3M牙根与IAC之间的解剖关系。然而，对于在OPG上有证据显示靠近IAC的阻生M3M，经验丰富的外科医生在没有CBCT的情况下也可以决定治疗方式。
