正畸牵引法辅助拔除接触下牙槽神经管的埋伏阻生牙1例报告

阻生下颌第三磨牙拔除是口腔颌面外科的一种常见手术.由于低位阻生的下颌第三磨牙牙根位置常与下牙槽神经(inferior alveolar nerve,IAN)关系密切,神经损伤是该手术的严重并发症之一.目前,国际上主要有3种避免IAN损伤的方法:截冠法、部分牙冠切除术和正畸牵引法.本文报告1例下颌第三磨牙近中斜位低位阻生的患者,采用改良正畸牵引法,分两步将牙根牵离神经管,牵引完成后顺利拔除患牙.     

第三磨牙手术过程中下牙槽神经损伤的放射预测

下牙槽神经走行于下牙槽神经管中,常常邻近下颌第三磨牙的根尖,在拔除阻生的下颌第三磨牙过程中可能损伤下牙槽神经,而引起下唇、下颌牙龈及下前牙感觉的减弱或丧失。临床拔牙前为了观察阻生牙与下牙槽神经的关系,必须进行 X 线检查,这对下牙槽神经损伤的预测很有帮助。     

CBCT在下颌阻生第三磨牙拔除术前风险评估中的应用

目的：运用CBCT评估下颌阻生第三磨牙拔除术中下牙槽神经损伤的手术风险,并指导拔牙手术径路选择。方法：对曲面体层片显示下颌第三磨牙根端与下颌神经管接触重叠,评估下牙槽神经易损伤病例42例,65侧下颌阻生第三磨牙,进行CBCT检查。两组医师（每组口腔外科医师和颌面影像科医师各1名）分别根据曲面体层片和CBCT图像评估拔除下颌第三磨牙时下牙槽神经损伤的风险程度并进行手术设计,应用x2检验两种影像评测结果之间的差异度。结果：评估拔除下颌阻生第三磨牙时出现下牙槽神经损伤的可能性经曲面体层片和CBCT对比研究差异具有统计学意义（P＜0．001）。与曲面体层片相比,CBCT为临床医师提供了阻生磨牙与下颌神经管之间三维影像的空间距离,有效辅助了牙拔除手术方式的设计（P＜0．001）。结论：拔除下颌阻生第三磨牙可能造成下牙槽神经损伤的评估中,与曲面体层片相比,CBCT可以更好地评估手术风险,能指导术者帮助选择更恰当的术式。     

冠根分次去除法在疑或累及下牙槽神经的下颌第三阻生磨牙拔除术中的应用

目的:评价应用截冠法分次拔除紧贴下牙槽神经的下颌阻生第三磨牙的效果。方法:对10例术前全景片及CT均显示牙根紧贴或接触下牙槽神经的下颌阻生第三磨牙患者采用截冠留根法,于釉-牙骨质界去除阻力牙冠,包埋牙根于牙槽骨内;术后观察,待牙根移动远离下牙槽神经后再行拔除术。结果:10例患者术后反应轻微,均无下牙槽神经损伤,无感染情况出现;仅1例牙根未能上移至远离下牙槽神经的位置,留根于牙槽骨内,牙龈创面愈合,随访1年无不适。结论:根尖紧贴或接触下牙槽神经的下颌阻生第三磨牙,经截冠留根术后,断根有上移萌出趋势,可远离下牙槽神经管,后期拔除断根,可明显降低下牙槽神经损伤的风险。     

微创牵引辅助拔除近中阻生下颌第三磨牙1例报告

近中阻生下颌第三磨牙拔除是口腔外科常见手术。中、低位近中阻生的第三磨牙牙根与牙根位置常与下牙槽神经(inferior alveolar nerve, IAN)关系密切,由于近中邻牙的阻力,拔除时创伤较大,易造成第二磨牙损伤及神经损伤。本文报告1例牙根压迫下牙槽神经的近中阻生下颌第三磨牙患者,采用微创正畸牵引法,直立患牙,牵引完成后顺利拔除。     

以下颌神经管为参照的下颌阻生第三磨牙的分类及临床意义

目的：以下颌神经管为参照,探讨与下颌神经管(inferior alveolar canal,IAC)相交的下颌阻生第三磨牙(impacted mandibular third molars,IMTMs)的阻生类型,并观察手术拔除阻生牙后下牙槽神经损伤与阻生类型间的关系。方法：对锥形束CT(cone beam computed tomography,CBCT)确诊为下颌阻生第三磨牙与下颌神经管接触或相交的378例患者共658侧阻生牙,以下颌神经管为参照,将阻生牙分为4类：Ⅰ类位于神经管的上方,Ⅱ类位于神经管的颊侧,Ⅲ类位于神经管的舌侧,Ⅳ类下颌神经管位于牙根之间。所有病例均采用手术拔除,术后观察容易引起下牙槽神经损伤的阻生类型,统计各种类型神经损伤的例数,应用SPSS13.0软件包对数据进行χ²检验。结果：阻生牙拔除后,下牙槽神经损伤率为6.8%(45/658)。其中,第Ⅰ类15例(15/332)发生下唇麻木、第Ⅱ类19例 (19/108) 发生下唇麻木、第Ⅲ类11例(11/210)发生下唇麻木,第IV类未发生下唇麻木(0/8)。统计学分析显示,阻生牙拔除后,第Ⅰ类和第Ⅱ类、第Ⅱ类和第Ⅲ类下牙槽神经损伤率有显著差异(P<0.01),第Ⅰ类和第Ⅲ类之间无显著差异(P>0.05)。结论：以下颌神经管为参照,CBCT冠状位可将下颌阻生第三磨牙与下颌神经管相交的患者分为4类,手术拔除过程中均有损伤下牙槽神经的危险,尤其是位于下颌神经管颊侧的阻生牙。     

累及下牙槽神经的下颌第三磨牙拔除方法研究进展

 累及下牙槽神经的下颌第三磨牙传统拔除方法常会引起以下牙槽神经损伤为主的并发症,为此有众多学者提出新的拔除方法,如截冠法、正畸牵引辅助及冠周去骨法等,以减少下牙槽神经损伤的发生。文章就累及下牙槽神经的下颌第三磨牙拔除方法的原理、适应证、操作注意事项及优缺点等做一综述。     

累及下牙槽神经的下颌第三磨牙拔除方法研究进展

累及下牙槽神经的下颌第三磨牙传统拔除方法常会引起以下牙槽神经损伤为主的并发症，为此有众多学者提出新的拔除方法，如截冠法、正畸牵引辅助及冠周去骨法等，以减少下牙槽神经损伤的发生。文章就累及下牙槽神经的下颌第三磨牙拔除方法的原理、适应证、操作注意事项及优缺点等做一综述。     

牵引拔除压迫下牙槽神经的下颌第三磨牙

目的：应用牵引技术拔除压迫下牙槽神经的下颌第三磨牙,以减少术后并发症。方法：对20例全景片和CT显示下颌第三磨牙牙根压迫或紧贴下牙槽神经的患者,先应用正畸牵引技术牵引,经3～10周的牵引,使牙根远离下牙槽神经后再行拔除术。结果：20例牙根压迫下牙槽神经的患者,经牵引拔牙后,无1例发生下唇麻木,术后反应轻微。结论：应用牵引拔牙技术拔除下颌第三磨牙,解决了术后下唇麻木、骨折等高风险并发症的发生,也使拔牙更容易、更快。     

牵引增隙辅助拔除高危垂直阻生智齿8例报告

探索牵引增隙辅助拔除紧邻下牙槽神经管和舌侧骨板低位阻生智齿的效果.锥形束CT(cone-beam CT,CBCT)显示紧邻下牙槽神经管和舌侧骨板的垂直阻生智齿8例,微种植钉增强支抗,NiTi悬臂梁颊向牵引智齿4～6周,当牵引点颊向移动距离>2 mm后转外科拔除.所有智齿拔除后均未出现严重并发症.牵引增隙可有效降低拔除紧邻下牙槽神经管和舌侧骨板垂直阻生智齿的风险.     

Gow-Gates法下牙槽神经阻滞麻醉在下颌阻生第三磨牙拔除术中的麻醉效果研究

目的 通过临床随机对照试验的方法评价Gow-Gates法下牙槽神经阻滞麻醉在下颌阻生第三磨牙拔除术中的麻醉有效性和安全性。方法 使用左右半口设计,32例患者的左右下颌阻生第三磨牙分别随机采用Gow-Gates法和传统注射法进行下牙槽神经阻滞麻醉,并拔除下颌阻生第三磨牙,记录麻醉效果及不良事件。结果 所有患者均完成研究。Gow-Gates法的麻醉成功率为96.9%,传统注射法的麻醉成功率为90.6%,二者的麻醉成功率无统计学差异（P=0.317）。在麻醉程度上,Gow-Gates法麻醉程度为A和B级的比率为96.9%,明显好于传统注射法的78.1%（P=0.034）。Gow-Gates法的回抽出血率明显低于传统注射法（P=0.025）,2种注射方法均未出现血肿。结论 Gow-Gates法下牙槽神经阻滞麻醉在下颌阻生第三磨牙拔除术中的麻醉效果好且较为安全,可以作为传统注射法的有效补充。     

微创拔除压迫下牙槽神经的第三磨牙方法分析

目的: 应用牵引拔牙、截冠和超声骨刀微创拔牙技术拔除压迫下牙槽神经的第三磨牙,观察术后产生下唇麻木等并发症的发生情况。方法: 选择60例全景片和锥形束CT（CBCT）显示下颌第三磨牙牙根压迫下牙槽神经的患者,分别采用3种方法拔牙各20例,术后检查下唇麻木情况。结果: 应用牵引拔牙技术和截冠方法拔除压迫下牙槽神经的第三磨牙,术后无人发生下唇麻木,而应用超声骨刀微创拔牙的患者中有1例出现轻微的下唇麻木症状,经用药1个月后好转。结论: 牵引拔牙技术、截冠和超声骨刀3种方法均可有效避免智牙拔除后下唇麻木的并发症。     

Removal of a deeply impacted mandibular third molar through a sagittal split ramus osteotomy approach

We describe the case of a 48-year-old man who, after a 5-year history of recurrent infection and intermittent trismus associated with a deeply impacted lower right third molar tooth, presented to the accident and emergency department with severely limited mouth opening, extensive facial swelling and pyrexia. The lower right third molar was later removed successfully through a sagittal split ramus osteotomy approach. This case shows that the sagittal split osteotomy continues to have a valuable role in the removal of deeply impacted lower third molars, particularly when they are in close proximity to the inferior alveolar nerve.     

Preoperative assessment of the relationship between the mandibular third molar and the mandibular canal by axial computed tomography with coronal and sagittal reconstruction

OBJECTIVE: We sought to evaluate the relationship between the mandibular third molar and the mandibular canal by using axial computed tomography with coronal and sagittal reconstruction for third molar surgery. STUDY DESIGN: Forty-seven impacted third molars in 41 patients were found in close association with the mandibular canal during a panoramic radiographic assessment. The relationship between the mandibular third molar and the mandibular canal was evaluated by using computed tomography and compared in terms of operative exposure of the inferior alveolar nerve and postoperative labial dysesthesia. RESULTS: Twenty-four (51%) mandibular canals were buccal relative to the third molar, 12 were lingual, 9 were inferior, and 2 were between roots. At the time of the surgical procedure, the inferior alveolar nerve was visible in 7 patients. Postoperative lower lip dysesthesia occurred in 1 patient whose mandibular canal was in the lingual position. CONCLUSIONS: Axial computed tomography with coronal and sagittal reconstruction provides useful information to surgeons regarding the relationship between the mandibular third molar and the mandibular canal.     

Frequency of trigeminal nerve injuries following third molar removal.

PURPOSE: To estimate oral and maxillofacial surgery reporting of the frequency of temporary and permanent inferior alveolar and lingual nerve damage from lower third molar extraction and injury etiology, and to identify factors associated with injury rates. MATERIALS AND METHODS: A postal survey was sent to all members of the California Association of Oral and Maxillofacial Surgeons requesting information on known instances of inferior alveolar and lingual nerve damage that had occurred in their practices over a 12-month period and known instances of permanent damage over their entire careers. RESULTS: Replies were obtained from 535 California Oral and Maxillofacial Surgeons (OMFS) representing 86% of all OMFS in California. Instances of injury to the inferior alveolar nerve in a 12-month period were reported by 94.5% of OMFS; 53% reported instances of lingual nerve injury in a 12-month period. Instances of permanent nerve injury of the inferior alveolar nerve were reported by 78% of OMFS; 46% reported permanent lingual nerve injury occurring during their professional lifetime. The overall estimated self-reported rate of injury was 4 per 1,000 lower third molar extractions for the inferior alveolar nerve and 1 per 1,000 extractions for the lingual nerve for all cases (temporary and permanent). In most cases (80%) of inferior alveolar nerve injury the cause was known, but in a majority of cases of lingual nerve injury (57%) the injury etiology was unknown. Self-reported rates of permanent injury were 1 per 2,500 lower third molar extractions for the inferior alveolar nerve and 1 per 10,000 lower third molar extractions for the lingual nerve. Injury rates were associated with provider experience (ie, extractions per year) and years in practice. CONCLUSION: This survey included a high percentage of California OMFS. Injury to the inferior alveolar and lingual nerve was reported by most OMFS in California following lower third molar removal, and many reported cases of permanent nerve injury, frequently with unknown cause.     

智齿冠切除术的手术方法及常见并发症

当下颌阻生第三磨牙拔除术引发下牙槽神经损伤的风险较高时,下颌阻生第三磨牙冠切除术（coronectomy）就成为一种降低风险的手术方式。许多文章都认为冠切除术可以显著降低下牙槽神经损伤的风险,且并发症的发病率亦较低。本文总结概述了冠切除术的手术方法,常见的并发症及处理方法。