下颌骨牵引成骨术对下牙槽神经功能影响的实验研究

目的　研究下颌骨牵引成骨术对下牙槽神经功能的影响。方法　对青年恒河猴 16只 ,全麻下行下颌角部骨截开术及牵引器置入术 ,术后第 5天开始以 0 5mm× 2次 /d的速度牵引 ,共15d。采用八导肌电图仪 ,表面电极在颏孔处刺激 ,针电极在卵圆孔附近记录 ,分别在术前、牵引完成后 0、2、4、6、9、12周时行感觉神经动作电位测试。结果　牵引完成时潜伏期较术前增加 2 2 18% ,其后逐渐降低 ,至牵引完成后 12周时仍较术前高 10 70 %。牵引完成时波幅降至术前的 2 8 5 4% ,牵引后 12周时恢复至术前的 99 84%。结论　下颌骨牵引成骨术对下牙槽神经的功能会产生暂时性影响 ,随着神经髓鞘和轴突的再生 ,神经功能可逐渐恢复正常。     

三叉神经躯体感觉诱发电位评价慢性咀嚼肌疼痛神经功能的初探

目的采用三叉神经躯体感觉诱发电位（trigeminal somatosensory evoked potential，TSEP）检查方法，分析比较慢性咀嚼肌疼痛（masticatory muscle pain，MMP）患者与对照组TSEP各波潜伏期的变化规律，初步探讨慢性MMP患者神经功能变化的机制及TSEP的诊断价值。方法收集慢性MMP患者12例（患者组），以及年龄、性别与患者组匹配的健康人12名（对照组），分别行双侧颏神经和咬肌TSEP检查。归纳全部受试者面部两侧共4个部位的TSEP波形，分析出现率为75％～100％且双侧对称的波形。对测得的波潜伏期进行配对和独立样本t检验。结果获得5个TSEP波（P1、N1、P2、N2和P3）。患者组两侧颏神经TSEP的P1潜伏期缩短，与对照组相比差异有统计学意义（P〈0．05）；其余各波与对照组相比潜伏期延长，左侧P2、N2的差异均有统计学意义（P〈0．05）。咬肌区各波潜伏期的变化不一致。结论慢性MMP患者TSEP波潜伏期的变化有一定规律，初步证明患者中枢和外周神经功能的改变。慢性MMP患者P1潜伏期变短，提示三叉神经节以下外周神经传导活化；P2潜伏期变长提示脑干可能受到抑制。     

变速牵引成骨对兔下牙槽神经的影响

目的　研究变速牵引兔下颌骨15mm对下牙槽神经的影响。方法　5只新西兰白兔单侧下颌骨截开。延迟5d ,以每天1 5mm ,每天2次牵引9mm ,然后继续以每天1mm ,每天2次牵引6mm ,完成牵引后固定15周,分别行肉眼及组织学观察和电生理学检查。结果　下颌骨延长15mm ,新骨生成良好。下牙槽神经牵长2 1. 99% ,牵引结束时神经变性明显,感觉神经动作电位波幅下降为术前的9. 70 % ,潜伏期较术前有所延长,随后出现恢复趋势,到固定15周时,波幅恢复到术前的33. 85 % ,潜伏期基本恢复正常。结论　下颌骨变速牵引15mm后,下牙槽神经受到明显的影响,到15周时,下牙槽神经的功能有恢复的趋势,但恢复尚不完全。     

下颌支矢状劈开术不同固定方式对下牙槽神经功能的影响

目的 研究下颌支矢状劈开术（SSRO）常用两种内固定方式对下齿槽神经（IAN）功能的影响。方法 成年恒河猴12只，均行双侧SSRO后退术。左侧行双皮质骨螺钉固定，右侧行单皮质螺钉与夹板固定。于术前、术后即刻及术后2、4、8、12周时对两侧IAN行感觉神经动作电位（SNAP）检查。结果 SSRO术后即刻SNAP检测示IAN潜伏期延长，波幅减小，较术前有显著差异（P〈0.01），但两侧之间无显著差剐。术后2周起，IAN功能逐渐恢复。至术后12周时右侧IAN的潜伏期基本恢复至术前水平，左侧IAN潜伏期较术前延长15．4％（P〈0．05）；右侧的波幅恢复也要优于左侧（P〈0．05）。结论 SSRO术中使用双皮质螺钉固定舜口单皮质螺钉夹板固定对IAN功能均有影响，但随着时间的延长，IAN功能均有恢复。单皮质骨螺钉与夹板固定相对于双皮质骨螺钉固定对1AN的功能影响要小。     

上颌神经诱发三叉神经皮层电位的研究

目的　探讨三叉神经的分支上颌神经皮层诱发电位的特点及与三叉神经其他分支皮层诱发电位的差异。方法　通过刺激 10名健康成人的眶下神经 ,收集刺激对侧的三叉神经诱发电位 (TSEP)。结果　①刺激发生 2 0ms左右出现P1,其后N1～N5等 9个波峰依次出现 ;②P3、N3、P4潜伏期稳定 ,N3～N4振幅高且图形规律 ;③上颌神经皮层诱发电位与下颌神经皮层诱发电位无明显差异。结论　上颌神经TSEP中高峰电位出现于 110ms的N3P4波 ,波幅 >10 μV ,其潜伏期相对稳定 ,形成上颌神经TSEP的特点 ,早期的P1～N2波幅较低 ,但可以因周围神经的改变而有较大的变化 ;正常上颌神经的TSEP各波潜伏期、图形特点、峰峰电位差与下颌神经TSEP差异不明显。根据图形特点、参数可以作为临床三叉神经上颌支功能状态和病理改变的判定指标     

下颌垂直牵引成骨术后口腔种植修复患者咀嚼功能的评估

目的：评估下颌垂直牵引成骨术后口腔种植修复患者的咀嚼功能。方法：采用杏仁、小枣过筛称重法分别测量正常健康组、正常下颌骨高度种植惠者组和重度下颌骨高度不足垂直牵引成骨种植患者组的咀嚼效率，每组8人.结果：重度下颌骨高度不足垂直牵引成骨种植惠者组杏仁和小誊平均咀嚼效率分别达到正常健康组平均咀嚼效率的86．1％和898％采用单因素方差分析两两比较，除正常健康组与重度下颌骨高度不足垂直牵引成骨种植患者组采用杏仁测量的平均咀嚼效率有显著性差异（P〈0．05）外，其余各组两两比较平均咀嚼效率均无显著性差异（P〉0．05）在重度下颌骨高度不足垂直牵引成骨种植患者组中，采用配对1检验两两比较，种植冠、桥修复惠者平均咀嚼效率与种植覆盖义齿修复患者平均咀嚼效率无显著性差异（P〉0．05）。结论：下领垂直牵引戍骨术后行口腔种植修复，能够有效地恢复患者的咀嚼功能。     

下颌骨骨折颌间牵引对牙体牙周组织的影响

目的：评价带钩牙弓夹板颌间弹力牵引治疗下颌骨骨折对牙体牙周组织的影响。方法：牙弓夹板固定前、拆除牙弓夹板后第二天及牙弓夹板拆除后3个月，分3次调查41例患者（固定组）与41例对照健康人（对照组）的软垢指数，牙周治疗需要指数、龋失补牙数。结果：3次检查固定组一的龋均无显著差异（P＞0．05），第二次检查两组的软垢指数，牙周治疗需要指数差异显著（分别为P＜0．01，P＜0．05），第三次检查固定组软 指数稍下降，但仍明显高于对照组（P＜0．01），两组牙周治疗需要指数差异更为明显（P＜0．001）。固定组第二、三次检查软垢指数、牙周治疗需要指数均明显高于第一次检查，结论：牙弓夹板颌间弹力牵引治疗颌骨骨折，对牙体组织影响不明显，但对牙周组织有较大不利影响。     

微创牙冠延长术的临床疗效评价

目的：评价微创技术应用于牙冠延长术的临床效果。方法：将39例患者的45颗冠缺损达龈下最深位点1．5～4 mm患牙进行随机分组。对照组24颗患牙施行常规牙冠延长术；实验组21颗患牙是将微创技术应用于牙冠延长手术：术者头戴放大镜，翻瓣时采用显微牙周手术器械，去骨时采用超声骨刀，缝合时采用5-0不可吸收缝线。分别记录术前、术后1周（拆线）、术后8周（修复前）以及修复完成后6个月缺损最深位点处的探诊深度（ PD）、龈沟出血指数（ SBI）和松动度（ MD），以及修复后6个月牙龈退缩（ GR）率，并记录术后不良反应情况。结果：①两组患牙治疗后SBI、PD指标较术前有明显改善（P＜0．01）；术后1周MD较术前有加大趋势（P＜0．01），但到修复前和修复后6个月又趋于稳定（P＞0．05）。②术后1周实验组SBI和PD指标的改善优于对照组，两组间的差异有统计学意义（P＜0．01）；修复前和修复后6个月实验组PD指标的改善优于对照组，两组间的差异有统计学意义（P＜0．01），SBI指标的改善也优于对照组（P＜0．05）。③修复后6个月实验组均无牙龈退缩，对照组有6例出现0．5-1．0 mm的牙龈退缩，两组相比P＜0．05。④对照组有4例出现术后肿胀，3例术后出现疼痛；实验组均无术后肿胀、疼痛等并发症。结论：微创技术应用于牙冠延长术能够明显改善临床指标，降低术后不良反应以及术后牙龈退缩，获得更好的临床疗效。     

改良式下齿槽神经移位术同期植入种植体手术1例

在下颌磨牙区骨量不足病例的种植修复中,垂直骨高度不足是最难解决的问题,因为其常伴有水平方向的骨缺损和对颌牙的降低,所以诸如垂直向onlay植骨的难度和术后效果问题;利用钛网进行GBR手术获得成功的例子极少的问题;以及与牵引成骨手术一起所面临的颌间距离问题,一直困扰着种植科医生.而利用下齿槽神经移位术同期植入种植体的术式来弥补下颌骨骨高度不足的方法在临床上还存在着争议,主要是因为其对神经的损伤.我们在这例手术中根据下齿槽神经在下颌骨磨牙区的解剖特点采用改良的神经移位术,同期植入种植体,并于术前和术后给与相应的药物来减少神经的损伤和促进神经的恢复.我们获得了满意的初期稳定性和满意的颌间距离,患者的神经功能在术后一个月中逐渐恢复,5个月后已完全恢复.现在是完成修复后一年,患者各方面情况良好.我们得出结论利用此改良神经移位术并辅以合理的用药,加上严格的适应症和术前患者的配合,这种方法在弥补下颌骨磨牙区骨高度严重不足的种植手术中是可行的.     

腭裂修复术同期中耳置管治疗渗出性中耳炎

目的：了解腭裂修复同期鼓膜切开中耳置管,对腭裂渗出性中耳炎及听力损失的治疗作用。方法：选择在腭裂修复前作声阻抗检查鼓室图为B型,声镫骨肌反射阴性,脑干听觉诱发电位检查V液反应阈大于等于30dB的患儿76例,随机分为置管组与常规组,置管组为行腭裂修复同期中耳置管45例,常规组为单纯行腭裂修复31例。术后两周分别进行鼓室图,脑干听觉诱发电位检查,并进行统计学处理。结果：置管组术前术后V波反应阈平均值,听力损失及鼓室图均有显著性（P＜0．001）,常规组术前术后V波反应阈平均值,听力损失及鼓室图均无显著性（P＞0．05）,术前置管组与常规组V波反应阈平均值,听力损失及鼓室图差异无显著性（P＞0．05）,术后置管组与常规组两组V波反应阈平均值,听力损失及鼓室图差异有显著性（P＜0．001）,结论：中耳置管可作为腭裂渗出性中耳炎及听力损失的常规治疗手段,提高患者听力,避免粘连性中耳炎发生。     

Evaluation of inferior alveolar nerve function during distraction osteogenesis in the dog

Purpose: A series of electrophysiologic studies were performed in a canine model to evaluate inferior alveolar nerve (IAN) function during distraction osteogenesis of the mandible.Materials and Methods: Fourteen dogs, including two controls, were used in the study. Twelve dogs underwent a 10-mm bilateral mandibular lengthening with an intraoral bone-borne appliance and midbody osteotomy. By using sensory nerve action potentials, IAN function was assessed before and immediately after surgery, before and at the completion of distraction, and before necropsy after 4, 6, or 8 weeks of fixation.Results: Twelve of the 24 nerves showed a complete loss of evoked potential after surgery without recovery at any point throughout the study. Acute nerve injury caused by either the osteotomy or screw encroachment was identified at necropsy. The other 12 nerves showed reproducible responses after surgery. Eight of these nerves had significant amplitude attenuation of the evoked potentials, which was identified at necropsy as a result of acute injury. The remaining four nerves did not show significant evoked potential abnormalities and appeared to be grossly normal at necropsy. During distraction, the amplitude of evoked potentials in all 12 nerves remained at the postoperative level, whereas latency showed a significant delay. In 7 of these 12 nerves, various degrees of evoked potential recovery were identified at the completion of the study.Conclusions: The high incidence of acute IAN injury in the current study was primarily related to device construction and osteotomy technique. If acute nerve injury is avoided at surgery, distraction osteogenesis with 10 mm mandibular lengthening appears to produce minimal deleterious effect on IAN function.     

Nerve growth factor injected systemically improves the recovery of the inferior alveolar nerve in a rabbit model of mandibular distraction osteogenesis

Our aim was to find out if nerve growth factor (NGF) injected systemically could improve the recovery of the inferior alveolar nerve in a rabbit model of mandibular distraction osteogenesis. We used 48 New Zealand white rabbits that were treated with bilateral distraction osteogenesis at a rate of 0.5 mm/12 h for 10 days. Immediately postoperatively, NGF or sodium chloride 0.6 μg/day was injected intramuscularly for 20 days. At the end of distraction and after consolidation times of 1, 2, and 4 weeks, the inferior alveolar nerves were evaluated histologically and histomorphometrically. Histologically, at 2 and 4 weeks there was less myelin debris, and more regenerating axons were present, in the NGF than the control groups. The density of myelinated axons was significantly greater in groups with NGF than controls at 2 and 4 weeks (p < 0.05). NGF given systemically can accelerate the recovery of the inferior alveolar nerve in rabbits after mandibular distraction osteogenesis, and is a promising treatment option for neurological complications of mandibular distraction osteogenesis.     

Changes in the inferior alveolar nerve after mandibular lengthening with different rates of distraction.

PURPOSE: This study investigated the changes in the inferior alveolar nerve after mandibular lengthening with different rates of distraction. MATERIALS AND METHODS: Bilateral mandibular corticotomies were performed in 8 goats. The mandibles in 6 goats were lengthened 10 mm using a custom-made distractor with 2 different rates of distraction (1 mm/d [n = 3] and 2 mm/d [n = 3]); the other 2 nondistracted mandibles served as a control. The goats with distracted mandibles were killed at 2 weeks after completion of distraction. The inferior alveolar nerve specimens from all animals were harvested and processed for histologic and ultrastructural evaluation. RESULTS: The mandibles were lengthened successfully in the distracted animals. Morphologic changes in the inferior alveolar nerves were observed when compared with the nondistracted controls. Moreover, signs of nerve degeneration, such as demyelination, axonal swelling, axoplasmic darking, and decrease in the number of axons, were more extensive and prominent in those nerves distracted at a rate of 2 mm/d. CONCLUSIONS: Degenerative changes in the inferior alveolar nerve occur after mandibular lengthening by distraction osteogenesis. The distraction rate of 1 mm/d appears to be tolerable and safe for the inferior alveolar nerve, but rapid distraction may cause serious degeneration.     

牵张成骨延长山羊下颌骨后下齿槽神经的组织学变化

目的 :研究下颌骨牵张成骨术后不同时间内下齿槽神经的组织学改变。方法 :对 8只成年山羊行双侧下颌体骨皮质切开术 ,经口外安置自行研制的下颌牵张器 ,以每天 1mm的速率向前牵引延长其中 6只山羊的下颌骨10mm。于牵张结束后第 2、4、8周各处死 2只动物 ,取双侧下齿槽神经作组织学检查 ,另 2只未牵张的山羊作对照。结果 :下齿槽神经受牵张力作用发生了一定程度的沃勒变性 ,主要表现为髓鞘肿胀、碎裂及轴索数目减少。但随着固定时间的延长 ,受损神经纤维逐渐得以再生。结论 :下颌骨牵张成骨术后下齿槽神经发生了轻度的退行性变 ,但这种退行性变在适宜的速率牵张下是可逆的     

Somatosensory-evoked potential to evaluate the trigeminal nerve after sagittal split osteotomy

OBJECTIVE: The purpose of this study was to assess the onset period of trigeminal nerve hypoesthesia during bilateral sagittal split osteotomy, with the use of the trigeminal somatosensory-evoked potential (TSEP). STUDY DESIGN: Subjects were 10 patients with mandibular prognathism who underwent setback surgery. Intraoperative TSEP was measured 4 times: just before the commencement of the surgery, immediately after the induction of general anesthesia; after the medial periosteal dissection of the alveolar neurovascular bundle; after the sagittal split of bone; and after semirigid fixation with a titanium miniplate with the use of a monocortical screw. Postoperative TSEP was measured after the start of postoperative weeks 2, 4, 12, and 24. Normal records of the TSEP wave comprised peak (13 ms), trough (16 ms), peak (22.7 ms), and trough (36 ms) (N1, P1, N2, P2, respectively). Trigeminal hypoesthesia was assessed by the latency of P1 and N2, because they indicated the most reproducible waveforms. RESULTS: The change in shape of the spectra indicated that prolonged latency was initiated on medial periosteal dissection and was extended further after the sagittal bone split and fixation. However, latency recovery was observed relatively quickly after the start of postoperative weeks 2 and 4. CONCLUSIONS: Trigeminal hypoesthesia appeared to be induced by direct injury to the alveolar nerve during the bone split or by compression injury after fixation. Accordingly, the occurrence of a long-lasting postoperative trigeminal sensory hypoesthesia seemed to depend on nervous involvement of the split surface, the manner of fixation, or the intraoperative care.     

失感觉神经支配大鼠下颌骨牵张成骨动物模型的建立

目的：建立一个新的可行性和重复性俱佳的失感觉神经支配大鼠下颌骨牵张成骨模型。方法：24只大鼠随机分为2组,实验组大鼠先自下颌孔至颏孔切除下齿槽神经后,从升支前缘至下颌骨下缘行全层骨切开,用螺钉固定特制的钛牵张器,对照组为保留下齿槽神经的大鼠下颌骨牵张成骨,5d延迟期后,均进行单侧下颌骨牵张,速率：0．2mm／12h,牵张期为lOd,随后进入固定期。分别于固定期第14d、28d处死大鼠,进行大体标本观察和组织学检测。结果：实验过程被所有24只大鼠很好的耐受,切口感染率低,无牵张器脱落。大体标本观察表明,在牵张间隙形成了很好的骨痂组织,牵张间隙达到了预期的长度。感觉神经缺失对牵张成骨具有负面调节作用。结论：成功建立了一个新的可行性和重复性俱佳的失感觉神经支配大鼠下颌骨牵张成骨模型,该模型有助于感觉神经对牵张成骨影响的分子机制的进一步深入研究。     

下颌骨牵张成骨对下牙槽神经影响的实验研究

目的　观察狗双侧下颌骨牵张成骨术中不同时间点的下牙槽神经的电生理功能及组织学结构的变化。方法　实验组 :12只狗行保留下牙槽神经的双侧下颌骨截断术 ,装上自制的口内牵张器 ,于术后第 8天开始牵张 ,1mm/d ,共 10d ,牵张长度约 10mm。分别在牵张中第 6天、牵张完毕后固定 2周及 8周时各处死 4只动物。分别在术前及术后的不同时期用电生理方法检测双侧下牙槽神经的传导功能 ,并于处死前取出双侧下牙槽神经进行组织病理学及超微结构组织学检查。对照组 :4只狗 ,其中 2只狗作为对照组 ,未行手术 ;另 2只狗为手术对照组 ,进行与实验组相同的骨切开截断术 ,上牵张器 ,但未行牵张和固定 ,于操作完毕时取出双侧下牙槽神经作为术后的组织学结构标本。结果　实验组动物的下牙槽神经在光镜下显示部分神经纤维稍肿胀变粗 ;电镜下显示部分神经纤维髓鞘的板层松解及脱髓鞘现象 ;电生理结果显示 ,神经传导的速度于截断术后的不同时期均低于术前 ,但仅术后第 8天 (即牵张前 )的传导速度与术前的传导速度差异有显著性 (P <0 .0 1)。结论　对狗的双侧下颌骨进行牵张成骨时 ,可一过性引起下牙槽神经损伤。其损伤的主要原因是手术过程所致。在适当的牵张速率、牵张长度和牢固的固定条件下 ,下颌骨的牵张成骨术对下牙槽 还原。     

Original sagittal split osteotomy revisited for mandibular distraction

Introduction: A malformed mandible and an abnormally positioned mandibular foramen make it difficult to plan an ideal osteotomy line for mandibular distraction. In addition, there have been reports of such complications as nonunion, damage and stretch injury of the inferior alveolar nerve and tooth germ damage when conventional osteotomy or corticotomy are used for mandibular distraction. The authors utilized the original sagittal split ramus osteotomy for mandibular distraction. Patients and Methods: Five patients (three unilateral hemifacial microsomia, one bilateral hemifacial microsomia, and one mandibular retrusion) were included in this study of distraction osteogenesis using the sagittal split ramus osteotomy. Extraoral distraction devices were applied to the first four patients. An intraoral device with mono-cortical screw fixation was used for the fifth patient. Result: In all five cases, the results of the distraction were satisfactory. Complications (as listed) of conventional osteotomy when used for distraction were avoided. Satisfactory results were achieved and these were also well maintained postoperatively (mean follow up: 36 months). Conclusion: The authors believe that sagittal osteotomy for mandibular distraction osteogenesis makes it possible, to avoid injury to the inferior alveolar nerve during operation and stretching injury during distraction and to prevent tooth germ injury. It is also possible to diversify the osteotomy line for various force vectors to enlarge the bony contact surface area. Therefore, we suggest that sagittal split ramus osteotomy should be used as a preferred modification of osteotomy for mandibular distraction. Copyright 2001 European Association for Cranio-Maxillofacial Surgery.