锥束CT在下颌角肥大整形术中的应用

目的 探讨锥束CT在下颌角肥大整形术中的作用.方法 随机选取20例青年女性行锥束CT扫描,获得DICOM格式的三维重建数据,将数据导入Invivo 5 软件,显示下颌神经管走行,并测量下颌神经管距下颌升支后缘及下颌骨体下缘的距离.选择临床11例下颌角肥大的患者,术前进行锥束CT扫描,定位下颌神经管,并进行弧形截骨线设计,指导临床操作.结果 下颌神经管与下颌后缘及下缘的距离呈先减小后增大的趋势:下颌升支前缘水平至第一磨牙水平所对应的距离逐渐减小,至第一磨牙后缘水平所对应的距离最小,左侧为(8.93±1.78)mm,右侧为(8.16±1.51)mm,之后距离逐渐增加.下颌神经管距下颌角最短距离,左侧为(19.25±3.79)mm,右侧为(19.15±3.17)mm.临床应用CBCT可术前准确定位下颌神经管,并辅助截骨设计,手术效果良好.结论 锥束CT可为下颌角肥大整形提供准确的下颌神经管解剖影像,提高了手术的准确性和安全性.     

下颌神经管三维CT定位在下颌角截骨整形术中的应用

目的 准确定位下颌神经管,以减少下颌角弧形截骨整形术中下齿槽神经血管束损伤的几率.方法 对30例青年女性下颌角肥大患者行下颌骨螺旋CT扫描、三维重建,定点后测量下颌神经管下缘在各点距下颌牙牙冠的距离.术中应用钢尺测量定位其在下颌骨体外表面的投影.指导截骨.术中、术后观察下颌神经管的完整性.结果 30例下颌角截骨术后下颌神经管骨壁均完整,未损伤下颌骨体内神经血管柬.结论 三维CT可以准确定位下颌神经管,指导下颌角截骨整形术的截骨设计与术中操作,减少下齿槽神经血管束损伤的几率.     

利用曲面断层摄影和螺旋CT进行下颌神经管定位

目的 通过利用曲面断层摄影、螺旋CT与实体测量的方法,对下颌骨第2磨牙区下颌神经管下缘至下颌下缘距离与该区下颌体高度比值进行比较,对下颌神经管在下颌骨中走行进行定位,为避免在下颌角肥大弧形截骨手术中损伤下牙槽神经血管束提供客观依据.方法 将16具下颌骨标本进行曲面断层摄影和螺旋CT扫描,分别测量第2磨牙区下颌神经管至下颌下缘距离与该区下颌体高度比值,再经该部位将下颌骨依冠状面锯开后进行测量,比较三者的差异.结果 第2磨牙区下颌神经管下缘至下颌下缘的距离与下颌体高度比值在曲面断层摄影、螺旋cT扫描和实测值中,差异无统计学意义(P＞0.05).结论 在下颌角肥大弧形截骨术及其他下颌骨的手术前,通过曲面断层摄影测量第2磨牙区下颌神经管下缘至下颌体下缘距离与下颌体高度的比值,可以为下颌神经管在下颌骨颊侧骨板的表面定位提重要临床依据.     

下颌角肥大截骨手术相关下颌管解剖标志的多层CT测量研究

目的 应用多层CT影像测量下颌骨与下颌角切除手术相关下颌管骨性解剖标志,为避免手术中损伤下齿槽神经血管提供指导.方法 选择60例正常成人下颌骨多层CT扫描图像,应用efilm 1.94图像处理软件分别在第2磨牙远中的垂直线,第2磨牙远中至下颌角连线及下颌孔下5.00 mm取下颌骨断面测量下颌管的解剖位置.结果 下颌管在下颌第2磨牙远中断面距颊侧骨面的距离为(6.26±4.34) mm;在第2磨牙远中至下颌角连线断面距颊侧骨面的距离为(5.18±2.12) mm;在下颌孔下5.00 mm断面距颊侧骨面的距离为(4.44±2.38) mm.下颌管在下颌第2磨牙远中垂面距下颌骨下缘的距离为(11.76±4.62) mm,在第2磨牙远中至下颌角连线断面距下颌角缘的距离为(19.86±5.40) mm,在下颌孔下5.00 mm断面距下颌骨后缘的距离为(16.12±6.46) mm.结论 参照测量获得的解剖数据在下颌角截骨术中能降低下齿槽神经血管损伤的发生率.     

下颌角肥大截骨线与下颌角解剖结构的相关研究

目的 分析下颌角肥大直线截骨的特点及其与下颌角相关解剖结构的关系,为手术及手术辅助器械的设计提供参考数据.方法 选择100例咬牙 合关系正常伴不同程度下颌角肥大的成人头颅侧位X线片,以下颌第一磨牙近中临面对应的下颌骨下缘为起点向后上方直线截骨将下颌角恢复到125°,对截骨线及其与下颌角相关解剖结构的关系进行测量分析.结果 截骨线长度及截骨线到下颌角的距离与原下颌角度呈负相关(P ＜0.01).截骨线长度为(60.0±5.2)mm;截骨线长度到下颌角的距离为(10.5±1.5)mm.下颌角区截骨线到下牙槽神经管的距离与原下颌角度呈正相关(P ＜0.01),截骨线到下牙槽神经管的距离为(10.3±1.5)mm.新下颌角到磨牙咬牙合平面的距离与原下颌角度的相关性无统计学意义(P ＞0.05),距离为(16.9±1.4)mm.结论 以下颌第一磨牙近中临面对应的下颌骨下缘为起点向后上方做直线截骨将下颌角恢复到125°时,截骨线与下牙槽神经血管神经束有相对安全的距离,下颌角截骨量比较充分,能够有效改善下颌角形态.新下颌角距磨牙咬牙 合平面的距离相对恒定.     

下颌角整形术安全平面的解剖学研究

目的 通过对下颌角区域主要血管和下颌管走行特点的解剖观察,探讨下颌角整形术的安全平面.方法 选取10例(20侧)成人头颅标本.在下颌骨各特定截面上测量下颌管后缘与下颌骨升支后缘以及下颌管下缘与下颌骨下缘的距离.各数据计算进行t检验分析.结果 下颌后静脉距下颌骨升支后缘的距离为(3.00±0.56)mm,距下颌角的距离为(12.20±1.09)mm.面动脉、面静脉在下颌骨下缘水平距下颌角的距离分别为(30.06±4.25)mm、(27.55 4±4.02)mm.第三磨牙外缘下颌管下缘距下颌角、颏孔处距下颌骨下缘分别为(16.64±0.88)mm、(15.22±1.29)mm.结论 下颌角区域血管和下颌管解剖结构关系复杂,但又有一定规律;综合以上因素确定安全平面,可提高手术的安全性.     

下颌角周围相关动脉走行的CTA定位研究

目的:应用CTA影像测量下颌角周围动脉与下颌角手术的解剖关系,为避免手术中损伤下颌角周围动脉提供指导。方法:选择30名正常成人下颌角及周围血管CTA扫描图像,应用ADW4.2图像处理软件测量面动脉距下颌角点;颈外动脉距下颌角点、颈外动脉距下颌骨升支后缘各点的三维解剖位置。结果:面动脉距下颌角点的距离为(28.26±8.34)mm;颈外动脉据下颌角点的距离为(18.66±6.34)mm;颈外动脉在下颌角点上10mm处距下颌骨升支后缘的距离为(12.28±5.12)mm;在下颌角点上20mm处距下颌骨升支后缘的距离为(9.58±5.42)mm;在下颌角点上30mm处距下颌骨升支后缘的距离为(6.38±4.12)mm,在下颌角点上40mm处距下颌骨升支后缘的距离为(3.46±2.56)mm,左右侧无显著差异。结论:在下颌角截骨或磨削手术时应注意面动脉和颈外动脉的损伤,位置越高颈外动脉距下颌升支边缘越近。手术安全范围应控制在距下颌角点上30mm以内的位置。     

超声骨刀在下颌角截骨整形术中的应用

目的探讨超声骨刀在下颌角截骨术中的应用效果。方法选取单纯下颌角截骨整形患者35例,术中使用超声骨刀配以骨刀手具进行截骨。结果全部35例患者术后经6个月至5年随访,口腔全景片示下颌骨双侧对称,下颌骨下缘平滑,下颌神经管清晰完整。1例患者术后单侧面部血肿,对症处理2周后完全恢复。结论下颌角截骨整形术中使用超声骨刀,截骨效果良好,患者对手术效果满意。     

下颌角缩小术三个关键点的分析

目的在下面部骨性轮廓改形的手术中,寻找下颌骨最佳截骨部位以获得更好的手术效果。方法对382例女性受术者,经口内入路,在气管插管全身麻醉下,利用电动往复锯片的弹性,原位调整锯片切入骨质的角度,一次性整体截除下颌骨升支下部、下颌角、下颌骨外板、下颌骨体下缘及部分颏骨,将残端磨削平滑圆润,线条流畅。结果早期为追求下颌角最大程度地截骨缩小下面部,致出现俗称“马脸”变形、第2下颌角,8例均是由于早期手术对下颌骨体及下缘、下颏处理不到位。术后随访101例,医患双方对效果非常满意61例,满意22例,基本满意11例,不满意5例,差2例。结论下面部骨性缩小的3个关键点足下颌角后份、下颌骨体中份和颏骨前份。     

小下颌畸形患儿下颌神经管CT解剖特征

目的 探讨小下颌畸形患儿下颌神经管的CT解剖特征.方法 在36例小下颌畸形患儿下颌骨冠状位CT图像上,分区测量下颌神经管内缘与下颌骨舌侧骨壁（舌侧指数）、外缘与颊侧骨壁（颊侧指数）、下缘与下颌骨下缘（下缘指数）间的距离.结果 第2前磨牙下颌神经管舌侧、颊侧和下缘的骨壁厚度指数为（4.71±1.25）、（2.77±1.02）、（2.92±0.83）mm,第1磨牙区为（2.64±0.99）、（4.33±1.12）、（2.38±0.72）mm,第2磨牙区为（2.44±0.76）、（4.20±0.89）、（3.38±1.31） mm,以上指数左、右侧比较差异均无统计学意义.在下颌第2前磨牙区至第2磨牙区,神经管偏舌侧走行68侧（94.4％）,偏颊侧4侧（5.6％）;颏孔开口于第2前磨牙区17侧（23.7％）,开口于第1前磨牙区与第2前磨牙间55侧（76.3％）;下颌神经管分支2侧（2.8％）.结论 小下颌畸形患儿下颌神经管大体走向为起于下颌孔,偏舌侧和下颌骨下缘走行,止于颏孔;存在下颌管分支、走行偏颊侧、颏孔后移等变异,应引起手术医师注意.     

Radiographic proximity of the mandibular third molar to the inferior alveolar canal.

OBJECTIVE: To determine the panoramic radiographic distance from the mandibular third molar tooth to the inferior alveolar canal. STUDY DESIGN: Five hundred sixty mandibular third molars were evaluated by panoramic radiography. The teeth were grouped into erupted vs unerupted and further subdivided by tooth angulation. The distance from the most inferior aspect of the mandibular third molar tooth to the superior border of the inferior alveolar canal was measured with digital calipers. A t test was performed to compare erupted and unerupted teeth, and ANOVA was used to determine if a significant difference exists based upon tooth angulation. A record review was performed to assess the incidence of inferior alveolar nerve paresthesia based upon measured distances. RESULTS: The mean distance from erupted mandibular third molar teeth to the inferior alveolar canal is 0.88 mm. This distance was significantly different from unerupted teeth (P=.002). The mean values for unerupted teeth indicated that the most inferior portion of all teeth measured was below the superior border of the canal (negative values) as follows: mesioangular (-0.97 mm), vertical (-0.61 mm), distoangular (-0.31 mm), and horizontal (-0.24 mm). The position of mesioangular impactions were significantly different than all other impaction groups (P=.0125). The incidence of inferior alveolar nerve paresthesia was 3.33% (18/541), most commonly associated with mesioangular impactions (-0.66 mm) in female patients. CONCLUSIONS: Unerupted mandibular third molar teeth are closer to the inferior alveolar canal than are erupted teeth. Mesioangular mandibular third molar impactions are most closely positioned to the inferior alveolar canal, and this may represent an independent risk factor for postoperative paresthesia.     

Clinical evaluation of inferior alveolar nerve block by injection into the pterygomandibular space anterior to the mandibular foramen.

The conventional inferior alveolar nerve block (conventional technique) has potential risks of neural and vascular injuries. We studied a method of inferior alveolar nerve block by injecting a local anesthetic solution into the pterygomandibular space anterior to the mandibular foramen (anterior technique) with the purpose of avoiding such complications. The insertion angle of the anterior technique and the estimation of anesthesia in the anterior technique were examined. The predicted insertion angle measured on computed tomographic images was 60.1 +/- 7.1 degrees from the median, with the syringe end lying on the contralateral mandibular first molar, and the insertion depth was approximately 10 mm. We applied the anterior technique to 100 patients for mandibular molar extraction and assessed the anesthetic effects. A success rate of 74% was obtained. This is similar to that reported for the conventional technique but without the accompanying risks for inferior alveolar neural and vascular complications.     

The position of the inferior alveolar nerve at the mandibular angle:: an anatomic consideration for aesthetic mandibular angle reduction

Mandibular angle reduction is a popular contouring surgery in Asia. Avoidance of injury to the inferior alveolar nerve is crucial during these procedures. Anatomic data regarding the position of the nerve in the mandibular angle area are sparse. The purpose of this study was to use 3-dimensional computed tomographic data to evaluate the nerve in patients with prominent mandibular angles and to compare the nerve position with a normative group. A total of 28 female and 5 male adult patients who presented with a complaint of prominent angles or a "square-face" look, as well as 20 female and 22 male adult normal subjects were included, for a total of 150 hemimandibles for extraction of the inferior alveolar nerve. The nerve and the mandible were displayed. Point O was defined on the oblique line along the anterior cortex of ramus, where it intersected with a line extending from the alveolar arch. From the O point, linear distances were defined, including horizontal distances to the posterior cortex, oblique distances to the gonion, and the vertical distances to the inferior cortex. Mandibular width was defined as the distance between the 2 gonion points. Results demonstrated significant differences mainly in the oblique distances (ie, from the O point to the nerve [O1], from the nerve to the gonion [O2], and from the O point to the gonion [O1-O2]) in both female and male patients. The O2 distance was 23.69 mm versus 20.66 mm in women and 27.30 mm versus 23.28 mm in men (square face vs norm). The mandibular width was significantly larger in the male square-face patients, but the difference was not significant between the female groups. These results provide useful information for surgeons planning mandibular angle reduction. These findings suggest that the mandibular contouring procedure should be aimed at correcting regional osseous dysmorphology in the angle area and improving the relationship to the chin, rather than merely reducing the mandibular width.     

下颌全牙弓后移量及最后界的测量

目的：研究下颌牙弓的有效后移量及找寻下颌牙弓移动的后界。方法：选取涉及拔除下颌第三磨牙或下颌第三磨牙缺失的病例18例（男6例,女12例）。采用种植支抗牵引下牙弓向远中,治疗完成时所有病例均明确到达下颌牙弓后界,即下颌第二磨牙远中到达下颌升支前缘软组织交界处。应用治疗前后的曲断片测量下颌第二磨牙远中到升支前缘的距离。结果：下颌第二磨牙后移量为（3.49±1.21）mm;治疗后磨牙后间隙的长度为（4.43±0.97）mm。结论：下颌牙弓可确定性地实现整体后移;最大后移量由磨牙后间隙的长度决定;其最后界止于下颌第二磨牙远中与下颌升支前缘软组织交界处。     

颞肌蒂下颌骨瓣修复面中份骨缺损的应用解剖

目的 为颞肌蒂下颌骨瓣修复面中份骨缺损提供解剖学基础. 方法 在30侧发育正常的成人尸体标本上解剖观测颞肌和下颌支的形态、血供及其两者的关系,并测量有关数据. 结果 颞肌主体呈扇形,向下分为3个肌束:前外侧肌束、前内侧肌束、后侧肌束,分别止于下颌支前缘、颞嵴和冠突内侧面后份,向下直至第3磨牙远中,附着于下颌支前份内侧面约3/4的区域;供应颞肌的动脉主要有:颞中动脉,外径(0.76±0.20)mm;颞深前动脉,外径(0.79±0.21)mm;颞深后动脉,外径(0.98±0.64)mm;多支细小的颞深副动脉.颞深动脉发出分支,形成肌动脉骨穿支和骨膜动脉网,为下颌支前份供血.下颌支呈矩形,以下颌切迹最低点、下颌孔和下颌管的连线为分界线,将下颌支分为前份和后份,前份可供骨量大小为(46.67±6.85)mm×(17.98±2.64)mm ×(11.49±0.99)mm. 结论 以颞肌为蒂下颌骨瓣具有血供可靠,骨量充足,应用该骨瓣修复面中份骨缺损,具有良好的解剖学基础.     

Anatomical study of position of the rib head for placing anterior vertebral body screws in a chinese population

In this study, the variability of rib head position in a Chinese population in terms of the spinal canal and vertebral body was analyzed using computed tomography (CT). Images from transverse CT scan of the T4 to T12 vertebral bodies of 30 normal individuals were 3-dimensionally reconstructed, and analyzed for measurement of parameters that define the relative anatomic position of the rib head. We have found that the distance between the anterior border of the rib head and the posterior margin of the vertebral body, posterior safe angle, and the distance between the most inferior border of the rib head and inferior end plate in the sagittal plane gradually decrease. However, the distance between the anterior boarder of the rib head and the anterior margin of the vertebral body, transverse dimension, anterior safe angle, and the distance between the most inferior border of the rib head and superior end plate in the sagittal plane gradually increase from T4 to T12. This indicates that the position of the rib head is oriented from a more anterior position to a more posterior position and from a more superior position to a more inferior position as the number of the vertebra increases, which is different from what has been reported from western populations. Our study has identified useful parameters to define the position of the rib head, and provides a comprehensive reference guide for accurate and safe instrumentation of vertebral body screws in treating related spine diseases.     

Anesthetic efficacy of buccal and lingual infiltrations of lidocaine following an inferior alveolar nerve block in mandibular posterior teeth

The authors, using a crossover design, randomly administered, in a single-blind manner, 3 sets of injections: an inferior alveolar nerve block (IANB) plus a mock buccal and a mock lingual infiltration of the mandibular first molar, an IANB plus a buccal infiltration and a mock lingual infiltration of the mandibular first molar, and an IANB plus a mock buccal infiltration and a lingual infiltration of the mandibular first molar in 3 separate appointments spaced at least 1 week apart. An electric pulp tester was used to test for anesthesia of the premolars and molars in 3-minute cycles for 60 minutes. Anesthesia was considered successful when 2 consecutive 80 readings were obtained within 15 minutes following completion of the injection sets, and the 80 reading was continuously sustained for 60 minutes. For the IANB plus mock buccal infiltration and mock lingual infiltration, successful pulpal anesthesia ranged from 53 to 74% from the second molar to second premolar. For the IANB plus buccal infiltration and mock lingual infiltration, successful pulpal anesthesia ranged from 57 to 69% from the second molar to second premolar. For the IANB plus mock buccal infiltration and lingual infiltration, successful pulpal anesthesia ranged from 54 to 76% from the second molar to second premolar. There was no significant difference (P > .05) in anesthetic success between the IANB plus buccal or lingual infiltrations and the IANB plus mock buccal infiltration and mock lingual infiltration. We conclude that adding a buccal or lingual infiltration of 1.8 mL of 2% lidocaine with 1:100,000 epinephrine to an IANB did not significantly increase anesthetic success in mandibular posterior teeth.