应用锥形束CT影像对颏管的三维定量测量及临床意义

目的:应用锥形束CT(CBCT conebeam computed tomography)影像对颏管三维结构、走向及毗邻关系进行定量测量,为确保颏孔区域牙种植手术的安全提供依据。方法:对我院门诊口腔科80例患者的160侧下颌骨CBCT影像进行回顾性分析,对颏管的曲面、矢状位、冠状位、水平位及3D影像进行测量分析。结果:曲面和矢状位影像可对下颌管进行全面的观察。水平位影像显示下颌管在下颌骨体部靠近舌侧与下颌骨体平行走行,之后,以23°±5°角偏离舌侧转向颊侧走行,下颌管向颊侧走行与颏管形成的角度为101.76°±18.27°,最终分成切牙管与颏管。冠状位影像测量颏管的长度为8.09±1.06mm,直径为1.68±0.52mm,与下颌骨体下缘所呈的倾斜角为36.48°±8.43°。颏管起始处至牙槽嵴顶的距离16.10±4.29mm。3D侧位影像可清晰显示颏孔位置。结论:CBCT影像可清晰显示颏管的三维结构、走向及毗邻关系,明确了此区域神经、血管的分布及骨组织的状况,为牙种植钉及手术入路的选择提供可靠依据。     

螺旋CT三维成像对下颌神经管走向的研究

目的通过螺旋CT探讨下颌神经管与下颌骨的实际位置关系。方法利用螺旋CT对正常青年人,进行下颌骨的横断面连续薄层扫描,并进行多平面重建后,测量并计算正常人群中下颌神经管在下颌骨中的实际位置及走行方向。结果下颌骨多平面重建的冠状位CT图像能清楚显示下颌神经管的位置及走向。①在垂直方向下颌神经管距下颌骨下缘的距离小于距牙槽嵴顶的距离,在第二磨牙区距离下颌骨下缘最近。②在颊舌方向,颏孔至第一磨牙间,下颌神经管距颊侧骨板的距离小于距舌侧骨板的距离。自第二磨牙向后,下颌神经管距颊侧骨板的距离大于距舌侧骨板的距离。③下颌神经管的走行方向在颊舌方向,下颌神经管总体走行是由舌侧逐渐向颊侧倾斜达颏孔,越近磨牙后区距离舌侧骨板越近,越近颏孔距离颊侧骨板越近。在走行高度上,在第三磨牙区由上向下走行。自第二磨牙开始下颌神经管逐渐由下向上走行达颏孔。结论螺旋CT通过多平面重建后,可以准确测量并计算出下颌神经管在下颌骨中的三维空间位置,利用螺旋CT对下颌神经管的位置和走行进行研究是可行的。     

下颌角手术相关颌后静脉走行的CTA研究

目的:应用CTA(血管造影术)影像测量颌后静脉与下颌角手术相关解剖,为避免手术中损伤颌后静脉提供指导。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图像处理软件测量颌后静脉距下颌角处颌骨各边缘的三维解剖位置。结果:颌后静脉距下颌角点的距离为(11.26±2.34)mm;在下颌角点上10 mm处距下颌骨后缘为(8.18±2.12)mm;在下颌角点上20 mm处距下颌骨后缘为(6.38±2.12)mm;在下颌角点上30 mm处距下颌骨后缘为(3.18±2.12)mm,在下颌角点上40 mm处距下颌骨后缘为(2.18±1.16)mm。结论:在下颌骨后缘手术时位置越高颌后静脉距下颌骨越近,手术越容易损伤颌后静脉;参照测量获得的解剖数据在下颌角成型手术中能避免损伤面前静脉及颌后静脉。     

颌内动脉起始部的临床解剖

本文观测30侧尸体头颅标本。通过乙状切迹水平线和下颌骨颈部后缘的垂直线测量颌内动脉起始部到它们之间的距离。结果显示,颌内动脉起始部位于下颌骨颈部后缘垂直线内测,其距离为0.24cm±0.11cm。位于外测其距离为0.33cm±0.13cm;上下活动范围为乙状切迹水平线上0.31±0.1cm,下为0.2cm±0.01cm。颌内动脉走行于翼外肌深层浅层率分别为10％和90％。     

颏管的应用解剖学研究

目的 :研究国人颏管的形态及颏管与下颌管、切牙神经管的位置关系 ,为口腔牙种植等颏区手术提供解剖学数据。方法 :磨开 13例 ( 2 6侧 )甲醛溶液固定的湿下颌骨标本的下颌管前段、颏管和切牙神经管始段 ,直接观察测量。另取 2 1侧经过脱钙处理的下颌骨标本 ,解剖并显露下颌管、颏管和切牙神经管进行观测。结果 :下颌管前端分成 2个管 :颏管和切牙神经管。大多数颏管行向后上外开口于颏孔 ,颏管长为 :( 5 .61±1.0 7)mm ,管径为 :( 2 .5 3± 0 .47)mm ,颏孔前缘至下颌管前端的水平距离为 :( 2 .82± 1.2 9)mm ,颏孔下缘到下颌管上缘的垂直距离为 ( 3 .83± 1.43 )mm ,颏管与下颌管之间的角度为 ( 63 .5 7± 13 .71)° ,颏管内有颏神经和颏血管行走。结论 :下颌管向后上外方续为颏管再通向颏孔 ,并非以往认为的下颌管自后上内向前下外方向直接开口于颏孔。     

中日两国成年人颏孔位置比较研究

目的 通过对中日两国成年男女下颌骨的测定，确定颏孔的基本位置，并对中日双方的数据进行统计学分析和比较，为临床医生提供更为丰富的人类学资料，对临床起指导作用。方法 取上海成年人下颌骨：男39例，女38例；日本成年人下颌骨：男33例，女38例。年龄均为25-45岁之间。以颏孔最大横径和最大纵径交点为颏孔中心，测量其至正中联合的水平距离和下颌下缘的垂直距离。结果 颏孔至下颌下缘和正中联合的距离中方男女平均为：15.11mm、30．09mm和14．61mm、27．89mm；日方男女平均为：14．78mm、29．08mm和14．25mm、27．44mm。结论 (1)颏孔至下颌下缘的距离在中方男性与日方男性，中方女性与日方女性间无明显差异。(2)颏孔至正中联合的距离在中日双方男性之间．中日双方女性之间亦无明显差异。     

颏孔区域的解剖学研究

目的　研究国人下颌管前端的位置及其延续关系 ,为临床手术提供解剖学依据。方法　打磨 6 0侧湿下颌骨标本 ,暴露下颌管前端及其延续部分并直接观察和测量。结果　下颌管前端分出同一方向前行的切牙神经管和向后、上、外转弯的颏管。颏管开口于颏孔 ,其管径为 (2 .2 6± 0 .6 0 )mm ,管长 (4 .0 1± 1.2 0 )mm。切牙神经管的管径为 (1.76± 0 .2 6 )mm ,其下缘至下颌骨下缘的垂直距离为 (9.5 3± 1.43)mm ,其始端对应颏孔前缘的水平距离为 (3.5 4± 0 .72 )mm。下牙槽神经的终末支颏神经和切牙神经分别走行与上述两管内。结论　颏管和切牙神经管由下颌管发出 ,其内分别为同名神经。     

下颌切牙神经解剖学观察

目的:研究国人切牙神经在下颌骨内的行程和分布,为临床自体骨移植的颏部取骨和种植体植入手术提供解剖学数据.方法:磨开13例(26侧)国人在体下颌骨标本,解剖21侧脱钙下颌骨,显示下牙槽神经末段、切牙神经和颏神经全程,对切牙神经直接观测,另选22侧下颌骨作切牙神经横断面观测.结果:下牙槽神经前端分为切牙神经和颏神经,有牙颌切牙神经直径为1.74±0.25 mm,无牙颌切牙神经直径为1.50±0.22 mm;有牙颌切牙神经长度为20.60±2.62 mm,无牙颌切牙神经长度为17.00±2.85 mm;有牙颌的切牙神经(在尖牙处)至牙槽嵴顶的距离为25.95±4.50 mm、无牙颌为13.66±4.05 mm,至牙根尖为11.56±2.35 mm,至颌下缘为9.62±1.75 mm,至唇侧骨板的厚度为5.19±1.46 mm,至舌侧骨板的厚度为4.66±1.40 mm,切牙神经主要分布到下颌尖牙和切牙.结论:切牙神经和颏神经均由下牙槽神经出发,颏神经向后上外,切牙神经向前呈弓状,位于下颌体前部的中下1/3处,偏舌侧.     

多普勒超声仪测量颏动脉血流量的实验研究

目的建立一种测量下颌骨中心动脉血流变化的方法。方法8只北京本地犬在笼中饲养1周后,使用0．05g／ml的盐酸氯胺酮将实验犬全身麻醉（0．5ml／kg）。使用发射频率为4MHz的探头,在口内下颌尖牙、第一前磨牙和第二前磨牙颊侧粘膜,估计为颏动脉穿出下颌骨处测量颏动脉血流量;经颌下切口暴露颏神经动脉束,直接测量颏动脉血流量。对无创方法与有创方法测量的颏动脉血流量的数据用配对t检验进行统计学比较。结果在实验动物的不同个体中,多普勒超声仪测量结果差异较大,不同时间测量得到的数值也不一致;多普勒口内无创测量颏动脉的方法与直接测量暴露颏动脉方法的测量结果没有统计学差异。结论口内无创多普勒测量颏动脉血流量的方法可靠,为临床提供一种显示下颌骨中心血管血流的方法。     

CBCT观察颏孔与下颌第二前磨牙根尖位置关系

目的：测量下牙槽神经管及颏孔与下颌第二前磨牙根尖位置关系,分析其分布规律,以期为显微根尖手术提供解剖学依据。方法：选取83例双侧锥形束CT（CBCT）图像,分析颏孔开口位置分布规律,并测量下牙槽神经管及颏孔与下颌第二前磨牙根尖位置关系。结果：颏孔到牙槽嵴顶、下颌骨下缘的平均距离分别为（12．96±1．91）mm、（13．24±1．57）mm;在曲面体层片上,下颌第二前磨牙根尖到颏孔的最短距离平均（2．64±1．61）mm;若颏孔位于下颌第一、二前磨牙之间或第一前磨牙下方时,下颌第二前磨牙根尖到下牙槽神经管的平均距离（5．35±2．05）mm。男女性别分组对比在颏孔下缘距下颌骨下缘、下颌第二前磨牙根尖到下牙槽神经管距离的平均值差异均有显著性（P＜0．05）。结论：下颌第二前磨牙根尖与颏孔及下牙槽神经管关系密切,在进行下颌第二前磨牙的显微根尖手术过程中,应当给予充分重视。     

Surgical options in deep-bite mandibular deficiency with prominent chin - aesthetic considerations.

INTRODUCTION: A deep-bite hypoplastic mandible associated with a strong chin poses an aesthetic challenge. Functional correction of the distal occlusion can bring the chin point beyond the ideal or normal profile line. The aim of the study was to outline the indications and drawbacks of four approaches that are currently used to deal with this problem. MATERIAL AND METHODS: A retrospective study was done using lateral cephalograms and pre- and postoperative pictures of 40 randomly selected patients, judged by a panel of four surgeons. The following parameters were studied apart from occlusion: A-P chin position, chin height, mentolabial and submental folds, cervicomental and gonial angles, antegonial notch, lower lip position, and anterior mandibular bowing. RESULTS AND CONCLUSIONS: Procedures that involve a setback of the chin are potentially prone to create or increase submental fullness, especially the mandibular advancement/chin setback osteotomy. Procedures involving advancement of the anterior dentoalveolar segment relative to the symphyseal prominence (e.g. mandibular advancement/chin setback osteotomy, dentoalveolar mandibular advancement osteotomy) are prone to flatten the mentolabial fold excessively. The position of the chin point after mandibular advancement-posterior rotation osteotomy is difficult to predict. Maxillomandibular posterior rotation has potentially the best aesthetic outcome, provided that the chin point is not set back.     

The vascular anatomy of the digastric muscle

There are plenty of flaps for the reconstruction of defects of the head and neck region. In the literature, local muscle and myocutaneous flaps such as sternocleidomastoid, pectoral, and deltopectoral flaps are proposed for obliteration of pharyngocutaneous fistulas. Restoration of facial nerve palsies in which nerve repair and nerve grafting are not feasible is accomplished by means of regional muscle transpositions. The vascular anatomy of the digastric muscle to be used in such instances is investigated after latex application to 18 neck regions of nine cadavers. The dissection continued anteriorly from the origin of the facial artery to the end of the submental artery, preserving all the branches piercing and nourishing the muscle. The submental artery courses over the posterior surface of the anterior belly of the digastric muscle, giving off the major pedicle of the muscle 1 cm after exiting behind the submandibular gland. The submental artery gives off another branch, the first minor pedicle of the muscle distal to the major pedicle at a distance of two thirds of the muscle length in a standard fashion in all the cadavers. The artery ends in the distal portion of the muscle, the second minor pedicle of the muscle. The artery gives off periosteal branches to the mandible after coursing through the insertion muscle. The anterior belly of the digastric muscle could be classified as a type II muscle, with a major pedicle and two minor pedicles, according to the system of Mathes and Nahai. The anterior digastric muscle can be a good alternative in obliteration of pharyngocutaneous fistulas, and defects of the mandible, including the body and angle of the mandible, can be amended with the split mandibular myo-osseous digastric flap.     

Deep middle masseteric artery (dMMA) attributed to hemorrhage in resection of masseter muscle and mandibular angle

This study aimed to investigate pertinent arterial supplies of masseter muscle to prevent fatal hemorrhage in resection of masseter muscle and/or mandibular angle ostectomy. Fifty-three postmortem cadavers of Koreans were used for the work. Color latex was injected into the arteries to outline 17 of 53 specimens. We found that an artery branches off the external carotid artery and enters the masseter muscle at the midpoint of its posterior margin 31 mm above the gonion. We termed this the middle masseteric artery. The middle masseteric artery is divided into superficial and deep branches. The deep branch of the middle masseteric artery travels deep in the muscle close the periosteum of the mandible in 94% of cases. The average diameter is 1.23 +/- 0.26 mm. A small artery with 1.23-mm diameter is enough to cause massive bleeding if severed. The deep branch of the middle masseteric artery is vulnerable in such procedures as resection of the masseter muscle and/or ramus and angle of the mandible.     

Topography of the submental artery that should be considered in bleeding during dentoalveolar surgery

ABSTRACT: The purpose of the present study was to provide precise data regarding the branching pattern of the submental artery, which should be considered in occasions of bleeding during various dentoalveolar surgical procedures of the mandible, such as implant surgeries, tori removal, and iatrogenic injuries.Twenty-six embalmed adult hemifaces from Korean cadavers were used in this study. The vertical distance, horizontal distance, and diameter of the submental artery were measured from the site of the first premolar to the third molar. In cases where there was penetration of the mylohyoid muscle by the main branches of the submental artery, the same items were measured at that point.The vertical distance between the submental artery and the inferior border of the mandible decreased toward the premolar, whereas the horizontal distance from the lingual plate of the mandible increased gradually as it traveled in the anterior direction. The diameter of the artery narrowed slightly toward the premolar. The main branches of the submental artery perforated the mylohyoid muscle in 14 (54%) of the 26 specimens.As a result of this study, the submental artery is located higher from the inferior border and closer to the lingual plate of the mandible in the region of the molar than that of the premolar. Therefore, clinicians should be more careful of bleeding when performing surgery in the molar region compared with the premolar region. Where the mylohyoid muscle is perforated by the main branches of the submental artery, its point of insertion can be observed in diverse locations.     

我国北方成年人下颌骨骨密度的测量研究

目的 研究健康人下颌骨与全身骨密度的相关性.方法 选择中国北方健康志愿者221名,分别将不同性别的志愿者按年龄分为6组,即≥20岁(男21人、女23人)、≥30岁(男20人、女21人)、≥40岁(男21人、女22人)、≥50岁(男20人、女21人)、≥60岁(男16人、女15人)、≥170岁(男11人、女10人).从每人下颌骨颏部及双侧下颌角各选10个感兴趣区,用双能X线骨密度仪测量骨密度值,同时测量腰椎(L2-L4);并行统计学分析.结果 该人群的下颌骨颏部的骨密度值为(1.310 9±0.035 5)g/cm2,左下颌角的骨密度值(1.048 9±0.013 7)g/cm2,右下颌角的骨密度值(1.054 7±0.014 1)g/cm2,腰椎(L2-L4)的骨密度值(1.1211±0.0172)g/cm2.男女之间下颌角、腰椎的骨密度比较,差异有统计学意义(t(左)=2.017 5,t(右)=2.446 9,P<0.05).50岁以后下颌角、腰椎的骨密度明显减低.结论 下颌骨与腰椎的骨密度密切相关,下颌骨可以作为测量全身骨密度的一个敏感部位进行骨质疏松的预测.     

Effect of mandibular positioning on preimplant site measurement of the mandible in reformatted CT

The purpose of this study was to evaluate the effect of mandibular positioning on measurement of the reformatted cross-sectional image of the mandible in computed tomography (CT) according to the area on the mandible. Five dried mandibles, partially edentulous in the premolar and molar areas, were selected. The inferior border of the mandible was placed at 0-, 5-, 10-, 15-, and 20-degree angles to the CT scanning plane, and CTs were taken. The marked area of the reformatted cross-sectional image taken at each angle was found, and the distance from the most superior border of the mandibular canal to the alveolar crest was measured. As the angle between the CT scanning plane and mandibular plane increased, the distance from the most superior border of the mandibular canal to the alveolar crest also increased. The degree of increase was more pronounced in the posterior portion of the mandible than in the anterior portion of the mandible. As mandibular positional change in the CT gantry can affect the vertical measurement of the reformatted cross-sectional image, a correct guiding plane is necessary to accurately position the jaw to the CT scanning plane.     

下磨牙区种植体尖端与下颌管间安全距离的探讨

目的:探讨下颌磨牙区植入的种植体尖端与下牙槽神经管上缘之间的安全距离。方法:用游标卡尺测量23例患者全景片中的30颗下颌磨牙区种植体长度,除以对应的种植体实际长度,计算全景片中下颌磨牙区垂直放大率(vertical magnification factor,MF);选择种植体尖端至下牙槽神经管上缘间距离小于2mm的8例患者的全景片,测量片中12颗种植体尖端至下牙槽神经管上缘间的距离,除以对应种植体的垂直放大率,计算其实际距离;记录该8例患者有无下唇和(或)颏部感觉异常。结果:①全景片中下颌磨牙区垂直放大率为1.27±0.02;②12颗种植体尖端距下牙槽神经管上缘之间的距离为(1.19±0.33)mm(0.69～1.89mm);③8例接受种植体植入的患者,无一例出现下唇或颏部感觉异常。结论:下颌磨牙区植入种植体的尖端与下颌管上缘之间保存完整的骨壁,是防止损伤下牙槽神经的最关键因素之一。     

理论髁突距的研究及其在颌骨复位重建中的初步应用

目的 通过对颌骨解剖标志的三维测量分析获得理论髁突距（TCoD）,用于颌骨复位重建中确定下颌骨宽度。方法 收集100例正常颌骨CBCT数据,将Dicom数据导入Mimics中,重建后对6个骨性标志进行标记,并获得12个线性和角度变量。通过Spss软件对数据进行统计分析,获得TCoD。通过10例下颌骨折病例的回顾分析验证可行性。并在临床中指导1例下颌骨骨折复位。结果 不同性别、个体角度变量的差异通常小于长度变量,升支高度和下颌角的总体变异系数（COV）最大。但是,关节窝距（FoD）与髁突距（CoD）具有高度的一致性,50岁以下CoD等于FoD（P＞0.05）。并且CoD与FoD之差与年龄存在线性关系（P＜0.05）,因此在50岁以上的患者可以通过修正获得TCoD。通过10例骨折患者术后回顾分析,TCoD与FoD相比更接近术后髁突距。1例下颌骨粉碎性骨折的无牙颌患者,进行术前虚拟手术通过TCoD对下颌骨复位重建进行指导和验证,获得满意效果。结论 理论髁突距可以作为确定下颌骨宽度的理想参数。     

Anatomical variation in arterial supply of the mandible with special regard to implant placement

The aim of this study was to explore the anatomical variation of the sublingual artery in relation to the mandible, and provide preoperative information to avoid hemorrhagic complications of implant placement. One hundred adult human cadavers injected with red latex were examined. The main arterial supply to the anterior mandible is the sublingual artery as a branch of the lingual or submental artery. This artery exhibited three notable branches, termed ascending, middle and descending. In 73% of cases the sublingual artery originated from the lingual artery to give ascending (72%), middle (98%) and descending (54%) branches. In the remaining 27 cases the sublingual artery originated from the submental artery, giving ascending (69%), middle (98%) and descending (50%) branches. It was possible to identify anastomotic patterns between the sublingual and inferior labial arteries in 52%, sublingual and submental arteries in 40%, and submental and inferior labial arteries in 54% of cases. Of the branches supplying the floor and gingival mucosa of the anterior mandible, mucosal branches of the sublingual were found in the territory of the lateral incisor in 72%, canine in 62%, and first premolar in 81% of cases. Disruption of these anastomoses by implant placement could cause life-threatening hemorrhages. These data should prove useful in the placement of mandibular implants.     

Treatment of unilateral ankylosis of the temporo-mandibular joint when a class II skeletal relationship exists

If, in a case of ankylosis of the temporo-mandibular joint, a class II skeletal relationship exists, advancement of the mandible into a class I skeletal relationship should be an integral part of the treatment plan. The advantages are: better aesthetics (especially the appearance of the chin), more efficient action of the suprahyoid muscles (mouth openers), diminished contact of the angle of the jaw with the sterno-cleido-mastoid muscle, increased distance of the lower incisors from the axis of rotation of the mandible (resulting in increased incisal distance at the same rotational angle) and the possibility of correction of the sometimes traumatic occlusion against the palatal mucosa all in the same session. The method advocated in unilateral cases is the insertion of a costo-chondral graft on the affected side and a lengthening osteotomy on the opposite side with fixation into a class I skeletal relationship initially disregarding the incisal relationship.