无牙牙合患者修复前后双侧颞下颌关节盘-髁关系的初步分析

目的:观察无颞下颌关节症状和体征的无牙颌患者修复前后双侧颞下颌关节(TMJ)盘-髁关系、关节腔积液及髁突骨质异常的变化。方法:通过8例无牙颌患者全口义齿修复前后双侧颞下颌关节的磁共振成像(MRI)检查,比较其修复前后双侧颞下颌关节MRI影像表现的差异。结果:修复前,8例无牙颌患者的16个关节中,10个关节盘移位(62.5%),包括7个关节盘内侧移位(43.8%),2个关节盘外侧移位(12.5%),1个关节盘前移位(6.25%);关节腔积液7个关节(43.8%);髁突骨质异常4个关节(25.0%)。修复后,8例无牙颌患者的16个关节中,10个关节盘移位(62.5%),包括7个关节盘内侧移位(43.8%)、2个关节盘外侧移位(其中1个关节盘外侧移位好转)和1个关节盘前移位(6.25%);关节腔积液7个关节(43.8%);髁突骨质异常4个关节(25.0%)。除1个关节的积液增加外,其余关节积液无变化。结论:长期缺牙可能引起无牙颌患者颞下颌关节的结构紊乱。无牙颌患者全口义齿修复后近期,关节盘移位、关节腔积液及髁突骨质异常无明显改变。     

颞下颌关节钝挫伤急性期损伤程度的磁共振成像分析

目的 应用磁共振成像（magnetic resonance imaging,MRI）分析颞下颌关节钝挫伤急性期的损伤程度。方法 收集2021年2月至2022年10月于山西医科大学第二医院口腔科就诊的22例颞下颌关节钝挫伤急性期患者的临床和影像学资料进行回顾性分析,包括下颌骨未骨折和非髁突骨折患者各11例,分别记为下颌骨未骨折组和下颌骨非髁突骨折组。通过MRI检查结果分析22例患者44侧颞下颌关节的状态,并对损伤程度进行分级。结果 MRI检查显示,22例患者的44侧颞下颌关节均发生损伤,主要表现为关节盘移位（占84.1%）、关节腔积液或积血（占79.5%）及关节盘后区损伤（占72.7%）;此外,还有31.8%的颞下颌关节发生关节盘穿孔。对损伤程度进行分级发现,Ⅰ、Ⅱ、Ⅲ级损伤构成比依次为9.1%(4/44)、59.1%(26/44)和31.8%(14/44)。下颌骨未骨折组Ⅰ、Ⅱ、Ⅲ级损伤构成比依次为4.6%(1/22)、36.3%(8/22)和59.1%(13/22),下颌骨非髁突骨折组Ⅰ、Ⅱ、Ⅲ级损伤构成比依次为13.6%(3/22)、81.8%(18/22)和4.6%(1/22);...     

145例颞下颌关节紊乱病患者的磁共振影像分析

目的 研究145例颞下颌关节紊乱病（TMD）患者的磁共振（MRI）影像学表现,为临床治疗提供依据。方法 利用MRI对145例TMD患者的290侧关节完成开闭口斜矢状位、闭口斜冠状位T1/T2加权成像,观察盘突关系,髁突骨质改变,关节腔积液,关节盘形态改变等情况,并进行分类统计。结果 MRI检查结果显示：37.2%患者双侧TMD病变,71%患者伴有不可复关节盘前移位,10.3%患者伴有可复性关节盘前移位,6.9%患者伴有髁突骨质改变,4.8%患者伴关节腔积液,52.4%患者伴关节盘明显变形。结论 TMD患者中以关节盘不可复性前移位最为常见,提示正常盘突关系的重要性。MRI可以为临床医师提供可靠的影像学诊断依据。     

导致颞下颌关节强直的成人髁突骨折类型分析

目的: 回顾分析导致颞下颌关节强直的成人髁突骨折类型。方法：回顾口腔外科关节组2010—2012年收治的由髁突骨折保守治疗导致颞下颌关节强直,从损伤到发生强直有完整CT资料的成人病例,按照下颌支残端与关节窝的位置关系,将髁突骨折分为3级,0级为下颌支残端位于关节窝内,与之无接触;1级为下颌支残端位于关节窝内,与之有接触;2级为下颌支残端外上方脱位出关节窝。结合髁突骨折类型、骨折块移位程度和关节盘的位置、下颌骨其他部位骨折情况等,分析关节强直形成的原因。结果：13例(24侧)导致关节强直病例的髁突骨折有完整的CT资料,导致关节强直的髁突骨折类型均为囊内骨折,其中B型占70%。下颌支残端与关节窝的位置关系中,0级0侧;1级10侧,占41.7%;2级14侧,占58.3%。0级和1级的关节盘均伴髁突骨折块移位,后外侧带断裂。形成关节强直的髁突骨折中,77%伴颏部骨折,导致牙弓增宽。结论：下颌支残端与关节窝的位置关系对于预后判断有重要作用,其中0级不易引起关节强直;1级较容易引起关节强直,是手术的相对适应证;2级最容易引起关节强直,是手术的绝对适应证。其他危险因素还有髁突囊内B型骨折和合并牙弓增宽的下颌骨骨折。     

髁突矢状骨折CT和MRI诊断及其相关性研究

目的 通过CT和MRI检查,研究髁突矢状骨折后骨折移位和关节盘移位的相关性.方法 对26例(41侧)髁突矢状骨折CT检查,将骨折分为:裂隙型、移位型和脱位型.根据MRI检查结果将关节盘的移位程度分为A型移位、B型移位;按照异常颓后附着的形态分为拉长型和断裂型.19例(32侧)同时进行CT和MRI检查.结果 41侧髁突矢状骨折的CT结果显示:裂隙型5侧(12%)、移位型18侧(44%)、脱位型18侧(44%).在MRI斜矢状位上,裂隙型骨折5侧,关节盘位于正常位置;移位型骨折15侧,其中A型移位3侧,B型移位12侧;脱位型骨折12侧,关节盘均为B型移位.关节盘颞后附着形态:裂隙型骨折中4侧(4/5)正常形态;移位型骨折中14侧(14/15)颞后附着拉长;12侧脱位型骨折均颞后附着断裂.髁突矢状骨折20侧(63%)显示关节上腔积液;裂隙型骨折中,1侧(1/5)关节上腔积液;移位型和脱位型骨折中,分别有13侧(13/15)和6侧(6/12)关节上腔积液.结论 髁突矢状骨折后,关节积液、关节盘移位和颞后附着形态与骨折块的移位程度有关.     

MRI在诊断颞下颌关节紊乱病及评价RW咬合板治疗效果中的应用

目的研究颞下颌关节紊乱病（TMD）患者的磁共振成像（MRI）特征,探讨MRI在评价RW咬合板（RW-splint）治疗效果中的应用价值。 方法收集经临床确诊并行MRI检查的TMD患者32例,回顾性分析32例患者共64侧颞下颌关节的MRI图像,总结TMD的MRI特征;其中21例患者进行RW咬合板治疗,治疗前、后均行MRI扫描,测量关节盘-髁突角度及关节盘长度并进行统计学分析。 结果64侧颞下颌关节中,46侧关节盘形态异常,其中可复性前移位21侧、不可复性前移位25侧;46侧髁突均可见不同程度骨质增生、骨皮质缺损,其中13侧髁突运动过度、5侧髁突运动受限;10侧关节腔内可见积液。21例患者RW-splint治疗后,可复性前移位患侧关节盘-髁突角度由（25.7 ± 2.6）°减小至（19.1 ± 1.6）°;关节盘长度（11.1 ± 1.3）mm缩短至（9.1 ± 0.7）mm,治疗前、后患侧关节盘-髁突角度及关节盘长度变化差异均具有统计学意义（t_角度= 2.889,P_角度= 0.014;t_长度= 2.354,P_长度= 0.023）;不可复性前移位患侧盘突角度由（26.4 ± 2.3）°减小至（24.1 ± 2.1）°,关节盘长度（12.0 ± 1.3）mm缩短至（11.9 ± 1.2）mm,治疗前后患侧关节盘-髁突角度、关节盘长度变化差异均无统计学意义（t_角度= 1.897,P_角度= 0.082;t_长度= 1.076,P_长度= 0.124）。 结论MRI不仅能够无创、准确诊断TMD,而且能够客观评价RW-splint治疗效果。     

髁突囊内骨折的临床特点和分类研究

目的：探讨髁突囊内骨折的临床特点,并提出一种能全面反映囊内骨折的分型,为临床制定治疗计划提供依据。方法：统计上海交通大学医学院附属第九人民医院口腔颌面外科关节组自1999—2008年住院手术和2007年6月—2008年12月门诊非手术治疗,经全景片和CT确诊为髁突囊内骨折的连续病例242例329侧,进行临床特点分析。部分病例经MRI检查观察关节盘移位情况。根据CT冠状位重建对囊内骨折进行分类,根据骨折线的位置,将髁突囊内骨折分为4型。A型骨折的骨折线位于髁突外1/3,B型骨折的骨折线位于中1/3,C型骨折的骨折线位于内1/3,M型骨折为粉碎性骨折。结果：囊内骨折占髁突骨折的66.8%,摔伤是主要的致伤原因。45%的囊内骨折合并下颌骨骨折。骨折侧下颌支残端外上方移位或脱位出关节窝的比例是8.8%,其中73%伴颏部或下颌体骨折。95%的囊内骨折伴关节盘前内侧移位。囊内骨折类型中,A型最多（155侧）,占47.8%;其次是B型（95侧）,占29.32%;M型（61侧）,占18.8%;C型最少（13侧）,占4%。结论：囊内骨折是下颌骨髁突骨折的最常见类型,易合并下颌骨骨折,导致下颌支残端移位或脱出关节窝。以冠状CT为主要依据的分类方法,能较全面地反映髁突囊内骨折的类型。     

髁状突矢状骨折类型与关节盘位移的关系

目的探讨下颌骨髁状突矢状骨折后骨折类型与关节盘位移情况的关系。方法通过计算机体层摄影术(CT)确诊下颌骨髁状突矢状骨折(A、B、C型)患者74例74侧,进行颞下颌关节磁共振成像(MRI)检查,明确关节盘移位情况,利用卡方检验分析不同骨折类型与关节盘移位的关系。结果 74例髁状突矢状骨折(A、B、C型)病例中,26例A型骨折中颞下颌关节盘不可复性前移位较多(57.69%);24例B型骨折中关节盘可复性前移位较多(62.5%);24例C型骨折中正常髁盘关系较多(50%)。不同骨折分型与髁盘关系间的差异有统计学意义(χ2=29.555,P=0.000)。结论下颌骨髁状突发生矢状骨折后,大部分病例中的关节盘出现相应位移,位移情况则与矢状骨折类型相关。关节盘移位以前移位为主,受伤程度越大越容易发生不可复性前移位。     

颞下颌关节紊乱病的MRI评估

颞下颌关节紊乱病的常见表现包括关节盘移位及退变、关节腔积液、髁突及翼外肌异常改变。MRI软组织分辨率较高,成为目前颞下颌关节紊乱病诊断的金标准。了解颞下颌关节紊乱病的常见MRI表现对于口腔医师选择正确的临床治疗决策具有重要意义。     

下颌骨髁突囊内骨折的治疗探讨

目的：根据髁突囊内骨折的分类,提出相应的治疗原则,经临床应用验证该原则的可行性和可靠性。方法：对上海交通大学医学院附属第九人民医院口腔颌面外科关节组自1999年至2008年住院手术和2007年6月至2008年12月门诊非手术治疗、经全景片和（或）CT确诊为髁突囊内骨折的连续病例242例329侧进行分类,部分病例经MRI检查观察关节盘的移位情况,由此制定非手术治疗和手术复位固定的基本原则。在此基础上,根据囊内骨折的不同类型、骨折块移位程度、下颌支残端移位情况、年龄、是否伴发其他部位骨折和错等制定相应的治疗适应证。治疗前后进行问卷调查、临床检查和CT检查,以评价治疗效果。随访期均在3个月以上。结果：非手术治疗91例121侧,其中16例因为咬合紊乱进行颌间弹性牵引。54例获得随访,随访率59%。其中有长期CT随访者29例,儿童髁突出现完全或几乎完全改建者占78%（7/9）,成人髁突主要表现为骨折的错位愈合,占55%。9例出现关节强直（外院转诊自然愈合病例）,2例出现关节区疼痛,保守治疗疗效为76%。手术治疗的适应证为下颌支残端外上方脱位于关节窝外侧的任何类型骨折,不能通过非手术治疗复位以及骨折块明显移位或脱位的囊内骨折。开放性手术151例208侧,其中A型111侧,B型60侧,C型8侧,M型25侧。178侧进行了骨折块复位固定;23侧行骨折块取出、关节盘复位。术后有CT复查者89例115侧,达到解剖复位或接近解剖复位的比率为95.6%。35例术后随访3个月～5a,随访率23%,其中10例12侧儿童患者的髁突内固定术后出现继续生长,占63.2%;成人髁突骨折愈合良好者占92%。术后并发症为关节区弹响1侧,钛板位置过高、引起髁突骨质吸收行取出术2侧,面神经颞支损伤3侧。结论：本文提出的囊内骨折的治疗原则及其治疗适应证,经临床初步应用,证实为一种切实可行的办法,但仍需加强随访和开展随机对照的前瞻性研究。由于儿童的改建能力强,在同等条件下,儿童较成人更多选用非手术治疗。A型以手术复位固定为主,B、C、M型以观察为主。     

Magnetic resonance imaging assessment of temporomandibular joint soft tissue injuries of intracapsular condylar fracture

We evaluated the soft tissue of the temporomandibular joint (TMJ) with magnetic resonance imaging (MRI) after intracapsular condylar fracture. Eighteen consecutive patients (19 TMJ) were diagnosed between 1 January 2010 and 30 October 2011. They were examined using bilateral sagittal and coronal MRI, which were obtained immediately after injury to assess the displacement of the disc, whether there was a tear in capsule or the retrodiscal tissue, and whether there was an effusion in the joint. On the affected side MRI showed disc displacement in 15 of 19, tears in the capsule in 9, and tears in the retrodiscal tissue in 16. All 19 had joint effusions. It also showed 2 joints with abnormalities on the unaffected side. We conclude that MRI is useful for diagnosis and for estimating the amount of damage to the TMJ, and is helpful in planning treatment.     

MRI in the assessment of internal derangement and pain within the temporomandibular joint: a pictorial essay

In this pictorial essay we aim to illustrate the normal temporomandibular joint (TMJ) and the common abnormalities of the osseous, cartilaginous and soft tissue components. These include disc (meniscus) displacement, deformities and perforations, abnormalities of disc and condylar movement, joint effusions, synovial proliferation, condylar deformity and erosions, degenerative change and abnormal retrodiscal enhancement.     

Magnetic resonance imaging findings of temporomandibular joint soft tissue changes in type V and VI condylar injuries.

PURPOSE: The objective of this study was to describe the incidence of acute temporomandibular joint (TMJ) soft tissue lesions associated with the occurrence of type V (high condylar fractures with dislocation) and type VI condylar fractures (condylar head fractures). PATIENTS AND METHODS: The study comprised 11 consecutive patients, who were assigned a diagnosis of a uni- or bilateral type V or type VI condylar fracture. Bilateral sagittal and coronal magnetic resonance (MR) images were obtained immediately after injury to establish the presence or absence of disc disruption, capsular tear, retrodiskal tissue tear, and hemarthrosis. RESULTS: There was 1 condylar fracture site showing signs of disc disruption (16.7%). Tears in the capsule and retrodiscal tissue were found with an incidence of 77% and 71%, respectively, while the incidence of hemarthrosis accounted for 100%. MR imaging failed to show any signs of soft tissue lesions for condylar nonfracture sites. CONCLUSIONS: Type V and type VI condylar fracture sites are associated with a high incidence of injuries to the joint capsule and retrodiscal tissue. Investigation of longitudinal evidence, including risk factors, natural history, and response to treatment appears warranted and necessary.     

A retrospective study of temporomandibular joint ankylosis secondary to surgical treatment of mandibular condylar fractures

We investigated the incidence of ankylosis of the temporomandibular joint (TMJ) after open operations for fractures of the mandibular condyle, and analysed possible risk factors in a total of 385 patients with 492 condylar fractures who had been operated on in our department from 2001 to 2010. Sixteen patients developed postoperative ankylosis of the TMJ with 26 joints (5%) affected during a follow-up of 6 months–10 years. Of the 492 condylar fractures, the most common ones that were associated with postoperative ankylosis were those of the condylar head (20/248), followed by the condylar neck (6/193). Subcondylar fractures did not cause postoperative ankylosis (0/51). Among the 16 patients with postoperative ankylosis, 13 had associated anterior mandibular fractures. Long-screw (bicortical screw) fixation of fractures of the condylar head seemed to be associated with a lower incidence of postoperative ankylosis than fixation by miniplate and wire or removal of the fractured fragment. The articular discs were damaged in all ankylosed joints, and the remaining fractured fragment was found in 10 ankylosed joints after fractures of the condylar head. The results suggest that fractures of the condylar head are more prone to lead to postoperative ankylosis of the TMJ, and that the possible risk factors seem to include the technique used for fixation and damage to the disc, together with an anterior mandibular fracture with the fractured fragment remaining.     

Pathological changes after the surgical creation of a vertical intracapsular condylar fracture

The aim of this study was to create in a sheep model an intracapsular oblique vertical split fracture, and observe the histopathological changes in the temporomandibular joint (TMJ) condylar head. In 10 sheep, the right TMJ was operated through the preauricular region. The anterior and posterior attachments of the disc were cut; an oblique vertical osteotomy was made from the lateral pole of the condyle to the medial side of condylar neck. The condylar fragment was pushed anteriorly, inferiorly and medially together with the disc. The non-operated left TMJ served as control. Two sheep were killed at 1 week and four at both 4 and 12 weeks. Computed tomography scans were taken and histopathological changes of the joint observed. There was severe bone erosion and a new bony outgrowth on the lateral side of the condylar stump and temporal bone. The joint spaces were filled with fibrous tissue, cartilage tissue and bone in the 4 and 12 weeks operated groups. These results show that an oblique vertical intracapsular fracture through the lateral condylar pole, combined with an anteriorly and medially displaced condylar fragment and disc and damaged lateral capsule, are likely to result in the pathological changes of osteoarthritis, and the progressive development of ankylosis in a sheep TMJ.     

MRI examination of the TMJ after surgical treatment of condylar fractures

The position of discs in 20 adult patients whose unilateral condylar fractures were treated by open reduction was investigated by means of magnetic resonance imaging. In four (20%) of the 20 cases, the disc was anteriorly displaced in both the closed mouth and open mouth positions. Three of the four cases had a high condylar neck fracture with dislocation and one had a high condylar neck fracture with displacement. The results of this study showed that repositioning the dislocated condyle did not always lead to anatomical restoration of the joint structures.     

Potential role of disc repositioning in preventing postsurgical recurrence of traumatogenic temporomandibular joint ankylosis: a retrospective review of 17 consecutive cases

The potential role of disc repositioning in preventing postsurgical recurrence of traumatogenic temporomandibular joint (TMJ) ankylosis was investigated. Seventeen cases of traumatogenic TMJ ankylosis underwent disc repositioning during arthroplasty. During surgery, the dislocated disc was carefully dissected outside the ankylotic TMJ and repositioned over the top of the condylar stump, and then sutured to the soft tissue of the zygomatic root. In the 22 ankylotic TMJs of the 17 patients, dislocated discs were found in front of the ankylotic TMJ, behind the ankylotic TMJ or between the ramus and fossa. At the last follow-up (longer than 1 year) examination, interincisal opening distances ranged from 24 to 43 mm (mean 32.86 mm). No recurrence and TMJ symptoms were found during the period of follow-up. Disc repositioning in the treatment of traumatogenic TMJ ankylosis proves to be a feasible and effective method of preventing recurrence of this condition.     

Viscoelastic properties of bovine retrodiscal tissue under tensile stress-relaxation

To test the hypothesis that the condylar part of the retrodiscal tissue of the temporomandibular joint exhibits resistance to tensile force, we investigated its viscoelastic properties and stress-relaxation behavior under tension. Ten specimens were tested. Stress-relaxation tests were conducted from four different initial stress levels. The tissue exhibited a non-linear stress-strain relationship, which could be represented by a bilinear relation of two line segments. The stress-relaxation curves showed a marked drop in load during the initial 10 s and after 2 min the stress reached an almost steady non-zero level. This feature can be well represented by Kelvin's model. It is concluded that the condylar part of the retrodiscal tissue (a) exhibits a non-linear strain-dependent viscoelastic behavior (b), has a great capacity for energy dissipation and resistance to tensile forces, and (c) contributes to maintain the position of the disc relative to the condyle during jaw closing.