Occult fractures of articular eminence and glenoid fossa presenting as temporomandibular disorder: a case report

We report an unusual case of occult fractures of the articular eminence and glenoid fossa due to a previous traffic accident presenting as a temporomandibular disorder. A 24-year-old Japanese man was referred for trismus and pain in the right temporomandibular joint, and was suspected of having temporomandibular disorder. Although the magnetic resonance image did not show displacement of the articular disk, T2-weighted images revealed disruption of the cortical low-intensity line of the right articular eminence. On a computerized tomography (CT) scan, an isolated bone fragment of the right articular eminence was clearly seen, and fractures of the right glenoid fossa and articular eminence were noted. The patient was treated by instructing him not to open his mouth widely and to remain on a soft diet for 4 weeks. A CT examination performed 1 year after the treatment showed complete healing of the fracture in the right articular eminence and glenoid fossa.     

A three-dimensional method of visualizing the temporomandibular joint based on magnetic resonance imaging in a case of juvenile chronic arthritis

Summary. Aim . The purpose of this study was to present a new visualizing method for temporomandibular joint (TMJ) pathology in 3D at several condylar positions and to apply the method to a case of juvenile chronic arthritis (JCA) with previously diagnosed bilateral TMJ disorder and to a subject without signs and symptoms from the TMJ.
Subject . The 20-year-old female patient had suffered from polyarticular JCA from the age of 6 years 8 months. The present study is based on a follow-up examination after the completion of orthodontic treatment with the Herbst appliance. Both TMJs were examined using magnetic resonance imaging (MRI) at closed and open mouth positions. The mandibular condyle, the glenoid fossa and the articular disc were segmented and 3D reconstruction of these structures was carried out.
Results. The condyle was characterized by an increased sagittal diameter with osteophyte-like formation at the anterior aspect of the condylar head and flattening of the superior surface. The depth of the glenoid fossa was reduced and the articular eminence was remarkably flat. The articular disc was markedly diminished and posteriorly placed on the condylar head. The distance of the condylar path during mouth opening was reduced and the curvature of the condylar path was quite flat. The disc moved slightly posteriorly on the condylar head and remained in the glenoid fossa during mouth opening.
Conclusion. The imaging modality described improves visualization of TMJ morphology and gains insight into the TMJ pathology of the JCA patient, adding to understanding of the clinical problems.     

Craniofacial morphology and inclination of the posterior slope of the articular eminence in female patients with and without condylar bone change

This study investigated the association of craniofacial and glenoid fossa shapes and temporomandibular joint (TMJ) pathology in 39 orthodontic patients with signs and symptoms of TMJ disorders, using helical CT scans. Cephalometric measurements showed that 21 subjects with bilateral condylar bone change (BBC) had significantly smaller SNB angles, ramus heights and S-Ar/N-Ba ratios, as well as larger mandibular plane angles and lower anterior facial height than the 18 subjects with no condylar bone change (NBC). The average posterior slope of the left and right articular eminence in their central and lateral sections was significantly steeper in NBC than in BBC. Condylar bone change might, therefore, not only be related to the morphology of the mandible, but also of the glenoid fossa and cranial base. This appears to reflect adaptive changes in the condyle, articular eminence and cranial base in response to changes in loading.     

单侧颞下颌关节不可复性盘前移患者面部对称性的三维测量分析

目的:观察单侧颞下颌关节不可复性关节盘前移对面部对称性的影响.方法:选择单侧颢下颌关节不可复性关节盘前移患者17例,其中男2例,女15例,年龄13～28岁.所有患者均接受头颅CT扫描.用Simplant11.04软件对患者头颅CT数据进行三维重建,设立颞下颌关节窝及邻近结构、下颌骨、上颌牙合平面三部分测量项目,垂直向以FH,平面为参照平面,横向以正中矢状面SAG为参照平面,建立相关结构的三维测量方法.测量数据采用SPSS11.0软件包进行配对t检验.结果:患侧外耳道最上点Po点、颞下颌关节窝最上点GIF点及关节结节最下点ArE点垂直向位置均较正常侧低(P<0.05),两侧差异量分别为(1.26±0.55)mm、(1.37±0.57)mm及(1.22±0.49)mm.研究对象患侧髁突长度较正常侧短(4.18±4.16)mm(P<0.01).患侧髁突内、外侧最大径CoI-CoO较正常侧小(1.90±1.48)mm(P<0.01).患侧下颌支长度及下颌支投影长度分别比正常侧短(6.67±3.26)mm(P<0.01)、(5.76±4.92)mm(P<0.01).患侧下颌支宽度Ra-Rp也较相应正常侧窄(1.05±1.09)mm(P<0.01),下颌体长度Go-Gn较正常侧短(1.40±2.60)mm(P<0.05).所有研究对象须顶点均向患侧偏斜,平均偏离正中矢状面的距离为(3.62±2.49)mm.研究对象患侧上颌牙合平面3个观察点位置均较正常侧相应观察点高,即患侧上颌牙合平面较正常侧高(P<0.01).结论:单侧颞下颌关节不可复性关节盘前移可造成患者面部不对称,累及颞下颌关节窝及邻近结构、下颌骨及上颌牙合平面,患侧髁突高度减小是面部不对称的主要原因.     

Changes in temporomandibular joint morphology in class II patients treated with fixed mandibular repositioning and evaluated through 3D imaging: a systematic review

To estimate the effects of skeletal class II malocclusion treatment using fixed mandibular repositioning appliances on the position and morphology of the temporomandibular joint (TMJ). Two independent reviewers performed comprehensive electronic searches of MEDLINE, EMBASE, EBM reviews and Scopus (until May 5, 2015). The references of the identified articles were also manually searched. All studies investigating morphological changes of the TMJ articular disc, condyle and glenoid fossa with 3D imaging following non‐surgical fixed mandibular repositioning appliances in growing individuals with class II malocclusions were included in the analysis. Of the 269 articles initially reviewed, only 12 articles used magnetic resonance imaging and two articles used computed tomography (CT) or cone‐beam CT images. Treatment effect on condyle and glenoid fossa was discussed in eight articles. Treatment effect on TMJ articular disc position and morphology was discussed in seven articles. All articles showed a high risk of bias due to deficient methodology: inadequate consideration of confounding variables, blinding of image assessment, selection or absence of control group and outcome measurement. Reported changes in osseous remodelling, condylar and disc position were contradictory. The selected articles failed to establish conclusive evidence of the exact nature of TMJ tissue response to fixed mandibular repositioning appliances.     

间接性羊颞下颌关节损伤实验动物模型的建立

以不同力量撞击１０只山羊一侧下颌角部，方向平行于下颌角—颞下凹中点连线，间接造成ＴＭＪ损伤。结果发现：不同撞击力可间接引起ＴＭＪ不同程度的损伤，其损伤程度与被撞击部位的压强成正相关关系。ＴＭＪ局部出现髁突进入颅中凹，关节囊内血肿形成，关节盘挫裂、扭曲，滑膜撕裂，髁突表面软骨碎裂等病理改变。实验证明：所建立的间接性ＴＭＪ损伤动物模型操作简便，致伤力量可控，具有一致的可重复性，可引起ＴＭＪ不同程度损伤，其病变与人类相似，病变典型，因此可做为研究ＴＭＪ间接性损伤的实验动物模型。     

成人与儿童颞下颌关节骨性形态比较研究

目的:比较成人与儿童颞下颌关节(temporomandibular joint,TMJ)骨性形态的差异。方法:用多排螺旋 CT(multislice CT,MSCT)对30例健康成年志愿者和20具咬合关系正常的儿童尸体 TMJ 扫描,结合影像中心保存的10例正常儿童 TMJ 的 MSCT 资料,在工作站上对上述60例120侧 TMJ 的 MSCT 图像进行多平面重建和参数测量,SPSS 软件对反映 TMJ 骨性形态特征的参数或其比值作统计学分析。结果:髁突纵轴倾斜角、髁突颈最小/髁突头最大横断面积、髁突前后径/关节窝前后径、髁突内外径/关节窝内外径、髁突在关节窝中后间隙/前间隙、关节窝前斜面倾角、关节窝深度、关节结节倾角,成人和儿童差异有显著性(P<0.05)。结论:成人与儿童 TMJ 骨性形态存在部分差异,它对 TMJ 疾病的防治有指导意义。     

The effect of indirect trauma on the rat temporomandibular joint

The effect of indirect trauma to the rat temporomandibular joint (TMJ) is analysed by means of an experimental model. The trauma, applied from an angle-glenoid fossa direction, produced injury of the TMJ. The histological data demonstrated that the impact could produce fractures of the glenoid fossa, but no hemarthrosis was observed. Trauma, both with or without fracture, caused proliferative changes in the TMJ. The glenoid fossa, the articular disk and the articular surface of the condyle were injured. Thickening of the articular surfaces had resulted in reduced joint space. Subsequently, remodelling changes in the condyle were found.     

Articular soft tissue injuries associated with mandibular condyle fractures and the effects on oral function

The majority of studies debating the optimization of treatment for condylar mandibular fractures focus on the bony aspect first. However, fractures of the mandibular condyle may go together with soft tissue injury of the temporomandibular joint. An electronic literature search for this topic was undertaken. Assessment of quality was carried out using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Sixteen articles were included in this review. The reviewed literature showed that intracapsular fractures and dislocated condylar fractures result in more severe injuries. Serious injury to the disc and capsule of the temporomandibular joint is a contributing factor towards development of complications after closed treatment. The results of this review give an overview of the published studies focusing on articular soft tissue injuries caused by condylar mandibular fractures. Additionally, an overview of the magnetic resonance imaging (MRI) settings used to detect these injuries is provided. Until now, the relation between soft tissue injuries and type of condylar trauma and their influence on clinical outcome has been insufficiently investigated. Before considering reduction of soft tissues next to reduction of the fracture, more research is needed into the impact of soft tissue injuries on oral functioning, in which a uniform classification is used.     

Associations between the articular eminence inclination and condylar bone changes, condylar movements, and condyle and fossa shapes

Objectives

The purpose of the present study was to determine the inclination and height of the articular eminence with respect to the condylar bone changes, condyle shape, fossa shape and condylar movements in patients with and without temporomandibular joint (TMJ) dysfunction using cone-beam computed tomography (CBCT).

Methods

The associations between the eminence inclination and the condylar bone changes, condylar movements, condylar shape and fossa shape were evaluated in patients with TMJ disorders and control patients without TMJ disorders. The measurements of the articular eminence inclination were established on central sagittal slices of the TMJ. The central coronal slices were used to determine the condyle and fossa shapes. The types of movements of the condyles were determined on open-mouth images, and mandibular hypermobility or hypomobility was noted for each joint.

Results

There were no significant differences in the eminence inclination and height with respect to the condylar bone changes and condylar movements in the TMJ disorder group. However, there was a significant association between the eminence inclination and the fossa shape in the TMJ disorder group and significant associations between the eminence inclination and both the condyle and fossa shapes in the control group. The articular eminence inclination was steeper in the control group than in the TMJ disorder group.

Conclusions

The eminence inclination was steeper in the control patients than in the patients with TMJ disorders, and was not correlated with the condylar bone changes or condylar movements.     

颞下颌关节侧向咬合位与对刃位薄层塑化断面对照研究

目的:对比分析下颌对刃位、侧向咬合位颞下颌关节的运动解剖形态,为颞下颌关节病变提供解剖依据。方法:将8例新鲜尸头摆置成对刃位5例、下颌侧向咬合位3例,以颞下颌关节为中心,切割成8cm×8cm×10cm的标本块,利用生物塑化技术,制成斜矢状位、斜冠状位、轴位塑化断层标本共16套。下颌侧向咬合位工作侧、非工作侧关节形态改变与对刃位相对照。结果:下颌侧向咬合位工作侧,髁突在关节窝内向后、向上、向外移位,关节盘位置无变化,关节盘双板及后带受压;非工作侧,髁突向下、向前、向内侧移位,关节盘后带位置向下移位,无前移位,关节盘中带外侧位居上下关节面之间,明显受压变薄。结论:关节盘并非随髁突作同步同向运动。关节盘在髁突作滑动运动时发生移位;当转动运动、滑动运动复合出现时,关节盘发生移位;而在关节窝内发生的转动运动,关节盘不发生移位。     

A comparison of MRI, radiographic and clinical findings of the position of the TMJ articular disc following open treatment of condylar neck fractures

We examined the position and function of the articular disc after open treatment of condylar fractures by comparing magnetic resonance images (MRI) and radiographs with clinical data. MRI and radiographs were taken after treatment of 28 patients with 33 fractures of the mandibular condyles. In all cases, the disc was located in the fossa after open reduction and internal fixation (ORIF). The MRI, radiographic and clinical findings did not correlate, and damage to the temporomandibular joint (TMJ) could be seen more clearly on MRI than on clinical or radiographic examination. Damage to soft tissues seen on MRI after treatment was more pronounced in dislocated than in displaced fractures.     

Regeneration of mandibular condyle following unilateral condylectomy in canines.

PURPOSE: The purpose of this experimental study was to investigate regeneration of the mandibular condyle after unilateral condylectomy in canines. MATERIAL AND METHODS: Five 2-year-old beagle dogs underwent unilateral mandibular condylectomy and were sacrificed either immediately postoperatively (n=1) or 3 months later (n=4). Temporomandibular joints were examined radiologically and histologically, and sides were compared. RESULTS: All joints showed postoperative regeneration of the condylar head. Maximum regeneration of the condyle occurred medially, where most bone of the glenoid fossa was present, rather than laterally. From an anteroposterior perspective, regeneration of the condylar head was more favourable anteriorly, facing the inferior slope of the glenoid fossa. Regenerated articular cartilage was irregular. Articular discs displayed central thickening compared with unoperated joints. The bone of the glenoid fossa was normal. CONCLUSION: Unilateral mandibular condylectomy in canines resulted in a certain degree of condylar regeneration during a 3-month postoperative period, with some irregular articular cartilage formation.     

Orthodontic finishing after TMJ disk manipulation and recapture

Orthodontic treatment has as its goal in most patients to achieve a cosmetic and functional result. There are functional goals for all orthodontic treatment and in some few cases the functional outweigh the cosmetic; an example would be a cleft-palate case. Orthodontic finishing to a specific condylar position is not routinely a goal of orthodontic care. The reason for this is that only patients who have pain, dysfunction and a negative change in quality of life from their temporomandibular apparatus need this tangential type of treatment. Research has shown that most patients suffering from a temporomandibular disorder (TMD) have displacement of the temporomandibular disk(s). Research has shown that when the mandibular condyle is repositioned to the Gelb 4/7 position that the temporomandibular joint disk is recaptured to a normal position between 85% and 96% of the time. The Gelb 4/7 position has been equated to the physiologic position of the mandibular condyle in the glenoid fossa. TMJ condyle repositioning to the physiologic position has been correlated to disk recapture proven by magnetic resonance imaging (MRI). A case is shown in which a displacement without reduction is manipulated into reduction and maintained with orthodontic correction. TMJ disk displacement without reduction is usually preceded by TMJ disk displacement with reduction. Pumping of the upper joint compartment can assist in reducing the TMJ disk displacement without reduction. Magnetic resonance imaging before and after the manipulation and after orthodontic treatment are shown. A detailed method of orthodontic finishing that maintains a specific condylar position and TMJ disk recapture is shown.     

Synovial chondromatosis of the temporomandibular joint with glenoid fossa erosion: Disk preservation for spontaneous anatomical recovery

Synovial chondromatosis (SC) of the temporomandibular joint is a pseudoneoplastic condition characterized by benign cartilaginous metaplasia of synovial tissue mesenchymal residues with intra-articular nodule formation. TMJ involvement is rare. Interposition of loose bodies in the articular space can generate pressure, leading to glenoid fossa erosion with intracranial extension.The aim of this study was to present six SC cases with intracranial extension treated using a surgical procedure.All the patients were treated with open surgery. The superior compartment of the TMJ was opened widely to carefully remove the metaplasic mass. Temporal synovectomy was then performed. Attention was paid to preserving the integrity of the articular disc. The exposed dura mater was also preserved. No material was used to reconstruct the gap in the glenoid fossa.A 1-year follow-up showed no swelling or pain. Patients demonstrated good recovery of mouth opening, with improvement over previous mouth limitations. Morphological studies, performed using MRI and CT, showed complete anatomical recovery of the TMJ and total bone reconstruction of the glenoid fossa.Simple removal of intra-articular nodules, with TMJ arthroplasty and articular disk preservation, represents an efficient treatment option for full anatomical and functional recovery in synovial chondromatosis of the temporomandibular joint with glenoid fossa erosion of less than 1 cm².     

3T磁共振成像显示颞下颌关节盘的技术研究

目的探索3T磁共振成像（MRI）显示颞下颌关节盘的序列、参数及电影成像方式的技术特点,并为临床研究颞下颌关节盘病变提供形态与功能影像学参照。方法选择15例正常志愿者和7例颞下颌关节损伤患者为研究对象,采用GE Signa HD 3T MRI和颞下颌关节专用表面线圈对颞下颌关节进行扫描,获得斜矢状、斜冠状闭口位FSE-XL/T1WI、FLAIR/T1WI、FSE-XL/PDWI、FSE/PDWI+FS、FRFSE-XL/T2WI、FRFSE/T2WI+FS扫描及斜矢状张口位FSE-XL/T1WI、FSE-XL/PDWI图像。由口腔颌面外科医师和MRI医师共同对各序列进行打分,分析各序列不同加权像对颞下颌关节盘的显示效果。结果PDWI对关节盘的显示效果得分最高,能清楚显示关节盘的解剖结构与形态。T2WI对关节盘损伤、撕裂、穿孔和关节囊积液显示良好,对关节盘移位情况则以PDWI序列显示效果为好。结论3T MRI可以清楚地显示关节盘在关节运动中的动态改变与病变受累情况,对颞下颌关节软组织损伤的诊治有重要价值。T1WI、PDWI及T2WI应作为常规的扫描方法。     

间接创伤对幼年大白鼠颞下颌关节血供的影响

目的　探讨间接创伤对幼年鼠颞下颌关节的影响。方法　Wistar幼年大白鼠颞下颌关节间接创伤后,应用放射性同位素测定方法对其关节区进行动态观察。结果　与正常组比较,随着创伤后对颞下颌关节区不同时间段同位素测定,创伤后颞下颌关节区放射性强度随时间增加,两周达高峰,1月时放射性强度仍比正常对照组高,在任何时间段,创伤侧都较非创伤侧颞下颌关节区放射性强度高。结论　间接创伤可以引起幼年鼠颞下颌关节局部血流变化     

颌下切口下颌升支垂直截骨在髁突高位骨折手术中的应用

目的:探讨应用颌下切口下颌升支垂直截骨术治疗髁突高位骨折的效果。方法:对16例(19侧)下颌骨髁突高位骨折患者采用颌下切口下颌骨升支后缘垂直截骨取出升支后缘骨块将骨折的髁突游离后取出,体外直视下将骨折片与升支后缘骨块复位固定后再回植,行颞下颌关节重建。结果:于术后6、12、24个月复查全部患者的开口度为30～48 mm,平均34.92 mm。所有患者咬合关系良好,无关节疼痛症状。部分病人有轻度开口偏斜,均<3 mm,有1例患者有关节弹响。结论:颌下切口下颌升支垂直截骨是治疗髁突高位骨折的一种可选择方法,具有操作简便、复位准确、近期疗效满意等优点。     

Alloplastic reconstruction of the temporomandibular joint

The Proplast TMJ condylar implant, the glenoid fossa implant, and the TMJ interpositional implants should be singled out as having provided a new and more predictable mode of TMJ reconstruction. The use of these implants in cases of ankylosis, degenerative joint disease, orthognathic deformities, and traumatic injuries has greatly contributed to the success of these reconstructions. These implants represent the state of the art in TMJ reconstruction and increasing data from longer-term follow-up have shown a rate of success much higher than any previous implant used in the TMJ. TMJ reconstruction requires careful surgical planning, meticulous surgical technique, and intelligent perioperative care. Postoperative physical therapy is considered essential in the management of these patients. Complications related to reankylosis have been virtually eliminated, as no postoperative immobilization is required in most cases. Long-term stability of these implants, due to the ingrowth of tissue into Proplast, appears to be assured. Continued experience with the implants and close follow-up of reconstruction patients is necessary in the future to adequately assess the performance of the newer glenoid fossa and TMJ interpositional implants. Certainly, a new era in TMJ reconstruction has begun, resulting in increased benefits to the patients whom we all serve.     

Experimental study on three-dimensional adjustable condyle prosthesis for reconstruction of temporomandibular joint]

OBJECTIVE: To study the possibility of reconstructing TMJ with a modified three-dimensional adjustable condylar prosthesis (TDACP). METHODS: The modified TDACP was placed immediately after resection of the mandibular ramus and condyle in 3 adult rhesus monkeys. The results were evaluated by radiography, histological and anatomical examinations, as well as chewing function at 3, 6, and 14 months after surgery. RESULTS: Through adjustment the condyle prosthesis could fit exactly, the functions were good, every part of the prosthesis was firm, the screws were osteointegrated, there was no adverse soft tissue reactions and no pathological changes in the TMJ of non-operated opposite condyle. Problems were: the distribution of fixation stress of screws was somewhat unreasonable, the downward sliding of the condyle was limited, there was erosion of the posterior slope of the glenoid fossa, and the articular disc could not keep its in situ place and function. CONCLUSION: The results suggests that the prosthesis needs further improvement.