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。     

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.     

Current problems in the diagnosis and treatment of injuries to the temporomandibular joint

Complex examination of 2103 patients with temporomandibular joint (TMJ) injuries was carried out. This examination included contrast arthrotomography, computed tomography (CT) and MR tomography of the TMJ. It gas been established, that in mandibular condyle fractures not only bone structures of the TMJ, but also soft tissue ones (the articular disk and capsular-ligamentous apparatus) are being injured. Our investigation has shown that condylar fractures in the region of condylar base and neck are combined with the injuries of the articular disk and capsular-ligamentous apparatus in 54.1 +/- 5.4% cases, mandibular head fractures with its dislocation--in 100%. The term "TMJ injuries" reflecting the injuries of bone and soft tissue structures of the TMJ has been introduced. The classification of TMJ injuries including TMJ contusion, mandibular dislocations, condylar and glenoid fossa fractures, the injuries of the articular disk and capsular-ligamentous apparatus has been developed. Distant results of traditional methods of treatment used in TMJ trauma have been studied and the necessity of the restoring of correct relation: glenoid fossa --articular disk--mandibular head--has been shown. The method of TMJ reconstruction consisting in the restoration of TMJ bone structures and the articular disk and capsular-ligamentous apparatus has been developed.     

Double contours and craniofacial morphology

This study was done to try to clarify the relationship between double contours and craniofacial morphology. The study sample included 56 pre-orthodontic patients with signs and symptoms of temporomandibular joint (TMJ) disorders. A comparison of craniofacial structures was done on 32 subjects with bilateral condylar bone change (BBC group: 28 female and 4 male) and 24 subjects with no condylar bone change (NBC group: 21 female and 3 male). The BBC showed significantly greater antegonial and ramus notch depths, as well as significantly more retruded mandibles, shorter ramus heights, and larger mandibular plane angles than the NBC. BBC subjects with bilateral double contours showed significantly more retruded mandibles, larger antegonial notch depth, and shorter lengths from the Sella to the Articulare than BBC subjects with no double contours. The study showed that important relationships exist between the presence of double contours and mandibular morphology and TMJ position.     

Mandibular antegonial and ramus notch depths and condylar bone change

The present study sought to clarify the relationship between antegonial and ramus notch depths and condylar bone change, and analyse the effects of such change on craniofacial structure. The study sample was of 28 pre-orthodontic patients with signs and symptoms of temporomandibular joint (TMJ) disorders, who underwent helical computed tomography to diagnose their TMJ pathology. Craniofacial structures were compared between 14 subjects with bilateral condylar bone change (BBC group: two male and 12 female) and 14 subjects with no bone change (NBC group: two male and 12 female). Sella-nasion-point B (SNB) and point A-nasion-point B (ANB) angles were significantly smaller in BBC than in NBC, with ramus height and mandibular body lengths significantly shorter in BBC than in NBC. The BBC lower facial height and SN-Go-Ar angle, as well as antegonial and ramus notch depths, were significantly greater than in NBC, and the mandible was significantly more retruded in BBC than in NBC. These results showed that condylar bone change might be related not only to mandibular size (e.g. retrusion) but also to mandibular outline (including antegonial and ramus notch depth).     

Condylar bone change and sagittal incisal and condylar paths during mandibular protrusive excursion

This study showed significant differences in sagittal condylar and incisal path angles during mandibular protrusive excursion, as well as flattening of the condylar path related to the existence and type of condylar bone change. Twenty-eight (28) patients with signs and symptoms of TMJ disorders were studied, using a six-degrees-of-freedom measuring device and helical CT. Sagittal incisal and condylar path angles at two mm and three mm condylar path lengths (CPL) were significantly shorter in the bilateral condylar bone change (BBC), compared to the no bone change (NBC) group. Also, NBC incremental sagittal condylar path angles from three to five mm CPL and NBC condylar path curvature at five mm CPL were both significantly larger than in BBC. Comparing types of bone change, incremental sagittal condylar path angles from three to five mm CPL was significantly less in osteophyte than in NBC or erosion groups. Condylar path curvature at five mm CPL was also significantly less in osteophyte than in NBC.     

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.     

Associations between the location of the glenoid fossa and its remodeling. An experimental study in the rabbit.

The growth of the glenoid fossa is assumed to follow that of the cranial base. It has been observed recently that distal displacement in association with an obtuse cranial base angle is reduced on remodeling of the fossa anteriorly as a consequence of a more anterior position of the condyle in the fossa. The aim of this investigation was to simulate the increased distal displacement experimentally by causing a premature artificial cranial synostosis. Ten 10-day-old rabbits underwent gluing of the interparietal and temporoparietal sutures. These and ten controls were killed at 50 days for examination, and the articular surface of the right glenoid fossa was marked with a soft metal wire. The skulls were roentgenographed in standardized lateral projection. The articular surface was significantly shallower in relation to the skull base in the experimental group, and the glenoid fossa was located more superiorly and posteriorly. The most likely reason for the more horizontal direction of the articular surface is the more anterior location of the condyle, exerting increased pressure on the eminence. This becomes important, as it has recently been shown that in rabbits this shallowing of the fossa is associated with increased forward growth of the mandible.     

Temporomandibular joint growth changes in hyperdivergent and hypodivergent Herbst subjects. A long-term roentgenographic cephalometric study.

The aim of this long-term study was to assess the amount and direction of glenoid fossa displacement, condylar growth, and "effective" temporomandibular joint (TMJ) changes (= the sum of glenoid fossa displacement, condylar growth, and condylar position changes in the fossa) in 3 vertical facial-type groups of Class II Division 1 malocclusions treated with the Herbst appliance. A comparison was made between 38 normodivergent (ML/NSL= 26.5 degrees -36.5 degrees), 17 hypodivergent (ML/NSL or= 37 degrees ) subjects. Lateral headfilms from before, after, and 5 years after treatment were scrutinized. Glenoid fossa displacement, condylar growth, and "effective" TMJ changes were analyzed. Treatment changes: in all facial-type groups, the glenoid fossa was displaced anteriorly and inferiorly. No differences existed between the 3 groups. Condylar growth and "effective" TMJ changes were directed posteriorly and superiorly. The changes in posterior direction were more apparent in the hyperdivergent group than in the normodivergent and hypodivergent groups. Posttreatment changes: in all facial-type groups, the fossa was displaced posteriorly. No differences existed between the 3 groups. Condylar growth and "effective" TMJ changes were directed more vertically compared with the treatment changes. The changes in posterior direction were more pronounced in the hyperdivergent group than in the other 2 groups. It was found that the amount and direction of TMJ growth changes (fossa displacement, condylar growth, and "effective" TMJ changes) were only temporarily affected favorably in the sagittal direction by Herbst treatment. Condylar growth and "effective" TMJ changes were directed more posteriorly in hyperdivergent than in hypodivergent Herbst subjects. This was true for both treatment and posttreatment period changes.     

Morphology of the articular eminence in temporomandibular joints and condylar bone change

The purpose of the present study was to investigate the relationship between the inclination of the articular eminence and temporomandibular joint (TMJ) pathology in orthognathic surgery patients with signs and symptoms of TMJ disorders. Twenty-one female orthognathic surgery patients with signs and symptoms of TMJ disorders were examined using pre-treatment helical computed tomography scans. The slope of the eminence in the medial, central and lateral sections of the subjects with osteophyte formation was significantly less than in the subjects with no bone change, and the medial section of the subjects with osteophyte formation was also significantly less steep than in the subjects with erosion. The central and lateral sections in the subjects with anterior disc displacement with reduction were significantly steeper than in subjects with anterior disc displacement without reduction. These results suggest that eminence flattening might occur during changes from erosion to osteophyte formation and from anterior disc displacement with reduction to anterior disc displacement without reduction. This appears to represent adaptation of the condyle, articular disc and articular eminence to changes in loading.     

Relationship of degenerative changes of the temporomandibular joint (TMJ) with the angle of eminentia

The purposes of this study were threefold: (i) to assess the degenerative changes of the temporomandibular joint [TMJ (condyles and articular eminence of the glenoid fossa)], (ii) to determine whether the TMJ degeneration levels differ by ethnic group and gender and (iii) to assess the association between the angles of eminentia and TMJ degeneration, while controlling for gender, ethnicity, age and number of teeth. The sample included 245 20th century dry skulls: 130 African-American (82 male and 48 female) and 115 European-American (75 male and 40 female), with a mean age of 46.4 +/- 19.9 years. The angles of eminentia were measured in a sagittal plane. The medial, central and lateral portions of the articular slope and anterior portion of the condyle were assessed for degenerative changes. Degeneration scores were calculated for the eminentia and condyles. Statistical analyses included two-way anovas, Pearson's correlation coefficients and linear regression models. There were differences in the degree of TMJ degeneration of the African-American and European-American males and females. European-American females retained fewer teeth, had the highest TMJ degeneration scores and exhibited significant relationships between the eminentia angles and degeneration. When the independent variables were entered into the regression model, only the degeneration of the eminentia was significantly associated with the angles of eminentia. Although the degeneration of the eminentia explained some of the variation of the eminentia angles, it is clear that the inclusion of multiple factors is essential to study the remodelling of the glenoid fossa.     

Amount and direction of temporomandibular joint growth changes in Herbst treatment: a cephalometric long-term investigation

The amount and direction of condylar growth, glenoid fossa displacement, and "effective" temporomandibular joint (TMJ) changes (a summation of condylar growth, glenoid fossa displacement, and condylar position changes within the fossa) were analyzed in 35 Class II, Division 1 malocclusions (23 boys and 12 girls) treated with the Herbst appliance. Lateral head films in habitual occlusion and with the mouth wide open from before (T1) and after 7.5 months of Herbst treatment (T2) as well as 7.5 months (T3) and three years (T4) after treatment were evaluated. As a control group, a sample of 12 untreated male Class II Division I malocclusions was used during a 7.5-month time period corresponding to the treatment period (T2-T1) of the Herbst cases. The results revealed that during the treatment period (T2-T1) condylar growth was directed posteriorly about twice the amount as in the control subjects, and the fossa was displaced in an anterior inferior direction. The effective TMJ changes showed a pattern similar to condylar growth but were more pronounced. During the first posttreatment period (T3-T2), all TMJ changes reverted. The glenoid fossa was displaced backward; the amount of condylar growth and effective TMJ changes was reduced, and the changes were more superiorly directed. During the second posttreatment period (T4-T3), all TMJ changes were considered physiological. Conclusion: During Herbst treatment, the amount and direction of TMJ changes (condylar growth, fossa displacement, and effective TMJ changes) were only temporarily affected favorably by Herbst treatment.     

Correlation between temporomandibular joint temporal component pneumatization and morphology: analysis by cone beam computed tomography

The aim of this study was to evaluate whether a correlation exists between temporal bone pneumatization and the morphology of the articular eminence and glenoid fossa. A sample of 100 cone beam computed tomography scans was used, for a total of 200 temporomandibular joints (TMJ). Paracoronal and parasagittal images of the TMJ were evaluated by two examiners. For all TMJ, pneumatization was classified in the mid-lateral direction using a score of 0 or 1, and in the anteroposterior direction using a score ranging from 0 to 3. The inclination and height of the articular eminence and the thickness of the roof of the glenoid fossa were obtained. Pneumatization was found in the mid-lateral direction in 83.5% of the cases and in the anteroposterior direction in 88%. The age of the patient and side did not influence the prevalence or degree of pneumatization (P = 0.051–0.953), but female patients showed more pneumatization in the mid-lateral direction than male patients (P = 0.014). The presence of pneumatization did not affect articular eminence and mandibular fossa morphology. It is concluded that the presence and extent of pneumatization of the TMJ temporal component does not affect its morphology. However, professionals should be aware of the high prevalence of pneumatization and take this into account when performing TMJ assessment.     

采用锥形束CT分析安氏Ⅱ类1分类错牙合患者Twin-block矫治前后颞下颌关节的变化

目的 运用锥形束CT（CBCT）分析安氏Ⅱ类1分类错牙合在Twin-block矫治前后颞下颌关节位置及形态结构在三维方向上的变化。方法 选取20例处于生长发育高峰前期或高峰期的安氏Ⅱ类1分类错牙合患者,拍摄其功能矫治前后双侧颞下颌关节的CBCT片,运用InVivoDental软件对CBCT片进行三维重建并测量线距和角度,对测量结果进行统计学分析。结果 与治疗前相比,治疗后矢状向关节前间隙减小,关节上间隙和后间隙增大,冠状向关节上间隙增大（P<0.01）;髁突高度、矢状向髁突角度、横断面髁突前后径增加（P<0.01）。结论 采用Twin-block矫治器治疗安氏Ⅱ类1分类错牙合患者后,髁突在关节窝的位置和髁突部分骨性结构发生了一定程度的改变,髁突有新骨沉积,高度增加,在关节窝内的位置更向下和向前。CBCT的应用使颞下颌关节结构的变化得以量化,能对正畸治疗效果进行客观评价。     

Alliance Call for Action in Washington

Abstract

The present study was undertaken to investigate the correlation between condylar position, articular eminence morphology, and mandibular deviation using helical CT in a group of 22 female subjects (mean age 19.2±5.3 years) with mandibular deviation. There was a significant difference in the angles of the posterior-slope of the articular eminence (PSA) between the deviated (44.27±10.29°) and non-deviated (42.50±9.90°) sides. Mandibular deviation also correlated significantly with both medial joint space (r=0.581) and the PSA (r=0.653). A significant negative correlation was also found between mandibular deviation and the anterior/posterior joint space ratio (r=-0.450). These results demonstrated that patients with mandibular deviation possibly show asymmetries not only in their glenoid fossa morphology but also in their condylar position.     

The relationship between morphological changes of the condyle and condylar position in the glenoid fossa

AIMS: To investigate whether condylar morphological changes influence the condyle position in the glenoid fossa as well as the amount of condylar movement from the intercuspal position (IP) to the reference position (RP). METHODS: Helical computed tomography was used for precise measurement of the joint spaces at IP and RP in 22 subjects (mean age 22.7 years). Subjects were divided into 2 groups, those without condylar bone changes (n = 11) and those with condylar bone changes (n = 11). The latter group was further subdivided into a flattening subgroup and an osteophyte subgroup, according to the type of condylar bone change. RESULTS: There were no significant differences in the width of the anterosuperior or posterosuperior joint spaces at IP between either the 2 groups or the 2 subgroups. On the other hand, during condylar movement from IP to RP, the condyles moved significantly more superiorly and posterosuperiorly in the bone-change group than in the no-bone-change group. There was also greater absolute horizontal condylar movement between IP and RP in the bone-change group. In addition, within the bone-change group, the type of condylar bone change influenced the amount of condylar movement. Joints with osteophyte formation showed the most superior, posterosuperior, and absolute horizontal movement from IP to RP. CONCLUSION: The findings that condyles of the bone-change group, especially those with osteophyte formation, were located significantly more anteroinferiorly in the glenoid fossa at IP than RP than the condyles of the no-bone-change group suggest that condylar IP-RP positional changes might be related to condylar shape alteration.     

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。     

Relation of the glenoid fossa to craniofacial morphology, studied on dry human skulls

The purpose of this work was to compare glenoid fossa dimensions and craniofacial morphology on the basis of standard lateral roentgenograms. To overcome the difficulties encountered in making exact measurements on living subjects, 59 dry skulls were used. Eight angular measurements were taken to describe the form of the skull base, mandible, and articulating surface of the glenoid fossa, four linear measurements to describe the position of the fossa, and one to describe the size of the whole skull. A close relationship was observed between the morphology of the articulating surface of the glenoid fossa and the mandibular morphology. The skull base angulation was associated with the position of glenoid fossa in two ways. Basically, the position of the fossa is related to skull base characteristics, but the location of the articular eminence in relation to the clival plane suggests that the mandibular condyle may cause a remodeling of the eminence anteriorly when the glenoid fossa otherwise is translocated posteriorly in association with the flat skull base.     

Asymmetry of the articular eminence in dentate and partially edentulous populations

The purpose of this study was to assess the degree of right-left asymmetry of the glenoid fossa. The specific aims were (1) to determine whether there were relationships between age, number of teeth, slope of the articular eminence, fossa depth, and the degree of right-left asymmetry, and (2) to compare the right-left asymmetry of two populations, one characterized by an acceptable occlusion (A-Occ), the other by an unacceptable occlusion (partially edentulous; Un-Occ). A-Occ was defined as possessing a minimum of 28 teeth that would allow for hand articulation of the mandibular teeth to the maxillary teeth. Un-Occ had fewer than 17 teeth, which would make it impossible to articulate the mandible with the maxilla. The sample included 20th century dry skulls: 70 African-American (44 male, 26 female) and 64 European-American (49 male, 15 female), ranging in age from 21-105 (mean 47.1 +/- 19.9). The medial (M), central (C), and lateral (Lat) aspects of the right (R) and left (L) slopes of the articular eminence were measured in a sagittal plane. The R and L fossa depth also were measured. The raw absolute differences IR-LI and relative differences [IR-LI/IR+Llx100] of the articular slope angles (M, C, and Lat) and fossa depths were computed. Statistical analysis included paired t-tests, independent t-tests, and Pearson's correlation coefficients, significance at p < or = 0.05. Ninety percent (90%) of the population exhibited right-left asymmetry of the glenoid fossa. The right articular slopes (M, C, and Lat) were significantly steeper than the left articular slopes; the right fossa depths were significantly deeper than the left. There generally were no differences in the articular slope steepness or fossa depths between the partially dentate and the dentate, nor were there statistical differences between the two groups in the raw absolute differences or relative differences of the M, C, and Lat slopes or fossa depths. No significant relationships were found between right-left asymmetry, age, or number of teeth. With only 10% of the subjects exhibiting symmetry of the glenoid fossa depths or articular slope angles, clinicians should consider bilateral asymmetry the norm and not an anomaly.