生长发育高峰前期与高峰期安氏Ⅲ类错(牙合)颞下颌关节CBCT比较分析

目的 应用锥形束CT(CBCT)分析安氏Ⅲ类错(牙合)不同CVM分期颞下颌关节(TMJ)的生长发育差异.方法 分别对60名恒牙早期均角安氏Ⅲ类患者和60名恒牙早期正常(牙合)在牙尖交错位进行CBCT扫描,按颈椎CVM分期进行分组,使用Invivo5软件对影像重建并进行数据测量.通过SPSS22.0软件采用LSD法分析比较生长发育高峰前期与高峰期的髁突生长发育差异.结果 安氏Ⅲ类错(牙合)组相比正常(牙合)组中髁突绝大多数位于关节凹前位.安氏Ⅲ类错(牙合)组CS3-CS4期与CS1-CS2期生长变化差值显示髁突上间隙、前间隙减小量、后间隙增长量与正常(牙合)组相比有统计学差异(P<0.05);髁突前后径减小量、髁突高度增长量与正常(牙合)组相比有统计学差异(P<0.05);关节窝深度、关节后斜面角减小量、关节窝前后径增长量与正常(牙合)组相比有统计学差异(P<0.05).结论 安氏Ⅲ类错(牙合)生长发育高峰期相对于高峰前期髁突绝大多数位于关节凹前位且在关节凹中的位置更靠前上.髁突垂直向发育过度,更为细长,关节凹浅而宽.     

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.     

颞下颌关节盘前移位患者关节骨形态与矢状向关节盘位置的关系

目的　利用磁共振成像（MRI）技术和锥形束CT（CBCT）分析颞下颌关节盘前移位患者矢状向关节盘位置与关节骨形态的关系。方法　对97例患者的178个颞下颌关节（TMJ）进行回顾性分析，根据矢状向MRI上关节盘的位置分成4组，即对照组（关节盘无移位）、轻度组（关节盘轻度前移位）、中度组（关节盘中度前移位）和重度组（关节盘重度前移位）。然后利用Mimics 20软件基于CBCT数据进行TMJ的相关形态学参数测量，包括髁突线性尺寸（宽度、长度和高度）、髁突体积和表面积，关节窝的深度和长度，关节结节倾斜角，关节前、上、后间隙等，并对各组矢状髁突位置进行评估。使用方差分析、非参数检验和卡方检验等比较关节形态及位置参数的组间差异，采用相关性分析探索矢状关节盘位置与关节测量参数之间的相关性。结果　髁突的线性尺寸、关节窝深度、关节倾斜角、关节间隙和矢状髁突位置分布在4组间差异有统计学意义，而关节窝长度在4组间差异没有统计学意义；相关性分析显示：髁突的线性尺寸、髁突的体积及表面积、关节窝的深度、关节结节倾斜角和关节上间隙与关节盘矢状位置之间存在显著负相关，而关节后间隙与矢状关节盘位置之间存在显著正相关。结论　TMJ骨形态与不同矢状关节盘位置之间存在相关性，应警惕临床看到的关节骨形态的退行性改变可能是患者存在关节盘前移位的标志。     

Association between condylar position, joint morphology and craniofacial morphology in orthodontic patients without temporomandibular joint disorders

The present study investigated condylar position and joint morphology in adolescent patients and elucidated the possible association between the joint structure and condylar position, and craniofacial morphology. Sixty-five adolescent patients were selected as subjects and their tomograms and lateral cephalograms were analysed. No significant differences in joint spaces were found between the right and left temporomandibular joints. Both the condyles in this population were located slight anteriorly in the glenoid fossa. With respect to the association between condylar position, joint morphology and craniofacial morphology, the ramus plane angle also exhibited significant negative correlations with posterior, lateral and medial joint spaces. Furthermore, there was a significant negative correlation between the gonial angle and the anterior joint space. These findings imply that the condyle was likely to show more posterior position in the glenoid fossa when the mandible exhibited clockwise rotation. In conclusion, the condyle in the adolescent subjects showed a symmetrical anterior position relative to the glenoid fossa. In addition, the joint spaces and it ratios were significantly related to the craniofacial morphology associated with vertical dimension. It is suggested that the condylar position may be affected by craniofacial growth pattern.     

Effects of osseous structure based on three-dimensional reconstructive imaging evaluation in the assessment of temporomandibular joint disc position

Objectives

This pilot morphological study aimed to investigate the association between anterior disc displacement (ADD) and the status of the mandibular condyle and articular fossa.

Materials and methods

Thirty-four patients were divided into a normal articular disc position group and an ADD with and without reduction group. Images reconstructed were used to determine multiple group comparisons of these three different types of disc position, and the diagnostic efficacy for the morphological parameters with significant group difference was analyzed to assess.

Results

The condylar volume (CV), condylar superficial area (CSA), superior joint space (SJS), and medial joint space (MJS) all exhibited obvious changes (P < 0.05). Additionally, they all had a reliable diagnostic accuracy in differentiating between normal disc position and ADD with an AUC value from 0.723 to 0.858. Among them, the CV, SJS, and MJS (P < 0.05) had a significantly positive impact on the groups by analysis of multivariate logistic ordinal regression model.

Conclusions

The CV, CSA, SJS, and MJS are significantly associated with different disc displacement types. The condyle in ADD exhibited altered dimensions. These could be promising biometric markers for assessing ADD.

Clinical relevance

The morphological changes of mandibular condyle and glenoid fossa were significantly influenced by the status of disc displacement, and condyles with disc displacement had three-dimensionally altered condylar dimensions, irrespective of age and sex.

     

Autogenous auricular cartilage implantation following discectomy in the primate temporomandibular joint

The purpose of this study was to evaluate the histologic changes in primate temporomandibular joints (TMJ) treated with autogenous auricular cartilage grafts following total discectomy. Four Macaca fascicularis monkeys underwent bilateral TMJ disc removal and high condylar shaves. One TMJ in each monkey was treated by grafting autogenous auricular cartilage to the glenoid fossa; the contralateral joint served as a control. Monkeys were killed at 6, 12, 16, and 24 weeks postoperatively. Viable auricular cartilage was found in all grafted joints. There was a variable amount of fibrous connective tissue surrounding the cartilage grafts, with some grafts being directly fused to the glenoid fossa. One joint showed significant fibrous connective tissue adhesions between the condylar surface and the inferior portion of the graft. Degenerative changes in the grafted joint appeared grossly to be less severe than in the control joints. The cartilaginous tissues appeared to be a suitable autogenous tissue graft, maintaining its viability and functioning as an interpositioning material between the condyle and fossa.     

颞下颌关节盘前移位关节间隙改变的X线研究

目的测量颞下颌关节盘前移位患者与健康成人许勒位片上的关节间隙,分析髁突在关节窝中的位置,探讨髁突后移位在关节盘前移位临床诊断中的价值。方法选择120例（120侧）关节盘前移位患者和30例健康成人,拍摄许勒位片,使用AutoCAD计算机软件,采用2种线距测量方法（张震康法和Kamelchuk法）在许勒位片上测量关节间隙,并计算ln（P/A）值,比较关节盘前移位患者与健康成人（对照组）关节间隙的差异。结果2种测量方法的测量结果均显示：关节盘前移位组的关节上间隙和后间隙均小于对照组,其差异有统计学意义（P<0.05）,而关节前间隙与对照组的差异无统计学意义（P>0.05）;关节盘前移位组ln（P/A）值均小于对照组相应ln（P/A）值,其差异有统计学意义（P<0.05）。结论许勒位片上显示的颞下颌关节髁突后移位在一定程度上提示有关节盘前移位的存在;但正常髁突位置也存在变异,单纯的许勒位片尚不能作为关节盘前移位的确切诊断依据。     

The assessment of the short‐ and long‐term changes in the condylar position following sagittal split ramus osteotomy (SSRO) with rigid fixation

Summary The purpose of this study was to compare the short‐ and long‐term changes in condylar position related to the glenoid fossa, and skeletal and occlusal stability after orthognathic surgery. All of the study patients were assessed by cone‐beam computed tomography images for condylar rotational changes and anteroposterior position in the pre‐surgery, post‐surgery and post‐retention period. The condylar positions were evaluated on three planes: axial, coronal and sagittal. In the skeletal and occlusal measurements, there was no significant difference between the post‐surgery group and the post‐retention group. After sagittal split ramus osteotomy (SSRO), the condyle on the axial plane rotated inward (P < 0·05) and maintained during the post‐retention period. In the anteroposterior condylar position related to the glenoid fossa, the condyles had changed from the anterior position in the pre‐surgery group to a concentric position in the post‐surgery group and then returned to the anterior position in the post‐retention groups. These results suggested that the changed anteroposterior condylar position in the glenoid fossa after SSRO with rigid fixation had moved from a concentric to anterior position for post‐retention period.     

Correction of condylar displacement following intraoral vertical ramus osteotomy

Fifteen patients who demonstrated condylar sag after intraoral vertical ramus osteotomy for the correction of mandibular prognathism were treated nonsurgically to establish the desired postoperative occlusion. A mean inferior displacement of 3.33 mm and anterior displacement of 2.18 mm were observed tomographically after surgery. Postoperatively, a geometric splint was constructed to compensate for the magnitude of condylar displacement and was used to replace the original splint to hold the distal segment in an overcorrected position. Skeletal fixation was maintained for 5 to 6 weeks. Tomographic evaluation of the temporomandibular joint (TMJ) during maxillomandibular fixation showed a slight superior (1.03 mm) and posterior (0.51 mm) movement of the condyle in the fossa. After release of fixation and removal of splint, a further superior (2.05 mm) and posterior (1.01 mm) repositioning of the condyle was observed. This later movement correlated with the placement of light class III elastic traction to seat the condyles into the glenoid fossae and establish a class I occlusion. Temporomandibular joint tomograms confirmed complete seating of the condyles in the fossa and lateral cephalograms demonstrated a corresponding change in the position of the mandible to the desired postoperative position. This technique has been effective in preventing postoperative malocclusion resulting from condylar sag.     

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.     

Human lateral pterygoid muscle activity on the return phase of contralateral and protrusive jaw movements

Normal function of the lateral pterygoid muscle is not well understood. The principal aim of this study was to determine whether there is a progressive decrease in lateral pterygoid activity as the condyle moves posteriorly and superiorly during the return phase of a contralateral or protrusive jaw movement, as would be expected if the muscle is involved in controlling or stabilizing the condyle during the return phase of these movements. In seven humans, electromyographic activity was recorded in the superior (SHLP) and inferior (IHLP) heads of the lateral pterygoid, the masseter, anterior temporal, posterior temporal and submandibular group of muscles, together with condylar movement, during contralateral and protrusive jaw movement. In most individuals, there was a progressive decrease in rectified and smoothed IHLP activity in relation to condylar movement during the return phase of contralateral and protrusive jaw movement. However, this pattern usually was not seen when SHLP activity was studied in relation to condylar movement. Further, there was a high correlation coefficient between condylar displacement and the rectified and smoothed IHLP and anterior temporal muscle activities during the return phase of contralateral or protrusive jaw movement, while SHLP presented a much lower correlation. For example, the mean (+/-SD) correlation coefficient between posterior condylar movement (along anteroposterior axis) and IHLP activity during the return phase of a protrusive jaw movement was -0.73+/-0.36 (for contralateral movement: -0.71+/-0.56), for the anterior temporal 0.69+/-0.21 (contralateral: 0.81+/-0.09), and for the submandibular muscles, -0. 77+/-0.15 (contralateral: -0.34+/-0.71). For the SHLP, masseter and posterior temporal, values were -0.34+/-0.61 (contralateral: -0. 48+/-0.37), -0.24+/-0.57 (contralateral: 0.16+/-0.80), and 0.16+/-0. 77 (contralateral: 0.64+/-0.14), respectively. These findings suggest an important role for the IHLP and anterior temporal in controlling the movement of the condyle to the glenoid fossa on the return phase of contralateral and protrusive jaw movements. Further studies are needed to clarify the function of the lateral pterygoid muscle during these and other jaw movements.     

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.     

Proximal segment positioning in bilateral sagittal split osteotomy: intraoperative controlled positioning by a positioning splint

PURPOSE: Most techniques of proximal segment positioning hinder intraoperative condyle displacement. However, merely maintaining condylar position cannot optimize the preoperative condyle-disc-fossa relationship. This study attempts to optimize condylar position in the osteotomy patient. PATIENTS AND METHODS: A study group of 23 bimaxillary operated patients had intraoperative joint positioning by positioning splint and plates (9 Angle Class II, 14 Class III). After assessing the habitual and appraising the optimized condyle position on preoperative sonograms and magnetic resonance images, positioning splints were constructed as acrylic occlusal wafers in a semi-individual articulator. Set in occlusion before adaptation of positioning plates, they were intended to move the condyles into the calculated position. Eighteen bimaxillary operated control patients had conventional plate positioning according to the habitual occlusion (9 Angle Class II, 9 Class III). Clinical follow-up, axiography, or sonography was maintained for 24 months. Preoperative lateral cephalograms were scrutinized for horizontal and vertical joint spaces and compared with the immediate postoperative radiography. RESULTS: Postoperative Class II study group patients had less dorsal and more vertical joint space and Class III patients more dorsal and vertical space compared with the controls. The study group exhibited significantly less postoperative dysfunction compared with the control group (2-way analysis of variance: P <.021, F = 9.2, alpha =.05 significance level), disc dislocation prevalence was lower (P <.07, F = 9.2), postoperative changes in condylar translation were smaller (P <.014, F = 4.9), and 8% skeletal relapses versus 22% in the controls were seen. CONCLUSIONS: A proximal segment-positioning splint effectively positioned the condyle in the desired direction, but with considerable relapse, significantly reduced postoperative dysfunction, disc dislocations, changes to the condylar translation, and incidence of skeletal relapse at 24-month follow-up.     

Achieving improved visualization of the temporomandibular joint condyle and fossa in the sagittal cephalogram and a pilot study of their relationships in habitual occlusion

Improved glenoid fossa and condyle visualization is achieved by adapting the Denar TMJ Orthoceph Slimline Cassette (Denar Corp., Anaheim, Calif.) to sagittal cephalometry. This cassette contains rare-earth intensifying screens to enhance the temporomandibular joint region. A plastic template of circles of varying diameters is positioned so that the appropriate circle size is tangent to the superior, anterior, and posterior borders of the glenoid fossa seen on the resultant radiograph. The planar geometric center of the glenoid fossa is then identified coincident with the center of the template circle. The condyle planar geometric center is similarly identified. The relationships of these centers with respect to each other is described by using a rectangular coordinate system with the origin at the glenoid fossa geometric center. The condyle center is further described as being in any one of four quadrant locations or concentric with the glenoid fossa geometric center. This method was then applied to 38 patients who were free of temporomandibular joint symptoms in a pilot study relating the condyle quadrant location with the dentition in habitual occlusion. Findings revealed 89% of the condyles were in any one of the four possible quadrants. Fifty-three percent of the condyles were located in a downward and forward position (quadrant IV). Eleven percent of the condyle geometric centers were concentric with the glenoid fossa geometric center. (Am J Orthod Dentofac Orthop 1996;109:635-8.)     

髁突在关节窝中的位置及其在临床诊断治疗中的意义

临床治疗中,特别是髁突外伤骨折、正颌手术、修复咬合重建、正畸治疗以及在颞下颌关节紊乱病的诊断和治疗中,要考虑髁突在关节窝中的位置变化。本文通过文献回顾,结合我们的研究成果,讨论髁突在关节窝中的正常生理位置及其在颞下颌关节紊乱病特别是关节盘移位的诊断和治疗中的意义。目前多项研究认为,健康成年人髁突平均位置为基本中性,但存在较大变异;髁突后移可能是关节盘前移位的危险因素,关节盘前移位也可导致髁突后移;在关节盘移位的牙合垫治疗中,髁突在牙合垫戴入后显著向前、下移位,可有效改善盘突关系;稳定牙合垫使髁突前下移位不明显,改善盘突关系的效果有限。此外,再定位牙合垫使髁突前下移位还可促进髁突骨质的改建。     

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.     

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??Abstract??The condylar position should be taken into account in the diagnosis and treatment of condyle fracture??orthognathic surgery??occlusal reconstruction and temporomandibular disorders. The normal condylar position in the glenoid fossa and its clinical significance in the diagnosis and treatment of temporomandibular disorders??for example the disc displacement??will be discussed here through the literature review and the combination of our research findings. Many research data suggested a centric position of condyle in a normal joint??with individually variances. A posterior condylar position might be a risk factor of disc displacement??and on the other hand??the disc displacement might induce condyle to move posteriorly. With the use of anterior repositioning splint for treating anterior disc displacement with reduction??the condyle moved anteriorly and inferiorly??the condyle-disc relationship could be improved immediately. Besides??splint therapy may facilitate regenerative remodeling of condyles.     

Assessment of Optimal Condylar Position in the Coronal and Axial Planes with Limited Cone‐Beam Computed Tomography

Purpose: No quantitative standards for the optimal position of the mandibular condyle in the glenoid fossa are yet available in the coronal and axial planes. We previously reported measurements of this position in the sagittal plane, using recently developed limited cone‐beam computed tomography (LCBCT) capable of imaging the craniofacial structures with high accuracy. In this study, we assessed the optimal condylar position in the coronal and axial planes. Materials and Methods: The study included 24 joints in 22 asymptomatic patients (10 male, 12 female; age range 12–25 years, mean age 18 years) who had no disc displacement as confirmed by magnetic resonance imaging. Their joints had optimum function with the starting and end points of all functional jaw movements coincident with maximum intercuspation. Joint‐space distances between the condyle and glenoid fossa were measured at the medial, central, and lateral positions in the coronal plane, and medial and lateral positions in the axial plane. Results: The mean coronal lateral space (CLS), coronal central space (CCS), and coronal medial space (CMS) were 1.8 ± 0.4 mm, 2.7 ± 0.5 mm, and 2.4 ± 0.5 mm, respectively. The ratio of CLS to CCS to CMS was 1.0 to 1.5 to 1.3. The mean axial medial space (AMS) and axial lateral space (ALS) were 2.1 ± 0.6 mm and 2.3 ± 0.6 mm, respectively. There were no significant sex differences in these measurements. Conclusions: These coronal and axial data, along with previously reported sagittal data, might provide norms for 3D assessment of optimal condylar position with LCBCT.     

Condyle position as a predictor of temporomandibular joint internal derangement.

STATEMENT OF PROBLEM: The significance of the position of the mandibular condyle in the glenoid fossa remains a controversial subject. PURPOSE: This study evaluated the relationship between condyle position and disk displacement. MATERIAL AND METHODS: Fifty-two asymptomatic volunteers and 130 symptomatic patients underwent linear tomography and bilateral temporomandibular joint magnetic resonance scans. RESULTS: There was a higher prevalence of distal condyles in symptomatic patients with disk displacement compared with asymptomatic volunteers (P <.05). Distally positioned condyles identified joints with disk displacement with reduction, disk displacement without reduction, or a symptomatic normal joint with a sensitivity of 0.64, 0.56, and 0.33, respectively. Distally positioned condyles identified joints with disk displacement with reduction, disk displacement without reduction, or a symptomatic normal joint with a specificity of 0.56, 0.65, and 0.55, respectively. CONCLUSION: There were more distal condyles in symptomatic subjects with disk displacement, but the reliability of a distal condyle to predict the presence or absence of disk displacement was low.     

Condylar and disc positions after intraoral vertical ramus osteotomy with and without a Le Fort I osteotomy

The purpose of this study was to examine the changes in temporomandibular joint (TMJ) morphology and clinical symptoms after intraoral vertical ramus osteotomy (IVRO) with and without a Le Fort I osteotomy. Of 50 Japanese patients with mandibular prognathism with mandibular and bimaxillary asymmetry, 25 underwent IVRO and 25 underwent IVRO in combination with a Le Fort I osteotomy. The TMJ symptoms and joint morphology, including disc tissue, were assessed preoperatively and postoperatively by magnetic resonance imaging and axial cephalogram. Improvement was seen in just 50% of joints with anterior disc displacement (ADD) that received IVRO and 52% of those that received IVRO with Le Fort I osteotomy. Fewer or no TMJ symptoms were reported postoperatively in 97% of the joints that received IVRO and 90% that received IVRO with Le Fort I osteotomy. Postoperatively, there were significant condylar position changes and horizontal changes in the condylar long axis on both sides in the two groups. There were no significant differences between improved ADD and unimproved ADD in condylar position change and the angle of the condylar long axis, although distinctive postoperative condylar sag was seen. These results suggest that IVRO with or without Le Fort I osteotomy can improve ADD and TMJ symptoms along with condylar position and angle, but it is difficult to predict the amount of improvement in ADD.