Modified trans-oral approach for mandibular condylectomy

Different approaches to the mandibular condyle have been described. In this paper, a modified trans-oral technique to access the mandibular condyle is described and illustrated. This technique was used in a small group of patients; the clinical outcomes are promising. The technique can be used in various temporomandibular joint (TMJ) operations, such as condylar resection, high condylectomy or tumor removal. It provides adequate intra-oral surgical access to the mandibular condyle and avoids complications from extra-oral approaches to the TMJ.     

Trifid mandibular condyle: A case report

A few cases of bifid, but no case of trifid mandibular condyle, have been reported in the literature. This article presents the first reported case of trifid mandibular condyle in a living subject with a history of previous trauma to the temporomandibular joint (TMJ). Additionally, the patient's other condyle was bifid. The patient had no complaint related to the functions of TMJ except for minimal weakness following chewing. The etiology and the prognosis of bifid and trifid condyle are discussed briefly. We considered computed tomography essential to rule out early stages of TMJ pathology in similar cases that resemble trifid mandibular condyle on conventional radiographs.     

Endoscopically assisted reconstruction of the mandibular condyle with a costochondral graft through a modified preauricular approach

We describe our experience with reconstruction of the mandibular condyle with a costrochondral graft (CCG). We retrospectively evaluated 122 patients with diagnoses including osteoarthrosis, ankylosis, tumours, idiopathic condylar resorption, comminuted condylar fracture, and chronic osteomyelitis of the temporomandibular joint (TMJ). We used a modified preauricular approach and an endoscopically assisted technique. The grafts were followed-up by computed tomograms (CTs) and magnetic resonance (MR) examinations. All patients had successful reconstruction of the mandibular condyle with a CCG. No patient had permanent weakness of the facial nerve or any other severe complication. With its wide range of indications, the endoscopically assisted reconstruction of the mandibular condyle with a CCG through a modified preauricular approach can produce good aesthetic and functional results while reducing operating time and tissue damage.     

髁突纵行骨折与横断骨折的对比实验研究

目的 探讨幼年期髁突纵行和横断骨折对颞下颌关节的继发性影响。方法 中国实验用小型猪１４头,２－３月龄,分别造成左侧髁突纵行和横断骨折模型。在术后３个月与６个月进行肉眼和光镜观察。结果 髁突横断骨折引起ＴＭＪ的适应性变化,而髁突纵行骨折后ＴＭＪ形成明显的关节盘髁突粘连及双髁突畸形。光镜下显示：盘突 组织内可见大量成纤维细胞及软骨细胞,关节盘内出现血管及脂肪细胞。结果 幼年期髁突纵行与横断骨折对ＴＭＪ     

髁状突游离再植颞下颌关节重建术治疗髁突颈部骨折

目的:介绍髁状突游离再植行颞下颌关节重建术治疗髁突颈骨折的方法与疗效。方法:对12例伤员16侧髁突颈骨折行髁状突游离再植克氏针内固定术,术后定期行X线片及CT检查。结果:全部伤口一期愈合,追踪1～4年无关节疼痛、弹响及明显功能障碍,有3例面神经颞支损伤,2例轻度错畸形,影像学示髁状突形态多稍小且不规则。结论:本方法操作简便、损伤较轻、复位准确、固定可靠,并发症较少且轻微,适用于有严重移位的髁突颈骨折,髁状突的形态改变与长期影响需继续观察     

Histologic analysis of costochondral and sternoclavicular grafts in the TMJ of the juvenile monkey

Variability in growth response of the mandible after replacement of the mandibular condyle with the costochondral junction of a rib (CCJ) is common. Other donor graft sites that are more similar to the mandibular condyle might be more suitable for mandibular condylar replacement. Previous studies have shown the histomorphologic and developmental similarities between the sternoclavicular joint (SCJ) and temporomandibular joint (TMJ). The purpose of this study was to evaluate histologically short-term adaptations within the TMJ after replacement of the mandibular condyle with the autogenous sternal head of the clavicle, and to compare these adaptations with autogenous CCJ and mandibular condyle (surgical control) transplants. Bilateral vertical ramus osteotomies were performed in 12 juvenile Macaca mulatta with the left condyle being immediately replaced and the right condyle removed and replaced with either the sternal head of the clavicle or costochondral junction of a rib. All grafts were stabilized with maxillomandibular fixation for five weeks. Two animals in each group were killed at five, 11, and 17 weeks postsurgery and prepared for histologic analysis. The results indicate that: 1) incorporation of all grafts into the recipient site occurred and all animals had good mandibular function and occlusion throughout the follow-up period; 2) the clavicular and mandibular condylar grafts were incorporated sooner than the CCJ grafts; 3) clavicular graft changes resembled those of the condylar grafts histologically while the costal grafts remained inert and unchanged; and 4) a new condylar process with cartilage similar to that of a normal mandibular condyle regenerated in the costal graft animals from cells presumably contributed by the periosteum of the mandibular ramus and TMJ capsule.(ABSTRACT TRUNCATED AT 250 WORDS)     

Change in condylar and mandibular morphology in juvenile idiopathic arthritis: Cone Beam volumetric imaging

AIM: The aim of this study was to show the importance of Cone Beam Computerized Tomography (CBCT) to volumetrically quantify temporomandibular joint (TMJ) damage in patients with juvenile idiopathic arthritis (JIA), measuring condylar and mandibular real volumes. Methods. Thirty-four children with temporomandibular involvement by JIA were observed by CBCT. Four were excluded because of several imaging noises. The mandible was isolated from others craniofacial structures; the whole mandibular volume and its components' volumes (condyle, ramus, emibody, emisymphysis on right side and on left side) has been calculated by a 3D volume rendering technique. Results. The results show a highly significant statistical difference between affected side volumetric values versus normal side volumetric values, above all on condyle region (P<0.01), while there was no statistical difference between right versus left side. Conclusion. The CBCT represents a huge improvement in understanding of the condyle and mandibular morphological changes, even in the early stages of the JIA. In children the JIA can lead to TMJ damage with facial development and growth alterations.     

Mandibular advancement using a retrocondylar cartilage graft: a 20-year prospective study

We examined the outcome after a mean of 46 months (range 18-204) of 73 patients with severe mandibular retrusion who had surgical advancement of the mandible by a post-condylar cartilage graft. The extent of the mandibular advance and the change in position of the condyle were measured by a previously described cephalometric method. Tomograms of the temporomandibular joint (TMJ) were taken at defined intervals and any changes in the articulation recorded. The mandible was advanced by a mean (S.D.) of 9.8 (3.4) mm. The mean postoperative change recorded on the final cephalometric radiograph was 0.4 (4.7) mm forward (95% CI -0.70 to+1.50). The mandibular condyle was advanced horizontally by a mean 7.2 (2.1) mm and depressed vertically by a mean of 5.9 (2.6) mm. postoperatively the condyle relapsed horizontally by a mean of 1.5mm and moved vertically downward by a mean of 0.2mm. Eleven patients had substantial skeletal relapse. Eight patients were regarded as clinical failures. Skeletal relapse did not always lead to clinical failure because of compensatory mandibular growth. Changes in the condylar region, which contributed to relapse, included condylar absorption and remodelling (n=7) and absorption of the cartilage graft (n=6). There were no postoperative functional problems with the TMJ. We conclude that the post-condylar cartilage graft is a useful technique for the treatment of certain cases of mandibular retrusion. The postoperative morbidity was less than that reported after other techniques of mandibular advancement including distraction. Skeletal relapse was found in more cases than clinical results had suggested.     

Spatial deviations of the temporomandibular joint after oncological mandibular reconstruction

Spatial deviations of the temporomandibular joint (TMJ) after oncological mandibular reconstruction are important to the aesthetic and functional rehabilitation. The aim of this study was to clarify whether and how three dimensionally (3D) printed patient-specific surgical plates, and the preservation of the condyle or ramus, affect spatial deviations of the TMJ. A total of 33 patients who underwent mandibular reconstruction via computer-assisted surgery were included. Regarding absolute deviations, patients in the 3D-printed plate group showed smaller TMJ deviations compared to those in the conventional plate group. There was no difference in absolute deviations of the TMJ regardless of whether the condyle or ramus was preserved. Regarding physiological deviations, the impact on the contralateral TMJ was smaller in the 3D-printed plate group. Patients with both the condyle and ramus removed had significantly higher deviations of the condyle and joint space. In summary, 3D-printed patient-specific surgical plates improved the spatial accuracy of the TMJ. Under physiological conditions, TMJ deviations on the operated side were mainly affected by the preservation of the condyle. Removal of both the condyle and ramus caused more severe spatial interference to the TMJ; this should be further confirmed.     

Temporomandibular joint condyle changes after surgically induced non-reducing disk displacement in rabbits: a macroscopic and microscopic study

Experimentally induced displacement of the temporomandibular joint (TMJ) disk has previously been shown to induce shortening of the mandibular ramus on the ipsilateral side. The aim of this investigation was to reveal whether this shortening develops due to primary influence on condyle growth or by secondary loss of condyle mass due to degenerative tissue breakdown. Disk displacement was created in the right TMJ in seven 3-month-old rabbits, the posterior disk attachment kept intact. Seven rabbits underwent surgical opening of the TMJ without disk intervention. Seven additional animals served as references. After a 3-month experimental period, the animals were sacrificed. Previous analysis revealed shortening of mandibular height and length caused by ipsilateral TMJ disk displacement. The condyles were examined macroscopically and by histologic sectioning or scanning electron microscopy. All condyles were covered with smooth articulating soft tissue and without visible signs of degenerative changes. Four condyles from joints with disk displacement demonstrated substantial regressive remodeling resulting in a change of condyle shape with forward/downward rotation of an enlarged articulating surface. It was concluded that TMJ disk displacement in a growing individual can induce reduction of mandibular height and length before a stage where visible osteoarthrotic changes develop. It implies a primary adverse effect on condyle growth.     

Surgical treatment of osteochondroma of the mandibular condyle in the adult. A 5-year follow-up

Five adult patients with temporomandibular joint (TMJ) pain and impaired mandibular function and with clinical and radiographic features of unilateral osteochondroma of the mandibular condyle was included in a 5-year prospective follow-up study. All patients were surgically treated with condylectomy and reshaping of the condylar neck which was then positioned underneath the preserved TMJ disk. The yearly follow-up evaluations comprised measurements of maximum interincisal opening and protrusive movements, assessments of occlusion and TMJ pain as well as tomographic interpretation of recurrent growth. No patient showed recurrence of growth at the 5-year follow-up and mandibular function and occlusion was normalized in all patients. The results indicate that this conservative surgical approach can be recommended for treatment of osteochondroma of the mandibular condyle.     

Posterior dislocation in intact mandibular condyle: an unusual case

Dislocation of the temporomandibular joint (TMJ) represents 3% of all reported dislocated joints. Traditionally, dislocation of the TMJ occurs when the mandibular condyle is displaced anteriorly beyond the articular eminence. Traumatic dislocation of the condyle into the middle cranial fossa is well defined in the literature, but posterior dislocation without fracture is rarely described. This report documents a case of young male with posterior dislocation of the intact mandibular condyle after facial trauma. The clinical symptoms, diagnosis and treatment are discussed, and a critical review of the literature is provided.     

Arthroscopic eminoplasty for habitual dislocation of the temporomandibular joint: preliminary study.

A unique surgical technique, arthroscopic eminoplasty was undertaken in 16 joints of 11 patients with habitual dislocation of the temporomandibular joint (TMJ). There were 10 joints with subluxation and 6 joints with complete dislocation in 4 male and 7 female patients with a mean age of 33 +/- 20 years. The procedure consisted of conventional diagnostic arthroscopy, followed by shaving of approximately 3 to 5 mm in height of the articular eminence with an electric motorized shaver with bone files, depending on the bone thickness as detected by preoperative imaging. The arthroscopic eminoplasty was accomplished without any peri- or postoperative complication. During the postoperative follow-up period of 19 months on average (6-36 months), all patients were free of dislocation of the TMJ, except for one joint. The patients could open their mouth 42 +/- 6 mm without arthralgia 2 weeks after surgery, and finally 47 +/- 7 mm without any subjective symptom but small joint noises (clicking or crepitus) in 10 joints. On postoperative radiographs only minor changes of the mandibular condyle were apparent in four joints. Arthroscopic eminoplasty might become a significant procedure for habitual dislocation of the TMJ and seems to produce results comparable to open arthrotomy. Further study will be required to assess this method as an acceptable modality in the future.     

Comparative study of the temporomandibular joint space in maximum intercuspation and canine edge-to-edge positions in deep bite and non-deep bite subjects

In order to study the relationship between morphological properties of the TMJ and the mathematically predicted force distribution in the TMJ, the geometric distribution of the joint space on top of the condylar surfaces was evaluated. Seven deep bite subjects and seven non-deep bite subjects were used, and the joint space in the maximum intercuspation and canine edge-to-edge positions was analysed in each group. Standardized images of the TMJ were taken with computed tomography (CT) using a mandible positioner. The comparative ratio of joint space (CRJS) between the maximum intercuspation and the canine edge-to-edge positions was calculated and summarized on the map of the mean morphological outline of the condyle. On the balancing-side condyle, the CRJS of small value was distributed mainly on the anterior edge of the condyle in the non-deep bite group, whereas, in the deep bite group, it was distributed on the centre of the condyle. On the working-side condyle, the small CRJS was distributed around the lateral pole of the condyle in the non-deep bite group, whereas, in the deep bite group, it was found around the posterior part of the condyle. The distribution pattern of CRJS on the upper surface of the condyle in the non-deep bite group was consistent with the results of previous studies on mathematical simulation of TMJ loading. From the results of this study, it was suggested that the distribution of mechanical loading on the TMJ in the eccentric mandibular position would be highly affected by the comparative ratio of joint space. As the comparative ratio of joint space would be highly affected by the condylar position, the analysis of the morphology of the TMJ in relation to mechanical joint loading, in a future investigation, should be carried out on specific mandibular positions in relation to the function of the TMJ to be studied.     

血管化腓骨肌瓣下颌骨重建中髁突不同处理方法对颞下颌关节功能的影响评价

目的 对髁突采用不同处理方法的血管化腓骨肌瓣下颌骨缺损重建后评价患者的临床及颞下颌关节(TMJ)功能状态.方法 患者41例,其中男性21例,女性20例.41例均为累及下颌升支上部且未超过下颌中线的颌骨良性病损,其中应用腓骨替代髁突法重建24例、游离髁突法重建5例、保留髁突法重建12例.采用Fricton TMJ功能量表评价患者术后的TMJ功能,并进行统计学分析.结果 所有患者均未发生关节强直,术后最大开口度31～53 mm,平均值(42.8±5.7)mm.不同术式患者术后面部外形、进食及语音功能比较,差异无统计学意义(P＞0.05);但患者的TMJ功能指数,即功能障碍指数(dysfunction index,DI)及功能紊乱指数(cramiomandibular index,CMI)间比较,差异有统计学意义(P＜0.01).保留髁突组患者的TMJ功能优于腓骨替代髁突组.结论 保留髁突的血管化腓骨瓣下颌骨重建有助于恢复TMJ功能;以腓骨瓣末端替代髁突进行下颌骨重建时,重建髁突的位置和形态对于TMJ的功能有明显影响.     

腭裂引起反的前牵引与下颌髁突位置关系的初步研究

目的　评价应用口外弓加面具对唇腭裂继发骨性反牙合畸形进行早期阻断性治疗后 ,下颌骨髁突位置的变化。方法　对 8例患者治疗前和治疗 6个月的薛氏位片进行分析 ,比较颞下颌关节 (TMJ)前、上、后间隙的宽度。结果　治疗前后双侧TMJ的 3个间隙均无明显改变 (P >0 .0 5 )。结论　应用口外弓加面具作上颌骨前牵引后 ,未发现髁突位置的明显改变。     

Autogeneous coronoid process as free graft for reconstruction of mandibular condyle in patients with temporomandibular ankylosis

Objective

This study was conducted to determine the efficacy of using the autogeneous coronoid process as free graft for reconstruction of mandibular condyle and to achieve structural, functional, as well as esthetic rehabilitation of patients with temporomandibular joint (TMJ) ankylosis.

Materials and Methods

This article presents the clinical results of an evaluation of ten cases of TMJ ankylosis treated by using autogeneous coronoid process as free graft for reconstruction of mandibular condyle after resection of ankylotic mass.

Results

Satisfactory mouth opening were obtained in all ten cases. No patient showed signs of re-ankylosis at 12 months follow-up. Preoperative mouth opening ranged from 0 to 15 mm with mean being 4.8 mm. As a result of successful procedure, the immediate postoperative mouth opening increased ranging from 24 to 31 mm (mean, 26.5 mm). Follow up of patients at the first and 12th month showed good results with increase in mouth opening from a range of 24 to 31 mm (mean, 27.8 mm ) to 26 to 36 mm (mean, 33.13 mm).

Conclusion

The results of this study suggest that the autogeneous coronoid process as free graft is a suitable graft material for reconstruction of mandibular condyle after resection of ankylotic mass.     

Histologic comparison of the costochondral, sternoclavicular, and temporomandibular joints during growth in Macaca mulatta

The costochondral joint (CCJ) is commonly used to replace defective mandibular condyles in children for the restoration of normal temporomandibular (TMJ) growth and function. However, continued and harmonious growth following rib grafting is the exception rather than the rule. This may be due to the differences in the growth characteristics of the costal cartilage and the condyle. A joint that is similar both developmentally and structurally to the TMJ is the sternoclavicular joint (SCJ). The purpose f this study was to describe histologically the SCJ and CCJ during growth in Macaca mulatta and to compare the histomorphologic features with those of the TMJ. Costochondral and sternoclavicular joints were obtained from infant, juvenile, adolescent, and adult Macaca mulatta. The histologic sections were compared with mandibular condyles of the same ages available in our laboratory. The results indicate that the TMJ and SCJ are very similar morphologically throughout the growth period. The clavicular head contained layers of cartilage typical of the mandibular condyle, i.e., articular, prechondroblastic, chondroblastic, hypertrophic, and endochondral ossification layers, at each age during growth. Like those in the condyle, the hypertrophic cartilage cells were arranged in an apparently random, noncolumnar fashion. The CCJ, however, did not resemble the condyle but appeared to be more similar to the growth plate in a long bone epiphysis during growth. The results of this investigation indicate that the SCJ may be more suitable for mandibular condylar replacement than the CCJ.     

Fate of Free Fat Dermis Graft in TMJ Interpositional Gap Arthroplasty: A Long Term MRI Study

Introduction

Free fat dermis graft is a good interpositional material for TMJ gap arthroplasty. Analysing the fate of the graft by magnetic resonance imaging (MRI) images helps in excellent visualization of both bony and soft tissue anatomy of the operated TMJ joint as well as in assessing the changes in dermis graft which was previously placed.

Purpose of this Study

To investigate the radiological fate of the dermis-fat graft within the TMJ using MRI.

Materials and Methods

Five joints of five patients who had dermis-fat grafts placed in their TMJ following gap arthroplasty were recruited for this study. Each patient had undergone TMJ gap arthroplasty with immediate dermis-fat graft placement. All the patients are then subjected to MRI.

Results

Fat graft was identified in close proximity to the mandibular condyle in all cases, with only three joints demonstrating fat covering the entire articular surface of the mandibular condyle. In the remaining joints the interpositional material found in the MRI defined joint space with mainly grey appearance, suggesting tissue change to other than fat, i.e. scar or granulation tissue.

Conclusion

When free fat dermis graft is placed as interpositional material the graft occupied the entire TM joint and prevented it from recurrent ankylosis. The graft placed aids in normal functioning of the temperomandibular joint without any complications.