Rare case of superolateral dislocation of the condyle

Background

Dislocation of the mandibular condyle occurs most commonly in the anterior direction. When there is an intracranial displacement of the condyle, it is often associated with CSF leak. Superolateral dislocation of the condyle from the glenoid fossa is a rare condition which commonly occurs following traumatic insult to the mandible. When there is a superlolateral displacement, the condyle is often lodged in the temporal fossa.

Case report

We report an unusual case of a 50-year-old male with a superolateral dislocation of the left mandibular condyle into the zygomatic arch along with a fracture of the right mandible following road traffic accident. Manual reduction of the condyle was first attempted under general anaesthesia which was futile, following which the displaced condyle was reduced by a combination of open traction and manual reduction using Keen’s approach in left maxillary vestibule. After reduction of the condyle, intermaxillary fixation (IMF) was done and X plate was used to fix the mandible fracture on the right body. Postoperatively, patient was placed on IMF for a period of 2 weeks.

Discussion

Superolateral dislocations of the condyle can be unilateral or bilateral. These types of dislocations generally occur following traumatic injury to the mandible when the mouth is open. Early diagnosis and reduction of the condyle is required to achieve satisfactory occlusion which should be followed by physiotherapy to prevent ankylosis.     

Treatment of habitual temporomandibular joint dislocation with miniplate eminoplasty: a report of nine cases

Eminoplasty using T-shaped titanium miniplate was performed on 15 joints in nine patients suffering from recurrent dislocation of the temporomandibular joint with several general complications. After the conventional pre-auricular approach to the zygomatic arch and eminence, the bent over miniplate was inserted anteriorly against the articular eminence and fixed to the zygomatic arch with miniscrews to limit the over-movement of the condyle. In one case, the miniplate fractured, but no recurrence of dislocation was observed. In another case, it was possible to evaluate the mandibular movement by Sirognathograph analysis, which proved satisfactory function of the joints.     

The use of TMJ Concepts prostheses to reconstruct patients with major temporomandibular joint and mandibular defects

Temporomandibular joint (TMJ) reconstruction may be required in complex cases in which there are additional mandibular or zygomatic arch defects. The reconstructive options include autogenous tissue, alloplastic material, or combinations of these. The authors describe 4 cases in which TMJ reconstruction was performed with TMJ Concepts customized joint prostheses. The prosthetic components were designed to restore major defects in the zygomatic arch and the mandibular ramus and body, including one case in which the mandibular component was used to restore total mandibular continuity. The prosthetic components used in these cases provided excellent anatomical reconstruction, and were a viable treatment option in cases in which the pathological process made autogenous grafts unsuitable. The prostheses have been functioning for up to 6 years. In one case a revision operation was required because the lack of a pterygomasseteric sling resulted in the condyle dropping out of the fossa. The authors’ clinical experience with these cases suggests that a customized prosthesis combined with TMJ reconstruction can be a reliable treatment alternative for bridging complex, major maxillo-mandibular defects.     

Craniomandibular bone density in the primate as assessed by computed tomography

Ten normal rhesus monkeys, five juvenile and five adult animals, were analyzed for symmetry in bone density across the cranioskeleton with computed tomography (CT). Fifty contiguous axial CT scans were done using 1.5-mm thick scans between the lower mandibular border and inferior orbital ridge, and 3-mm thick scans from the inferior orbital ridge to the rostral level of insertion of the temporalis muscle. Eleven regions comprising areas of the lower mandibular border, lower ramus, upper ramus with condyle, the coronoid process, the zygomatic arch, and cranial bone were analyzed for symmetry using small regions of interest. Only one region, the condyle, demonstrated a statistically significant difference between the two sides with all other measured sites demonstrating the same bone mineral density bilaterally. Large area analysis of five regions--the lower mandibular border, upper ramus with condyle, the coronoid process, the zygomatic arch, and upper cranium--demonstrated no significant difference in the distribution of CT numbers. This analysis of bilateral distribution of bone density in the primate craniofacial skeleton demonstrates a basic symmetry that can be used to study altered patterns of neuromuscular function and their effects on bone density.     

Osteochondromas associated with facial asymmetry and masticatory dysfunction: report of two cases.

Two cases of solitary osteochondromas interfering with mandibular motion are presented along with a brief review of the literature. A single incidence of an osteochondroma developing from the mandibular condyle is added to the growing number of case reports. In addition, an osteochondroma developing from the zygomatic arch is reported. Our review of the literature has shown no previous report of occurrence at this site.     

Accessory mandibular condyle at the coronoid process

Coronoid process hyperplasia is a rare cause of mandibular hypomobility. It can result from temporalis muscle hyperactivity, trauma, and neoplasia, but often is idiopathic. Enlargement of the coronoid process leading to pseudojoint formation with the zygomatic arch is known as Jacob's disease. It results most commonly from an osteochondroma of the coronoid process. This is the first reported case of a non-neoplastic accessory mandibular condyle located at the coronoid process articulating with the zygoma.     

Dautrey's procedure: an alternative for the treatment of recurrent mandibular dislocation in patients with pneumatization of the articular eminence

Temporomandibular joint (TMJ) dislocation is an involuntary forward movement of the mandible beyond the articular eminence with the condyle remaining stuck in the anterior-most position, leaving the patient unable to close their mouth. Conservative treatment for this condition includes the injection of sclerosing agents or the intramuscular administration of botulinum toxin type A, while surgical therapy requires either removal or augmentation of the articular eminence. Once the surgical treatment plan has been determined, pneumatization of the articular eminence may turn a relatively simple procedure into a great surgical challenge. We present herein the cases of two patients suffering from recurrent mandibular dislocation who happened to have pneumatization of the articular eminences. Both patients were treated with a down-fracture of the zygomatic arch, known as Dautrey's procedure, modified by the application of a miniplate connecting the displaced arch and the lateral portion of the articular eminence. Neither patient had suffered a new episode of dislocation at their most recent postsurgical visit.     

Mechanical analysis of the malformed, yet functional, mandibular joints of a wild timber wolf, Canis lupus

In spite of grossly malformed jaw joints, presumably from birth, the animal survived in the wild for at least 3 years. Instead of a deep glenoid fossa folded over a cylindrical condyle to form a hinge, both joints had freely open articulating surfaces and a mandibular condyle without neck. The neckless condyle produced a shorter moment arm of resistance in all biting positions. The moment arm of the masseter, the jaw-adductor tending to disarticulate the jaw, was longer as a result of an elongated angular process. The combined effect at the carnassials was a 36 per cent improvement in the efficiency of the lever for which the joint is the fulcrum and thus an equivalent reduction in the disarticulating force. The joints were held together by an extra stout ligament about 5 mm in diameter and 8 mm long, linking the lateral pole of the condyle to the zygomatic arch.     

“Management of recurrent temporomandibular dislocation using orthodontic traction screws.”

Temporomandibular joint dislocation is defined as the loss of joint congruency between the mandibular condyle and the glenoid fossa of the temporal bone. Multiple therapeutic options have been proposed for the treatment of recurrent TMJ dislocation. The aim of this paper is to present two recently treated cases with a modification of Wolford's technique, replacing the Mitek anchors with orthodontic screws. Case series: The first case concerns a 36 year-old women with recurrent temporomandibular dislocation, and the second one a 26 year-old patient with the same diagnosis. In both cases, one 8mm orthodontic screw was placed in the lateral pole of mandibular condyle, sutured with PremiCron® 2/0 to a hole made in the root of each zygomatic arch. At twelve-month follow-up (first patient) and at six-month follow-up (second patient), patients had not presented new episodes of mandibular dislocation and mouth opening range remained stable.This technique can be considered as an alternative to Wolford's technique in treating recurrent temporomandibular dislocation when conservative management fails.     

Mitek anchors for treatment of chronic mandibular dislocation.

OBJECTIVE: The purpose of this study was to present a new technique for limiting mandibular translation in patients with chronic mandibular dislocation. TECHNIQUE DESIGN: This relatively simple procedure uses 2 Mitek mini bone anchors with osseointegration potential. One anchor is placed in the lateral pole of the condyle, and the other is placed in the posterior root of the zygomatic arch. Heavy suture material is threaded through the eyelet of each anchor and tightened to function as a restraining ligament. RESULTS: This technique has been used on 5 patients with a follow-up of 2 to 4 years, with no failures. CONCLUSIONS: This technique provides an effective method for the prevention of condylar dislocation while permitting some controlled translation.     

Treatment of fractures of zygomatic bone and zygomatic arch. A method for the reduction of fracture by the use of U-shaped elevator

The occurrence of maxillofacial bone fractures has gradually increased. These were two-hundred-fifty-nine cases of maxillofacial bone fractures from 1981 to 1988, in which fourteen cases were fractures of zygomatic bone and zygomatic arch. (The number of the fractures of zygomatic bone, zygomatic arch, zygomatic bone and arch, and zygomatic bone and mandibular bone were 5, 2, 4, and 3 cases, respectively). Pathognomonic symptoms were infra-orbital neuroparalysis, tristmus and recess of the buccal region. The incisional for open reduction were applied for the lateral brow, the lower eyelid, or intra-oral approach. U-shaped elevator was used for the reduction and miniplate and stainless wire were used for fixation.     

The zygomatic arch and its possible influence on craniofacial growth and development.

This study was designed to investigate the role of the zygomatic arch and craniofacial growth along the anteroposterior axis. One may conclude that: 1. Surgical intervention on the zygomatic arch results in a generalized inhibition of regional zygomatic arch growth. 2. When only one zygomatic arch is sectioned, the posterior root of the sectioned side appears to be displaced posteriorly. This is a possible result of the normal growth process proceeding without the restraints of an intact zygomatic arch. 3. A decrease in anteroposterior dimension occurs in the posterior zone as a result of surgical intervention. 4. Further studies to determine the influence of the zygomatic arch on transverse maxillary growth must be completed before any clear or complete concepts of its role in craniofacial growth and development may be more fully elucidated.     

Human masticatory muscle volume and zygomatico-mandibular form in adults with mandibular prognathism

Although several investigators have reported associations between masticatory muscles and skeletal craniofacial form, there is no agreement on the association. We tested the hypothesis that masticatory muscle volume correlates with the size and form of the adjacent local skeletal sites. For this purpose, we investigated the morphological association of the cross-sectional area and volume of temporal and masseter muscles with zygomatico-mandibular skeletal structures using computerized tomography (CT) in 25 male adults with mandibular prognathism. Muscle variables significantly correlated with widths of the bizygomatic arch and temporal fossa but not with the cranium width. Masseter volume significantly correlated with cross-sectional areas of the zygomatic arch and mandibular ramus. Masseter orientation was almost perpendicular to the zygomatic arch and mandibular antegonial region. The zygomatic arch angle significantly correlated with the antegonial angle. The results of the study suggest that the masticatory muscles exert influence on the adjacent local skeletal sites.     

Mechanical properties of the periosteum in the pig,Sus scrofa

The fibrous periosteum forms an intermediary between muscle and ligament forces and the underlying osteoblastic tissue, thus the mechanical properties of the periosteum are critical to understanding osteogenic stimuli. Regional and directional variation in periosteal properties may contribute to the biomechanical regulation of growth in some bones. Periostea of the pig mandibular body, zygomatic arch and metacarpal were loaded to failure under continuous tension. Each tissue type was tested in both the long-axis and transverse orientation. Stiffness, peak stress and peak strain were compared between orientations and among regions. Within the zygomatic periosteum there was little indication of regional difference, and neither zygomatic nor mandibular periosteum showed directional differences. The metacarpal periosteum showed a directional effect only in peak strain, which was greater longitudinally than transversely. There were striking differences, however, among the periostea of the three bones. The zygomatic arch periosteum was the stiffest tissue (91.7+/-30.5 MPa) and showed the highest strength (12.3+/-4.6 MPa). The metacarpal periosteum demonstrated slightly lower stiffness and strength (84.7+/-35.1 and 11.3+/-5.3 MPa), and peak strains in zygomatic and metacarpal periostea were similarly high (17.7+/-3.7 and 17.9+/-3.7 MPa, respectively). The periosteum of the mandibular body was the most deformable tissue (63.0+/-25.4 MPa), with the lowest-peak strain (15.6+/-3.0 MPa) and the least strength (8.2+/-4.1 MPa). These results correspond with those of previous work in long bones, in that periosteum interfacing with ligament or muscle (e.g. zygomatic, metacarpal) demonstrates greater stiffness and strength than periosteum adjacent to loose connective tissue (e.g. mandibular body). Therefore, the degree to which the periosteal tissue serves as a functional interface between bone and muscle is reflected in the different failure properties of periostea from different bones. The structural fortification of the zygomatic arch periosteum relative to other periosteal tissues suggests a role for the periosteum in stabilizing the zygomatic arch-muscle functional complex. On the other hand, the similar failure properties of zygomatic and squamosal periostea from the zygomatic arch mean that the differential growth of these bones cannot be attributed to mechanical stimuli intrinsic to the periosteal tissue.     

Superolateral Dislocation of Bilateral Intact Mandibular Condyles: A Rare Case Series

Background and Purpose

The dislocation of mandibular condyle is a clinical condition in which the head of condyle has been displaced out of the glenoid fossa. Complete dislocation of the mandibular condyle can occur in anterior, posterior, lateral and superior direction. Among these dislocations, bilateral superolateral dislocation of mandibular condyles is quite rare and often misdiagnosed. Because of its rare occurrence and unusual clinical course, the best treatment is debatable.

Patients and Method

We present the first case series of true bilateral superolateral dislocation of intact mandibular condyles (Type 2B) without fracturing the Zygomatic arch, associated with symphysis fracture.

Conclusion

This article intends to provide information regarding the possible biomechanics and management of bilateral superolateral dislocation of mandibular condyles associated with symphysis fracture.

     

Orthodontic Treatment and Implant‐Prosthetic Rehabilitation of a Partially Edentulous Patient

This article describes the treatment of a 61‐year‐old man who had a completely edentulous maxillary arch and partially edentulous mandibular arch. The patient was orthodontically treated to correct an anterior crossbite by distalization of the mandibular teeth using a removable prosthesis serving as an anchorage unit. Subsequently, the patient received two zygomatic implants, five conventional implants in the maxillary arch, and six conventional implants in the mandibular arch. By the end of treatment, the convexity of the facial profile improved, and esthetic and functional occlusion was established.     

Anterior Mandibular Repositioning in a Patient with Temporomandibular Disorders: A Clinical and Tomographic Follow-up Case Report

A 42 year old female with temporomandibular disorders (TMD) was treated by anterior mandibular repositioning which was followed-up clinically and tomographically. The authors tomographically reconfirmed the mandibular repositioning and discovered a type of condyle remodeling which they had not seen previously. Although clinical signs and symptoms of TMD were removed and the condyle was centered tomographically by the anterior repositioning, the MRI image indicated the disk was displaced anteriorly and laterally. The results suggest that image analysis of temporomandibular joint (TMJ) is beneficial and careful application of the treatment for anterior repositioning is recommended.     

Surgical treatment of fractures of the mandibular condyle: a comparison of long-term results following different approaches - functional, axiographical, and radiological findings.

AIM: While functionally stable osteosynthesis is a generally accepted method to treat all dislocated fractures of the skull, open reduction and rigid fixation of fractures of the mandibular condyle are still controversial. The risks involved in the surgical approaches and the difficulties during reposition are the main controversies. Improvements made in surgical access and osteosynthesis materials as well as the development of special instruments were the reasons for re-evaluating the surgical results. METHODS: Forty patients with displaced or dislocated fractures of the mandibular condyle were re-examined. In 20 patients (21 fractures) an intraoral approach, in 20 more patients (24 fractures) an extraoral perimandibular approach was applied. The results were compared by means of axiography and radiology as well as clinically with regard to function 6 months postoperatively. RESULTS: While almost all fractures were correctly reduced following application of an extraoral access, reduction was correct in only 50% of the patients treated with an intraoral approach. Re-displacement and complications during osteosynthesis were the reasons. The group of patients treated via the intraoral approach showed less favourable results radiologically, clinically, and as judged by the patients' subjective feelings. Especially axiographical examination of the latter fractures revealed a restricted translation indicating that the fractures had not healed primarily. CONCLUSION: In order to avoid complications, the only fractures which should be treated intraorally are those which allow exact reduction even under the conditions of a limited view and reduced possibilities of surgical manipulation during reduction. This applies in general to fractures of the mandibular condyle with a laterally displaced condyle and a shortened ascending ramus. For all other dislocated or displaced fractures, extraoral reduction and osteosynthesis are the methods of choice.     

Changes in zygomatic arch position following experimental lateral displacement

In order to obtain information about the stability of augmentation procedures in the area of the zygomatic arch, the zygomatic arch on one side was displaced laterally in eight rhesus monkeys by an osteotomy of the anterior portion of the arch and placement of an 8 mm bone graft obtained from the supraorbital ridge. The other side served as a control. The post-operative changes were studied on submento-vertex head films during a 24 month follow-up period. Three months post-operatively the amount of lateral displacement was reduced by 55%. During the next 9 months of follow-up only small changes occurred in the individual animals, and the mean values remained predominantly unchanged. Between 12 and 24 months the distance from the zygomatic arch to the midline increased with growth. On the control side this distance increased from three months on. At 24 months only 18% of the difference in width that was created by the surgical repositioning remained.     

Histopathological changes in rabbit craniomandibular joint associated with experimentally induced anterior disk displacement (ADD)

Several studies have shown that anterior disk displacement (ADD) of human temporomandibular joint (TMJ) can lead to cellular and extracellular alterations in the disk proper, bilaminar zone (BZ), condyle, articular eminence and synovial membrane. Due to lack of an animal model for this disease, it is not known whether the mechanical displacement of the disk could lead to the observed histopathological changes. The purpose of this experiment was to investigate the histopathological changes that occur in the rabbit craniomandibular joint (CMJ) following surgical induction of ADD. The right CMJ was exposed surgically and the discal attachments were severed except for the BZ attachments. Then the disk was displaced anteriorly and sutured to the zygomatic arch. The left joint served as surgical control. The CMJs were removed after 24 h, 1 week, 2 weeks or 6 weeks and stained with H&E or modified Masson stain. The results showed neovascularization, cell clustering and fibrillation of the displaced disk. The BZ showed marked fibrosis. The condyle showed subchondral hemorrhage and fibrosis followed by osteoarthritic changes in the articular cartilage. The articular eminence showed chondrocytic clustering and an increase in the amount of chon-droid bone. Synovial membrane exhibited marked hyperplasia. We concluded that surgical induction of ADD in the rabbit CMJ leads to cellular and extracellular alterations in the disk proper, BZ, condyle, articular eminence and synovial membrane similar to those described previously in human ADD. It appears that the mechanical trauma resulting from ADD could lead to a cascade of reparative and degenerative changes of the affected joints similar to those described for osteoarthritis.