[Changes in the temporomandibular joint after orthodontic interventions]

Temporomandibular joint alterations were reported which were determined on the basis of reproducible preoperative and postoperative roentgenograms. The films were produced with the help of the Hanel. C arch in the transcranial, lateral oblique projection. Displacements were demonstrated particularly in the anterior and the caudal directions. This method however does not allow a definite statement to be made concerning the postoperative position of the condyles.

[The effect of prognathism surgery on the temporomandibular joint. (A clinical and radiological evaluation of temporomandibular joint changes after various methods of surgery for prognathism)]

On the basis of clinical and roentgenologic examinations of progenia patients which were planned according to our occlusal concept and monitored postoperatively, we established that the condylar displacement in the roentgenogram offers an exact parameter for the extent of operative displacement of the condyles. Nevertheless, a direct conclusion concerning the clinical symptoms or freedom of complaints cannot be established on the basis of this roentgenographic analysis. The roentgenogram also showed considerable condylar alterations in patients with temporomandibular joint symptoms; greater displacement of the condyles was frequently demonstrable with temporomandibular joint complaints.

One more look at the mandibular condyle

A great deal of attention has been given over the years to the development of highly specialized x-ray equipment that, in many instances, has reduced the complex nature of the radiographic procedure. However, it is impossible, and probably always will be, to design equipment that will automatically produce the proper radiographic position. This will remain a distinct function of the technologist, and the individual's skill will have great bearing on the quality of the radiograph. One need only review the literature to realize how innovative our profession has been in developing countless numbers of radiographic positions for demonstrating specific anatomical regions. Moreover, many useful radiographic positions can be found that, for various reasons, never gained the level of acceptance perhaps anticipated by their originators. Consequently, the practical value of these positions often escapes our attention. To illustrate this point, I have selected a radiographic position described some thiry years ago for visualization of the mandibular condyle. It is my intent to demonstrate the practical value of this projection, as well as that of some others not usually thought of, for radiography of the mandibular condyle.

Temporomandibular joint marking for radionuclide bone scintigraphy

Anatomical marking of the temporomandibular joint has led to a practical method of delineating and evaluating the temporomandibular joint and glenoid fossa by radionuclide bone scintigraphy.

Splitting the condyle--a method of removing the condyle in cases of fibrous ankylosis

A method used to remove a fibrous ankylosed condyle is discussed. To overcome the complications of the conventional condylectomy, the risk of opening the neurocranium and laceration of the internal maxillary artery, the condyle is split in a latero-medial direction. Four patients have been operated upon successfully.

The validity of temporomandibular joint radiographs using the head positioner

1. TMJ radiographs made using the head positioner provide a valuable adjunct to diagnosis and treatment planning for patients with MPD syndrome. 2. Where extensive restorative procedures are anticipated, TMJ radiographs can be useful before embarking on a treatment plan and in documenting the postoperative results. 3. Bilateral condylar symmetry is a reasonable objective of extensive restorative dentistry. 4. Radiographic retrusion is more frequently accompanied by signs and symptoms than bilateral condylar symmetry and protrusion.

Limits of perceptibility of condyle displacements on temporomandibular joint radiographs

The present study investigated to what extent condyle positions have to be different from each other in order to be clearly detectable under clinical conditions on serial radiographs of the temporomandibular joints in identical projection. For that purpose of ten test subjects serial radiographs in optimal lateral oblique and identical projection were made with various positions of the joint. The joint was brought to these positions by displacement of the mandible to an exactly known extent with a special device. Evaluation showed that mean differences between condyle positions of 0.61 +/- 0.16 mm can be recognized clearly. It was statistically proved that this value did not depend upon the experience of an examiner in reading radiographs but upon the technical quality and the interpretability of the radiographs as well as upon the radiographic dimension of the posterior joint space.

[Radiological examination of the temporo-mandibular joint. Basic principles (author's transl)]

Radiological examination of the temporo-mandibular joint remains technically difficult. Standard views using usual X-ray techniques are inadequate. Preference must be given to selective tomography (sagittal, frontal or even axial) after determination of the axis of the condyles on a Hirtz position film. In certain cases, arthrography may also make it possible to define the contours of joint surfaces not seen on plain films. Radiocinematography is little used.

Inferior joint space arthrography and characteristics of condylar paths in internal derangements of the TMJ

Inferior joint space arthrography and measurements of the condylar path provide scientific documentation of derangement of the TMJ disc and condyle. These derangements are described as an anterior displacement of the disk associated with posterior-superior displacement of the condyle when the teeth are closed into the intercuspal position. Clinical studies demonstrate that approximately 70% of a TMJ patient population present with some type or stage of these derangements. These observations have far-reaching implications regarding contemporary dental curriculum, particularly concerning exegesis of the MPD syndrome theory and concepts of dysfunctional dental occlusion.

Facial asymmetries following unilateral condylar replacement. An experimental study in monkeys using metatarsal transplants

The aim of the present study was to evaluate qualitatively and quantitatively the effect of metatarsal transplantation on the mandibular condylar region. Two series of experiments were performed in four groups of Rhesus monkeys, a fifth group served as a nonoperated control group. The surgical procedures involved either the condyle and part of the ramus or the condyle only. Following the postoperative observation period the skulls of the animals were examined macroscopically, measured anthropologically and measured indirectly on vertical cephalograms. A new method developed by the authors for description of facial asymmetries was used. In all of the operated animals well-functioning joint structures were revealed, though all experimental groups showed the classical deformation features. Continued growth of the transplant was observed in only one case. The facial asymmetries were described as angular deviations from the true symmetry axis. No significant difference between the transplant and the corresponding nontransplant groups was detected for the two kinds of resection performed. However a difference in the degree of asymmetry between the ramus resection group and the condylectomy group was seen. It is concluded that a metatarsal transplant does not prevent the development of facial asymmetry following plain condylectomy or resection of the posterior third of the ramus of the mandible including the condyle.

Centric relation. Its effect on occluso-muscle harmony

The most common cause of pain in the region of the temporomandibular joint is occluso-muscle imbalance. This results most often from disharmony between the articulation of the teeth and the centric relation of the condyles. Muscle tenderness of palpation indicates that muscle is involved. An examination must then be done to determine the cause of the muscle tenderness. Before the condyle-occlusion relationship can be evaluated, an accurate centric relation must be determined and verified. The condyles are in centric relation when they are in the most superior position possible in the fossae. From that apex of force position, the condyle can travel neither forward nor backward without moving downward. This position can be located with careful bilateral manipulation and then verified if it can resist firm pressure with no tension or tenderness. Until this correct centric relation is located and verified, it is not possible to properly evaluate the occlusal relationship to the temporomandibular joints. If the occlusion is harmonized to a centric related condyle that can resist firm pressure with pressure with no discomfort, there will be no reason for the muscles to protect either the teeth or the joints. If an occlusion is adjusted to a malrelated condylar position, the occluso-muscle imbalance will be perpetuated and often intensified. Centric relation is the starting point of occlusal contact. Incline interferences in excusive movements must also be eliminated and the occlusion must be harmonized to the envelope of function for each patient. If centric relation is not properly located, occlusal interferences will remain regardless of what procedures are used to record or adjust excursive movements.

Sagittal splitting of the mandibular ramus. Electromyography and radiologic follow-up study of temporomandibular joint function in 44 patients

A follow-up study was performed on 44 patients operated with sagittal splitting of the mandibular ramus for correction of a mandibular protrusion. The study included clinical examination, electromyography and masticatory efficiency test as well as radiography of the temporomandibular joint. The maximum opening capacity and protrusion of the mandible decreased one to three years after the operation. The activity of the temporal muscle decreased in rest position after the operation. Masticatory efficiency was unchanged. The position of the condyle in the fossa was unchanged postoperatively, while a posterior and superior condylar movement occurred during the fixation period. Normalization of the condylar position tended to occur one year after the operation. In 37 of 86 condyles, a double contour was seen on the postesuperior margin of the condyle one year after the operation. Possible mechanism behind the development of the new condylar bone layer is discussed.

Surgical correction of mandibular prognathism by the oblique sliding osteotomy. A clinical and radiological follow-up study of 112 consecutive cases

The oblique sliding osteotomy has been used for surgical correction of mandibular prognathism, sometimes in combination with open bite, in 112 patients treated from 1969 to 1978. The method has proved to be connected with few surgical complications and minimal relapse tendency. No correlation was found between the degree of posterior positioning or closure of open bite at the operation and relapse tendency. Consequently no limitations in the field of application concerning the degree of mandibular protrusion or open bite have been found in this study.

An unusual case of acquired unilateral condylar hypoplasia

A case is described of acquired unilateral condylar hypoplasia, in which the right condyle seemed to have been fractured at an early age. There is evidence to suggest that the unresorbed condylar remnant persisted in the glenoid fossa and that a new condylar head had developed anterior to the articular emminence. This 'new head' showed a carrot-shaped radiolucent wedge suggestive of the condylar growth cartilage and, clinically, exhibited some growth potential. A complex composite odontome present in place of the mandibular right third molar may also have been caused by this early trauma.

Use of a miniaturized detector in facial bone scanning

A high resolution cadmium telluride probe was used in conjunction with standard bone imaging methods in two cases of facial asymmetry. The probe improved localization of the abnormalities and led to rational treatment.

[A case of osteochondroma of the mandibular condyle]

A case of mandibular condyle osteochondroma is reported, special attention being paid to radiographic aspects and to the functional changes brought on by this neoplasia. Surgical and meta-operative treatment to correct residual latero-deviation and occlusal relations are described.

Treatment of fractures of the articular process by functional stable osteosynthesis using miniaturized dynamic compression plates

The application of miniplates in fractures of the base of the articular process, developed by Schilli for orbital stabilization of malar bone impression fractures, is reported. The ends of the fragments after open reposition and reduction of the proximal fragment could be fixed durably by functional stable compression osteosynthesis in 35 patients with fractures and luxation or dislocation. In spite of the technical difficulties in performing this operative method the procedure should find a large application because of the optimum anatomic and functional results.

Selective tomography of the TMJ and the myofacial pain-dysfunction syndrome

Tomography is the only technique that gives a precise representation of the temporomandibular articulation. To delineate a discrete impingement upon the articular space and compare before-and-after treatment modalities it is essential to strictly respect the angular criteria. Selective tomography can be accomplished only if three criteria are met: 1. To make an axial cephalogram perpendicular to the submental-vertical film and to measure the angle of the grand axis of each condyle with the median sagittal plane; 2. To orient the incident ray perpendicular to this axis for the sagittal sections and parallel for the frontal sections; 3. To be sure of the exact position of the head on the tomograph. The teeth also must be placed in maximum occlusal contact.

Histochemical and radiologic studies of the human fetal mandibular condyle

Histochemical investigations on the mandibular condyle were performed on 72 human embryos and fetuses of crown-rump lengths (CRL) ranging from 26 to 186 mm, representing skeletal maturity indices expressed in CNO values (CNO = composite number of ossified bones in the hand and foot) ranging from 0-0 to 19-12. The development of the mandibular condyle is described according to morphology and to histochemical reactions for glycosaminoglucuronglycans, collagen, glycogen, alkaline and acid phosphatase, and nonspecific AS esterase. The development is described for (1) the bony component of the mandibular condyle, (2) the condylar cartilage, and (3) the fibrous cover of the mandibular condyle. For each tissue component, maturation steps are set up and included in the total evaluation of the condylar maturity stages. The developmental sequence set up on the basis of the morphologic and histochemical findings was followed by all condyles investigated. From this it may be presumed that the developmental sequence in human mandibular condylar components is constant during the former half of the prenatal period. The material available did not justify a description of skeletal development in the mandibular condyle as a function of fetal size, CRL, or skeletal maturity in the hand and foot.

Multiple myeloma involving the temporomandibular joint: report of case

A case of multiple myeloma was reported in which the initial symptom was pain and dysfunction of the TMJ that resulted from pathological fracture of the mandibular condyle. An initial radiographic skeletal survey showed no evidence of further lesions, although hematological and biochemical tests indicated a diagnosis of multiple myeloma. Treatment resulted in improvement of symptoms and of an evident regression of the lesion after 18 months. After a year, however, radiographs disclosed generalized skeletal involvement; deterioration of the general condition followed.

Laminagraphic study of mandibular condyle position when recording centric relation

Laminagraphs were made of each temporomandibular joint of 20 subjects (1) with the mandible forcefully retruded to centric relation and (2) with the mandible positioned by a closing force while an anterior guidance prosthesis was being used. The radiographs were compared by measurements of condylar position; results indicated the condyles to be significantly more superior in the glenoid fossa when anterior guidance was used. The difference in anterior-posterior positioning of the condyles appeared to occur randomly. Measurements of the joint spaces with the mandible in centric relation using anterior guidance indicated that mandibular condyles were not centered in the fossae. There seemed to be a range in the size of the space that could be considered normal.

Histological and microradiographical studies of human mandibular condyle

Twenty-one clinically normal human mandibular condyles were examined by histologic and microradiographic methods obtaining some measurements. The histologic structures of condyle were quite different between the child group and other aged groups. The difference in the surface articular zone composed of the fibrous tissue was not so great in all age groups, while there was quite a difference in the structure in the remaining zones. It was clearly demonstrated by microradiogram that the osteons of the subarticular bone plate were more prominent in aging. Abnormal structures of the condyle were revealed in some individuals of the adult and old age groups, which were assumed probably to be the reactive remodelling against the functional changes of the temporomandibular joint.

Closed condylotomy in the treatment of recurrent dislocation of the mandibular condyle

Twenty-one patients 10-79 years of age were operated on for recurrent dislocation of the mandibular condyle using Kostecka's closed condylotomy method. The procedure alters the condyle position and will indirectly shorten the lateral pterygoid muscle, thus eliminating its pulling power to the condyle, even though it still functions. For the study, a late examination was performed with at least 1 year's follow-up. Seventeen patients were cured after unilateral or bilateral condylotomies, and two patients were asked to undergo a second operation on the opposite side. In normal cases any joint operated on was cured. Two cases suffering from congenital torticollis or disseminated sclerosis were felt to be unsuccessful. One exceptional case resulted in a pseudarthrosis, and was repaired by rib bone cartilage transplant. The method is the simplest and least traumatic when recurrent dislocation of the temporomandibular joint is treated surgically.

The concept of the sagittal condylar guidance: biological fact or fallacy?

The clinical concept of a sagittal condylar guidance pertaining to the human temporomandibular joint is discussed in the light of selected studies on the anatomy, radiography and cineradiography of this joint, and clinical attempts at recording a sagittal condylar guidance. It seems as if there is no single and well defined sagittal condylar guidance in vivo, and thus no single and well defined sagittal condylar guidance angle applicable to the adjustable articulator.

Bilateral mandibular condylysis-a morphanalytic diagnosis

Four cases of bilateral mandibular condylysis are presented. The condition does not appear to be included in current teaching or existing nomenclature and consists of an acquired absence of the mandibular condyles, unassociated with temporomandibular ankylosis or aural/facial anomalies. In the literature of condylar maldevelopment four published cases appear to justify reclassification as bilateral mandibular condylysis, bringing the recorded total to eight. Whereas previous writers have regarded the condition as a prenatal condylar aplasia or hypoplasia, morphanalysis studies of the four current cases have shown that the probable aetiology is postnatal local disturbance in the condylar region. The term condylysis has been chosen to emphasise the locally destructive (or lytic) mechanism which appears to be involved. Mandibular condylysis is distinguished from condylar aplasia by its non-association with aural/facial anomalies and because normal development appears to proceed until the lytic event occurs. It is further distinguished from primary and secondary condylar hypoplasia because the condyle is absent rather than small, because normal development appears to proceed until the lytic event occurs and because of its non-association with aural/facial anomalies or temporomandibular ankylosis.

Zygomatico-coronoid ankylosis

Although zygomatico-coronoid ankylosis may have been encountered by many oral surgeons, its occurrence has rarely been reported. A review of the literature has disclosed only nine reported cases. The treatment of these cases has been by coronoidectomy with either an intraoral or extraoral approach.

Mandibular condyle dislocation into the middle cranial fossa

A case is reported of a woman aged 25 with a dislocation of the right mandibular condyle into the middle cranial fossa. The most striking clinical feature is a strongly limited mandibular movement and the fixation of the mandible in the dislocated position. Adequate radiographic examination including tomography is necessary to obtain the proper diagnosis and to determine the position of the condyle and the displaced bony fragments of the cranial base. Early diagnosis and treatment are very important for a successful reposition. In the described patient manual reposition of the dislocated condyle was obtained 2 days after trauma. The risk of intracranial complications makes close cooperation with a neurosurgeon necessary.

Condylar fractures of the mandible. II. a radiographic study of remodeling processes in the temporomandibular joint

Remodeling processes in 76 temporomandibular joints were studied on radiographs from 67 individuals sustaining condylar fractures. The indivuduals were ranged into four age groups: 3-11, 12-15, 16-19, and larger than or equal to 20 years of age at the time of fracture. The radiographic examinations were to be performed at the time of the trauma and 3, 6, 12, 24 and 36-48 months after the injury. In the age group 3-11 there was a complete return to normal skeletal relations in 20 of the 27 joints. Joints in teenagers (12-19) did not become normal to the same extent and in adults only minor remodeling was observed. In children the remodeling of the condylar process was extensive but indistinctly outlined. With increasing age there was a shift towards a more distinct apposition of bone on the posterior part of the condylar head visualized as a double contour. This contour first appeared in the late teens. In adults the remodeling processes seemed only to be part of the functional adjustment. Thus, the remodeling processes of the condylar process in a clinical sense may be looked upon as restitutional in children and adjusting or functional in adults. As regards the articular fossa, in children the remodeling processes were first observed as a double contour, of which the new one became more and more distinct, while the original roof gradually disappeared. The final results was a flattened fossa. In adults, a sclerosis of the roof of the fossa was found.

Oral radiographic changes in patients with progressive systemic sclerosis (scleroderma)

Intraoral and panoramic radiographs were made of 35 patients with progressive systemic sclerosis. Of those patients, 13 (37%) were found to have abnormally thickened periodontal ligament spaces. Six of the 35 demonstrated mild to significant resorption of the posterior mandibular angle. Three patients, including two showing angle resorption also had some degree of coronoid process destruction. All patients with this disease should receive initial and follow-up panoramic radiographic examinations to determine any osseous changes.

Tomographic evaluation of 100 patients with temporomandibular joint symptoms

In this study the temporomandibular joints of 100 patients were examined radiographically. While the results leave many unanswered questions, studies of this type do contribute to an increase in the knowledge of this complex structure. It is anticipated that polycycloidal tomography will provide even greater knowledge of the bony components of the TMJ. More accurate, objective radiographic evidence will unquestionably allow us to approach subjective clinical evidence with greater confidence in relating these factors to diagnosis. Dentistry must recognize that the newer and more sophisticated methods must be utilized to evaluate pathologic changes or disease entities, such as temporomandibular joint dysfunction. A health profession must be provided with maximum information for total diagnosis.

Chondrosarcoma of the mandibular condyle. Report of a case with special reference to radiographic features

A case of chondrosarcoma of the mandibular condyle is described. With carefully taken tomographs, a diagnosis of chondrosarcoma of the mandibular condyle can be made with some degree of certainty, on radiological evidence alone. Chondrosarcomata of the mandibular condyle may manifest with the typical symptoms of the temporomandibular joint dysfunction syndrome. Tumours of the condyle can reach a large size without producing clinically obvious swellings. The literature pertaining to chondrosarcoma of the mandibular condyle is reviewed.

Early condylectomy to prevent prognathism: a preliminary report

The effect of bilateral condylectomy in the child with prognathism is described. Reference is made to the anteroposterior growth component of the mandible as measured by peroperative and postoperative cephalometric radiographs. The interruption in the growth of the mandible, coupled with the retropositioning that occurs immediately after the operation, reduces absolute or relative prognathism. Preliminary observation indicates that this prophylaxis does not prevent reformation of the condyle, nor does it result in any clinically discernible change in mandibular movements. Should the condyle reform before body growth is complete, a recommencement of anteroposterior growth in the mandible occurs.