Amplitude and frequency spectrum of temporomandibular joint sounds from subjects with and without other signs/symptoms of temporomandibular disorders

Temporomandibular joint (TMJ) sound is one of the most commonly recognized signs in patients with temporomandibular disorders (TMD) but is also frequently seen in asymptomatic individuals. Sound recording is therefore only meaningful if the sounds from a normal healthy joint can be differentiated from those in patients. In this study, the amplitude and power spectrum of the TMJ sounds from symptomatic patients and asymptomatic individuals were recorded and compared. The result showed that TMJ sounds from symptomatic patients had a larger amplitude than sounds from asymptomatic subjects. A significant proportion of sounds had frequencies between 2000 and 3000 Hz. It was concluded that the characteristic amplitude is worthy of further study as a sign of possible diagnostic value. Secondly, the bandwidth of the sensors used at electronic TMJ sound recording should not be less than 3000 Hz.     

Ortho cubic super-high resolution computed tomography: a new radiographic technique with application to the temporomandibular joint

OBJECTIVE: The purpose of this study was to present a newly developed ortho cubic super-high resolution computerized radiographic technique (Ortho-CT) and its application to the temporomandibular joint. METHOD AND PATIENTS: A prototype was assembled on a Scanora (Soredex Findent Co) with the use of a 4-inch image intensifier instead of film. Data were collected from a single 360 degrees scan and a cylinder 32 mm in height and 38 mm in diameter. Images were reconstructed with a software program on a personal computer. Imaging data consisted of 240 (height) x 280 (diameter) cubic voxels, each with a dimension of 0.136 mm. With this small voxel size, the image resolution was high and was the same in any direction. Three patients with temporomandibular joint disease (trauma, pain and dysfunction, fibroosseous ankylosis) were evaluated with Ortho-CT, and the images were compared to routine radiographic films. CONCLUSION: Preliminary clinical experience with Ortho-CT demonstrates subjectively superior image quality compared to panoramic and conventional tomographic images. The images were similar to conventional computed tomography, but this new radiographic technique is less expensive, takes less space, and gives a lesser patient dose.     

The risk of damage to facial nerve, superficial temporal vessels, disk, and articular surfaces during arthroscopic examination of the temporomandibular joint

The risk of complications occurring during arthroscopic examination of the temporomandibular joint is not well documented. We therefore performed arthroscopic examinations of the upper compartment of the temporomandibular joint of fresh cadavers and during subsequent dissection studied possible damage to the facial nerve, superficial temporal vessels, disk, and articular surfaces. Damage to the facial nerve was not seen in any joint. The distance between the puncture site and any branch of this nerve was 3 mm or more in all but one of the specimens. The puncture site was repeatedly located immediately adjacent to the superficial temporal vessels, but damage to these vessels was not seen in any case. Scratch marks on the articular surfaces resulting from intra-articular manipulations with the instrument were seen in more than half of the joints. It was concluded that the risk of damage to the facial nerve or the superficial temporal vessels during arthroscopy of the temporomandibular joint is small. There is, however, a risk of damage to the articular surfaces. The frequency of this type of injury can probably be reduced in patients by sufficiently distending the joint before the instrument is inserted.     

Diffuse lipogranulomatosis involving soft tissues of the head and neck due to multiple self-injections of mineral oil

We describe imaging findings of a 45-year-old man with a 6-month history of gradually increasing diffuse swelling of the neck. CT showed diffuse thickening and infiltration of the superficial and deep soft tissues bilaterally. On further investigation of his history, the patient stated that he had injected mineral oil into his neck to clean out his body from drugs. Biopsy results showed multinucleated giant cells and inflammatory infiltrates confirming the diagnosis of lipogranulomatosis.     

Histologic features of the temporomandibular joint disk and posterior disk attachment: comparison of symptom-free persons with normally positioned disks and patients with internal derangement

To gain further knowledge about the differences between normal and pathologic anatomy of the temporomandibular joint disk, we examined histologically disks obtained at autopsy from 10 symptom-free persons and compared our findings with observations involving 17 surgically removed disks. The surgical patients had internal derangement and severe long-standing temporomandibular joint pain and dysfunction. The normal disks were biconcave, whereas the surgically removed disks were deformed and thicker than the normal disks. Chondrocytes (4 joints), a surface layer of proliferative connective tissue (4 joints), vessels (2 joints), and splitting (4 joints) were seen in the surgical specimens but not in the normal specimens. The surgical specimens also showed higher maximal density of fibroblasts and vessels. It was concluded that surgically removed temporomandibular joint disks demonstrated several histologic alterations that were not seen in normal disks. These characteristics may serve as the basis for development of a histologic grading of pathologic conditions of the temporomandibular joint disk and the posterior disk attachment.     

Sideways and rotational displacement of the temporomandibular joint disk: diagnosis by arthrography and correlation to cryosectional morphology

Arthrography and arthrotomography were performed on 29 fresh temporomandibular joint autopsy specimens to diagnose medial and lateral disk displacement. A horizontal contrast medium margin crossing over the condyle (edge sign) and the relative size of the anterior recess of the lower joint compartment in the lateral and medial parts of the joints were used as indicators of the mediolateral position of the disk. Arthrographic findings were compared with coronal cryosections in a blinded fashion. The edge sign underdiagnosed all the joints with lateral disk displacement and about 50% of the joints with medial disk displacement. The assessment of the relative size of the anterior recess of the lower joint compartment underdiagnosed 50% of the joints with medial disk displacement and overdiagnosed lateral disk displacement by 100%. It was concluded that arthrographic diagnosis of medial and lateral disk displacement may be difficult and includes substantial risks of both overdiagnosis and underdiagnosis. Other diagnostic methods should be considered when these types of disk displacement are suspected.     

Temporomandibular joint: diagnosis of medial and lateral disk displacement with anteroposterior arthrography. Correlation with cryosections.

The purpose of this investigation was to determine whether it is possible to diagnose medial and lateral disk displacements by single-contrast lower-compartment arthrography with an anteroposterior projection. Contrast medium was injected into the lower joint space of 29 fresh temporomandibular joint autopsy specimens. Anteroposterior arthrograms and anteroposterior arthrotomograms were obtained. Enlargement of the medial or lateral recess of the lower joint space was considered an arthrographic indication of medial or lateral displacement of the disk. After arthrography the joints were deep frozen and cryosectioned in the coronal plane. Imaging findings were correlated to observations in the cryosections in a blind fashion. The anteroposterior arthrograms were 48% accurate in determining the position of the disk in the coronal plane. The anteroposterior arthrotomograms were 59% accurate. It was concluded that anteroposterior lower joint space arthrography as well as arthrotomography is not reliable for diagnosis of medial or lateral disk displacement.